EPA-R2-72-051
September 1972               Environmental  Protection Technology
 Development of  the  Aqueous

 Processes  for Removing NOX

       From Flue  Gases
                                Office of Research and Monitoring
                                U.S. Environmental Protection Agency
                                Washington, D.C. 20460

-------
                                            EPA-R2-72-051
DEVELOPMENT  OF  AQUEOUS  PROCESSES
FOR  REMOVING  N0   FROM FLUE GASES
                        By
                 Gilford A. Chappell
         Esso Research and Engineering Company
            Government Research Laboratory
              Linden, New Jersey  07036
               Contract No.  68-02-0220
             Program Element No:  1A2014
          Project Officer:  Stanley J. Bunas
              Control Systems Division
        National Environmental Research Center
      Research Triangle Park, North Carolina  27711
                   Prepared for
           OFFICE OF RESEARCH AND MONITORING
         'U.S. ENVIRONMENTAL PROTECTION AGENCY
               WASHINGTON, D.C.   20460

                  September 1972

-------
               EPA REVIEW NOTICE

This report has been reviewed by the Environmental
Protection Agency and approved for publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the Agency, nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use.
                      11

-------
                               ABSTRACT

          This report summarizes the findings of the laboratory program
for "Development of Aqueous Processes for Removing NOX from Flue Gases"
(EPA Contract 68-02-0220) .  A screening study was conducted to evaluate
the capability of aqueous solutions to scrub NOX from the flue gases
emitted by stationary power plants fired with fossil fuels.

          The key findings of this program are as follows:
  •  The addition of N0£  to flue gas  to improve NOX  (mostly NO) absorption
     does not  appear promising.  While the presence  of N(>2 does improve  the
     absorption of NO,  the magnitude  of the  increase is  insufficient  to
     support a viable process.
  •  Sulfite solutions  and slurries are efficient N02-S02 absorbents.
     Soluble sulfites (Na2SO-j) are better NO  absorbers  than  insoluble
     slurries  (CaSOg) because of the  higher  level of sulfite  ion  in solution,

  •  Calcium,  magnesium,  and zinc hydroxide  slurries are effective N02~S02
     absorbers.  The sulfite formed when S02 is absorbed is necessary for
     efficient N02 scrubbing.

  •  Limestone (CaC03)  is also a good N02-S02 absorbent  for the same  rea-
     sons as for Ca(OH)2*
  •  NOo scrubbing is enhanced by removing oxygen from the flue gas or by
     adding an anti-oxidant such as hydroquinone to  the  scrubbing solution.

  •  Sulfide solutions  are excellent  N02 and S02 absorbers but do generate
     a  small amount of  NO.

  •  Part of the absorbed SO 2 is oxidized to sulfate.

          Combined NOX-SOX scrubbing  seems feasible  using any of  several
 hydroxide or carbonate  systems provided NOX  (NO) can be  efficiently oxidized
 to N02  upstream from the  scrubbing unit.


                               ACKNOWLEDGEMENTS
          This work was conducted by the Government Research Laboratory
of the Esso Research and Engineering Company for the Environmental Protection
Agency under EPA Contract 68-02-0220.  Dr. Gilford A. Chappell, the Principal
Investigator for the work reported herein, is a member of the Air Conservation
Section managed by Mr. Alvin Skopp.

          The advice and assistance of Dr. Victor Engleman and Dr. Henry Shaw
is gratefully acknowledged.

          The invaluable assistance of Mr. William Moss in the laboratory
during the entire project is sincerely appreciated.

          Mr. Stanley J. Bunas was the EPA Technical Project Officer during
the program.
                                   iii

-------
iv

-------
                            TABLE OF CONTENTS
    ABSTRACT	

1.  INTRODUCTION 	     1

2.  LABORATORY STUDIES 	     4

    2.1  Apparatus	     4

         2.1.1  Flue Gas Blending System	     4
         2.1.2  Flue Gas Scrubbers	     4
    2.2  Analysis	     8

         2.2.1  Gas Analysis	     8
         2.2.2  Solution Analysis	     9

    2.3  Experimental Results	    10

         2.3.1  Absorption of NOX from Flue
                Gases Containing No S02	    1°
                2.3.1.1  NOX Absorption by Water 	    10
                2.3.1.2  NOX Absorption by Metal
                         Hydroxides and Slurries 	    11
                2.3.1.3  NOX Absorption by Ammonia
                         and 2-Aminoethanol Solutions	    14
                2.3.1.4  NOX Absorption by Acidic Solutions	    15
                2.3.1.5  NOX Absorption by Salt Solutions	    16
                2.3.1.6  Sulfate Formation in Sulfite Scrubbers. .  .    17

         2.3.2  Scrubbing Flue Gas Containing N02 and S02	    20
                2.3.2.1  N02-S02 Absorption by Sulfites	    20
                2.3.2.2  N02-S02 Absorption by Hydroxides
                         and Carbonates	    22

         2.3.3  Miscellaneous Scrubbing Experiments	    24

3.  CONCLUSIONS AND RECOMMENDATIONS	    28

    3.1  Conclusions	    28

    3.2  Recommendations for Future Work	    29

-------
                               APPENDICES
Appendix A  Energy Requirements for Regeneration
            of Spent Sorbent	30
            A.I  Electrochemical Reduction of
                 Sulfate to Sulfite	30
            A. 2  Thermal Regeneration of MgO from MgSO^	30
            A. 3  Thermal Regeneration of MgO from MgS03	31
Appendix B  Experimental Results - Flue Gas Scrubbing	32
            B. 1  Emission Data and Run Sheets	35
                                    vi

-------
                            1.   INTRODUCTION
          The oxides of nitrogen, NO and N02 are essential components in
the formation of photochemical smog in addition to being pollutants  in
their own right.  Large fossil fuel fired boilers, such as those found
in electric power generating plants, are major sources of these oxides.
In such boilers, the nitrogen oxides are formed by the reaction of molecular
nitrogen and oxygen in the high temperature combustion zone of the furnace.
The immediate product of this reaction is the thermodynamically favored NO.
As the combustion gases cool, part  of the NO, typically less than 10%,
oxidizes to N02.  The two oxides are generally considered together as NOX.
If the fuels contain organically bound nitrogen, as do coal and oil, part
of this nitrogen is also converted to NO during combustion.  The composition
of different flue gases is shown in Table 1.
                                 TABLE 1

                   TYPICAL COMPOSITIONS OF FLUE GASES

                                   Volume % Combustion Of

               Component
                  0>2
                  H20
                  S02

                  NO
                    x
               Participates
               grams/ft3
Coal 011(b>
76.2
14.2
6.0
3.3
0.2
0.5(e)
77.0
12.0
8.0
3.0
0.15
0.01
Gas
72.3
9.1
16.8
1.8
)

               (a)  Calculated for burning with 20% excess air a typical
                    high volatile bituminous coal of the following com-
                    position = carbon -70.1%, oxygen -6.6%, hydrogen -4.9%,
                    nitrogen -1.4%, sulfur -3.0%, ash -12.7%, and H20 -1.3%.

               (b)  Calculated a typical residual fuel oil of the following
                    composition = 86.5% carbon, 10.3% hydrogen, 2.5% sulfur,
                    0.7% nitrogen with 20% excess air.
               (c)  Calculated for burning natural gas with 10% excess air.
               (d)  This is an average value.  Actual values range from
                    0.01% to 0.15%.
               (e)  Assumes 90% participates removal.

-------
                                  - 2 -
           In Volume II of the report, "Systems Study of Nitrogen Oxide
 Control Methods  for Stationary Sources" (1-1) , Esso Research and Engineering
 Company assessed the various NOX control techniques.  One promising pro-
 cedure was aqueous alkaline scrubbing of the  flue gas to which N0£ had
 been  added.  Nitric oxide, the chief NOY constituent, does not itself com-
                                       A
 bine  with water  or basic solutions.  Absorption requires that some of the
 NO be oxidized to N0£.  A mixture of NO and N0£ reacts to form a small
 amount of N20_.
                         NO + N02
 Sherwood and Pigford  (1-2) found the rate of absorption of NO + N02 by a
 46% NaOH solution to be approximately proportional to the first power of
 the N203 concentration, indicating it to be the reacting specie.  Mi rev
 et al.  (1-3) found that the completeness of the reaction between an NaOH
 solution and NO /NO 2 mixtures reached a maximum at a 1:1 molar ratio of the
 oxides .

          The N£03 hydrolyzes rapidly in basic solutions to form nitrous
 acid  and nitrite salts.
          N2°3 + H2°	^   2HN°2       >   2N02   +  2H2°


          Based on  the promise of aqueous alkaline scrubbing, a flue
 gas scrubbing apparatus was  constructed and used to screen
 a  large number of potential  scrubbing solutions.  The original NOX levels
 were  350 ppm  each of NO and  N02 with no S02 present.  The S02 was eliminated
 to simplify the scrubbing chemistry since S02 would also be absorbed by the
 alkaline scrubbers.

          The poor  results of the early work led to a second phase directed
 toward N02 absorption by aqueous solutions, notably sulfites.  This effort
 presumed the  prior  oxidation of NO to N02 by a suitable technique such as
ozone addition or catalysis.   In  these latter scrubbing studies,  S02  was
usually present  in the flue  gas  and was found to be beneficial for N02
absorption.   The results  from the second phase are  quite promising and
indicate the possibility  of  simultaneous N02/S02 scrubbing.

          The objectives of  our program were to:

          1.  Screen various aqueous  sorbents for NOX scrubbing potential
              using a flue gas containing equimolar NO and N02 but no

          2.  Otpimize NOX absorption in promising systems by varying
              experimental parameters.

          3.  Explore effect of SO. on NO  scrubbing.
                                  ^      X

-------
                                -  3 -
                               REFERENCES
1-1  Bartok,  W.,  Crawford,  A.R.,  Cunningham,  A.R.,  Hall,  H.J.,  Manny,  E.H.,
     and Skopp,  A.,  "Systems Study of Nitrogen Oxide  Control Methods  for
     Stationary  Sources",  Esso Research and Engineering Company,  Final
     Report GR-2-NOS-69,  Contract No. PH 22-68-55  (PB 192 789), November
     1969.

1-2  Sherwood, T.K., and Pigford, R.L., "Absorption and Extraction",
     Chem.  Eng.  Series, McGraw-Hill, 1952.

1-3  Mirev, D.,  Balarev,  Khr., Boyadzhiev,  L., and  Lambiev,  D., "Absorption
     of Nitrogen Oxides by Vibrating Layers of NaOH Solutions", Compt. Rend.
     Acad.  Bulgare Sci.,  14 :  250-62, 1961.

-------
                                  - 4 -
                         2.  LABORATORY STUDIES
          This section of the report describes the laboratory apparatus
used to screen the various aqueous solutions and slurries for NOX scrub-
bing potential.  The experimental results are contained in the latter part
of this section.

     2.1  Apparatus

          The basic scrubbing apparatus consisted of a flue gas blending
system and the gas scrubbers.  The blending system was capable of producing
a wide variety of flue gas compositions by mixing the pure components in
different proportions.  The flue gas passed through heated lines to the
scrubbers where the NOX and S02 were absorbed.  The effluent gases were
carried by heated lines to the gas analyzers for the determination of the
residual NO, N02, and S02.  The different components of the total scrubbing
system are described in greater detail below.

     2.1.1  Flue Gas Blending System

          The blending system was designed to produce a heated flue gas
from the various components contained in cylinders.  The flue gas con-
taminants S02» N02» and NO were each contained in a separate high pressure
gas cylinder at 5 mole % (50,000 ppm) with nitrogen making up the balance.
Other cylinders contained pure oxygen, pure C02 and pure nitrogen.  Each
gas was delivered through 0.25 inch O.D. stainless steel tubing to a
calibrated rotameter for flow measurement prior to mixing.  Wet steam,
which was available in the laboratory, was dried by passing through
heated aluminum coils.  The dry, hot steam also passed through a calibrated
rotameter before mixing with the other components.  Figure 2-1 shows
a schematic of the gas blending system.  The order of mixing was important
for minimizing gas phase reactions between N02 and S02-

                          N02 + S02  	>   NO + SO


After passing through their respective rotameters, N£, C02, 02, and S02
fed into a common line which passed through the heated steam box where
steam was added to the mixture.   At this point the dewpoint of the gas
was about 115°F and the lines were maintained at approximately 200°F.
After blending with NO and N02,  the entire mixture passed through a
heated rotameter to determine the total flow rate.  The synthetic flue
gas was delivered through heated lines to the gas scrubbers.   The com-
position of a typical blend was  350 ppm NO, 350 ppm N02, 2400 ppm S02,
3 mole % Oo, 12 mole % 2» 10 roole % steam, and N2 as the balance.  The
flue gas blending system functioned satisfactorily.

-------
                                         FIGURE 2-1
                                     GAS BLENDING SYSTEM
 To
 Scrub
4	9
House Steam Input
                          O
                          O
                          O
                          O
                          o
                           CN
                          (^.Electric Steam Box
•  All lines downstream of the
   steambox were heated.

-------
                                  - 6 -
          A recurring annoyance, however, was the destruction of the
viton  '0' rings in the rotameters by N(>2.  This corrosive gas should not
contact anything organic for long time periods except possibly teflon.
The degradation products from the viton tended to foul the rotameters,
which necessitated periodic cleaning.  Fortunately, this did not occur
often.

          The heated steel lines initially underwent a conditioning
process bv the flue eas.  The composition of gas exiting from the
system varied for 10-20 minutes before stabilizing.  If the system
was not used for several days, the lines required reconditioning.

          No gas phase reactions were observed.  Nitric oxide (NO) was  not
oxidized to NC>2 in the lines and N0£ did not react with S02 at these low
concentrations.

          2.1.2  Flue Gas Scrubbers

          The gas scrubber was a two-liter round-bottom glass flask con-
taining one liter of scrubbing solution or slurry.  A teflon-coated
magnetic stirring bar agitated the solution.  The scrubber temperature
was maintained by an electric heating mantle which was controlled by a
thermocouple immersed in the solution.  The thermocouple was clad with
stainless steel.  The temperatures of the scrubbing solution, the heated
lines, and the steam box were continuously recorded by a 24 point
temperature recorder.

          The hot flue gas was introduced into the absorbing solution
through a porous glass frit located approximately four inches below the
surface.

          The temperature of the scrubber was maintained at approximately
125°F for most runs.   This is the approximate adiabatic humidification
temperature of an actual flue gas.

          Figure 2-2 contains a schematic of the scrubber portion of the
system.  Three scrubbing units were available and could be run in series
or parallel.   This flexibility allowed one significant advantage in that
we could quickly start a second run after finishing the first by simply
turning several valves and directing the flue gas to bypass the first
scrubber and to enter the second.  Thus, the second scrubber could be set
up and heated to the operating temperature while the first scrubber was
running.

          The gas exiting from the scrubber was carried by heated lines
to the gas analyzers which measured the NO, N02, and 802 levels.

-------
                                                FIGURE 2-2
to "C
                     pot  "B"  jumper   vent
                                                           mixture
                                                            from
                                                           pot "a"
   SCRUBER
                                                                            Note:  •  all lines are stainless steel,
                                                                                  •  all lines heated,
                                                                                  •  all connections either
                                                                                       ground glass or swagelok
                                                                         thermocouple
                                                                       2 liter flask
                                            heating mantle

-------
                                 - 8 -
2.2  Analysis

     2.2.1  Gas Analysis

          The heated line carrying the scrubber effluent entered a junction
from which three lines exited.  These lines transferred the hot gas to the
analyzers for measurements of the NO, NC>2 , and S02 levels.

          The S02 and N02 were analyzed independently by two DuPont 400
spectrophotometers.  These were double-beam instruments containing analyzer
cells maintained at 212° F.  The flue gas passed through the cells
continuously.  The two analyzers were totally separate except that they
shared the same light source; the two gas cells were oriented at 90° to
each other.  Each analyzer contained a set of filters to isolate the
pertinent spectral line.  Each unit also had a calibration filter which
was equivalent to a fixed ppm level of gas at a fixed temperature and
total pressure.  The filter was normally outside the light path but could
be positioned in the beam to check the response of the instrument.  The
signals from the N02 and S02 analyzers were recorded continuously by
strip chart recorders.  The two DuPont instruments were rugged and reliable
and no difficulties were encountered.

          The NO analysis involved considerable problems.  Initially, a
Whitaker "NOX Box" measured total NOX  (NO + N02) and was insensitive to
water vapor.  However, the flue gas had to be cooled below its dewpoint
before analysis in order to keep water droplets from forming inside the
instrument.  Unfortunately, the water trap removed part of the NOX from
a  flue gas  containing equal parts NO and N02.  This occurred by the
hydrolysis  of ^03 within the trap to yield nitrous acid and nitrate ion.
The N£0  forms  in  the vapor phase  from NO and N02.
                       N0(g)+N°2(g)   ^=^    N2°3(g)

                       N2°3(g) + H20(1)  ^    ^   2HN02 (ln solution>
 Eventually,  the  trap would equilibrate with the gas stream and NOX
 fluctuations would  cease.  This problem  caused a significant lag in the
 response  of  the  instrument to  changes in the NOX levels.  If the primary
 NOX constituent  is  NO,  this problem does not occur.

           Following the initial attempts with the Whitaker NOX Analyzer,
 a Beckman NDIR (Non-Dispersive Infra-Red) was used for NO measurements
 because of its better signal stability and because it read NO directly,
 not total NOX.  However, all of the water had to be removed from the gas
 because the  instrument  read the moisture as NO.

-------
                                 - 9 -
 In order  to eliminate the NO-NC^-I^O interaction in the water trap, the
 NC»2 had to be  removed before the trap.  After trying several approaches,
 a saturated solution of sodium sulfite at room temperature was finally
 adopted for use as the N02 absorber because of its capacity to remove
 all traces of  N02-  Part of the NO was also removed by the Na2S03 trap,
but the fraction of the NO absorbed depended on the amount of N02 in the
gas stream.   The sulfite trap was calibrated with known gas mixtures so
that the NO level before the sulfite trap could be calculated from the
NDIR reading,  the N02  reading,  and the calibration chart.   In the final
arrangement for NO analysis,  the flue gas passed through the Na2S03 solu-
tion,  then entered a cold trap chilled with  dry ice and methanol.  The dry
 gas was warmed to room temperature before entering the NDIR.  The  cold  trap
 was packed with glass beads to increase  surface  area and  to  reduce  the
 dead volume.

          The  sulfite trap also  removed  all S02  from the  gas stream.
 Had this  not occurred, the S02 would have condensed in the water trap.

          The  final configuration of the gas analysis section proved  to be
 reliable  and stable and was used for the majority of the experiments.

     2.2.2  Solution Analysis

          As the nitrogen oxides are absorbed by the alkaline scrubbing
 solution, nitrite and nitrate ions are produced.

                        N2°3(g) + H2°(1)  - ^ 2HN02(aq)
                                 OH"
                  2N02(g) + H20  (1) - >

                    HNO  + OH~ - >  HO + N03"

 At first,  an Orion  Specific  Ion  Electrode was used  for nitrate ion measure
 ments.   The nitrite level was determined by oxidizing the N02~ to NO 3"
 with hydrogen peroxide followed by a  total nitrate  measurement;  the
 initial nitrate reading was  then subtracted  from the total nitrate.   While
 this procedure worked well with dilute solutions, it proved somewhat
 cumbersome.  With concentrated salt solutions,  interference becomes a
 problem so a spectrophotometric procedure developed by Wetters and
 Uglum (2-1) was used.

-------
                                - 10 -
          Simultaneous determinations of nitrite and nitrate were achieved
by measuring the light absorption of the sample at two different wavelengths
in the ultraviolet region.  Nitrite absorbs at 355 nm and 302 nm with molar
absorptivities of 23.3 and 9.12 respectively, whereas nitrate absorbs only
at 302 nm with a molar absorptivity of 7.24.  The absorbance due to nitrate
in a sample can be calculated by dividing the nitrite absorbance at 355 nm
by 2.5 and subtracting the quotient from the total absorbance at 302 nm.
We used cells with a path length of four centimeters to measure nitrate
and nitrite levels down to 1 x 10~4 molar.  The procedure was rapid and
reliable.  However, at high pH, 002 produces carbonate ion which interferes
with the spectrophotometric measurement.  Also, nitrite ion converts to
nitrous acid at a pH less than 5 and this species interferes with the
determination.  Most measurements were made in a pH range of 7.5 to 9.5.

          Sulfate ion also formed in the scrubber and derived from the
oxidation of sulfite ion by oxygen and NOX.  In some experiments, the
sulfite was added to the scrubber as a salt (e.g., Na2S03) , whereas in
other runs the species was produced by the absorption S02 from the flue
gas by the scrubbing solution.  Once formed, the sulfate level was
determined by the standard gravimetric procedure which involved 'acidifica-
tion with HC1 followed by boiling and then precipitation with BaCl2
solution.  This is one of the most accurate of analytical procedures.

2.3  Experimental Results

           The first part of  the program used  a  flue  gas  containing  equal
 parts  NO and N02  but no S02•   The absence of  S02  simplified data  interpreta-
 tion.   In addition,  the NOjj  scrubber in an actual  system might  be  located
 downstream from the S02 level in the gas entering  the  NOx unit.

          The second part of  the program was concerned with NOX and S02
absorption by solutions and slurries.  In particular, N02 scrubbing by
sulfites was investigated.  In  these experiments the flue gas contained
S02.

          The details of each  run are recorded in Appendix  B.

     2.3.1  Absorption  of NOX From
            SO? Free Flue Gas	

          2.3.1.1  NOy  Absorption by Water

          The first series of runs used water to scrub a flue gas con-
taining  3% oxygen, 8-10% steam,  12% C0£,  approximately 350  ppm each of
NO and N02, and nitrogen as the balance.  The  flow rate  was  3200 cc/min
at room  temperature  (75°F) and pressure.  Table 2 contains  some of  the
results.

-------
                                 - 11 -
                                TABLE  2

                        NOX SCRUBBING WITH WATER



                Input  (ppm)    % Absorption*      Solution      Run Time
     Exp.  f      NO     N02    NO       N02     Temp.  (°F)       (min)

    11-10-71    400     390    -5**      18         125          220

    11-16-71    175     400    -9**      23         123          220

    11-17-71    360     380    1         23         129          250

    11-18-71    305     350    -6**      20         126          240
     *  % of the input concentration being absorbed at  the  end of the  run.

    **  Negative absorption signifies net % generation.

Nitric oxide was absorbed during the early part of the  runs,  but as  the
level of nitrous and nitric acid increased, NO was generated  by the
hydrolysis of N02.
                            + H20  - >  NO + 2HN03


During experiment #11-10-71, an average of 45 ppm of NOx was absorbed for
215 minutes.  The total dissolved NOX should have been, 0.9 x 10~3 molar.
Solution analysis yielded 0.9 x 10~3 molar nitrate and 0.2 x 10~3 molar
nitrite which totaled 1.1 x 10~3 molar.  This constitutes a reasonably
good NOX mass balance.  In addition, the agreement in scrubbing efficiency
among the runs listed in Table 2 shows good experimental reproducibility.

          2.3.1.2  NOX Absorption by Metal Hydroxide
                   Solutions and Slurries _

          The hydroxides of sodium, calcium, magnesium, and zinc were
investigated for their scrubbing potentials.  Both slurries and solutions
were used and gave somewhat different results.  Table 3 contains a summary
of the data which may be found in its entirety in the Appendix.  The total
gas flow rate was 3200 cc/min in all experiments.  The two NaOH runs listed
with the Ca and Mg runs used solutions with the same initial pH as the
saturated solution of the corresponding metal hydroxide.  The scrubbing
efficiency varied somewhat during a run so the values in Table 3 are
approximate.

-------
                                                    TABLE  3
                                     NO.,. SCRUBBING  WITH METAL HYDROXIDES
Exp. #
11-19-71
12-5-71
1-19-72
1-27-72
2-8-72
12-20-71

12-7-71
2-9-72
12-13-71
12-17-71
2-9-72
12-15-71
Absorbent
5N NaOH
5N NaOH
50 Wt. % NaOH
14.8 molal (45 Wt %) NaOH
Ca(OH)2 Slurry**
Ca(OH)2 Sat. Soln.

NaOH
Mg(OH)2 Slurry
Mg(OH)2 Sat. Soln.
NaOH
ZnO Slurry
ZnO Sat. Soln.
Initial
pH
14
14
14
14
11.5
11.5

11,5
8.9
8.9
8.9
7.5
7.5
Input
NO
350
274
345
333
353
390

311
330
377
404
353
400
(ppm)
N02
400
320
330
360
365
380

360
350
360
370
370
400
% Absorption
NO
20
35
28
47*
20
8

10
6
7
6
7
8
N02
18
34
23
28
21
29

29
23
22
24
16
29
Solution
Temp. (°F)
126
112
120
80
124
121

120
125
122
120
121
119
Run Time
(min)
\ »*»^** /
180
60
30
80
130
300
i
"0 M
60
80
90
130
90
 *  This value decreased to 28% as the solution temperature increased to 140°F.
**  The porous glass frit plugged with CaC03 early in the run and had to be replaced with an open tube.

-------
                                            -  13 -
                     In most  of  the  runs,  the N02  absorption was only slightly improved
           over pure water; however, the NO  absorption was  significantly better  in
           several experiments.   A qualitative  temperature  effect was observed in the
           first four NaOH runs  listed in  the Table.  As  the temperature of  the
           scrubbing solution decreased, the scrubbing efficiency increased.

                     The  data from the saturated solutions  of  Mg(OH>2 and  Ca(OH)2
           agree with the data from  the corresponding NaOH  solutions which implies
           a pH effect.   Thus, the Ca(OH>2 system was more  alkaline than the Mg(OH)2
           system and absorbed more  NO .   Increasing  the  pH to 14 (5N NaOH)  from 11.5
           did not improve the absorption  efficiency  at the same temperature which
           indicates that the influence of pH is not  simple.  The ZnO [Zn(OH>2]
           slurry absorbed only  16%  of the N02  whereas the  solution absorbed 29%.
           This seems unusual and no explanation is proposed.

                     The  NOX  mass balance  between solution  and gas phase was
           determined at  the  end of  several  runs.  In general  the balance  is
           satisfactory as shown in  Table  4.  The  one exception is exp. #12-17-71
           where the solution analysis is  much  greater than the gas analysis.  This is
           probably  due to dissolved carbonate from the C02 in the flue  gas.
                                            TABLE 4
                                     N0y MATERIAL BALANCE
 Exp.
Absorbent
                            Time  NOX Absorption (ppm)   Solution Anal
12-17-71  NaOH (pH = 8.9)

12-20-71  Ca(OH)2 sol'n

12-13-71  Mg(OH)2 sol'n
12-15-71  ZnO sol'n
                70

               300

                80

                90
AND

 30

 32

 25

 25
                                                             Total Dissolved NOX
                                                               Calculated From
Gas Anal .
1.1*
5.9
1.2
1.6
Sol'n Anal
1.6*
5.0
0.9
1.7
*  Concentration unit is millimoles per liter.
           Although the overall balance is reasonable,  the ratio  of nitrite  to  nitrate
           in solution is significantly higher than expected,  assuming that  only simple
           hydrolysis occurs.
                         3N0
                                 NO + 2HN03 (source of nitrate)

                                     2HN02 (source of nitrite)

-------
                                 - 1.4 -
           The  data in Tables  3  and  4  indicate  that  the hydroxide scrubbers
 are not  good NOX  absorbers  in the absence  of SC»2  and N0£  recycle is not
 attractive under  these  conditions.

           2.3.1.3  NOX  Absorption by  Ammonia and
                    2-Aminoethanol Solutions	

           The  best NO removal observed  occurred with a 28 Wt. %
 scrubbing  solution which  removed 74%  of the NO and  80% of the N02
 Table 5  contains  these  results  in addition to  scrubbing data from a
 similar  system, 2-aminoethanol.
                                 TABLE  5

                        NOX SCRUBBING WITH AMINES
                           Input  (ppm)   % Absorption   Solution   Run Time
  Exp  //       Absorbent     NO     N02   NO       N02  Temp.  (°F)     (min)

 1-26-72   NH4OH (28 Wt  %)   330     355   74        80       70          40

 2-3-72   2AE*             340     320   40        91      128          95

 2-4-72   50%  2AE**        340     330   48        88      127         120

 2-4-72   25%  2AE           347     350   48        86      127         110

 3^-8-72   25%  2AE           360     360   47        89      126         480
  *  2AE  is  2-aminoethanol.

 **  50%  by  volume  2AE  and 50% water.

          The vapor pressure of NH3 above the NH^OH scrubber dicated
operation at room temperature.  A water scrubber (one liter of H20 at
70°F) was placed downstream from the NltyOH scrubber to trap NH3 vapors
for continued scrubbing.  Thus, the data in the table result from two
scrubbers in series.  When the water scrubber was by-passed, the % absorp-
tion changed to 54% for NO and 58% for the N02-  A flask containing dilute
I^SO^ was placed downstream from water scrubber to protect the analyzers
from ammonia vapor.  The l^SO^ trap was saturated with NOX before putting
the NH^OH scrubber on line.   The interdependence of NO-N02 absorption was
shown by varying the input levels of each specie.  Halving the N02 input
dropped the NO absorption from 74% to 49%.  On the other hand, reducing the
NO input to zero dropped the N02 absorption from 80% to 51%.  The problems
associated with the high NH3 vapor pressure led to considering a higher
boiling amine, 2-aminoethanol, for scrubbing.

-------
                                 - 15  -
          The vapor pressure of 2-aminoethanol  (2AE)  is  much lower than  that
of 28 Wt. % NItyOH.   The pure araine has a vapor  pressure  of 7 Torr at  150°F
whereas the NH3 partial pressure over the ammonia solution is 570 Torr at
70°F.  The use of 2AE in the scrubber did not eliminate  the need for a
dilute H2SC>4 trap.   The small amount of amine vapor emanating from the NOX
absorber had to be removed before the gas stream entered the analyzers.
The mist which formed above the scrubbing fluid when N02 was present in
the flue gas, was removed from the effluent by the l^SO^ trap.  Before
recording data, this trap was saturated with NOX.  As Table 5 shows,  the
2AE solutions were excellent NOX scrubbers but  did not remove as much NO
as did the ammonia solution.  The 2AE was observed to heat up when C02 was
present in the flue gas indicating that C02 is reacting  with the solution.
This is to be expected since this type of compound is used commercially for
scrubbing C02 from gas streams.  The color of the 2AE solutions changed
from colorless to orange as the runs progressed.  An attempt to determine
the exact nature of the reaction proved inconclusive.  A variety of
products may result when a primary amine reacts with N203 (NO + N02).
These include molecular nitrogen (N2), alkyl ammonium nitrites and
nitrates, and alkyl nitrites and nitrates.  Secondary amines form dialkyl-
ammonium nitrites and dialkyl N-nitroso compounds which  are colored.   These
reactions are essentially irreversible.
          2.3.1.4  NOx Absorption by Acidic Solutions

          In order to compare the NOX absorption potential of acidic
solutions with alkaline baths several runs were made with sulfuric acid
and glacial acetic acid.  The results were not particularly impressive
as indicated by Table 6.

                                 TABLE  6

                         NOx  ABSORPTION BY  ACIDS


                            Input  (ppm)  %  Absorption Solution   Run  Time
  Exp.  # 	Absorbent	NO     N02 NO       NO? Temp.  (°F)    (min)

 12-3-71 H2S04 (79  Wt.  %)     350     350 1.        14.     202       120

 4-25-72 H2S04 (30  Wt.  %)     350     300 0         20.     120       110

 1-19-72 Glacial Acetic Acid 335     370 0         80       120         20

-------
                                       - 16 -
      Approximately 18 ppm of S02 was generated during run # 4-25-72.  The S02
      analyzer was not turned on during run // 12-3-71 so SC>2 may also have been
      produced in that experiment.  Sulfuric acid is a poor NOX absorber whereas
      acetic acid removes most of the N02 but no NO.
                2.3.1.5  NOX Absorption by Salt Solutions
                A number of aqueous salt solutions have been screened for NOX
      scrubbing potential and some of these appear very promising.  Table 7
      summarizes the experimental data.
                                       TABLE 7
                          NOX ABSORPTION BY SALT SOLUTIONS

                                                  % Absorption   Solution   Run Time
                                                           N02  Temp. (°F)    (min)
                                                           100      112        150
                                                           100      129         25
                                                           100     70-85       140
                                                           100      122         60
                                                           100      125         90

                                                            25      119        100
                                                            49      123         80
                                                            39      123        160
                                                           100      122         60
                                                           100      127         60
                                                            26      126         90
                                                           100      124         40
                                                            60      125         40
 *  4.1m (NH4)2S03 means 4.1 molal (NH4>2S03.
**  Copius amounts of S02 were generated during solution preparation and during
    scrubbing run.  The pH at the start of the run was 2.4.
Exp. #
12-5-71
12-21-71
12-21-71
1-3-72
1-10-72
1-17-72
1-18-72
1-24-72
1-28-72
2-15-72
2-10-72
3-3-72
3-7-72
Absorbent
4.1m (NH4)2 S03*
5N NaOH Sat'd with Na2S03
same as above
Sat'd Na2S03
f3.6tn NH4HS03*A
1.9m NH4HS04 J
6M NaOAc
8.4m NH4C1
8.4m NH40Ac
2.3m Na2S03
2.5m Na2S03
1.0m Ammonium Citrate
1.0m Na2S03
CaS03 Slurry
Input
NO
328
357
380
375
360
340
330
362
355
358
358
355
390
(ppm)
N02
350
355
330
350
330
360
350
360
500
350
350
400
380
% i
NO
23
12
27
21
24
18
27
31
18
16
25
15
33

-------
                                 - 17 -
          Not included in the table is scrubbing run # 1-26-72 which
involved passing flue gas through.a 2.3 molal solution of Na2S.  Despite
some experimental difficulties, the results show 100% absorption of N02
and minor absorption of NO from a flue gas containing approximately 350
ppm of each.

          The data in Table 7 has one, very clear,  message; sulfite ion
is an excellent N02 absorbent but a poor NO absorbent.   The agreement
between several Na2S03 runs again demonstrates the  stability and
reproducibility of our procedures.  Runs # 1-3-72,  1-28-72, and 2-15-72
all show 100% absorption of N02 and 21%, 18%, and 16% reduction of NO,
respectively.  Also, run # 1-10-72 shows that low pH and high sulfate
levels do not inhibit the absorption of N02 by sulfite or bisulfite solu-
tions.  The absorption of NO by the (NH4)2S03 solution (run # 12-5-71)
dropped  to zero when N02 was eliminated from the flue gas.  In addition,
a NOX material balance was made for the (NH4)2S03 run and after 140 minutes
on line, the gas analysis indicated a loss of 7.5 millimoles of NOX (6.3
N02 and 1.2 NO) whereas the solution analysis showed 5.8 millimoles of
dissolved NOX (5.2 N03~ and 0.6 N02~).  A similar balance determined at
the end of run // 1-28-72 (2.3m Na2S03) showed a loss of 4.4 millimoles of
NOX (3.9 N02 and 0.5 NO) from the flue gas and 2.4 millimoles of NOjj
(2.0 N03~ and 0.4 N02~) dissolved in the scrubber.   The reason for the
imbalance is unclear.  Another balance was measured at the end of run
# 2-15-72.  In this case, the gas analysis indicated a loss of 3.2
millimoles of NOX (2.7 N02 and 0.5 NO) while solution analysis gave 5.3
millimoles of dissolved NOX (4.2 N03~ and 1.1 N02~).

          2.3.1.6  Sulfate Formation in Sulfite Scrubbers

          When flue gas containing oxidants such as NOX and 02 is bubbled
through a sulfite containing scrubber, some sulfate is .formed which con-
stitutes a problem if solution regeneration is comtemplated.  In order
to ascertain the magnitude of the problem, several runs were made with
saturated sodium sulfite solutions.  The flue gas did not contain S02
but did have 350 ppm each of NO and N02, 3% 02, 8% H20, 12% C02, and the
balance was nitrogen.  Runs were made with and without 02 and NO.  In
addition, hydroquinone  (HQ) was used in some scrubbers to reduce oxidation.
Table 8 contains the results.

-------
                                          - 18 -
                                         TABLE  8

                      SULFATE  FORMATION IN SATURATED Na2SCh  SCRUBBERS
Flue Gas 	 >•
Scrubber 	 >
Initial S04= (wt . %)
Final SO*" (wt. %)
Complete
no HQ
1.28
1.51
Complete
with HQ
0.33
0.61*
Without NOX
with HQ
0.22
0.23
Without 02
with HQ
0.31
0.37
Without 02
no HQ
0.46
0.58
Without NOX
no HQ
0.10
0.40
(60  min  on  line)
           A..            0.23      0.28        0.01         0.06        0.12        0.30
            oU
 millimoles S04=         29.        36.          1.3          7.6        15.         39.
 formed
 *  Run  lasted for  70 minutes.
                   The  scrubbing  solution  consisted of one liter of liquid whose
         specific  gravity was  1.22.   All of  the N02 was absorbed plus 60 ppm of the
         NO with gave a total  NOx absorption of 410 ppm.  The solutions absorbed
         3.2 millimoles of NOX per hour while being exposed to 234 millimoles of
         oxygen per hour.  The presence of hydroquinone did reduce sulfate formation
         except in the  case  of the "complete" flue gas; however, these two runs may
         be suspect due to the unusually high initial and final sulfate levels.
         The data  suggest that oxygen is involved in the oxidation of sulfite to
         sulfate.

                   The  effect  of  initial pH  upon the sulfate  formation was
         investigated in 1.0 molal ^2803  scrubbers.  The flue gas did not contain
         S02 but did have 380  ppm N02 and  370 ppm NO.  All of the N02 and 60 ppm
         of the NO were absorbed  by  the solutions.  The initial pH was raised by
         adding a  small amount of concentrated NaOH and was lowered with hydrochloric
         acids.  The pH changed rapidly upon introducing flue gas into the solution.
         These runs lasted for 50 minutes  and Table 9 contains the results.

                                          TABLE 9

                            EFFECT  OF pH  ON SULFATE FORMATION
J.IIJ.LJ.CIJ. pa 	 '^ /./ j.u -L^._»
wt. :
wt. ;
Wt. !

I S04=
I 804°
I so4=

(t
(t
(t

= o)
= 25
= 50


min)
min)

0
0
0
0
.51
.74(7.
.97(7.
.46

6)
6)

0
0
0
0
.73
.86(7.
.97(8.
.24

9)
0)

0.33
0.64(8.0)
0.90(8.1)
0.57

-------
                                     - 19 -
              The numbers in parentheses are the pH's at the end of the
    specified time.   No trend is apparent,  but as before, more sulfate is
    formed than NOX absorbed.

              In other runs, an aqueous slurry containing 8 grams of CaS03
    per liter was used to scrub NOX and to  generate sulfate data.  Several
    different initial pH's were employed with the results shown in Table 10.
                                    TABLE 10
                             NOX SCRUBBING BY CaSOq
Initial pH  Input NO  Input N02  Input S02   A NO (ppm)   A NQ2 (ppm)   A S02  (ppm)

    7.2      380 ppm     380          0         132          250

    8.0      390         370          0         132          220

   12        390         370          0     125-KL87+125     370+150

    7.6        0         340        500          —          220        500+440


    The first three runs, which did not involve SC>2,  lasted for 50 minutes each.
    The best NOX absorption occurred in the most basic slurry.  The pH was
    raised to 12 by the addition of a small amount of concentrated NaOH solution.
    In this run, the NO absorption increased linearly with time over a 40 minute
    period.  After 40 minutes, the ANO was 187 ppm.  Between 40 and 50 minutes
    on line, the absorption dropped back to 125 ppm NO.   Similarly, the N02
    absorption was complete for the first 40 minutes; however, during the last
    ten minutes on line the absorption rapidly dropped to 150 ppm.  The last run
    shown  in the table lasted for two hours.  During the first 70 minutes, the
    S02 absorption gradually dropped from 500 ppm to 440 ppm.  This trend
    continued until the end of the two hours when the absorption of S02
    rapidly decreased to almost zero.  This is probably due to saturation and
    the decline in pH.

              The sulfate formation occurring in the  CaS03 experiments is
    shown in Table 11.

-------
                                  - 20 -
                                 TABLE  11
                     SULFATE  FORMATION  IN  CaSCh  SLURRIES
         Initial pH
7.2
8.0
12
 Wt.  %  S04   (t =  o)

 Wt.  %  S0^=  (t =  25 min)

 Wt.  %  S04=  (t =  50 min)


        A50
0.29
0.33
0.36
0.07
0.18
0.23
0.31
0.13
0.16
0.45
 7.6  (S02 in Flue Gas)

0.16



0.51*

0.35
  *  Run  lasted  70 minutes.
 The higher pH's  dropped  rapidly with the  introduction of  flue gas so that
 no runs were made  at constant acidity throughout  the experiment.  The
 trend  in these data is to  greater sulfate  formation at  the higher pH.
 The presence of  S02 also increased  the  formation  of sulfate.

      2.3.2  Scrubbing Flue Gas
             Containing N02 and S02

          The data of section 2.3.1.1 to 2.3.1.6 indicated that the
addition of N0£ to  flue gas did not  significantly  improve  NO absorption
whereas N02 absorption by sulfite solutions appeared feasible assuming
the NO  could be oxidized to N0£ upstream from the scrubber.   In order to
explore N02-S02 absorption,  several solutions and slurries were screened
for scrubbing potential.

          2.3.2.1  N02- SO?  Absorption by Sulfites

          Sulfur dioxide  readily dissolves in alkaline solutions but not
in acids.   The sulfite solutions are more or less basic depending on the
solubility of the salt.   The hydrolysis of the soluble sulfite ion
raises the pH.
                                                 HSO.,  + OH
  Flue  gas  contains  approximately 12  volume % (X>2  which is also soluble
  in alkaline  solutions, but  because  of the relative  acid strengths  of  1
  and H2C03, there is  a range of pH where  S02 is quite  soluble  whereas  C02
  is only slightly so.   This  range, which  is around pH  7,  would be optimum
  for scrubbing N02-S02.   The absorption of N02 by sulfites is  not  sensitive
  to pH.

-------
                                          - 21 -
                   Several sulfite scrubbers were screened for simultaneous N02-
         S02 scrubbing.   Table 12 contains a summary of the results.

                                         TABLE 12

                              N02-SO? ABSORPTION BY SULFITES
                              Input (ppm) % Absorption  Solution  	p_H	 Run Time
_Exp. It 	Absorbent	N02_   S02    N09   S02 Temp.  (°F)  Initial   Final   (min)
3-13-72 CaS03 Slurry (8 g/1)  330     500     60    92     125      7.6      5.0      70

3-30-72 MgS03 (5 g/1)          690    2610 100+45   100     126      9.4      3.7      40

4-3-72  CaS03 Slurry (25 g/1) 860    1890    100   100     126      9.1      7.2      75
i-24-72(2TI
       \0.
;»5»H4H«>3_1       700    2370     94    83     122      5>9      5>9     145
                              500            100
6-22-72 (NH4)2S03 Mixture*     +     2860     +     97     128      6.3      6.3      70
                           (450 NO)       (22% NO)
*  Mixture consisted of 11.2 Wt. % NfyHSO^ 14.6 Wt. % (NH4)2S03, 16.6 Wt. %
   and 57.6 Wt. % H20.  The specific gravity was 1.24.


                   The S02 removal was good in all the runs but the N02 absorption
         varied with the amount soluble sulfite present.  After going on line, the
         pH of the CaS03 slurry in run # 3-13-72 dropped to 5.3 within 30 minutes.
         This run was continued for 290 minutes and at 115 minutes the slurry became
         saturated with S02.  When S02 broke through, its value exceeded the input
         level for about an hour, then gradually decreased to slightly less than the
         input value.  Apparently, some of the sulfite or bisulfate evolved S02 for
         a short while.  With a greater solids loading in the slurry as in run
         # 4-3-72, the absorption of N02 and S02 was improved.

                   The sulfite in the MgS03 experiment may have been rapidly
         depleted by the 02 in the flue gas.  This would account for the continuous
         decrease in N02 absorption during the run.  The original sulfite level was
         0.08 molar (MgS03 is quite soluble).

-------
                                 - 22 -
          The last two runs listed in Table 12 again indicate that the
presence of sulfate does not inhibit N02 absorption as long as sufficient
sulfite ion is available.  Run # 6-22-72 also included NO in the flue gas
which reaffirmed the earlier conclusion that sulfites are not attractive
NO absorbents.

          2.3.2.2  N02-S02 Absorption by
                   Hydroxides and Carbonates

          Several metal hydroxide slurries were screened for N02-S02
scrubbing potential.  In addition, a limestone (CaCC>3) slurry was investigated.
Since magnesia, lime and limestone scrubbing systems are presently under
consideration for S02 scrubbing, the results on the combined scrubbing
are significant.  A summary of results  is  contained  in Table  13.

          The results show these slurries to be less efficient for N02
scrubbing than the sulfite slurries and solutions.  However, they exhibit
excellent absorption of S02-  The presence of S02 is vital for N02 absorp-
tion as indicated by the two runs numbered 3-17-72.  Only 19% of the N02
was absorbed in the absence of S02 wherease 50% was scrubbed out in its
presence   Thus, the sulfite formed during S02 scrubbing becomes the
absorbent for N0«.

          A NOX material balance was measured at the end of run #3-22-72, which
 employed a Mg(OH)2 slurry.  Gas analysis indicated 6.9 millimoles of N02 re-
 moved.  Solution analysis showed 6.1 millimoles of N03~ and 2.0 millimoles of
      produced.  Nitrate ion is the main product of N02 absorption from flue gas.
          All of the slurries demonstrated roughly equal scrubbing efficiency
on the full flue gas.  When oxygen was eliminated from the gas stream, the
scrubbing efficiency improved markedly.  For example, during run # 4-10-72
the 02 was removed from the stream with the result that the N02 absorption
increased from 63% to 90%.  With the oxygen, flow turned on, the N02 absorp-
tion dropped back to 69%.  Similar effects were observed with the other
slurries.  The presence of hydroquinone , an anti-oxidant , diminished the
negative influence of oxygen  upon N02  absorption.  Run  //  4-18-72 provides
an example.  A  flue  gas  containing  670 ppm N02  and 2400 ppm  S02 but no  02
was. bubbled into an  Mg(OH>2 slurry.  All  of the NC»2  and S02  was  absorbed.
When  3% oxygen was added to the  flue gas,  the N02 absorption dropped  to
57% while the S02  continued to be totally  removed.   The  addition of 1.0
gram  of HQ to the  slurry instantly  caused the N02 absorption to  increase  to
93% in the presence  of oxygen.   The HQ was still effective 200 minutes
later, when the  run  was  terminated.  Similar effects were observed with
other  slurries but were not as dramatic.   An endurance run (#5-5-72) was made
with  a slurry containing 15g  of  Mg(OH)2  and 1.0 gram of HQ.   The  flue
gas contained 675  ppm N02, 2280  ppm S02  and  3%  02 in addition to the  normal
constituents.   The S02 absorption was  complete  for the  full  390  minutes of
the run.  The N02  absorption  was about 100%  during the  first 200 minutes
of the run but  gradually decreased  to  82% at the end of the  experiment.
The slurry slowly  turned yellow  as  the run progressed.   The  HQ is  acting
as an  oxidation inhibitor but undergoes slow degradation, perhaps due to
reaction with N02.

-------
TABLE 13
N02-S02 ABSORPTION
Exp. #
3-17-72
3-17-72
4-10-72
4-7-72
3-22-72
4-7-72
4-10-72
4-14-72
4-14-72
Absorbent
Ca(OH)2 slurry (10 g/1)
(continuation of 3-17-72)
Ca(OH)2 slurry (15 g/1)
Ca(OH)2 slurry (18 g/1)
Mg(OH)2 slurry 7.4 (g/1)
Mg(OH)2 slurry 14 (g/1)
ZnO slurry (10 g/1)
CaC03 slurry (10 g/1)
CaC03 slurry (4 g/1)
Input (ppm)
N02 S02
740
730
700
680
830
680
700
650
650
0
800
2490
2460
2460
2610
2490
2280
2280
BY HYDROXIDES AND CARBONATES
7* Absorption
N02 S02
19
50
63
56
58
56
63
46
46
81
100
100
100
100
100
100
100
Solution
Temp. (°F)
132
132
126
125
126
126
126
128
128
PH
Initial
11.2
6.6
11.2
11.2
8.7
9.3
9.3
7.5
7.2
Final
6.6
6.0
6.4
6.5
7.8
7.9
6.3
6.2
6.3
Run Time
(min)
50
70
80
40
110
100
to
40 "
100
60

-------
                                   -  24  -
          Several experiments were conducted in order to determine sulfate
formation during Mg(OH)2 scrubbing.  These results are compared with
similar CaS03 scrubbing data in Table 14.

                                TABLE 14

                  SULFATE FORMATION IN MR (OH) 2 SLURRIES



                                          bMg(OH)2   CMg(OH)2
Wt. % S04= ( t = o min)         0.005       0.019     0.0079     0.16

Wt. % S04= (t = 100 min)        0.181       0.230     0.202      0.51*

                                0.176       0.211     0.194      0.35*

millimoles of S04= formed      18.6        22.2      20.5       37

millimoles of N02 absorbed      5.2         4.9       8.7        2

millimoles of S02 absorbed     31          30        31          4.5
*  70 minutes on line.

a  Contained 15g Mg(OH)2 per liter; S02 absorption was 2400 ppm;
   absorption was 400 ppm out of 700 ppm input.

b  Same as above except that the S02 absorption was 2300 ppm; N02
   absorption was 380 out of 640 ppm input.

c  Same as in footnote 'a' except that the N02 absorption was 670 ppm
   out of 670 ppm input and the flue gas contained no oxygen.

d  Contained 8g CaS03 per liter; S02 absorption was 500 ppm and the N02
   absorption was 220 ppm out of 340 ppm.

Of the several absorbents, the CaS03 formed the most sulfate.  Absorbent
rc' which scrubbed an 02-free flue gas, formed as much sulfate as the
other Mg(OH)2 slurries did in the presence of 3% oxygen.   However 'c1
absorbed almost twice as much N02 so that the number of sulfates formed
per unit N02 absorbed is lower than the other two.   The data show that
2/3 of the S02 absorbed by the magnesia absorbents  is converted to sulfate,

     2.3.3  Miscellaneous Scrubbing Experiments

          This section contains  a variety of scrubbing experiments that
did not  fit  into the  discussions above.  Table 15 presents the  results.

-------
                                           -  25 -
                                          TABLE  15
Exp.  //    	Absorbent	
2-2-72    Hydroquinone (1. g/1)
3-24-72   FeCl3-6H20 (5.  g/1)
3-24-72   3% H202
3-24-72   KMn04 (4 g/1)

4-13-72   1.88m Na2S
5-15-72   2.1m Na2S

5-3-72    3.8m Urea
5-3-72    3.8m Urea
5-3-72    3.8m Urea
N0x-S02 SCRUBBING
Input
NO
0
490
490
475
0
0
480
490
325
N02
360
0
0
0
650
370
0
0
400
ppm
S02
0
0
0
0
2250
0
0
2150
2160
% Absorption
NO
(gen)a
2
4
63
(gen)c
(gen)d
3.1
0
7.7
N02
47
—
, .b
(gen)
100
100
—
—
37
S02
—
—
95
—
70
70
                                                                         Solution
                                                                       Temp.  (°F)
                                                                            124
                                                                            122
                                                                             85
                                                                             80

                                                                            131
                                                                            125

                                                                            122
                                                                            122
                                                                            122
                                                                           Run  Time
                                                                             (min)
                                                                               70
                                                                             100
                                                                               40
                                                                               30

                                                                               80
                                                                               60

                                                                               10
                                                                               20
                                                                               15
5-2-72
5-9-72
0.47m Urea
in 40% HN03

1000 g of 10% Urea
sol'n + 360ml 6N H2S04
                                  475
                                  520
42
(gen)
135
                         125
75
                               30
a  Absorption of 170 ppm N02 generated 180 ppm NO.
b  Generated approximately 30 ppm N02.
c  Generated 35 ppm NO.
d  Generated 23 ppm NO.
e  Absorbed 200 ppm NO and generated 360 ppm N02.  If NO reacted with HN03 to produce
   N02 [NO + 2HN03 -* 3N02 + H20], 600 ppm N02 should have been generated.  We have other
   data, however, to indicate that urea in HN03 absorbs approximately 45% of input N02
   with negligible production of NO.  This indicates that we should expel roughly 325 ppm
   N02-into the effluent.  This is reasonably close to what we observed.
                    A solution of HQ was observed to reduce N02 to NO almost
          quantitatively.  The only scrubber that was found capable of successfully
          absorbing NO alone contained 4 grams of potassium permanganate.  The
          solution gradually changed color from deep purple to deep brown.  This
          appears to be due to the formation of lower oxides of manganese.  A slurry
          of Mn02 was found to have no effect upon NO absorption.  The same was
          true for a sodium arsenate solution (Na2HAs04).

-------
                                - 26 -
          Sodium sulfide solutions were excellent N0£ absorbents but
generated a small amount of NO.   The sulfide appears to become  oxidized
to sulfur which forms polysulfide ion in the presence of excess sulfide.
A small amount of spent absorbent was acidified with HC1 which  destroyed
the polysulfide ion and produced a milky precipitate of colloidal sulfur.
When S02 was absorbed by Na2S solutions, some I^S was generated.   An
attempt was made to analyze the  spent solution for nitrate  and  nitrite
levels but spectral interference by species in solution precluded this
approach.

          Several experiments were conducted with urea under a  variety
of conditions, however, none showed any promise.

-------
                                 -  27  -
                               REFERENCES
2-1  Wetters, J.H.,  and Uglum, K.L.,  Anal.  Chem.,  42:  335-340,  1970,

-------
                                 - 28 -
                  3.  CONCLUSIONS AND RECOMMENDATIONS

3.1  Conclusions

          A comprehensive screening program was instituted in order to
evaluate the capability of various aqueous systems to scrub NOX from the
flue gases emitted by stationary power plants fired with fossil fuels.
The conclusions of this study are listed as follows:

     (1) NO and N02 present in the flue gas but no S02

         (a) Slurries and solutions of calcium, magnesium, and zinc
             hydroxide are very inefficient.

         (b) Strong acid (H2SO^) and strong base (NaOH) are poor NOX
             absorbents-

         (c) Concentrated amines (ammonia and 2-aminoethanol) are efficient
             NOX absorbents but they have excessive vapor pressures (28 wt '/
             NH/OH) and may form exotic products such as alkyl nitrites and
             nitrates, and nitro and nitroso compounds which are difficult
             to regenerate and could not be introduced safely into the
             environment .

         (d) Potassium premanganate solutions are excellent absorbents of
             NO even in the absence of N02«  However, regeneration of the
             spent solution appears to be a formidable obstacle.
         (e) Sulfite solutions and slurries are excellent N0£ but poor NO
             absorbents.   The soluble sulfites are more effective N02
             absorbents than the insoluble slurries because of the higher
             sulfite levels attained in solution.

         (f) In general,  NOo recycle and addition to flue gas to achieve
             equimolar NO/N02 is not attractive.  While the presence of
             N02 does increase the absorption of NO, the magnitude of the
             increase is  insufficient for developing a viable process.
     (2) N02 and SO,, present in the flue gas but no
NO
         (a) Calcium, magnesium and zinc hydroxides are effective N02 and
             S02 absorbents .   The sulfite formed when S02 is absorbed is
             vital to N02 scrubbing.

         (b) Limestone is an effective N02/S02 absorber.

         (c) Sulfite solutions and slurries are efficient N02~S02 absorbers.

         (d) N0» scrubbing is enhanced by removing oxygen from the flue gas
             or by adding an anti-oxidant such as hydroquinone to the scrubb^

-------
                                - 29 -
         (e) A portion of the absorbed SO,., is oxidized to sulfate.

         (f) Sulfide solutions are excellent NO- and SO,, absorbers but do
             generate a small amount of NO.

         (g) Combined NOX - SO  scrubbing is possible using any of several
             hydroxide or carbonate systems provided NO can be oxidized to
             N0£ upstream from the scrubber.

         (h) Separate NO- absorption is feasible using the sulfite solution
             or slurry produced in the S0_ scrubber.

          Several scrubbing systems appear promising with a high degree of
flexibility available in their application.  However, this hypothesis must
be supported by further research aimed at obtaining scale-up information in
addition to spent-solution regeneration data.

3.2  Recommendations for Future Work

          Our results clearly indicate the technical feasibility of modifying
any of several aqueous alkaline flue gas desulfurization systems, now being
developed, to incorporate NOX emissions control.  These include aqueous
ammonia, limestone, magnesium hydroxide, and sodium hydroxide based systems.
Pilot plant studies are now needed, however, to develop the engineering
data essential for process scale-up.   Below are listed critical factors
which need to be defined under process conditions.

          •  The  rates of N02 absorption by  different alkaline solutions and
             slurries need measuring under pilot plant  conditions.  The
             influence of system parameters, such as  temperature  and flow
             rates, upon  the N0_ absorption  rates must  be determined.

          •  The  effect of scrubber design upon the gas absorption must
             be defined.

          •  The  requirements for  anti-oxidants must be assessed.

          •  The  product  distribution  for  the  absorbed  N0x  (i.e., NO^- vs
             NO^-) must be measured.

          •  The  study of spent-solution  regeneration will  require a  com-
             prehensive effort  in  order to  define sorbent make-up require-
             ments and the power,  fuel and  other utility needs.

          •  The  oxidation of NOX  to N02  upstream from  the  scrubber  is
              vital to  the project. Thus,  studies should be instituted to
              optimize  this reaction under flue gas  conditions  using
              catalysts or ozone.

           The final  goal  would be  to  successfully  cquple the NOX oxidation,
 scrubbing,  and  solution  regeneration  techniques into an integrated process
 which cleans flue gas  and simultaneously  minimizes  the effect  of scrubbing
 products upon the environment.

-------
                                 - 30  -
                               APPENDIX A
          This appendix  contains  idealized thermodynamic calculations
 for  the  energy required  to regenerate certain species found in spent
 sorbents .

 A.I   Electrochemical Reduction of Sulfate to Sulfite

          Sulfate  is formed during flue gas scrubbing via oxidation of
 sulfite  by  the NOy or 02 present.  In order to regenerate sulfite, which
 is useful for N02 absorption, from sulfate, the following electrochemical
 calculations are informative.
                                                    E°
                                                      298
                 40H~  - >  02 + 2H 0 + 4e-    -0.40 volts

     SOA= +  "2° + 2e~  - *  20H" + S03=        ~0>94 volts

 When these  half-cells are summed, we obtain

                     2SO ~  - *   0  + 2SO ~     -1.33 volts


 Since the electrical work required, assuming no overvoltage, is equal to
 the  Gibbs free energy of the reaction, we have

                 A G = nFE = 61. kcal per mole of SO,
                           = 0.071 kwh per mole of SO,
                                                     4
          If we consider 10  SCF of flue gas from which 400 ppm NO  are
scrubbed, we calculate that 32.3 kwh are needed to regenerate the sulfite
Assuming that one SO^" is formed per NOx absorbed.  This number represents
an idealized regeneration which may be scaled up or down depending on  the
amount of NOX absorbed and the number of sulfates formed per NOX absorbed.

A. 2  Thermal Regeneration of MgO from MgSO,


          Since sulfate is formed in NOX-S02 scrubbers using magnesia  as the
absorbent, it is of interest to calculate the theoretical energy requirements
for the thermal regeneration of MgO from MgSO, •

                     MgS04(s)  — ^-»  MgO(s) + S03(g)

                     -306 kcal        -144 kcal  -95 kcal

                    AH = 67 kcal/mole

If water of hydration is included in the calculation,  then an additional
reaction must be considered.

-------
                                    - 31 -
                MgS04-6H20(s)  —=->  MgS04(s)  + 6

                -737 kcal            -306 kcal  -348 kcal

               AH' =83 kcal/mole


The total theoretical energy required is 67 kcal per mol of anhydrous
MgS04 and 150 kcal/mole of the hexahydrate.  This translates into 0.078
(0.175) kwh per mole of sulfate formed.  The numbers in parentheses refer
to the hexahydrate.  If we scrub 10^ SCF of flue gas from which 400 ppm
NOV are absorbed and assume the one mole of sulfate is formed per mole of
  A
NOX absorbed, we require  35.8  (80.4) kwh for regeneration.  If we scrub
10o SCF of flue gas and remove 700 ppm NOX and form 10 moles of sulfate per
mole of NOx absorbed then 626 (1400) kwh are needed for regeneration.
A.3  Thermal Regeneration of MgO from MgSCL
          Magnesium sulfite is produced by the absorption of S02 by Mg(OH)2
slurries.  Magnesium oxide may be thermally regenerated from the sulfite.


                     MgS03(s)  —*-*>  MgO(s) + S02(g)
                     -241 kcal        -144 kcal -71 kcal
                    AH = 26 kcal/mole
                     MgS03'6H20(s) 	>  MgS03(s) + 61^0^)

                     -673 kcal            -241 kcal  -348 kcal

Regeneration requires 26 (110) kcal per mole of sulfite formed.  The numbers
in parentheses refer to the hydrate.  This is 0.030 (0.130), kwh per mole
of sulfite.  If 3000 ppm S02 are scrubbed from 10^ SCF of flue gas the
theoretical energy required for regeneration of MgO is 103.5 (448) kwh.

-------
                                -  32 -
                               APPENDIX B
          Herein are contained the experimental results depicted in graphical
form.  This style of presentation was chosen because it reflects the form
in which the data was originally recorded.  The continuous line presentation
also communicates data trends to the reader more effectively than does the
tabular format.   The leters 'BP1 signify that the flue gas by-passed the
scrubber.

          Following each graph is a data sheet which gives the flue gas
composition, solution composition, and temperature, pH, etc.  At the
bottom of each data sheet is a notation which indicates the sequence of
traps which treated that portion of the scrubber effluent going into the
NO analyzer.  For example,

                   NO:  Na2S03	>  Dry Ice 	> NDIR

signifies that part of the scrubbed gas bubbled through a saturated solution
of Na2S03 (to remove residual N02) , then passed through a dry ice cold trap
(to remove water vapor)  and finally entered the Beckman Non-Dispersive
Infra-Red (NDIR) nitric oxide analyzer.  Some NO was absorbed by the
various traps employed but all were calibrated with known gas compositions
before going on line.

          The following listing is an index to the data contained in this
appendix.


                        INDEX TO SCRUBBING EXPERIMENTS

                     Input
     Run #      NO    N02    S02         Absorbent  Composition        Page

   11-9-71      X      X            water
   11-10-71     X      X            water
   11-12-71     X      X            water
   11-16-71     X      X            water
   11-17-71     X      X            water
   11-18-71     X      X            water
   11-19-71     XX            5N NaOH
   11-22-71     XX            83 wt.% H2S04
   12-3-71      XX            79 wt.7» H2SOA
   12-5-71a     XX            5N NaOH

   12-5-71b     X      X            4.1m(NH4)2S03
   12-7-71      X      X            NaOH(pH=11.5)
   12-13-71     X      X            Mg(OH)2 solution (pH=8.9)
   12-15-71     X      X            Zn(OH)2 solution (pH=»7.5)
   12-17-71     X      X            NaOH(pH=8.9)
   12-20-71     X      X            Ca(OH)2 solution (pH=11.5)
   12-21-71     X      X            sat'd Na2S03 in 5N NaOH
   1-3-72       X      X            sat'd Na2S03
   1-10-72      X      X            NHAHS03 + NH4HS04
   1-17-72      XX            6m NaOAc

-------
                                - 33 -



                 INDEX TO SCRUBBING EXPERIMENTS (Cont'd)

                  Input
  Run #      NO    N02    S02        Absorbent Composition         Page

1-18-72      X      X            8.4m NH4C1
1-19-72      XX            28 wt.7o NH40H
1-19-72      X      X            Glacial acetic acid
1-19-72      XX            50 wt.% NaOH
1-24-72      XX            8.4m N^OAc
1-25-72      XX            7.m NH40Ac
1-26-72      XX            28 wt.% NH40H
1-27-72      X      X            14.8m NaOH
1-28-72      XX            2.3m Na2S03
1-31-72      X      X            2.3m Na2S03 + hydroquinone (HQ)
2-1-72       X      X            Varying Na2S03 + NH4S03
2-2-72       X      X            Hydroquinone (HQ)
2-3-72       X      X            2-aminoethanol (2AE)
2-4-72       XX            2AE + HoO (1:1)
2-4-72       XX            2AE + H20 (1:3)
2-8-72       X      X            Ca(OH)2 slurry
2-9-72       X      X            ZnO slurry
2-9-72       X      X            Mg(OH)2 slurry
2-10-72      X      X            1.0m ammonium citrate
2-15-72      XX            2.5m Na2S03 + HQ
2-18-72      XX            2.5m Na2SC>3
3-3-72       XX            1.0m Na2S03 (vary pH)
3-7-72       X      X            CaS03 slurry (vary pH)
3-8-72       x      X            2-aminoethanol
3-10-72             x      X     S02-N02 interaction in lines
3-13-72             x      X     CaS03 slurry
3-15-72             x      X     CaO + CaS03 slurry
3-16-72             x      X     Ca(OH)2 slurry
3-17-72             x      X     Ca(OH)2 slurry
3-22-72             x      X     Mg'(OH)2 slurry
3-24-72      X                   FeCla, H202, KMnO,
3-30-72             x      X     MgS03
4-5-72              X      X     CaS03 slurry
4-7-72              X      X     Mg(OH)2 slurry
4-7-72              X      X     Ca(OH)2 slurry
4-10-72             X      X     Ca(OH)2 slurry
4-10-72             X      X     ZnO slurry
4-11-72             X      X     Ca(OH)2 pre-doped with S02
4-13-72             X      X     1.88m Na2S
4-14-72             X      X     CaC03 slurry

4-17-72             X      X     H20 + CaCl2, MgSOA
4-18-72             X      X     Mg(OH)2 slurry + HQ
4-24-72             X      X     2m  NfyHSOs + 0.5m (NH4)2SO-
4-25-72             X      X     2m NltyHSOs + 0.5m (NHA)2
4-25-72      XX            30 wt.% H2S04
4-26-72             X      X     Mg(OH)2 slurry + HQ
4-27-72             x      X     Mg(OH)2 slurry + HQ

-------
                                 - 34  -



                 INDEX TO SCRUBBING EXPERIMENTS  (Cont'd)


                  Input
  Run #      NO    N02    S02        Absorbent  Composition          Pa;

4-28-72             X      X     CaC03 slurry + HQ
5-1-72              X      X     Ca(OH)2  slurry + HQ
5-2-72       X                   Urea in  HN03

5-2-72       X      X            Urea in  HN03
5-2-72              X            Urea in  HN03
5-3-72       X                   Urea in  H20
5-3-72       X             X     Urea in  H20
5-3-72       X      X            Urea in  H20
5-3-72       XXX     Urea in  H20
5-4-72       XXX     Mg(OH)2  slurry
5-5-72              X      X     Mg(OH)2  slurry + HQ  (endurance  test)
5-9-72       X                   Urea in  H2S04
5-9-72       X      X            Urea in  H2S04

5-9-72              X            Urea in  H2S04
5-9-72              X      X     Urea in  H2S04
5-9-72       XXX     Urea in  H2S04
5-15-72             X            2.1m Na2S
6-22-72      XXX     (NH4)2S03, NH4HS03 mixture

-------
                -  35  -
B.I  EMISSION DATA AND RUN SHEETS

-------
11-9-71
ppm
x 100
CM CM
3 O O
5 a CO
D 5 10 -
1
1 ' ' "
, i . -
1

848-
1
1 '
717-
536-

1
5 5 -


j 2, 4 -
1
} 3 -
! 1 2 -
1 -^
I i





BP








_ 	










0














^ -
^ -»***
.. •»*""








1 1 1
10 20 30
1





BP
*- ~^







-,



















2
H

01
U
|— .^

O
....










1
40










0)
•H

-------
                               - 37 -
                        NOX SCRUBBING DATA SHEET
DATE:    11-9-71	    SCRUB:   H2°
OBJECT:  Test  water trap
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


                                                          Final pH      —


                                                          0,
Pot Temp. 130 °F
H00
NO
10
312
7
/o
, PPm
Initial
CO,,
f. ™ 	
NO,,
pH
12
350
•
%
ppm
                                                           2
                                                                          ppm
COMMENT:


         (1)  Wet ice trap converts *£_ 8% of the N02 to NO


         (2)  The dryerite converts *s 11% of the
         NO:  (wet ice, or dry ice, or Dryerite)+NDIR

-------
11-10-71
ppm
x 100
CM esi
3 O O
5 Z w
LO 5 10 _
1 .
1 ' -
: •-
1
} 48 —
1
i '-
i
) 36-
i 1 5
1
^ 24-
i -
> 3
> 12-
L 1 —
lii



BP
. w
*^


• ••







^i^


t







^ -.- — •""""
•^ *~






-14%


) 20 40 60 80
t



5P
**


.-







••^


















i -15%


1 1 1 1
100 120



BP
*"*










^•M


















-16?


1 1 1
140 160



BP
t*









•••










+5.0%








-18% f


1 1 1 1 1
180 200



BP
^->


— • -VS

I
o.
QE
1


i^— —




                                                I.TJ.

-------
                                 - 39 -
                        NOX SCRUBBING DATA SHEET
DATE:    11-10-71
             SCRUB:    H2°
OBJECT:   Absorb NOX from flue gas
CONDITIONS:

    Pot Temp.
    H2°
    NO
               1500
Scrub volume @ 1666 ml
                                                          3100
   125
   10
                400
                     _ppm
            Total Gas Flow @ 3266 cm  per minute

Initial pH 	—          Final pH     —

C00 	
 12   7,
              N0r
350
    _ppm
                             so2
_ppm
COMMENT:
        (1) After a slight  initial  absorption of NO,  the water  appears  to
           hydrolyze  the N02 and create  some NO  (^20  ppm out  of  390 ppm
           N02 or   57o of  the N02) . N02  adsorption  is  relatively  constant
           14 —» 187o
                         3N0
                         NO + 2HNO,
            If only hydrolysis occurred,^5% NO  generation would  correspond
            to 15% N02 adsorption.

        (2)  Solution sample  taken at  215 minutes was  analyzed  by the nitrate
            ion electrode.   Solution  was 0.9 x  10~3 molar nitrite.
       NO:  Wet  Ice Trap
              »Whit.

-------
11-12-71
H.O
ppm
x 100

CM (
O 0 0
a ss en
10 5 1
II
.
9 9
1
| 1
8 4 £
1 "
1 1
7 1 7

636
1 '

5 ' 5
i :
424
II
i
3 1 3
2 1 2
1
1 1
1
On n
u u

i



•vj

0 _




•
^^


—
-
_
.

_
-


-
-
-
-






BP












._. -











(









^ ._.— —
^. •*• ™~
^^ ^*
f
t
/
7
f






-20%




1 I 1 1 1 1 1 1
J 20 40 60 80
1



BP
•f m







— -


























•~~v.
«<^
X
X
X




Pi
n
a
55
c
•H
O
4-1
CO
f18




1 1 1 1
105 125















+10%^







t




1 1
145 ie
1

BP
*"-*•



c
o
o
PQ

H
M
.
14-1
O
g
_ _
1
|





WHIT
iffijlts
Lot;
T
)5 1(
i
























_ U-?J ^.f J3


i i i
i5 185 2(



*- BP





















,2



)5

                                     Time ±n Minutes

-------
                                - 41 -





                        NOX SCRUBBING DATA SHEET



DATE:    11-12-71           SCRUB:  H20 (from 11-10-71)
OBJECT:  To compare the NDIR with the Whittaker  "NOX BOX"
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.     126 °p     Initial pH 	—         Final pH     —
    H20 _ 10    %     C02        12
    NO      varies   ppm     NQ2 _ 35° _ ppm      S02 _ — ppm



COMMENT :


         (1)  Already had 230 minutes (from 11-10-71)  at zero time on chart.
        NO:  Wet Ice    ">  NDIR

-------
11-16-71
ppm 1
x 100 1
CN CN
3 O O
5 B CO
10 5 10 -
» i H
848 —
1 ' -
7,7-
1 1 -
636 —
i • •
•:[•
424-
1 • -
3 ' 3 -
! i -
212 —
1 1 -
1,1-
1 ' '
I I \

BP






b—




1








1




\ i i
Q 20
V

BP
«- •>




^•^••1
— —




\













1 I 1 I
45 65

BP
•» *"^^





^m «^ ^B ^




1 1
85
1




AN02 @ 2l 22'5%
ANO @ ^ 9.1%







85 105 125 145 165
I

BP

























1 1 I 1
190 210

BP












                                              TUjna  in. \ti-nu.te.s

-------
                                 - 43 -
                        NOX SCRUBBING DATA SHEET
DATE:    11-16-71
           SCRUB:
                 .  H20
OBJECT:  Absorb NOX and gain experience with system
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.    123  °p     Initial pH 	      Final pH 	

    H20 	10   %     C02 	12	%      0,

    NO
180
                     ppm
NO,
370
                                _ppm
"I

S0n
COMMENT:
         The scrub generated NO after 10 min.  The NO generated (^17 ppm)
         is  9.1% of the NO and 4.2% of the N02 .
         The  reaction is:
       3N0
                                       NO + 2HN0
         .'.  12. 67* of  the  N09  adsorption is  due to  conversion
        NO:  Wet Ice Trap
               NDIR

-------
              11-17-71
                                                   H,
 ppm
 x 100
 CM    CM
O O O
55 a w
10 5  10
I   i  •

I   ill
8  4 8  -
     i
636-
5  |  5  -
I  '  I
424-
          BP
               r—
                      -6.5%
                   	1	
                            Down
                            in
                            Flow
      3-
I  i   I
212-

      '
1  I  1  -
I   !  I
Q  Q 0
lii
                      -18%
                    i
                   20
                       40
60
                                 BP
                                         -3.4%
                                          -21%
80
                                         100  120
                                                   BP
                                                         Water Meter
                                                         Frozefa Open
                          140
                                                            i   i  i  i   i  i
                                                           160   180  200  220
                                                                               BP
                                                                                        BP
                                                                                 -1.4%

-------
                                 - 45 -
                        NOX SCRUBBING DATA SHEET
DATE:    U-17-71
                   SCRUB:
                                 .   H20
OBJECT:  Absorb NOX and gain experience
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.     129 °F     Initial PH _      Final PH -

    H20 _ 10  %     C0            W       °      0-

    NO   _ 348 ppm
                      2

                    N09
                                          37°
                                                 PP™
J2

SO,
COMMENT:
           (1)   The water meter was inconsistent  and was sticking throughout
                the run.

           (2)   The NO was  initially  absorbed to  & 6-1/2%.  This decreased
                to 1.4%.  The N00  changed  from 18% to 23%.
NO:  Wet Ice Trap
                                   NDIR

-------
11-18-71
ppm
x 100
IN
O O O
S5 53 Cfl

10 5 1(
i
1
9 i <
i i 1
8 4
I

7 '
/ 1
1 1
6_ .
3 <
1 i
5 1 .
1 '
4 2 '
i
i t
3 '
1 '
2 1
1 ,
1 1
0 0 (
U


IN



) -
m

J -
-
5 _
_

7 -
•

5-
5 -


1
••
1 -
i
L -
) -
*
V





BP
->








™^^ ™





•«•••••••




1
















-9 . l%
r~



-18%




i
0
V





BP
(- -»








— -










20
\
















•P —•—•""""" "" ""




-19%




1 1 1 1 1 1
20 40 60
V





BP
<- >








_•>—•>










80
\















^- — — — -"""""





-21%



^^^^•••^^••^^••••••V^B
I 1 1 1 1
80 100 120 1





BP
*- ->









. « «•








^^^|BH|H
40 1
l














+6.5%

as a % of
N02, +5.6%



-20%




1 1 1 1 1 1 I 1 1 I
40 160 180 200 220 2'
\





BP
•»-













^•^^




I^^H
+0
1

-------
                                   - 47 -
                        NOX SCRUBBING DATA SHEET
DATE:
          11-18-71
SCRUB:
OBJECT:
            Absorb NOX and gain experience
CONDITIONS:

    Pot Temp,
Scrub volume @ 1000 ml

 126   „„
    NO
              10
             360
                    _ppm
 Initial pH
                             CO,
             Total Gas Flow
             12
 NO,
           330
                                  ppm
3200 cm  per minute

Final pH   ""	
°2

S0r
                                                %
COMMENT:
          (1)  In the beginning of the run, NO was absorbed to - 9.1%.  The
               system saturated with NO @ - 80 min. ( 0%) and was producing
               6.5% (5.6% as a frac. of N02> at the end of the run.

          (2)  The initial A N02 was 18%, the final 20%.  Of the final A,
               16.8% is accounted by 2N02 + H2Q => NO + 2HN03
           NO:  Wet  ice  trap  -> NDIR

-------
11-19-71
5N NaOH
ppm
x 100
CS CM
O O O
53 53 W5
10 5 10 ~
II'-
gig-
1 1 1 -
8 4 8 ~
1 , ' -
7 | 7 -
Ml-
636-
1 1 • -
5 1 5 -
Ml-
2 4
1 i ' •
31 *5
1 3
Ml-
212-
1 ' -
i1 ! r -
i • *
* i
1 1 1

BP






• ^m ^v •










0
1










-18.5;



-17.55




I
20
1

BP





"











20










-19.4%



-17.5%





40 60


BP
f~ ~~5











^





60
1










-20.6%


T £. t*y
— -10. OA




80 100 12


BP
e — i







^ ^H-^» M









0 12
1




NO drop
is 18.4%
of N02





-22.6%



-19. 7%




1 1 1 1 1
0 140 160 18
1

BP
t

















0

                                     Time in Minutes

-------
                                 - 49 -




                        NOX SCRUBBING DATA SHEET



DATE.      11-19-71         SCRUB.       5N NaOH
           NOX Absorption
OBJECT:              	
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
    Pot Temp.
126    °F      Initial  pH     ""	      Final  pH
    H20 	10     7.     C02       12	7.      02       3	7.


    NO       338     ppm     N02 	4QO	ppm      S02 	ppm
COMMENT:
            (1) The NO drop is nearly the same as the N02 which indicates that
               absorption Is by ^Oj formation.
           NO:  Wet  ice -> NDIR

-------
11-22-71
                                        83 wt %


ppm
x 100

CS CM
O O O
55 55 w

10 5 10 -

1 1 • -
9 1 9 -
I ' 1 -

848-
1 t ' -

7 1 7 ~
1 1 1 -

636-
I 1 ' •
i
5 | 5 ~
III-
I •

424 —
*T «• "
1 1
3 1 3 -
M|-
212 —
1 • -
1
1 . 1 —
III ^
Q 0 0 -
Hi




BP

































Off Scale
4

/


•

/
















	 -53%^

I i i
Q 10 20 30
I
NO
@
2000
ppm
BP

20
t
1
18
i
i

16
1
^
14
1

12
i
i

10
—1
1
1
T~l
\J
1
I
6
i
f-
4
1
2
i
1
1
1
i




















*H
O

1" CM
O
&
+ T or%
*v 120
	 i
L.
**fe?*
0
s »—
1
40 5




BP
•*- "^














M-l
O
g
cd
OJ
4J ^~~~>«
«W CO
14-1
o
pm ~0
ST?
"i
•
1 	
•
H
1 1 f mist in
• LLcell
0 5(
1












^ i
O
_
o
z






*<


+260 ppm


-220 pp" - — — —


i ill i
) 60 70 80 90 K
1




























-230 J

t
V^-..+250_
i
)0 110 1




BP
r»






O

u
Cu
m
<4-l
cd
> cs,

^/*z







-------
DATE:     11-22-71
                                  - 51 -
                        NOX SCRUBBING DATA SHEET
                        SCRUB:    83wt% H?SOA
OBJECT:
           NOX Absorption
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.    275  °F     Initial pH    — _      Final pH    —

                  10   7,     C02 _ 12 _ %      02 _ 3     %

                             N00 _ 390     ppm      SO, _     ppm
    H20
NO
             325
                     pptn
COMMENT:
           (1) The first attempt to run ended in failure.  The thermocouple
               dissolved causing all sorts of errors.  The system was rerun
               12-3-71 with temp, control in an aux. oil bath and a glass
               thermometer in the t^SO/.

           (2) The H2S04 was contaminated with Fe-Ni-Cr from the SS304 of
               the thermocouple.

           (3) Mist apparently forming in Dupont Cell; cell temperature 65°C.

           (4) Data suspect due  to (3).
           NO:   Wet ice -> NDIR

-------
12-3-71
                                          79%
ppm
x 100
£V| 0^
o o o
25 K OT
10 5 10 -
919-
1 ' -
8 4 8 -
1 , ' •
717 —
i | v —
i ' -
636-
1 , ' -
5 1 5 -
1 "
424-
3 ' 3 —
1 '
212 —
1 , ' -
111-
i-i




BP
-1























"^ 	 	 	
^"•^^^


I I
o 10 20 :
\




BP
* "*





^•MB
•MM*



>o :
t






	




"




X) 40 50 60 70 80 90 100 110 1
1 Time in Minutes




BP
1-
...





I^BK^



-
20
1
                                                                                                               Ui
                                                                                                               KJ

-------
                                  - 53 -
                        NOX SCRUBBING DATA  SHEET
DATE:
OBJECT:
12-3-71
SCRUB:   79wt%
            Absorb NOX
CONDITIONS:
     Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
Pot Temp.
H00
NO
202 °F
10 %
325
ppm
COMMENT:
                             Initial pH
                             CO,
                                         12
                                                Final pH
                                                0
                             NO,
                                        330
                                       _ppm
                               2
                              SO,
_ppm
           (1) N02 absorption was small, £"22%, .the same as for water.
           (2) NO was essentially unchanged with a max absorption of = 2.5%.
           (3) First 30 min N0_ meter unstable.
           NO:  Dry ice -> NDIR

-------
12-5-71
5N NaOH
ppm
x 100
IS CM
O O O
99 a co
10 5 10 —
1 ' -
1
9 | 9 -
Ml-
848 —
1 ' -
1
717-
. ' i -
636-
1 1 ' -
515-
i ' 1
1 1 -
424 —
1 , -
i
313-
Ml-
212 —
1 i
1 ! ! -
Ml-
\\\





BP









^ mi^^^ m





























- ^ 35% 	 -
-"""""


- ^34% 	
	



1 I 1
0 10 20 30
V





BP








._.



























i
\
\
\
U^_-41%



-35%




1 1 1
40 50 60





BP








— — — — — v
-i













                                           T-i.-nve.

-------
                                    - 55 -
                        NOX SCRUBBING DATA SHEET
DATE:   12~5-71              SCRUB:       5N  NaOH
OBJECT-     Sodium Hydroxide  comparison to  (NH,)2SO_
                                                                 3
CONDITIONS:     Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.    112    °F     Initial pH    	      Final pH    ~~	
    H20 	10     %     C02 	^	%      02 	I	%

                                         320
    NO  	274     ppm     NO- 	ppm      S02 	     ppm
COMMENT:
           (1) NO  & N02 scrubbing  was  in  the  35%  area with  the NO  increasing
              to  about 41%.

           (2) The N02 pullout was 120  ppm out of  340 &  the  NO 130  ppm out
               of 320.
          NO:  Dry Ice -> NDIR

-------
12-5-71
4.1 Molal (NH4)2S03
ppm
x 100




CM
O O CM
25 Z O

0 5 10 _

1
1 * -
1
1 1 .
1
i 4 8 -

, «
|
1 \ 7 ~
1 1 -
136 —
i
1
1 5 -
1 1 -
+ 24-
1 3
3,3-
' 1
212 —
! * -
' 1

1 1
! 1






BP
-*













	


































1
\
\
\
l.__^£2£_— — -






-100%







BP














—




































^ f~~* """"
-—•""""






-100%



p
cd
M
H
HI
O
M
4J
01

0
w
o
4-1
•H
to

__
|i_.


•-





















^
a
z
0)
4-1
C
o
4-1
4-1 C
O 0
CM CM
0 0
V—
i i
.J L.

-15%






-100%
















BP
t-



,
S
i











0 20 40 60 60 80 100 120 130 150
1 II II

Time in Minutes

-------
                                   - 57 -

                        NOX SCRUBBING DATA SHEET

DATE:    12~5-71            SCRUB:   4'1 Molal (NH4)2S03
OBJECT:      Absorb NOX
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
                  112
    Pot Temp.         °F     Initial pH       —          Final pH     —
    HO          10    7     CO           12       7      0           3     7
     0                       '•""'O                   fo      ^>n                la
              328                         350                         ——
    NO	ppm     N02 	ppm      S02 	ppm
COMMENT:
           (1) N02 scrubbing is 100%.
           (2) NO absorption starts @ 2.3% & drops 15% over  _ 2 hrs.
           (3) With N02 turned off, no NO is absorbed.
           (4) After 140 minutes on line solution analysis by UV showed 5.2
               millimoles of NO-j" and 0.6 millimoles of N02~.
           NO:   Dry ice trap -> NDIR

-------
12-7-71
                                      11.5 pH NaOH
ppm
x 100
cs co
O O O
2 2 CO
1
1
10 5 10 _
1 I ' '
9 j 9 -
II-
848-
1 . ' -
7 1 7 -
I ' l -
636 —
1 1 ' -
5 1 5 _
1 ' 1 -
424-
1 .
1 ( ' '
313-
1 ' 1
1 1 -
212-
1 , ' -
i i i _
lii
BP





01
i— i
0)






c













) 10 2(
BP
«-*





Sample


^•H



3 2
1













1 1 1
0 30 40 50 6C
1
X






-------
DATE:
12-7-71
                                  - 59 -


                        NOX SCRUBBING DATA SHEET

                            SCRUB:   NaOH @ 11.5 (3.16 X 10~3 molar)
                                     same as sat'd Ca(OH)2	
OBJECT:   Compare hydroxide scrubbing at same pH
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
    Pot Temp. 120____°F     Initial pH  11*5	      Final pH    6.3
                                                   7.      0.         3      7.
10   7,
    NO
              311
                     ppm
                             CO,
                   NO,
COMMENT:
            (1)   A NO   «  -10%
                A N02  -  -79%
                               12
                              360
                                                 ppm
                                                          S0r
                                                        _ppm
           NO;   Wet ice trap -> NDIR

-------
                  12-13-71
Mg(OH).
   ppm
  
C
r-i
O
§
1

-22%




1
0 10
1
Sampl
BP
/ >




_t 	













































-24%




20 3

Sample
BP
v «.




— — —




















Q 3
t







-4.9%




















0 40 * 50 6
Tt-4 — A 4-^ >JE-ln4.
Sample
BP
f •%


















f






0 6
\
4- A. A







-6%















-26%




0 70 8
I
Sample
BP
.
^


	




o
c
1














0
I

-------
                                   - 61 -
°ATE:    12-13-71
                        NOX SCRUBBING DATA SHEET


                            SCRUB:  Sat'd soln. with slight excess of

                                     Mg (OH ) _
OBJECT:   NOX Absorption
°NDITIONS :     Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

   p°t  Temp.    122    °F     Initial pH    8.9 _      Final pH    7-5

       _ _ 10

   N°
   H2°
C°MMENT :
                             C0
                                           12
                                          36°
                                                                          ppm
           (1) NO pullout was  -  5%

           (2) N02 pullout was -  25%

           (3) Scrub, turned from cloudy  to  clear after 10 minutes.

           (A) After 80 minutes on line,  solution analysis (spectrophotometric)
              gave zero nitrate  and 0.9  x 10~3 M nitrate.
          NO:   Sat'd Na2S03 in HOAc -> dry ice -> NDIR

-------
                  12-15-71
                                                              Zn(OH),
   ppm
   x  100
  es     CN
 O  O  O
 a  a  en
10 5  10


9   i  9  „

i   '   i
848
I
I

3
I
    '
       i
       7
 I      I
636
 I      I
424
3  —

 I   -
212
I      '


I   '   1
Q   0   Q


\\\
1
^*B
1
-H
]-
\
BP
.A
^T

— —
I
I





1 	 i—
a 10
l
BP

-------
                                  - 63 -
                         NOX SCRUBBING DATA SHEET
 DATE:     12-15-71           SCRUB-   Sat'd  soln-  °f  Zn(OH>2
OBJECT:    Absorb NOX
                                                                 3
               Scrub volume @ 1000 ml    Total Gas Flow (3 3200 cm  per minute

    Pot Temp.   119   °F     Initial pH    7.5            Final pH   6'9

    H n             10 „,
                             C02 	12	7o      02
    NO          397          ...           400
    NU	ppm     N00 	ppm
COMMENT:
           (1)  A  NO -   8.3%
               A  N02  *    29%

           (2)  After  90  minutes  on line,  spectrophotometric solution analysis
               gave 0.3  x 10~3 M nitrate  and  1.4  x 10~3 nitrite.
          NO:   HOAc •  NaS0  -> dry ice ->NDIR

-------
12-17-71
8.9 pH NaOH
ppm
x 100
tN CM
000
10 5 10 —
919 —
l ' 1 -
848

, ' -
717-
i ' 1 -
636-
1 ' -
5 ! 5 _
1 ' 1 -
424

1 ' -
3 I 3
1 ' 1 -
2 1 2 _
1 ' -
i ! i _
i • . -
\ i '

Sampl
BP






























|
i 1 	
0 10 2

Sample
BP














0 2<



— — —












3 30 40 50 60 7<

Sample
BP
•••• ^M-«













,
3 7(


-5.9%__







-24%





) 80 9C

Sample
BP
	













>

-------
                                    - 65 -
                        NOX  SCRUBBING  DATA  SHEET
DATE:    12-17-71	    SCRUB-    NaOH @ PH8-9>  same as sat'd Mg(OH>2
OBJECT:   Compare hydroxide scrubbing at same pH
 °NDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.   120   °F     Initial pH   8.9	      Final pH 	

    H2°	10 %     C0  	^f	%      0  	I	7.
    N°        4°4            N02         37°     ppm      S02             ppm
COMMENT:
           (1)  A  NO =    6%
               A  N02 =    24%

           (2)  pH dropped 4  after 70  minutes  on line.

           (3)  After 70  minutes  on line,  spectrophotometric  analysis  of
               solution  gave 0.3 x 10~3 M nitrate  and  1.3  x  10-3 M nitrite.
          NO:   Na2S03 in HOAc -> dry ice trap -> NDIR

-------
         12-20-71
Ca(OH).

ppm
x 100
es CM
O 0 O
23 23 W
10 5 10-
1 . •
9 | 9 -
1 ' 1 -
1 4 ? "
7 1 7 ~
636-
1 '
5 ' 5 -

424~
1 • -
1
3 I 3.
1 1 •
2 1 2 ~
1 ' "
i, ! n
1 i •
BP
"*








	 	





















i«





-39%


1
] 2
BP
< — *








— •









0 2










-7.6%





-27%



0 40 6
BP









	









D 6










-7.9%





-29%



0 80 100 1
BP









_—-









20 1










-7.8%





-29%



20 140 160 180 200 220 2
BP









•* ^» ••









40 2










-7.7%





-29%



40 260 280 3(
BP



















30
AW  V  V  V      V   V        I   \
                   I   I
I
                                   tA^BMa. ^ro. •Vt^«wxt.«.«.

-------
                                   - 67 -
                        NOX SCRUBBING DATA  SHEET
DATE:
           12-20-71
          SCRUB:    Sat'd  spin.  Ca(OH)2
OBJECT:    Absorb
NOX
   °ITIONS:     Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.    121   °F     Initial pH    H.5           Final pH     —
H2°

NO
COMMENT:
  10
                390
                    _ppm
           NO,
           (1) @ 0  +  20 min.
               20  +  60
               60  +120
              120  +240
              240  +300
              A NO =
                                           12
                                          380
                                     14%
                                     7.6
                                     7.9
                                     7.8
                                     7.7
                                             _ppm
A NO,, =
            2

           SO,
39%
27
29
29
29
                                                        _ppm
          (2) During first 100 minutes pH dropped from  11.5  to  7.5

          (3) After 300 minutes on line, spectrophotometric  solution
              analysis gave 0.4 x 10~3 M nitrate and 4.6 x 10~3 M nitrite.
         NO:  HOAc  -  Na-SO.  ->  dry ice trap -> NDIR

-------
12-21-71
Sat'd
in 5N NaOH
ppm
x 100
CN CS
O O O
25 55 c/3
10 5 10 -
1 , ' -
9 1 9 _
1
i 1 -
848-

1
I
717-
1 ' 1 -

636-
1 . ' -
5 1 5 _
i ' 1 -
424-

1
1 1
3 i 3 _
1
1 1 -
2 1 2 _
1 i -
i
1 , 1 _
,' i -
III





BP
*- ->
























I







M-l
14-1
O
4-1
a)
0)
f.
4-1
O
O.
-12% ^
M ^mmm ^^ ^m ^
*"*
**-»^^
A A A A "^ ^^ —27%
o o o o

C*l rH i— 1 O f^
r-t i— I iH i— 1 o
m
03
o
o





-100% -100%
D 20 40 60 80 100 120 140 160 180 200 220 24
\





BP
*"







" 	 — oo
1















0
\
                                       TL-ime irv

-------
                                  - 69 -
                        NOX SCRUBBING DATA SHEET


°ATE:     12-21-71	    SCRUB-   A saturated soln.  of Na2SO  in

                                     5N NaOH
OBJECT:    Study Scrubbing by Strongly Basic Na~SO
   °ITIONS:     Scrub  volume  @ 1000  ml     Total Gas  Flow @ 3200 cm  per minute

    Pot Temp.   Varies °F      Initial PH  _      Final PH  _
                                       12         7,       0         3
              357
                            N0        355 _ ppm       S0  _ ppm
          (1)   At the higher temperature (129° F) the NO removal was
               12%; N02 removal was 100%.

          (2)   A*? the temperature went down, the NO pullout increased
               to 27% @ = 80°F.
         NO:  HOAc  • NaS0   ->  dry  ice  ->NDIR

-------
1-3-72
Sat'd
ppm
x 100
CM 
-------
                                   - 71 -
                        NOX  SCRUBBING  DATA  SHEET
DATE :
            1-3-72
                             SCRUB:
Sat'd
                                      (approximately  2.3->  2.5  molal)
OBJECT:    Absorb NOX
NDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow


  p°t Temp.     122  °F     Initial pH _ 10


  H2° — . _ 10 %     C0

  NO
COMMENT:
                                         12
3200 cm  per minute


Final pH

            i
0
                340
                    _ppm
                           NO,
    340
           _ppm
J2

SO
                                       7
                                       /o
                                                                        _ppm
           (1) No  SO   generated.


           (2) A NO = 21%
                                    A N02 =  100%
           (3) Na2S03  •  7H20  @  196  gm/100ml (CRC handbook) = - 3.5 molal in
              Na2S03  @  40°C.   This is  higher than observed.
          NO:   Na2SO  -> dry ice -> NDIR

-------
1-10-72
and
ppm
x 100
eg r-j
O O 0
10 5 10 ~
1 1 ' "
9 ' 9 —
1 ' 1 -
848 —
l
7 | 7 —
1 1 -
636-
1 l -
5 « 5 -
i ' l -
424 —
3 ! 3 -
' ' 1 -
212 —
1 • -
1 ' 1 —
1 ; 1 -
\\V


>
BP
t— -*













(


Off Scale














1 1
1 10 20 3(
\


p
BP


m ^v^v^










) 3(
\


Off Scale





-24Z








1 | 1 I 1
) 40 50 60 70 80 9C


i
BP


"""""" l
^*
K
1








1
t

-------
                                   -  73  -
                        NOX SCRUBBING DATA SHEET

DATE-       1-10-72                   NK
    '   —                    SCRUB:   ^
                                     3.60 molal NH.HSCU. 1.88 molal NH.HSO,
                                                  £J   -J-.^
OBJECT.-    Nox Absorption
    JTIONS:     Scrub  volume  @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    p°t Temp.    125    °F      Initial pH 2.4	      Final pH 	

    H2° —        1Q   'I-      C02  	^	%      02 	3      %
    ^•"^                                   OOQ                          n
               360    ppm      N02  	ppm      S02 	     ppm
          (1)  Copies generation of S02 on mixing  [HSO^~ + HS03'
               804= + H2S03	^ H20 + S02J.

          (2) A N02 = 100%
              A NO - 24%
              generated S02 > 1000 ppm
         N°5 Na2s°3 -> dry  ice -> NDIR

-------
              1-17-72
6 Molal NaOAc
  ppm
  x 100
                                                                                                                       JS
                                                                                                                       I
V  \  \

-------
                                  - 75 -
                        NOX SCRUBBING DATA  SHEET
DATE:    1-17-72            SCRUB:       6 molal NaOAc
OBJECT-         Absorb NOX
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.  119    °F     Initial pH     ~~	      Final pH   —	
                                          12                        3
                  _10_%     C02 	7.      02 	
                                         o/" r\

    N0	340 ppm     N02 	ppm      S02 	ppm
COMMENT:
           A NO =   18%              A N02  =   25%
          NO:  Dry ice -> NDIR

-------
   1-18-72
ppm
X
CM
O
s=
10
1


9
1
8
1

7
1
6
1

5
1
4
1

3
i
2
100

0

5

i
I
1

4

1
1
I

3

1
1

2

1
1

1

o
cfl
10
i


9
1
8
1

7
1
6
i

5
1
4
I

3
1
2



-
_



-
—
-

•

—
-

^™
-
—
«•

—
-
—
BP
                           -27%
       -49%
                                               -40%
                                                        BP
                                   50
60
70
                                                     80

-------
                                  -  77 -
                        NOX SCRUBBING DATA SHEET
°ATE:  —  1-18-72          SCRUB:   8.4 m NH, Cl
°BJECT:      Absorb NOX
 °NDITIONS:     Scrub volume  @ 1000 ml    Total  Gas  Flow @ 3200  cm3  per minute

    Pot  Temp.    123   °p      Initial  PH    ~" _      Final  pH     —

    H2°  - _ 1°  %      C0           12        %      0         3        %

   N°  -- 33°    ppm     N0  _ 350     ppm       S0  _ ppm
           (1) A NO «   27%
              A NO *   49 ->   40%
          NO:   Dry ice ->  NDIR (= 23% conv.  N02 ->   NO)

-------
1-19-72


ppm
x 100

CN CM
o o o
S3 5= to


10 5 10 -
1 , • -
9 ] 9 -
1 1 -
848-
1 • -
1

i
1 1 -
1 1

636-

1 ' "
'
C ' C ^"
5 \ b
1 1 -
424-
i i
1 '
i
3 J 3 -
1 1 -
1
212-









BP






» ^" ^»«















1 ' -
i 1
1 ' 1 1
000 1
. \ . I
























\
\
\
\
\
^^
^(R*™
^ ^


!^^^^
^ ^
^^-'^^
\ \ I
1 20









BP






•»— —












^•^•^•^





40 4


fa
o
VO
CT\



O
O







M-l
O

O
&







/\
X N
^ \
\
\
-57%










u
o
M
a)

-------
                                 - 79 -
                        NOX SCRUBBING DATA SHEET
DATE:      1-19-72
                            SCRUB :
                            28 wt. % NH^OH
OBJECT:
Ammonia Scrubbing
CONDITIONS:     Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute
Pot Temp.    75    °F

      —.       10  %
                             initial pH
                                          Final pH
    H2°
    NO


COMMENT:
                             co2
                                             12
                                             1
              328
    _ppm
                         330
                                                 ppm
                                                       2
                                                      S0r
_ppm
           (1) An H2S04  trap was  used  to  protect  the  NDIR from NH3 .   The  trap
              was  allowed  to  equilibrate with  NO-N02 .   On by-pass without
              the  H2S04, the  NDIR read 83,  with  H?S04,  82 1/2.   The  N02
              was  unchanged.

           (2) test pullout was @ rm.  temp,  and was 57%  N02 ,  74%  NO.

           (3) At elevated  temperature (106°F)  NOX absorption  was 38% NO,
              26% N0.
              NH.j boil off is a severe problem.
          NO:   *See comment (1)* -> H2S04 -> dry ice trap -> NDIR
               (- 23% of N02 conv. -> NO)

-------
Glacial HOAc
1-19-72
                                                 50% NaOH
ppm
x 100
CM CM
000
s z co
10 5 10 "~
1 , ' -
9 1 9 -
1 ' 1 -
848-
1 , ' -
7 I 7 -
II-
636 —
1 i -
5 j 5 -
1 ' 1 -
4 2 4 —
1 , ' -
o 1 3 —
i ' 1 -
212-


BP


















glacial HOAc















*BP










	



1 ' -1 1 1
i | 1 .
1 I1 "I
000 — T^^
\ * • 1
\\ \ V
| -80%


0 10 2.0
\ \
                               BP
                                      50 wt.% NaOH
                                            28%
                                           -23%
                                   0    10    20    3C
                                    \
                                                                                                     00
                                                                                                     o

-------
                                   - 81 -
                         NOX SCRUBBING DATA SHEET
DATE:  _l-19-72             SCRUB-    HOAc 8lacial
°BJECT:  Absorb NOX
                                                                  3
               Scrub volume @  1000  ml     Total Gas Flow @ 3200 cm  per minute



    p°t Temp.   120   °F     Initial pH     —	      Final pH    —



    H~0            *•"  m     nr.            12        a/       «            3    o/
     2	.	       /0     COr,                 	/o       0^ 	L
    NO         335           XT^            370
        .	_.    	ppm     N00 	ppm      S09 	ppm
C°MMENT :
           (1)  NO  level not effected

               N00 =   80%
          NO: Dry ice -> NDIR

-------
                                  - 82 -
                        NOX SCRUBBING DATA SHEET
DATE:     1-19-72	    SCRUB:      50 wt' % NaOH
OBJECT:    Absorb NOX

CONDITIONS:
Pot Temp.
mo
NO

Scrub volume @ 1000 ml
120 °F Initial pH
10 % co.
345
ppm N00

3
Total Gas Flow @ 3200 cm
F ina 1 pH
12 „
la Vn 	
330
ppm S0?
P i
per minute
3 %
	 —
ppm
 COMMENT:
            (1) A N02 =   23%
                A NO  =  28%
             NO:   Dry  ice  -> NDIR

-------
1-24-72
                                     NH.OAc, 8.4 Molal
ppm
x 100
CM CM 1
D O O
B S W
10 5 10 -
i _
1
, I g _
' 1 -
348-
1 ' -
7 ! 7 -
i 1 -

336-
l
31 C
1 1 -
i 2 4 -

i —
* 1 3 -
' 1 -
2* f*
i "
1
L 1 -
1 -


I
1
/

1


BP
•«- -V





















(
1

















— _ *— — * ' ""









1 1 1 1 1 1 1
) 20 40 60 8





BP
#- -v












••^^
MBMHI







D 8
1
















-31%




-39%





I i I I I I i
0 100 120 140 16
1
/




BP
«
•T^




™ "" "~ ^ "~ 1
a
u
I













0
1
                                     Time in Minutes

-------
                                  -  84 -
DATE:
          1-24-72
                        NOX SCRUBBING DATA  SHEET
                        SCRUB:    8'4 Molal NH4 OAc
OBJECT:
         Absorb NOX
CONDITIONS:     Scrub volume @  1000  ml    Total Gas Flow @ 3200 cm  per m


                123                         —
               	°F      Initial pH 	      rinai nn	


                                                                        3
                                                                         inute
Pot Temp,
H20



NO
                10
             362
                 _ppm
                              CO,
                         NO,
                                    12
                                               "I
                                               to
                                        360
                                                  _ppm
                                                                        ptn
 COMMENT:
            (1)  A NO =  31%
                                     A N02  *  39%
              NO:   H2S04 (sat'd with NO & NO^ 	*• dry ice
                                                            NDIR

-------
                  1-25-72
 CM     CN

Z  Z  OT
10 5  10
                                                7.0 Molal NH OAc, Dual  Series Pots
-Jb-vr ^f -*-\S 	
1 ' "
9 ' 9 —
1
1 -
848 —


1 '
7 ' 7
|
1 -

636 —


1 ' '
5 1 5 -
I ,
1 -
424 —
3 1 3 -
1 I
1 "
919
i
i ! i -
1 i -
0 0 0 «.
1 ,
1 1
1 1




,-H
c
0





j*
c
o

4-1 4-J
PJ O,
4-1 T3
^ C
--? tS
PI 3
s-4 1-1

H










•••^••H

j=
H
-25%




-35%





1









I






-28%





-39%




1
•





CO

ol
~* Tj
4-1 I
O?
PQ 1
D J

r— n
H I











1

0 20 40 40
1 1 1
                                                               BP
                                                                                            BP
                                                                O 4-1
                                                                « M
                                                   -82%
                                                   •• ^ia» •

                                                   -77%
                                                                o^J
                                                                PU C
                                                               ^» o


                                                             i-J
                                                                    -<&
                                                               CO
                                                               i-H
                                                               Pn O
                                                               PQ CM
                                                                        PQ
                                                                                                                               00
                                                                                                                               Ul
                                                                               -59%
                                                                               -56%
                                         60    80    100    120   120

                                                             I      I
                                                       Time in Minutes
                                                                        140   160
  i

180

-------
                                 -  86 -
                        NOX SCRUBBING DATA SHEET
DATE:     1-25-72
              SCRUB:   7.0 Molal NH.OAc  Two Baths
OBJECT:   Double Bath Run
 CONDITIONS:
     Pot Temp.
H20
  Scrub volume  @ 1000  ml    Total  Gas Flow @ 3200 cm  per
    123
                         Initial pH
     NO
                 10
                           12
354
                         NO
                                         340
                                                  PPtn
                                                              pro
 COMMENT:
            (1)
  Two pots arranged in series sequence.
            (2)  From 120 ->  180 min.  /i NO  *    59%,  A N02 *  56%.   This is
                more than the sum of  the parts for  each individual bath.

            (3)  Are probably stripping NH3 from first pot & transferring to ^
                second pot to produce a scrub of NH^H + NH^OAc..   This is n ^
                possible when each pot is  run separately.  Thus,  the scrubb
                are much more efficient in series because of NH^OH scrubber*
                which is known to be a good scrub by itself.

            (4) Could smell NH3 being stripped from first scrub.   No odor
                after passing thru
             NO:
           (sat'd with NO  • N0_)	>  dry  ice	> NDIR

-------
1-26-72
28% NH^OH and
                                                  in Series
ppm 1
x 100 I
CN CM 1
O O O
Z "Z. in
10 5 10 —
1 ' -
? 1 9 —
1 .
1 -

8 4 8 —

*
i ""
1
7 1 7 -
' 1 -
6 3 6 -
.i',:
1 -
4 2 4 -
1
3 | 3-
1 -
212 —
1
1 ' 1
1 1 1
1 1 '
I i
; i
1 BP












— -
















ex
CO
M
H
O
f
JJJ

FL,






>"%*>


-12%



ci
•H
O
CO

4J
O
o.

0

af




r\
i
_5
X










CM
*!•

rH
(1)
W
O




w
-74%
-80%



o

§

£
o
cfl
pq

0)
0)
r-
i


*




L-












o
c
i






























BP











i
oo









i 1 I I 1
0 10 20 30 40 50 60
i i
                                    Time  in Minutes

-------
                                - 88 -
DATE:
          1-26-72
                        NOX SCRUBBING DATA SHEET
SCRUB-   28 Wt* % NH4OH & H2° dual bath
                                     sequence
OBJECT
          Free pickup of NH» in water bath & subsequent scrubbing
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200  cm   per tnmu
    Pot Temp.
                  70
    NO
 COMMENT:
                    10
 Initia 1 pH
                             CO,
            12
                330
 NO,
             355
                                                 _ppm
            (1)  To
                Gas
                                       Mix
                Analyzers
                                            H20
                         28% NH^OH
                Pot "C" (NH40H)  warmed from « 70°F ->86°F over = 20 min. &
                then cooled down to 65°F.

                The water (pot B) went from * 73°F -> 113°F over the run.

                The H2S04 (pot A) went from = 73°F -> 83°F

            (2) N02 is necessary for NO absorption.
            NO:  H2S04 -> HOAc  • Na2S03 ->  dry  ice  -> NDIR

-------
                                 - 89 -
                         NOX  SCRUBBING  DATA  SHEET
 DATE:     1-26-72            SCRUB:     2-3 Molal Na2S
OBJECT:     Absorb NO
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.   120   °p     Initial PH _ 12         Final pH _

    H2° __ 10     %     C02 _ 12     %      Q2 _ 3      7o
    N0	35°    ppm     N02 	35Q   ppm      S02 	     ppm
COMMENT :
           (1)  An attempt to use drierite rather than the Dry Ice trap failed,
               the drierite generating NO from N02 & also not stopping all
               the H20.   The system being fouled, the run was unsatisfactory.

           (2)  The one definite result is that 100% of the N02 was absorbed.
               If any  NO  was absorbed, it was  minor.

-------
                1-27-72
                                                        14.8 Molal NaOH
ppm
x 100
CM CM
O O O
S Z to
10 5 10 —
9 | 9 —
. 1
1 1 -
848 —

1 i -
7 ! 7 —
i ' 1 -

636 —
1 ' -
I
5 i 5 -
I
1 1 -
424 —

Ii
1

3 ! 3 -
1
1 .
212 —
1 ' -
i -i _
• 1 1






BP
*- -rl





»•«• •









^••••"M







	






h
O Pu O
o o o
CO O "H
^
I
^ I








-47%



-28%




1 I 1 1 1 1 1


*


BP



[
o
c
<










••M^BBMi















V f
, S* 0* &C
Jt o ^C***
l^ r-\ .
, .-I
I





**^W
**~~ /
^ ---•"* -28
^*r**



-27%




1 1 I 1 1 1 1





BP





i
VO
o






M^MB^H^









\  \  \
0    20    40    60     80   80     100    120  140    160
 \                        \     \                        V

-------
                                  -  91 -
                        NOX  SCRUBBING  DATA  SHEET
DATE:  _1-27-72            SCRUB:    14.8 Molal NaOH  (same  cone,  as
                                     28 wt.  % NHAOH)
OBJECT:  Comparison of NaOH & NH^OH
CONDITIONS:     Scrub volume @ 1000 ml    Total Gas Flow @ 3200  cm3  per minute

    pot Temp,   varies °F     Initial pH      ~	      Final pH   -	

    H_0         10     7     rr\                    "I      n                 7
     £.                  10     \J\Jn                   la      \Jn                la

    N0       333	^ppm     NO- 	360    ppm      S02 	ppm




           (1)  Had to use an open tube on the scrubber because the frit
               tended to clog.  (Probably with Na-CO )

           (2)  Temperature rose  due to heat liberated  upon CO- absorption.
          NO:  Dry Ice trap -> NDIR   (- 25% N02 conv.  -> NO  in  trap)

-------
1-28-72
2.3 Molal Na SO
ppm
x 100
CM CM
BO O
3 en
10 5 10 -
1 ' -
1 I
9 ' 9 -
1 ' 1 -
848 —
1 ' ' 1
717-
i ' 1 -
636 —
1 • -
1 1 -
424 —
1 ' -
1
313 —
1 ' 1 -
212 —
i1 : ; :
1- .1
V \ \



BP
e- — *




....








i
\









\
\
\ -18%








-100%
i i I i I
0 10 20 30 40 50 6
\



BP
*




I
K)
1









0
\

-------
                                   - 93 -
                         NOX  SCRUBBING  DATA  SHEET
 DATE:       1-28-72          SCRUB-    Na2S03>  2'3 Molal
OBJECT:    Absorb NOX
  COITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    pot Temp. 120-125 °F     Initial pH _ 10          Final pH    - _
                                                                       3
    H2°       10       "L     C0  _ 12     %      0  _ %
    N°       355     ppm     N02 _ 500  ppm      S02 _ ppm


COMMENT :

           (1)  A NO  =   18%     A N02  =   100%

           (2)  After 60  minutes  on line,  solution analysis  gave  2.0 millimoles
               of N03- and  0.4 millimoles of  NO^.
          NO:   Wet Ice Trap -> NDIR

-------
1-31-72
Na SO , 2.3 Molal and 0.062  Hydroquinone
ppm
x 100
CM CM
0 O 0
65 S3 tfl
10 5 10 -
1 ' -
i
9 ! 9 -
i ' 1 •
848-

1 • ' "
7'7-
i 1 i
1 1 -
636-
1 ' -
1
515-
i ' i -
424-
1 - -
' I
3 1 3 _
i ' I -
212 —
' « ' "
i i i A
\
\ \ -1


\ » *
\ \ \


BP









•*^ •••















,

1 	
V













-8.8%















-100%
t \
0 10 20 3
V


BP



u-
c
o
J


^ '


















0 3
\







a
o
b
ss
~S
\
I
i—
i —












^
*^
"*"*"*-.»., j
\ \ i
0 W 50 60 1(
\


BP









i
VC
j^1
I
















i
1
                                             i.-n.

-------
                                   - 95 -
                        NOX SCRUBBING  DATA  SHEET


           1-31-72                   2.3 Molal  Na0SO_ with Hydroquinone
          .	              SCRUB:                z   3	
                                     0.062 Molal



OBJECT;
   "ITIONS:     Scrub volume @ 1000 ml    Total Gas Flow @  3200  cm  per minute

    P°t Temn      ~\?'\  or,     •!-„,•)-,• o i  r^u      10            Final  pH   ~

                                                           o,	:	

                                                            '2 	     PPm
Temp. 123 °F
10 «
- 	 !^_PPm
Initial pH
CO,,
2. 	 ~
NO.
1U
12 %
340 ppm
                                                        2

NO
          (1) A NO   =8.8%
              A N02  -  100%


          (2) NO not required  for  N09  absorption.
         NO:   Dry Ice Trap -> NDIR

-------
                 2-1-72
                          Various Levels of S0_  as Na0S00  and NH,HS00
                                              ->       23        43
ppm 1
x 100 1
1



CM CM IBP I
O O O MS&\
ips

10 5 10 ~
1 i ' *
9 | 9 -
, ' ,
1 1 -
848-
1 ' -
7 j 7 -
1 1 H
6 3 6 —
' ' >' i
'' '1
424-
1 , ' '
3 i 3 —
i
. ' i
1 1 -
212-
1 , ' -
111 —
•
1





_











I 1 H

1





•K
i

o
3:
*i
c
i— i



6>S
•^
'




h-



BP
H
-H

S8^
o
O
CO
o
at
IS
^-s
^H
«
r-l
.i.
tM
O
iH
X
ao
\— *
g,
.-1
+













1 gm



I

1 An
Na2S03 1 Bp 1 1 BP
&Nofe,
f"~^ 1 f\






+6.8%
4~
/
/
/
/
/
w
/
/
/
*T-36%











<4-l
H-t
0
CM
O
....



HH^B*








U2





" •







MM




1
,.1,1 — W
• ' — '."-1-








(4-1
M-t
O
•H
rH
•H
4-1
ID
CM
0














10 gm Na2S03
No 0-
2




m
CO M-l
O 0
c/}
CM r
n) o
a a
a N<
o 1 *-~l
* 1 1
+ J 1
1
\ |
\ -35% ^*~'


<4-l
«n C
0 O
i
1
1

14-1
14-1
O
CN f* f
0 0
r? ^
J\ Q
.x^ \
-85% ^S^ \
	 \
\
' 0
2
""







BP
\f~ WJt&L









C
O
cs
0










x_












/"
r






yr
rc^
CM














BP I 1 BP
*l P
r fl I-.'^-
|| off ii


1 SC^
/
*



...
p*agp





«
o
1

~— •








i 	
V
0 10 10 20     40     60    60 70    70 80     100   120   140   160170   170180180190200   220
                                                                 t&VTVvi.te.a

-------
                                 - 97 -



                        NOX  SCRUBBING DATA  SHEET


 DATE:  __2-l-72	     SCRUB:   Varing levels of S03 = with Na?SO
                                                                   £~  ~J

                                      & NH,HSO^	
                                          't   J   "


  JECT:   See effect of concentration and of oxygen	




CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    pot Temp.   126   °F

    H2°	10     7,
    N°  -    355

COMMENT:
Initial pH
CO,,
2 	
NO,,
—
12 -
/o
340 pp.
Final pH -
3
SO-

%
ppm
          (1) With 1 gm/liter of Na2S03, the initial absorption is * 100%
              N02 & 36% NO.  This diminishes to « 29% N02 (same as H20)
              with 6.8% generated (also same as H20) .

          (2) The elimination of 02 from the 1st bath has no effect.

          (3) 10 gm per litre of Na2S03 => 85% N02 & 35% NO for = 30  min.
              It them starts behaving like the 1 gm bath.
              The small level of NH4HS03 behaves similarly except  generating
              an  off scale  NO signal.
          NO:   Dry Ice Trap -> NDIR (= 24% conv.  of N02 to NO)

-------
2-2-72
                                        Hydroquinone
ppm |
x 100


CM CM
o o o
2 JS en
10 5 10 —
1 ' -

9 | 9 -
j .
II-
848 —
1 i -
7 ! 7 -
1 ' l]
636-^
1 ' -
i
5 \ 5 -
1
1 1 -

4 2 4 —
', •-
3 3 -
"" 1 *J
I ,
1 1 -
212-
1 ' -

1 1 1 -
1 ' 1 -

\\ \
m





BP
< »






~







	 ;


1000 ml
of H20











6f W
• D/o







f
1 -24%
	 — 	
1
















BP 0
* 4






0.008 molal
Hydroquinone



f
k


i

— J



















l^ t



1
1
1

Ig,
u.
\ 0
\
\ °
\
\





Cf
ta
_i
o S>
o
h^. i
f
T
0









0 20 40 40
V \ \











'
-^







o
0














NO off o
«>. u.
) <,
B
oo
CM







f
I
t
1
1
I
1-



/\0, on






g
g\
ri
i
1
1












BP







l
v£>
00
1






,—
i



E
I'D o
1 4 CM






J s \
\ /^
1 1 \f\ 	 ~~ — — — — — ~
60 80 100 120 140 160 180 200
\

-------
                                    -  99  -
                         NOX  SCRUBBING DATA SHEET
DATE:     2-2-72              SCRUB:       Hydroquinone
OBJECT:    Effect of anti-oxidant
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.     124 °F     Initial pH      "	      Final pH     ~
    H2° _ 10     %     C0
                               2
                     ppm     N00 	-J^O	ppm      S0_ 	~	ppm

COMMENT:

           (1)  H20 blank @ A NO =   6.6%,  A N02   24%

           (2)  On line with HQ & the A N02 = =  39%.   The NO signal exceeded
               the scale.

           (3)  With the NO off & the N02 on, 50% of  the N02 was  converted to
               NO with a A N02 of =  50%.

           (4)  Solution turned red with Na-SO.,  addition.
          NO:   Dry Ice Trap -> NDIR

-------
                 2-3-72
                                                     2-Amino Ethanol
   ppm
   x 100
  cs      es
 O  O  O
 2  2  co
 10 5  10
 I       «
 9      9
 II-
 848
 I
 7   i  7
 I   '  I
 636
 I   ,  '

 i''5,
424
 I   ,   '
3   !  3   —
 II-
212   —
 000
 \
\
\
\



1
1
BP


I
n
J


™


^^


•
__
-



o
u

o
2



I
1
MM
-

-
••M



••M
-









i
\


from
129°F
-^ 134°F
^_ _t.



4.

tL

i—
O
0
u
c
u

O
1
a:
iH
6
O
+

--..^














c
O
O

-f-






128°FO
-40% T

1





-91%

1 1 1 1 1















o o
j^op 136^F 1401
f^f""mm~'
---"""'
0

o




' c


MH
li
O

o




1 —
1
I
1
r
i























i
i
i
i
•
i

i
i
i
0
^
o




0
.
"o

•-












M-l
"4-1
O
(
o
z
I
f~- 1
o
i








1 — 1
1
1
1
1
1
1
1
1
1
1
1
1





1 1 1 I 1 \



BP













O
O
1





••••••••••»







1 0 10 20 30 40 50 60 70 80 90 100 110 120 130
                                                               in.

-------
                                  - 101 -
                        NOX SCRUBBING DATA  SHEET
                            SCRUB:  2-Amino Ethanol
°BJECT:
               Scrub  volume  @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    pot Temp.   Varies °F      Initial  pH _      Final pH
   H2° -   10      %      C0           2
   N0                       N0         320       pprn       SQ               ppm
           (1)  Bath temperature with NOX absorption (NO C02).  With C02,
               it  heated even more rapidly.

           (2)  The bath developed a mist over it when N02 was run in.

           (3)  A NO «   40%            A  N02  ~91%

           (4)  H2S04 (dilute)  trap used  to absorb amine vapors  before
               effluent  enters  gas analyzers.

           (5)  Color of  bath  changed  from colorless  to  orange as  run  pro-
               gressed.
          NO:  H2S04->Dry Ice—> NDIR

-------
2-4-72
1:1 2-Amlno Ethanol:H 0
ppm
x 100
(SI
tsl O
O O W
52 21
10 5 10 —
1 ' "
919 —
1 ' i -
8 48 —
1 ' -
1
7 ' 7 —
~

6 36 —


1 -
1
515 —
i ' I -

4 24 —
1 • -
1
313 —
1 ' 1 -
2 12-4
' , ' -
1 i 1 — 1
I ' | -


\ \ \




BP
t 	 >








»_««













,


1
I
1 	
V











P4 pL|
O O
VO O
i — 1 rH (

1 i
<
I



-35%











0 10
\





1







4
^
o
CM 127 F
> I
5 |




I
V- 	 -48%






\ -88%
\
1 \ \ 	 \ 	 \ 	 1 	 1 T I I I
20 30 W 50 60 70 80 90 100 110 i
»T«3 	 	 A — ^«-l ___«- 	 -_




BP







___ .•











•^•^•i^^*








-20
\
                                                                                                          O
                                                                                                          N3

-------
                                  - 103 -



                         NOX SCRUBBING DATA SHEET


DATE:       2-4-72           SCRUB-    1:1»  2"Amino ethanol:  H20
                                       Tf} 1 limp  T*fl t"1 f) \
OBJECT:     Absorb NO
                                                                  n
CONDITIONS:    Scrub volume @  1000  ml     Total Gas Flow @ 3200 cm  per minute

    Pot Temp.     126 °F     Initial pH  	--           Final pH     —

    H2° 	10	7°     C02 	±2	?°      °2 	-	7°

    NO      340	ppm     N02 	330	ppm      S02 	ppm


COMMENT:
            (1)  With C02 present 35% of NO and 88% of N02 absorbed.

            (2)  Without  C02,  48% NO and 88% N02 absorbed.

            (3)  Bath heats  up from reaction with C02

            (4)  H2SQ trap removed atnine vapors from gas stream
           NO:  H2SO, —> Dry ice trap
NDIR

-------
2-4-72
                                  1:3 2-Amino EthanolrH 0
ppm
x 100
csi 
-------
                                   - 105 -
                         NOX SCRUBBING DATA SHEET
 DATE:
2-4-72
                             SCRUB:   	1:3. 2-Amino ethanol^ water

                                     	(volume ratio)	
°BJECT:     Absorb NOv
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    p°t Temp.    127  °F     Initial pH 	—          Final pH      —

    H2° —	10     7o     C02 	12	%

    NO
COMMENT:
                 347  pom
                 NO
   350
                                                 ppm
 2

SO,
                                                                %
                                                               ppm
(1)  A NO (without C02) ;
    A N02  X  86%
                                      48%
            (2) The addition of C02  caused bath  heating

            (3) Takes about 35 minutes  to saturate dilute H2S04  trap with
               NO and N02, before starting run.

            (4) H2S04 used to remove amine vapor before analysis
          NO: H2S04
             Dry ice
NDIR

-------
2-8-72
Ca(OH)  Slurry
ppm
x 100
CS OJ
o o o
10 5 10 —
9 1 9 —
I ' 1 -
8 48 —
7 j 7-
1 ' 1 -
6 36 —
1 . ' -
5 j 5-
II-
4 24 —
1 , ' -
3 1 3 —
1 ' 1 -
2 1 2 —
:.'H
\ V \


BP











i
I







-20%



-21%



iiiiiiili
0 10 20 30 ivO 50 60 70 80 90 1<
\


BP



. — .








30 1







- — 	 	 	 ""


i




1 l
00 110 120 1
\


BP



•*"*•• ^



••^•MM^M^




30
\
                                                                                                          o
                                                                                                          o\

-------
                                   -  107 -
                        NOX  SCRUBBING  DATA  SHEET
DATE:       2-8-72           SCRUB-       Ca(OH)2, 100 gm suspended in
                                         1000 ml H20







  JECT:  —  Slurry scrubbing
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute




    pot Temp.    124  °F     Initial pH     --	      Final pH      —




    H2° -	12	7°     C°2 	12	%      02 	2	%
    N0  _   353	ppm     N02 	365      ppm      S02 	ppm






COMMENT:





            (1) The frit plugged  and an open  tube had  to be used,




            (2) A NO ^20%          A NO  ^  21%
          NO: NaOH-Na2S 	^  Dry  ice	>  NDIR

-------
2-9-72
                                         ZnO Slurry
ppm
x 100
CM CO
O O O
!3 Z to
10 5 10—
1 1 ' -
9 1 9 —
1 ' 1 -
8 48-
1 i ' -
7 1 7 —
1 ' 1
i 1
6 36 —
1 1 ' '
'l ' 1 -
4 24 —
, ' -
1 ' 1 -
2 1 2 —
1 • 'i
'•'n
On f\
VJ V)
\ l *
\ \ \

BP













1
\






-7.1%
+*~



-16%




\\\\\\\\\\\\\
0 10 20 30 ivO 50 60 70 SO 90 100 110 120 130
\

BP




i-
c
ex
l










-------
                                   - 109 -
                         NOX SCRUBBING DATA SHEET
 DATE:       2-9-72	    SCRUB:   	ZnO slurry  (100 gm/lOOOQ .ml




                                          H20)	






 OBJECT:     Absorb NOv	











 CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute




    Pot Temp.     121 °F     Initial pH 	—         Final pH       —




    H2°        10       1     C02 	12	%      02        3       %




    N0      353	ppm     No2 	370     PPm      S02 	ppm






COMMENT:




           (1)  A NO  - 7.1%,          A N02  = 16%
          NO:  Na2S-NaOH 	>  Dry ice 	^ NDIR

-------
2-9-72
                                           Mg(OH)  Slurry
ppm
x 100
CM CM
0 O 0
S S CO
10 5 10 —
1 . ' -
9 ;, -
' i i
848 —
1 . ' -
7 !7 H
1 J
6 3 6 H
1 ' ' J
5 ! 5 H
1 ' 1 -
424 —
i ,

i
3 I 3 —
I
II-
212 —
1 ' -
1 1
1 1 1 — 1
i 1
1 M
\\\




BP
> — -H





1

— '














1
i
I












-6%








-23%






[
r~ I i i ' i
0 10 20 30 AO 50 6
\




BP
6-






I

I















0
                                        •Sisae.

-------
                                  -  Ill  -
                        NOX  SCRUBBING  DATA  SHEET
 DATE:       2-9-72	     SCRUB:       Mg(OH>2 100 gm/liter slurry in




                                         H20	






 OBJECT:     Absorb NCv
   °ITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute




    p°t Temp.     125  °p     Initial pH _ —          Final pH _ --
    H2° —      10     1     C0          12
                               2
    N0  —  330 __ ppm     N02 _ 350     ppm      S02             ppm





C°MMENT :





           (1)   A NO^  60%,             A N02 « 23%
          NO: Na2S-NaOH 	>    Dry  ice   	^   NDIR

-------
                2-10-72
                                                   1.0 Molal Ammonium Citrate
  ppm
  x 100
 CM     CM
O  O  O
JS  S5  W
                                                  -25%
                                                 -26%
                                                                          BP
 I

YO
I

2.O
                                          UO    SO    6O    1O    EO    9O
                                                                          \

-------
                                   -  113 -



                         NOX SCRUBBING DATA SHEET


 °ATE:       2-IQ-72          SCRUB:       1.0 Molal  fNHA)9HC6H5Q7

                                     	(ammonium citrate^	


 OBJECT:     Absorb NOV
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm   per minute

    Pot Temp.    126  °F     Initial pH 	—         Final pH     —

    H2° —      10      %     C02 	12	%      02        3	%

    N0     358	ppm     N02 	350     ppm      S02 	ppm


COMMENT:    (1) Pulled out  100% of 470 ppm  S02  in run with NO  and N02
               but  seemed  to generate NO.   362 into sulfide trap produces
               some H2S.   Thus Na2S  trap was followed by NaOH trap.
          NO: Na2S	>  Dry ice 	>•  NDIR

-------
2-15-72
                                  with no  0   and with  Hydroquinone
ppm
x 100
CS CM
o o o
10 5 10 —
' 1 ' "
9 19 —
i ' 1 -
848 —
717 —
1 ' 1 J
' 1
636 	
*-* -J \J ^^^^
1 • -I
5 ''5 "I
i • i 4
124—1
1 ' -
3 \3 -
1 ' 1 -
212 —
1 1 -

y , • 1




BP
«- •>
"1
1

^mmmm^^m




,
I

2.5 molal Na2SO



!
-16%





-100% 1
I'll!
0 10 20 30 40 50 6
\




fe!**
U-







0
I

2.5 molal Na SO.
in .06 molal TIQ3



	 -8.3%
- - -





-100% 1
l 1 1 I 1 1
0 10 20 30 40 50 6
\




fcP
i
M
K
i





3
\

-------
                                   - 115 -
                         NOX  SCRUBBING DATA SHEET
 DATE:     2-15-72	    SCRUB:   2.5 molal Na2S03  (without and

                                      with hydroquinone)
OBJECT:    Npx scrubbing with no 02 present and observe the effect of

           hydroquinone addition	



CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.   127    °F     Initial pH      10           Final pH 	


    H2° 	10      %     C02 	12    7,      02 	0      %

    NO	358   ppm     N0? 	350 ppm      SO^ 	     ppm
COMMENT:
          (1) The HQ lowered the efficiency of NO adsorption  from   16%
             to 8.3%,


          (2) After 60 minutes on line  (before HQ added) solution analysis
             gave 4.2 millimoles of NO- and 1.1 tnillimoles of N02-
        NO: Na S 	^ Dry ice	>  NDIR

-------
2-18-72
ppm
x 100
CM CM
0 O 0
E3 S3 OT
10 5 10 —
1 , ' -
9 1 9 —
l ' 1 -
848 —
1 • ' -
7 ! 7 —
1 1 -
636 —
1 . -
l
5*5 —
1 ' 'J
424 —
I i
' 1

1 1 -
212 —
1 , ' -
1 i * H
i i J


\ \ \


1 BP



















,


V







-6%















-100%
iiiiiiilliiii
O 10 20 30 M> 50 6O 70 8O 9O 100 110 120 130 1


BP






















<*0
t
                                              TA-m& -Vix 'Wixwxt&a

-------
                                   - 117 -
                        NOX  SCRUBBING  DATA  SHEET
DATE:  	2-18-72            SCRUB:   2-5mNa2S°3
OBJECT:   Study sulfite scrubbing with 02 In flue gas
                                                                 o
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   127   °F     Initial pH 	      Final pH 	

    H20 	10     %     C02     12	%      02 	3	%

    NO	350  ppm     N02     350	ppm      S02 	     ppm


COMMENT:


           (1) A N02 = 100%, NO = 6%.

           (2) NO & N02 meters not operating properly, sticking and
              pulsing; results questionable.
        NO:  Na2S	>  Dry  ice 	^ NDIR

-------
                  3-3-72
                                           Vary pH

ppm
x 100


CM CM
O 0 0
£5 ri ^
10 5 10 —
i , • -
9 I 9 —
Ml-
848 —
I . - '
717 —
I ' 1 -

636 —
1 , . -
515 —
i ' 1 -
1 1 • -
3 j 3 —
1 1 -
212 —
II ' -
111 —
\ ' \ -
000 —







9
1
BP
t- -}

._.._.









i !


1
4 —



1000 ml
1 molal
Na2S°3

6 8.0
• '





-15%
-- — ——————






,



	
T^T^^I^T™







12
'
BP
f- -i














1
\ 	
P


1000 ml
1 molal
Na2S°3

5 8.0
1 »






.— — m M.v«Ml










1 1 1 I
1 V






7
\
BP
(. -)














1
1 	







5
»

















-nr
                                                                                   BP
                                                                                                                                   00
                                                                                                                                   I
\
20
                                               20
40
                                                             Ti.ttie

-------
                                  - 119 -
                        NOX SCRUBBING DATA  SHEET
DATE:  __J-3-72            SCRUB:   1.0m Na2SQ3
OBJECT:    Study  effect of changing pH
    ITIONS:     Scrub  volume  @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    p°t Temp.   124    °F      Initial  pH   see  chart       Final  PH 	

   H2°	10     7.      C02 	12    %       02  	3      %

       .	    355   ppm      N02 	400 ppm       S02  	      ppm
         (1)  The NO readings were very noisy

         (2)  The pH made no difference in N0£ adsorption
         (3)  The  NO  absorption changed very slightly,  decreasing with
             decreasing pH.

             The  pH  was  increased with NaOH and decreased with HC1..
         ': Na2S trap—^ D :y ice  trap	^ NDIR

-------
3-7-72
                                      CaSO , Vary pH
ppm
x 100


 t
\ 1
\ *
\ I
^ •
\ i
Y i
\ i
\ .
\ »
N I
\ |
\ •
\ ;
\ /
/"





20 40 60
1






BP
I- -3


»._























0



8 gm CaSO
@ pH 8






























i i i i
20 40
1






BP
e ->


... _























0



8 gm CaSO
@ pH 7.2 J






























1 i 1 1
20 40
1






BP
(.


_ ___
1
H
K.
C
1






















                                     Time In Minutes

-------
                                   - 121 -
                         NOX SCRUBBING DATA SHEET
 DATE:     3-7-72	    SCRUB:    CaSQ-j  slurry;  8g/l
OBJECT:   Observe effect of pH upon scrubbing

CONDITIONS:
Pot Temp.
NO
Scrub volume
125 op
10 %
490 ppm
• Dry ice
NDIR

-------
3-8-72
2-Amino Ethanol


CM
O


10
1

9
1
8
1
7
1
6
1
1
4
1
3
1
2
I
1
1

1
ppm
x 100
CM
0 0
& W


5 30 —
i _
1
1 27 —
1 1 -
4 24 —
1 ' -
! 21-
' 1 -
3 18 —
1 ' -
2 12 —
) ' ~
! 9 -
i -
16 —
1 ' -
] 3 —
1 -
, •
! 1


BP
*" "*








m^»^m*











••^^^^^H
C





o o o o
O O O CD








•••»
.-!





^
»•••*





0 20
1














|
1
1
t

.





0 220 240 260 280 300
' (Continued)
                                     Time in Hlnutes

-------

ppm
x 100
o o cT1
SS S5 CO
10 5 30 ~
1 I -
1

9 ; 27 —
1 ' 1 -
8 4 24 ~~
1 i —
1 1
i
7 | 21 —
i 1 -

6 3 18 —

i i
1 *
5 \ 15 ~
1 ' |

4 2 12

1 i
1
i
3 ' 9 —
1 ' 1

216 —
1 f '
1 ! 3 —
i


1 ' i
1 : !
3-8-72










pot @ 126 -> 127°F for all of run







M-l
tt)
0)
i-H
OJ
£
B 	 -47%

ft

•o
0)
1
•rl
4J
a
o
0


~ ' 	 	 -89%

liiiiiiii iiiiiiiii
300 320 340 360 380 400 420 440 460 4*









BP

*~



**" •"•"•

i
ro


1





^^^^^^^^












iO
1

-------
                                  -  124  -
DATE:     3-8-72
                        NOX SCRUBBING DATA SHEET


                            SCRUB:   2-Amino  ethanol,  2570 by volume

                                      in  H20
OBJECT:   Determine nitrogen content of solution before and after run,
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   130   °F     Initial pH 	NA          Final pH   NA	

    HO         10     "/     CO               12   7
    lLf*\J          w     /O     \j\Jf\                   /ft

    NO  	368  Ppm     N00 	370 ppm
               2

              SO,
                                                                     NA
                                                                          ppm
COMMENT:
          (1)  The scrubbing of NOX was fairly good in the beginning but
              became worse with time.  This was probably due to the heating
              of the pot by an exothermic reaction of the amine with the
              flue gas (prob. C02 plus amine).  When the bath cooled
              down,  the scrubbing improved somewhat.

          (2)  The scrub turned progressively yellow with time and was
              orange after 8 hours of running.

          (3)  Measurement of total nitrogen content before and after run
              (in order to determine gain or loss of nitrogen) was
              inconclusive.
         NO:
                                Dry  ice
NDIR

-------
                                   - 125  -
                         NOX SCRUBBING DATA SHEET
 DATE:
           3-10-72
                   SCRUB
.   S02 - N02  interaction  in  the  lines
OBJECT
Observe reaction of pure S02 with N02 (5%) in the lines
CONDITIONS:
Pot Temp.
H^O
NO
Scrub volume
NA °F
0 %
0 ppm
@ 1000 ml Tota
Initial pH
CO,,
Wn varies
1 Gas Flow
NA
0 %
ppm
@ 3200 cm3
Final pH
o.
S00 var
per minute
0 7.
ies Dom
COMMENT:
          (1)  With pure S02 functioning with 5% N02  in the mix lines,
                60 ppm of N02  is  converted  to NO,  with a loss  of
              15 to 30 ppm of  S02.  Neither the temperature of the
              blending meter (varied  from 90 to 350°F)  nor the
              temperature of the  analysis lines (75  to  150°F)  made a
              difference.

          (2)  The problem does not occur if the N02  of  S02  are
              sufficiently  dilute before mixing.

-------
3-13-72
                                           CaSO,
ppm
x 100



is p>t
o o o
K !Z W
10 5 30 —
I '
i
9 ' 27 —
i ' 1 -
8 4 24 —
1 i -

7 ' 21 —
• ' 1 -
6 3 18 —
1 • • -
I
5 1 15 —
1 1 -
4 2 12 —
1 , ' '
i
319 —
i ' 1 -
216 —
1 . ' -
113 —
i ' i -
1 ! !
1 ! 1




BP
£-. v
t* ^^





7.
1














^•M • m


C












6 5.3 5.
V
















ii •• 	 ' — * ^^^™ ^ i^^^*
I i i i i i i
) 20 40 60
1




BP
^ ^^
• ^T





)











MM^^H



^^m^^t






pH
T






















_S 	 •*-^>i 	
^*^f ^" %*^. 	
^^^ * ^
^^^ 1
\ 	 ->'
i i i i i i i i i i i i i i i i
80 100 120 140 160 180 200 220 24




BP
fc^
c^








i
H
K>
1






•HM^H^^






0
t
                                    Time in Kinutes

-------
                                  -  127 -



                        NOX SCRUBBING  DATA  SHEET


DATE:     3-13-72   	    SCRUB:  _CaS03  (8 gm per litre of H20)
OBJECT*   CaC03 scrubbing with NOg solids SC>2 only
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   125   °F     Initial pH 	7.6         Final pH	
    H20 	10     %     C02 	12_%      02 	3      %

    NO  	NA   ppm     N02 	330 ppm      S02 	500  ppm
COMMENT:
          (1)  The N02>  in the beginning,  was  removed  quite efficiently.
              As  the pH dropped,  and  the  S02  broke through, the N02
              scrubbing became worse.
         NO: Na2S03	^Dry ice—> NDIR

-------
3-15-72
CaO Plus CaSO- Doped with SC>2
ppm
x 100

JS|
O O
8 &

10 5
I ,
1 !
8 4
1
1
7 1
1 '
6 3
1
i
5 I
1
4 2

1 ,
3 :
i
2 1
1 ,
1 !
i
0 0
li



CM
O
w

10—
i •
9 —
i -
6 —
1 -

7 —
i •
6 —
i -
5 —
i
1 '
4 —
i

3 —
1
1 -
2 —
1
I
1 '
i
I


BP


^ *^


'
C


















(

pH






3 y 50 ^ y 4.
5.7
^
5.5
^m




..
0
1 u
1
+



1
1 _
[ -71% 	 .- 	
7 	 ... — .-- 	
1 — — • *--" " *--> "
) 20 40 60 80 100 120 140 160 180 200 220
rr* J-_r-. 4 -A >Jt-4 -r>»i4- ^o









•
O



4.









^^4*
7

2t






BP
M^



1
H
N.
OC
1












tO
1

-------
DATE:
                                   - 129  -
                         NOX SCRUBBING DATA SHEET
          3-15-72
                            SCRUB-
-    31  ^ °f Ca° plus 8  ^  CaS03  in
                                     litre of water plus S02J  pH  6.4
OBJECT:   NOy scrubbing with CaO doped with CaSQ-3.
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   126   °F     Initial pH       6.4         Final pH   4.7

    H20 	10     7.     CO,

    NO     	--
            12	7.
                     ppm
                             N0
   380
               ppm
°2

SO,,
                                                                     3
_520   ppm
COMMENT":
          (1)  N02 was absorbed fairly constantly @ a level of  71%.

          (2)  The S02 dropped  to zero and came up steadily with time
              and  decreasing  pH.
         NO:  Na2S03	> Dry ice
   NDIR

-------
3-16-72
Ca(OH).


ppm
X

C**J
0 0
ss 2

10 5
\ ,
i
9 1
1
8 4
1
1
7 i
1
6 3
i ,
i
5 i
I
4 2
1
3 !
1
2 1
1
i
1 »
I i
1
0 0
li
100

CN
o
in

•10-
1 -

27
1 -
£4
1 -

r -
^3—
i -

,15"""
1 -
A2~"
1 -
,9 ~
1 -

6
i

3 ~~
1
1 "

i
I



1
1



BP
























pH


L.4 7.2 6.7 6.6 6.5 5ml 4.2
' ^F ^P ^P ^r ^P ^^
*

11.33 5.7 4.7 4.
T^_ ^B 1
T ^ 1
11.1
^P

10.5

7.7
i^^
w

,
/
*
'
/
'
/
/
-70% /
X^ /



X
_.-X
IIIIIIII Illl












^.i.

••^••^•B
1
1—
u
1















0 10 20 30 40 50 60 70 80 90 100 110 120 130
1 1
                                      Time In Minutes

-------
                                  - 131 -
                         NOX  SCRUBBING DATA  SHEET
 DATE:     3-16-72	     SCRUB:   Ca(OH)2  [10 gm per litre  of
OBJECT:    Absorb N02-S02
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.    125   °F     Initial pH    11.4           Final pH   4.1
                1Q     %     C02       12
    NO      NA _ ppm     N02 _ 710 _ ppm      S02      2400
COMMENT :
          (1)  After the initial pH drop, the N02 was absorbed to =86%.
               When the pH went under 6 ^ 6.5, the N02 absorption dropped
               to  70%.                                              VV


          (2)  Initially,  the S02 absorption was  100%.   At  =  pH 5.7  it
               started to  drop and declined steeply below a pH of 4.7.
         NO:  Na2S03 	>   Dry Ice	^  NDIR

-------
3-17-72
Ca(OH)  with an Open Tube
ppm
x 100

300
s is en
10 5 30 —
} 1 27 —
1 .
1 -
3 4 24 —
1 | -
7 1 21 —
1 ,
1 -
; i i Q

, i -
5 1 15 —
1 \ -
i 2 12 —
} i 9 —
1 •
1 -
» 1 6 —
i
L | 3 —
1 •
(«•



i i


11
i


BP


























,2 6.
i
1

9.4
Ll.l
V

7.0



















I I I i
0 10 20 30 40 5(


>
t

BP
t 	 >















^_^








) 51

PH
6.
1























^ ^
^r^
1 1 1 1 1 1


)
p








!
H-
Nl
1











h.


3 60 70 80 90 100 110 120
1
                                     Time in Hinutes

-------
                                  - 133 -
                         NOX SCRUBBING  DATA  SHEET
 DATE:      3-17-72	    SCRUB:   Ca(OH)? TIP em per litre nf
OBJECT:    Observe effect of S02 upon  N02  scrubbing.
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute




    Pot Temp.     132  °F     Initial PH    11.2           Final PH   6.0




    H2°       10       %     C02 	12	7.      02       3	%




    NO  	NA   ppm     N02 	740     ppm      S02 ___800_____ppm






COMMENT:




          The presence of S02 significantly improved N02 absorption.
         NO:  N32S03	» Dry Ice	> NDIR

-------
3-22-72
Mg(OH)  ; 7.4 gm per litre  =  10 gin Ca(OH>2



M
o

10
1
9
1
8
1
7
1
6
I
1
5
1
4
1
1
3
•J
I
2
1
1
1
1
I
ppm
X


0
z
5
i
1

4
,
1
1
3

1
1
1
2

1

1

1


t
i
100

1
7 V T
8.5
T









57.8% pullout




100% pullout
Illlllll l|
0 10 20 30 40 50 60 70 80 90 100 1]


pH




P

eP->
MIH^^^M

1
H
<*
-P
1












.0
1 i
                                      Time in Minutes

-------
                                    - 135 -
                         NOX SCRUBBING DATA SHEET
 DATE:    3-22-72	    SCRUB:   Mg(OH)2 slurry, 7.4 gm per

                                       of H20	
OBJECT:    Mg(OH)2 scrubbing as compared to Ca(OH)? with NO-? - SO?
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.     126  °F     Initial pH     8.7	      Final pH     7.3

    H20 	10   7.     C02 	12     %      o        3	7.
    NO  	NA   PPm     N0  	830      ppm      S0    2460
COMMENT:
           (1)  Absorbed 480 ppm N02 for the entire run.  Pullout
               is 57.8%.

           (2)  Solution analyses gave 6.1 millimoles of N03~ and 2.0
               mlllimoles of N02~ after 110 minutes.
         NO:  Na2S03 —>  Dry Ice 	> NDIR

-------
                 3-24-72
                                                   Oxidation in situ of NO
 ppm
 x 100
2.0 5
 I
1.8
1.6 4
 I
        CM
       o  2
       CO
       30-
       I   -
       27-
       I   -
       24—
       •
       I
1.4 i   21—
 l   '
1.2 3
 t
1.0 «
 I   '
.8  2
 I
    i

 I
       I   -
       18-
       I
       I   '
       15—
       12—
       9 —
       •
       I   -
       6 —
.2  [
 I
 0  0
       3 —
 I   i   i
5 gm FeCl '6
in 1000 ml H
@ 122°F
                 0
                  1
20
                                              T   1   l   I   I
                             140   160   180    200    220   240
                                                             I
                                   Time in Minutes
                                                                                                                       
-------
                                 - 137 -




                         NOX SCRUBBING  DATA  SHEET


 DATE:      3-24-72           SCRUB:   Water with additions
OBJECT:    To absorb NO
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.    122   °F     Initial pH 	      Final pH 	

    H..O           10  _%     C00       12	%      0^       3         f
    NO      485      PPm     N02       0	ppm      SO.,      NA     PDm


COMMENT:

          (1)  FeCl3 is not effective.  Neither is plain  3%  H202.


          (2)  30% H202 does work, but not well.   The addition of FeCl3,
               catalyzes the system well.

          (3)  The KMn04 proved best.
         NO:  Na2S03—> Dry Ice—> NDIR

-------
3-30-72
                                           MgSO,
ppm
x 100
CNl £M
3 0 O
a a to
LO 5 30
• i
) ' 27 —
1 i -
J 4 24 —
, i -
' ! 2.1-
> 3 18 —
, i -
i 15~
i -
2 12 — -
. i -
i 9 ~~
i -
16 —
i
i 1 "
! 3 "~"
1 i
1 -
I i
! 1



BP ^
«- — »















t





*'5












-f
)
1
                     5.3
                 6.3
                                                   pH
                                                                                                       u>
                                                                                                       00
           10
                                     Time in Minutes

-------
                                   -  139 -
                        NOX  SCRUBBING DATA  SHEET
DATE:     3-30-72	   SCRUB:    MgS03 (5 gm/1000 ml
OBJECT:    N02 - S02  Absorption
                                                                 o
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.    126   °F     Initial pH       9.4          Final PH     3.75
H0        10       7.     C02 _ 12 _ %      02
     2
    NO  _ NA   ppm     N02     690 _ ppm      S02     2610    DDm



COMMENT :

           (1)  N02 dropped quickly to zero and then increased steadily.
          NO:   Na2S03 —^ Dry Ice —» NDIR

-------
                4-3, 4-5-72
                                                CaSC>3 Long Term and Vary pH
  ppm
  x 100
 es
O
 I
      o
      w
1°'
   30
(    r

   T  -
4  2,4"
,    I
I   f\ i ~""
 6  3
    I
       I

      18*


      15'
       I
       I
 4  2  }2
 '   ,   I
 -  I   ~ —
 •2  X  ^
 1   >   I
    c     _
1      i
Q  Q  Q
I   '

             BP
                   7.6
                         7.4
                          T
                 Q
                 I
                      20
                         40
60
                                         BP
                                        E- -»
75
 I
i   r
  95
 115   135   180
        I     I
Time in Minutes
                                                                                                        300    320

-------
                                    - 141  -
                         NOX SCRUBBING DATA SHEET
 DATE:      4-5"-72	    SCRUB:   CaS03 (25 gm per litre of water)
OBJECT:    N02 - S02 absorption
CONDITIONS:    Scrub volume @  1000 ml    Total Gas Flow @  3200  cm3  per minute




    Pot Temp.    126   °F     Initial pH      9.1            Final  PH    7.25




    H00 	10      %     CO,       12	%       00         3      7
     2  	        i.	—        2



    NO        NA    PPm     N02       86°	ppm       SO,,       1890    PDm






COMMENT:



           (1)  The N02 and S02 were absorbed to the level  of 100%.
         NO:  Na2S03 —> Dry Ice —> NDIR






                              Page 1 of 3

-------
                                  - 142 -
                        NOX SCRUBBING DATA SHEET
DATE:     4-5-72
              SCRUB:   Bath from page 1
OBJECT:     Continue CaS03 scrubbing
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp. _125__°F     Initial pH     7.5           Final pH   3.5
NO
10
                                      12
0
ppm
N0
                  710
                                   ppm
                                           S0
                                                                  183
                                                                          ppm
COMMENT:
           (1)  When pH went below * 7.2, the N02 level increased quickly
               and settled down to =  46% absorption.

           (2)  After passing - pH 6.1, the pH dropped very quickly to
               3.5, reducing the N0£ scrubbing to =  34% and generating
               an off scale "NO" reading..
                                Page  2  of  3

-------
                                   - 143 -
                         NOX SCRUBBING DATA  SHEET
 DATE:      4-5-72	    SCRUB:   Bath from Page 2 with 2 qm of

                                       MgS03 added
OBJECT:    pH variation with H2S04 (*  10%)  and NaOH (=  10%)
CONDITIONS: Scrub
Pot Temp. 126
H^O 10
NO 0
vo lume
7,
_ppm
@ 1000 ml
Initial pH
C0rt
N0«
Total Gas Flow
6.1
12 70
700 ppm
@ 3200
Final
so9
3
cm per
PH
3
2250
minute

PPm
COMMENT:
          {!)  After going on line, the pH quickly dropped with the N02
               appearing to head back to the level recorded on page 2.

          (2)  At - pH 4.4, "NO" broke through to an off-scale reading.
               Turning the N02 off did not effect it.   Turning the SOo'
               off immediately brought the "NO" down.

          (3)   With the  S02 and N02 off,  a decrease  in  pH  (with  H?SO,)
               causes  the  "NO" to  again  rise;  increase  pH with NaOH
               again removes  the NO.
                              Page  3 of  3

-------
              4-7-72
Comparison  of Mg(OH)  and Ca(OH)
ppm
x 100
                                i  I   I   fV4   lri  I
                                                                                                                 4s

                                                                                                                 I

-------
                                  - 145  -




                        NDY SCRUBBING DATA SHEET




DATE.     4-7-72            SCRUB:    Mg(OH)2 and Ca(OH)2


                                      Mg(OH)2 @ 14 gm/1
OBJECT:   N02 - S®2 Absorption
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
    Pot Temp,
                126   °F     Initial pH     9.35          Final pH   7.6
    H o        10      %     C02 	12	%      02 	3	%


    NO       NA      ppm     N02       680	ppm      S02 	2610__ppm





COMMENT:
                                                          •3
           (1)  At 2610 ppm S02 and a total flow of 3200 cm /min, we would

               need 706 min of 100% absorption to yield 803" level of

               25 gm of MgS03<
          NO:  Na2S03—> Dry  Ice—^ NDIR



                               Page 1 of  4

-------
                                - 146 -
                        NOX SCRUBBING DATA SHEET
DATE:      4-7-72	    SCRUB:   Mg(OH)2 from Page 1  acidified to

                                      pH 7 from 7.6 with H2S04
OBJECT:      N02 - S02 Absorption
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   126   °F     Initial pH    7.0	      Final pH   see chart


    H20 	10      %     C02 	12	%      02       3	%

    NO       NA	ppm     NO, 	630	ppm      S09     2460    ppm
COMMENT:
          (1)  Large volumes of gas were liberated with the addition
               of the H2S04.  The pH dropped rapidly and then came
               back up slowly.
                               Page 2 of 4

-------
                                 - 147  -
                        NOX  SCRUBBING  DATA  SHEET
DATE:      4-7-72	    SCRUB:    Mg(OH)2 from Page 2 + more


                                      Mg(OH)2 + pH 8.35
OBJECT:    s crabbing NO
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute


    Pot Temp.   126   °F     Initial pH    8.35           Final pH 	


    HO       10	%     C00 	12	%      0           3
     2  	        z                           2	./°
    NO  	37°    ppm     NO, 	^	ppm      S0_     2460
                                                            J2 —tZ2iL__PPni



COMMENT:


          (1) No NO was absorbed.
                              Page 3 of 4

-------
                                 - 148 -
                        NOX SCRUBBING DATA SHEET
DATE:     4-7-72	    SCRUB:  Ca(OH)2  [17.8 gm Ca(OH)2 per


                                      1000 ml H20]
OBJECT:   Comparision of Ca and Mg systems
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.   125   °F     Initial pH   11.2 _      Final pH    6.4


    H20 _ 10      %     C02 _ 12 _ %      02 _ 3 _ %
    NO   .  NA _ ppm     NO  _ 680____ppm      SO.     2460    ppm




COMMENT :


          (1)  With oxygen present, the Ca(OH)_ appears to be more efficient.
                               Page 4 of. 4

-------
            4-10-72
                                  Ca(OH),
ppm
x 100
 CN    CS
000
fa  V5 W
10 5 30-
I   ,  M
9  j  J
I   '  I  4
8  4 24'
I   i
7  !  21-
•   '  i
6  3  18—|
I   I

.':r
 4  2  12
I  ,  i
 3 '  ,9
I  '  i
 216
1  ,  i
 1 |  3
I  '  i
 Q  Q  Q

   i i
        BP
                                            pH
                                            V
                                                             BP
                                                            k—>
                     6.5
                 7.0
              6.4
                                       V
                                 U-l
                                 m
                                 o
                                         ts
                                         o
                                               30%
0
I
                                           I  I  I  I   I  I   I
                 20    40    60    80    100   120   140   160   180

                                           Time in Minutes

-------
                                  - 150 -
                        NOX SCRUBBING DATA  SHEET
DATE:
       4-10-72
SCRUB:    Ca(OH)? slurry  (15 gm per litre

          of H20)	
OBJECT:    Ca(OH)2  vs. ZnO
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow

    Pot Temp.   126   °F     Initial pH      11.2
NO
            10
                                         12
                                                   70
         NA
                     ppm
                             N0
                                         700
                                                 _ppm
                                                      3200 cm  per minute

                                                      Final pH    6.5
                              °2

                              SO,
                                                                        7=
2490
                                                                     _ppm
COMMENT:
          (1)  After the pH dropped below 7, the N02 absorption was  63%.

          (2)  Without 02, absorption -  90% and later at pH of 6.4,
               with 02 back on, the absorption was  -69%.

          (3)  The S02 absorption was  100%.
          NO:   Na2S03
                      Dry Ice
         NDIR

-------
4-10-72
             ZnO
                                   PH

                                  T
                                         -49%
                                                                 BP
                                                                 °2
                                                                 on
                                                                                         BP
                                                        V
                                                                                                          i


                                                                                                          M

                                                                                                          Ul

                                                                                                          M


                                                                                                          I
                                                                              -63%
                          40
50
60    70    80    90
                                       Time  in Minutes
                                                               100
100


 I
                                            i

                                           110
                                                                                 120
130


 I

-------
                                  - 152 -
                        NOX  SCRUBBING DATA  SHEET
DATE:
           4-10-72
                        SCRUB:    ZnO slurry (10 gm per litre water)
OBJECT:    Ca(OH)2  vs.  ZnO
CONDITIONS:
Pot Temp.
               Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
                 126
    NO
             10
             NA
                    _ppm
                             Initial pH     9.3
                             CO,
                             NO,
                                    12
                                     700
                                                 ppm
Final pH   6.2

°2 	3	
SO,,
2520   ppm
COMMENT:
          (1)  N02 pullout was initially =63%.
          (2)  This dropped to 49% with lower pH  (6.2),
          (3)  With the 02 off, 68% of N02 absorbed.
          (4)  Back on with C>2, 63% N02 absorbed.
          (5)  S0» absorption was always 100%.
          NO:  Na2S03
                          ->  dry ice
                                        NDIR

-------
4-11-72
Ca(OH).
ppm
x 100
CN CS
D O O
3 Z W

0 5 30 —
*
, 1 -
\ | 27 —
1 i -
J 4 24 _
. i "
7 ' 21 —
| ,
1 -
6 3 18 —
1
, 1 -
5 1 15 —
i "
4 2 12 —
, i -
3 j 9 —
' 1
1 *
216 —
1
, 1 -
1 1 3 _
1 ,
1 '
Q Q 0 —

i i
! 1




6
BP 5
M ^
^ 4

— -_



















mmmmmm



V

1 4.9 4.6 4
T ^ i


no
°2



§
o











^^•^



• ••















r~ . -«-^*


******
-^— ***
^ **^"~

I 1 i >• i i i i i i i i I i I I ~i
0 20 40 60 80 100 120 140 160 1
1

PH


5
-


BP
t- ->
	

(
H
U
u
1
















0

Time in Minutes

-------
                                  - 154 -
                        NOX SCRUBBING DATA SHEET
DATE:      4-11-72	    SCRUB:    Ca(OH)2 slurry pre-doped with SO?;

                                      15 gm/1000 ml H20	


OBJECT:    To test Ca(OH)2 lower pH and high S03=	
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   124   °F     Initial pH    6.1	      Final pH    4.5

    H20      !Q        7.     C02        12	%      02      3	%
    NO    NA	ppm     N02 	670	ppm      S02     2400    ppm


COMMENT:

          (1)  The slurry of Ca(OH>2 (15 gm/1000 ml H20) was stirred, and
               through it bubbled an S02-N2 mixture until the pH was
               between 6 and 7.

          (2)  M>2 scrubbing was on a par with former runs.   The S02
               broke through early and rose steadily.
          NO:  Na2S03—> Dry Ice—*- NDIR

-------


ppm
x 100
CS CN
O O O
a z w
10 5 30 —
1
1,1-
9 1 27 —
, 1 •
1 1 '
8 4 24 —
' , i -
7 1 21 	
i > i
1
1 1
6 3 18 —
i , i -
5i 15 —
i > <
1 1 -
4 2 12 —
' , i -
3«9 —
I *
1 1
216 —
I
1 t 1 -
1 ! 3 —
• .
' ' i -
1 i i
n




BP
f- — »





	



















(
-J-J-" Na_S
2






pH = 9.32




















+35 ppm
=95T -100Z *
1 1 I If |^ 1
) 10 20 30 40 50 60 70 80
1 1





BP


pH = 9.0


— -


1
t-
Lr
i














Time in Minutes

-------
                               - 156 -
                        NOX SCRUBBING DATA  SHEET
DATE:      4-13-72	    SCRUB:    1.88 molal Na2S
OBJECT:   NC-2-S02 Absorption
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.   131   °F     Initial pH      9.32         Final pH    9.Q

    H2°       8"10     %     C02 _ 12 _ %      02      3 _ %
    NO       0 _ ppm     NO  _ 650 _ ppm      SO,     2250    ppm
COMMENT :
          (1)  The S02 absorption was  95% and for N02 was  100%.
               Also generated 35 ppm NO.

          (2)  Also generated H0S.
         NO:  Na2S03	> Dry Ice —> NDIR

-------
                  CaC03  (10  g/1)
4-14-72
CaC03 (4 g/1)
ppm
x 100
                                                   20     40     60     80

                                                     Time in Minutes
                                              •   i  i  r  i  I   i
                                             160   180   200   220
                                                              (Continued)

-------
CaCO  (Continued)
ppm
x 100
o o o
S S5 M
10 5 30 —
' • i -

9 ! 27 —
| •
I -
8 4 24 —
t
.
7 ' 21 —
1 i -
6 3 18—
,
, 1 -
5 | 15 —
1 i -
4 2 12 —
3 j 9 -
i -
216 —
. i -
i1 \~-

! 1
* i
i i



Off Scale
f Y
i
1 i
i i
! i
/ i
_ *
i i

L'j /~~"
1 ' ' •
i i /
t /
,' ' :
i i'
/fM/
i i;
i
-' /\














t
(
i







200 ?20 240 260 280 300

I Time in Minutes

-------
                                - 159 -
                        NOX SCRUBBING DATA SHEET
DATE-      4-13-72	    SCRUB:   CaC03> 10 gm in 1000 ml H20
       	4-14-72                                              ~
OBJECT:   Calcium Carbonate Scrubbing
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   128   °F     Initial pH     7.5           Final pH    6.2
             _10	%     C02 	12	%      Q2
    NO        NA     ppm     N07       650	ppm      S0      2280
COMMENT:
                    The flow slowly degraded during the run (frit was
          clogged) and the results are therefore inconclusive.  The
          run was continued on 4-14-72 after being run for 50 minutes.
         NO:  Na2SOo—>• Dry Ice	=> NDIR
                              Page 1 of 3

-------
                                  -  160  -
                        NOX SCRUBBING DATA SHEET
DATE:     4-14-72	    SCRUB:   CaC03 from 4-13-72
OBJECT:    CaC03 Scrubbing
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per  minute


    Pot Temp.    128  °p     Initial pH      >7           Final pH     6.2


    H20 	10    %     C02 	12      %      02  	3	7.
    NO      NA	ppm     N02 	650	Ppm      S02      2280    ppm



COMMENT:


          (1)  Scrubbing of N02 improved when 02 was removed from flue gas.
                               Page 2 of 3

-------
                                 - 161 -



                         NOX SCRUBBING DATA SHEET


DATE.      4-14-72	    SCRUB:    CaCOs, 4 gm in 1000 ml  H20
OBJECT:    N02-S02  Absorption
CONDITIONS:    Scrub volume @  1000  ml     Total Gas Flow @ 3200 cm  per minute

    Pot Temp.  128    °F     Initial pH    7.2	      Final pH   3.1

    HO        10       %     C00        12	%      00      3         7
    *^ O         	^^_'°        y  .— .. —i—•. .—— .•.. .11 • i   i .1 . —        o __^^_^^__^___^_ . a |B   /o
NA      ppm     N0        65°       ppm       S0       2280
    NO               ppm     N02           _ ppm      S02             PDm
COMMENT:
           (1)  The addition  of  40 rag (=3.3 x 10~  moles) of CaS03 at
               60 min had no effect.
           (2)  At 80 min,  the addition  of  40 mg Na2S03 had a momentary
               effect of reducing N02 by 10  ppm.

           (3)  The elimination of 02 caused  a decline in the N02 level
               that slowly rose again as the pH dropped.1

           (4)  At a very low pH (-  3.1) the  S02 broke through to about
               the bypass value and then started dropping off again.   At
               the same time, a surge of NO  was generated.
                              Page 3 of 3

-------
              4-17-72
                                                H_0 with Plus Product Salts
ppm
x 100
                                                                                     280   300
320   340   360
                                                   Time in Minutes

-------
                               - 163 -
                        NOX SCRUBBING DATA SHEET
DATE:
          4-17-72
                            SCRUB:    1000 ml H20 with salts added at

                                      time intervals
OBJECT
      .   To check the scrubbing of water and various product salts
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

                122   °F     Initial pH      6.7          Final pH 	

                                                   %      0
    Pot Temp.
    H20

    NO
             10
                       7«
                     ppm
CO,
                             NO,,
                                        12
                                     650
                   _ppm
'2

S0r
                                    2400
                  7
                  to
               _ppm
COMMENT:
           (1)  N02 pullout, with or without 02 but with S02 is * 42%.

           (2)  S02 pullout with or without 02 and with or without CaCl2
               is « 13%.

           (3)  The CaCl2 does not seem to effect the N02 pullout.

           (4)  Without S02, the N02 level slowly rises, though not very
               much (- 40 ppm in 40 min).

           (5)  Without 02 and with MgS04; S02 pullout is -23%, and N02
               - 46%.

           (6)  With 02 on and with MgS04, S02 level decreases to zero
               (100%) and the N02 seems unchanged.

           (7)  At an absorption of 280 ppm N02 (1st 10 min) and 3200 c
               of gas, using 4N02 + 2H20 •> 2HN03 + 2HN02 the theoretical
               pH is 3.44, (3.5 was measured) assuming total ionization.
           NO:   Na2S03
                           Dry  Ice
          NDIR

-------
4-18-72
Mg(OH),
SEE
ex ex ex
ex ex ex
o o o
o o o
j-j _- j _j
XXX

O P O
2; !s OT


10 5 30 —
'.I-
i i
i
9 i 27 —
I '
1 1 -
8 4 24 —
1 '
, 1 "
7 1 1 21 —
1 1 1
1
6 3 18 —
i
1 , 1 -
5 1 15 —
i 1 •
1 I -
4 2 12 —
| i
' , 1 -
319 —
i ' i -
i
216 —
f
1 1 -
1 1 '
f 'i~
1 |

II
i 1







B
p
L_!


IM
I
9
•M




















N02 + S02
w/o 02



o
1 bath




4
8.1 7.
V















I 1 1 1



NO
w/







BP

1
"• ~"
>
r
"" 	



















+ so
°2 2



o
2 bath


8.
6 8.5
' M

8^ 8^3









_ — 	 	






1 1 1


SO
on
in
ba






,BP ft



^MM




































y
2°
h





.0



















1 1
0 100 200 275 0 50 100 0 20 40









B
P

r\
1 bath
cont'd
w/ all
gases





T


••i

















2


<— 4






BP
' •
8.
t





(
















H
H
II

1
i i P





19-72 	 *








r










,
••^







1


2° bath cont'd


+ Hydroquinone

?H

7V8








r^
f








1 i M 1 1 1 1 1 1
0 330 100 120 190 300
1 110 1310 1










B
P
f —
7



••M

















                                     Time in Minutes

-------
                                 - 165  -
                        NOX SCRUBBING DATA SHEET
DATE:
           4-18-72
                 SCRUB:   Mg(OH)2 slurry 15 gm/1000 cm3

                           of H20	
OBJECT:   Observe effect of oxygen
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   124   °F     Initial pH    9.4	      Final PH    7.9
    H2°

    NO
             10
            7
            la
NA
         _ppm
CO,
NO,
                              12
670
         _ppm
°2

S0r
                           0
2370
                                             _ppm
COMMENT:
          (1)  Both the N02 and S02 dropped to zero and remained so
               for the 270 minutes of run time.
          NO:  Na2S03 —=> Dry Ice
                           NDIR
          Calibration filter in S02 analyzer Indicated improper readout,
          S07 value in question, is probably much higher.
                              Page 1 of 5

-------
                                 -  166 -
                        NOX SCRUBBING DATA SHEET
DATE:     4-18-72	    SCRUB:   Mg(OH)2  15 gm/1000 cm3 H20
OBJECT:
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp. _125__°F     Initial pH      9.6          Final pH    8.1


    H20   10	%     C02 	12    %      02      3	%
    NO       NA _ ppTO     N0     640 _ ppm      S0      2250    ppm
COMMENT :
          (1)  N02 dropped rapidly to - 250 ppm and then rose slowly
               to 275 ppm.


          (2)  All the S00 was absorbed.
                               Page 2 of 5

-------
                                 - 167 -
                         NOX SCRUBBING DATA SHEET
 DATE:      4-18-72
SCRUB:  Mg(OH)2>  15 gm/lOQQ cm3 of
OBJECT :

CONDITIONS: Scrub volume @ 1000 ml
Pot Temp. I25 °F Initial pH
H-0 10 % CO,
NO NA ppm NO, NA
Total Gas Flow @ 3200 cm3 per minute
8>0 Final pH 8.0
12 °L Oo 3 7
2. 	 	 	 '"
own SO., 2370 ppm
COMMENT:
          (1)  All the S02 was absorbed.

          (2)  The bath came back to a pH of 9.3 when allowed to stand
               over-night «? 20°C).
                             Page  3 of 5

-------
DATE:
4-18-72
         - 168 -








NOX SCRUBBING DATA SHEET





    SCRUB:   Mg(OH)2,  15 gm in 1000 ml



              H20; both from initial runs
OBJECT:
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute



    Pot Temp.     125 °p     Initial pH 	7.2          Final pH   6.95



                                                                   37
             "                  L         -                 Z 	


    NO •      "•
            NA
                    _ppm
                            670
                                       ppm
                                   2


                                  S0r
2490
                                                  ppm
COMMENT:
          (1)  pH at 7.2 after 20 minutes at thermal equilibrium and

               no gas flow.
                               Page 4 of 5

-------
                                 - 169 -





                        NOX SCRUBBING DATA SHEET



DATE:     4-lfr-72	    SCRUB:    Mg(OH>2
OBJECT:    Scrub N0£ - SC-2 in presence of Hydroquinone  (1.0 gram)
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.    125  °p     Initial pH      8.1          Final pH    7.7


    H20       1Q _ %     C02 _ ~ _ 7°      °2      3 _ 7o
    NO       NA _ ppm     N09 _ 650 _ ppm      SQ      2280
COMMENT:
          (1)  Addition of HQ increased N0_ absorption by
               = 250 ppm.
                              Page 5 of 5

-------
4-24-72
2 Molal NH HS03>  0.5 Molal


c
o



10


9
8
7



6
1
1

5

4


3

2


1


0


ppm
x 11
s
o
z


5

1
1
1
4
1

1


3


1
1
1
2

1
1
1
1

1
1
1

0
i
I
1

30
CM
O
OT


30 —
i
1 -
27 —
1
24 —
1
1 -


i
1 "
18 —
1
I -

15 —
I
-
1
12 —
i
I
9 —
1
6 —
i
1 "
•5 « g-—
I mm
[

I
1




PL.
pa



i
•i





















—
C





pH

'


i
93
5.85 5.8 5.75
'











+ NH.OH — j> pH 5
\\
\^
	

...
— —•-~— " ~~ -81%

-94%
— 	 — 	 	 	 -j
1 1 1 1 1 1 1 1 1 1 f 1 1 1
) 10 20 30 40 50 60 70 80 90 100 110 120 130 140 15
1


BP
( —






— — -











9










0
1
                                     Time in Minutes

-------
                                 - 171 -



                        NOX SCRUBBING DATA SHEET


DATE.     4-24-72	    SCRUB:   2 molal NH4HS03 with 0.5 molal

                                      (NH4)2S04	
OBJECT:    Maintain pH of solution.
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   122   °p     Initial pH      5.93         Final pH   5.9

    HO      10        %     C00    12	%      09      3	%
    H2u .	        2 	        2 	

    N0    —	ppm     N02     700	ppm      S02     2370    ppm
COMMENT:
           (1)  The S02/absorption decreased steadily through the run
               from  84% initially to 65% at 145 min.  The addition of
               base  (NItyOH) at 145 min, increased pullout to 81% at
               pH of 5.9.

           (2)  N02 pullout was =94%.

           (3)  It appeared that some NO was made, but within the
               sensitivity of the instrument, it is not possible to
               say exactly how much.  Approximately 5-10 ppm is the
               best estimate.
          NO:  Na2S03 —=> Dry Ice	> NDIR

-------
4-25-72
2 Molal NH,HS00. 0.5 Molal (NH.)0SO,
          43               424
CM CM
O O O

10 5 30 —
i i i -
9 j 27-
1 1 -
8 4 24~
1 . i -
7 ' 21-
1 i -
6 3 18 —
1 i
1 '
5 1 15-
1 ' i -
4 2 12 —
1 , i -
319 —
' i -
216 —
1 , i -
1 1 3 -
i ' i -

0 0 0 ~~
1 i i
BP
«- ~5
1

















^•^^•M
0
1

7 pH
NO @ -100%
so0 e -100%
4 F L
NO @ ^ + 10 ppm


x 150°F UO°F
o
!L
s
1^-
r-
•s.
o
4-1
•
<







^^^^^^^^^^^^^^^^^^ III
5 10 15 20 25 30 3'.
BP



— ^^^—

I
h-
N.
1











i
                                     Time in Minutes

-------
                                 - 173 -
                        NOX SCRUBBING DATA SHEET
DATE:     4-25-72           SCRUB:   2 molal NlUHSOq + 0.5 molal
OBJECT-    Observe  effect  of increased pH on  solution  used in  run    	


             4-24-72	


                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.  124    °p     Initial  pH 	7.7          Final pH 	
H20       10 _ %     C02 _ 12 _ %      02      3 _ %


NO       —      ppm     N0  _ 680 _ ppm      S0      2340    ppm
COMMENT:
                     ppm     N2 _   _ ppm        2
           (1)  S02 and N02 levels decreased after adding NltyOH;
               AS02 and AN02 are 100% with 10 ppm NO generated.


           (2)  Solution temperature rise due to heat of neutralization.
           NO:  N32S03	>  Dry  Ice—>•  NDIR

-------
4-25-72
                                        30 Wt.% H0SO.
                                                 2  4
ppm
x 100
.5-

1 -
—
__
_
i
^™
~

.5 "


J








BP
Cr -^



















(
1
























	 . 	 — 	 	 . _
1 1 i i 1 1 i i I 1
) 10 20 30 40 50 60 70 80 90 100 i]
1






BP
*~










— —•






LO
                                     Time in Minutes

-------
                                 - 175 -
                        NOX SCRUBBING DATA SHEET
DATE:      4-25-72	    SCRUB:  H2S04  30 wt. % in water
OBJECT:   NOX scrubbing with H2S04
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.   120   °F     Initial pH      —           Final pH    —

    H20     10	%     C02 	12	%      02       3	%
    NO     350	ppm     N00 	300       Ppm      SO,
                                                _ppm      S02     0	ppm


COMMENT:

          (1)  No NO was absorbed.

          (2)  Some N02 (- 50 ppm) was absorbed and approximately 18 ppm
               of S02 was generated.
              NO:  Na2S03—^ Dry Ice —*• NDIR

-------
4-26-72
Mg(OH)  with Hydroquinone
ppm
x 100

CM CM
O O O
Z Z en

10 5 30 —
1 •
1 1 I -
9 1 27 —
i ' i -
8 4 24 —
1 , i -
7 21 —
I i
1 1 -
6 3 18 —
i . i -

15-
, 1 •
1 1 -
1
4 2 12 —
1'
| -
3 i 9 -
1 ' I
1 1 -
21 £

1 , i -
1 i 3 —
i ' i -

III


9
i




BP




...
•^M




















Btt
» V i8 v

8.7 8.1
V V











a-
re
oo
6
VO

?



Leak —
"~\- 1
s^/


1 1










o-
X
£

•
CM
+



/ "
J














O1
a
oo
a
.—i
•
+



O^














g-

oo
e
^
i/*^
o
+






















(~\ flow down, NC»2 high
^-^| ^^tirrer stalled re-start




— L/
\s

1 I I I I 1 1 1 1 | 1 | 1 1 1 1 1 1 1 I 1 1 1 I 1 1 1
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
' Time in Minutes


55
1







e ->
BP

^^"^"™ i
i-
CT
1

















-------
                                 - 177 -









                        NOX  SCRUBBING DATA  SHEET







DATE:      4-26-72 _     SCRUB:    Me (OH) 2  slurrv.  15  gm




                                        H20
OBJECT :   Add various  amounts of Hydroqulnone
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute




    Pot Temp.   122   °p     Initial pH      9.38         Final pH   7.55




    H20      10 _ %     C02 _ 12 _ %      02      3 _ %
    NO     NA _ ppm     N02       705 _ ppm      SQ2     2220    ppm






COMMENT :




           (1)  Final N02 removal was * 70%, SO  absorption was 100%.
         NO:  Na2S03—V Dry Ice	> NDIR

-------
           Mg(OH)
ppm
x 100
4-27-72
                                 V
             Hydroquinone; variation of HQ level  and its net effect
                         PH
                   7.45
                   V
                                    S1
                                     01
                                     0)
                                    .-I
                                     o
   X

   CM

    •
   r~-
   rH

   +
                                                    o

                                                   in

                                                    o
                           20
30
 I

40
                                 cr
                                 ffi
                                                                   00
                                                                   
-------
                                 - 179 -
                        NOX SCRUBBING DATA SHEET
DATE:     4-27-72	    SCRUB:   Mg(OH)2 slurry, 3 gm in 1000 ml


                                    of H20
OBJECT:   Hydroquinone testing as an anti-oxidant
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.  126    °p     Initial pH      9.4          Final pH    4.5


    H20     10 _ %     C02       12 _ %      Q2      3 _ %
    NO     NA _ ppm     N02 _ 700 _ ppm      SO.      2250    ppm
COMMENT :
           (1)  The increasing amounts of HQ added had greater effect
               and also lasted longer.
NO:  NaS0
                     2S03 — ^ Dry Ice - ^ NDIR

-------
                                           CaC03 with and without CL and HQ
ppm
x 100
                                                   Time  in Minutes

-------
                                 - 181 -




                        NOX^SCRUBBING DATA SHEET


DATE:      4-28-72	    SCRUB:    CaC03 slurry  10 gm in 1000 ml

                                        of H20  (with and without HQ)


OBJECT:    Absorb N02-S02	
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute

    Pot Temp.  124    °F     Initial pH      ?*           Final pH    6.25

    H20      10	%     C02 	12	%      02      3**	%
    NO       NA      ppm     N02      700	ppm      SO      2220    ppm


COMMENT:

          *  pH electrodes were not working correctly
             (calculated pH @ 50°C = 10).

         **  02 level was varied from zero to 3%.

          (1)  N02 scrubbing was better without the 02.
               [~ 75% without and 64% with]

          (2)  The hydroquinone reduced the N02 to the 02 free level.
              NO:  Na2S03-^. Dry  Ice—>-NDIR

-------
5-1-72
Ca(OH) ,  Vary 0_ and Hydroquinone
ppm
x 100
CM CM
O O O
53 a co
10 5 30 —
i i i -
9 | 27 —
' i -
8 4 24 —
•
1 1 -
1 '
7 | 21 —
i ' i -

6 3 18 —
1 , i •
i i
5 1 15-
1
1 i -
4 2 12 —
1 , i •
3 1 9 —
' i -
216 —
I
1 1 -
1 '
-L * ~J
1 ' '
1 1 -
1 ! '
1 : t



12

BP
«- -»


e
<—_Q
4-1
ff*
	 3
-H
?
 8.2
W

7.9 7.25
T 7.3 *
^_
7,5
if



n
o
r
o










-86% j


20 40 60 80 100 120
TMTno







7.
1








O
EC
E
6
+



-71%
*
S
/
f


140 160
-f r» M-i r»n*-Q c

Pj





! 7.1
T









4-1

O
c-
O






-86%


i I i i i I i i
180 200 220 240




7.

























-90%

i I 1 i I
260 280 300




)
t



BP
*- — >


^ ^^ —

I
M
00
to
1

















-------
                               - 183 -
                        NOX SCRUBBING DATA SHEET
DATE:     5-1-72	    SCRUB:   Ca(OH)2 [10 gm per litre of water]
OBJECT:   Vary 02 and Hydroquinone
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   123   °F     Initial pH     12.2          Final pH    7.0

    H20      10	%     C02 	12	%      02      3	%
    NO       NA	ppm     N00 	700	ppm      S00     2265    ppm
COMMENT:
          (1)  Without 02, absorbs  approximately 86% N02, 100% S02;
               with 02 - 71% N02 and 100% S02; with 02 and HQ = 86%
               N02 and 100% S02.
              NO:  Na2S03—>-  Dry  Ice —•>• NDIR

-------
                5-2-72
                                                      Urea in HNO_
 I  a  t
 ex  ex  ex
    ex
 N    £SI
 o   o o
 a   \z> w

 o   o o
 o   o o
           .
 10  5  30 —

 I   j   i   -
 9   j  27 —


 I      i   -

 8   4  24 —
 7     21-


 I      i

 6  3  18 —
5


 I'
4  2
    ,
    I  15
       I
      12 -

       i
      o  „»^
       •

       I   -
216  —

 I   ,   i   -
      3 —
 I      i
000
                                                         ri
                                                           •
                                  NO only
                                                              NO

                                                              +

                                                              NO,
                                                                      BP
                                                     BP
                                                                                  NO
                                                                                    2 only
                                                                                                                   i

                                                                                                                  >->
                                                                                                                  00
                                   "T


                                   40
                                        T


                                         50
T

 60
-T


 70
                                                            0

                                                            I
T


 10
                                                   Time in Minutes

-------
DATE:
       5-2-72
                                - 185 -
                         NOX SCRUBBING DATA SHEET
SCRUB:  28.5 gm Urea in 1000 ml  40%
OBJECT:     N0x scrubbing with urea (NO only)
CONDITIONS:    Scrub volume @  1000 ml    Total Gas  Flow @  3200  cm   per minute
    Pot Temp.     135  °F     Initial PH      NA	      Final  pH    NA
             10        %
    NO      475
H20
COMMENT:
 CO,
12
            7
            /o
                              0
                     _ppm
                         NO,
          NA
                                                 _ppm
                    2
                   SO,
                                       NA
                                                                          _ppm
          (1)  No absorption = 42%.
          (2)  Made * 360 ppm N02, equivalent to 75% of input NO,
          (3)  Frit had tendency to clog.
           NO:   Na2S03-
                        Dry Ice  	> NDIR
                              Page  1  of 3

-------
DATE:     5-2-72
                                - 186 -
                        NOX SCRUBBING DATA SHEET
             SCRUB:   Urea in HNOi
OBJECT:   N0 + N0? Absorption
CONDITIONS:
    Pot Temp.
Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
                135
             10
              Initial pH
                             CO,
                              NA
                         12
                             Final pH
                                           0
                                          NA
    NO
           322
      ppm
NO,
                        310
ppm
          2
         SO,
COMMENT:
           (1)  Used an open tube for 1st 5 minutes.
           (2)  No absorption without frit = 23%; made 10 ppm
           (3)  No absorption with frit - 54%; made 50 ppm NO-
                                       NA
ppm
                              Page 2 of  3

-------
                                - 187 -
DATE:     5">72
OBJECT:
                        NOX SCRUBBING DATA SHEET
                            SCRUB:   Urea in HN03
                ^sorption
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute




                135   °F     Initial pH      NA           Final pH      NA




                       7.     C02 _ J^ _ %      02       3        %





                                                          S0
    Pot Temp.
    NO
COMMENT :
               10
             NA
ppm
                                                 PPm
                                                                  NA
          (1)  Absorption of N02 - 47%.




          (2)  Made - 20 ppm NO.




          (3)  Tried adding S02 but frit plugged immediately,
                                                                          ppm
                              Page 3 of 3

-------
5-3-72
Urea in
i e a
P. IX 0.
p.
CM fsl
O O O
O O O
O O O
rH H rH
LO 5 30 —
1 , i -
J | 27 —
1 i
1 -
3 4 24 —
7 I 21 —
1
1 '
io TO
> 1 15 —
t
1 "
i 2 12
. i "
» ! 9 —
16 —
i
1 1 -
1 3 _
• ' i -
i
! 1
BP
pH
3.
NO
only
35
i
BP
H
3.

9
NO
so2
1
•
/
V
BP
1
1
1
t
1
1
1
1
1
1
"
,
\
NO
N02
,
1
/\
BP
•f
I
I
1
NO
N02
so2

/
0 10 0 10 20 0 10 20 30 0 10
III It 1
Time in Minutes


                                                                                                                00
                                                                                                                00

-------
                                - 189 -





                        NOX SCRUBBING DATA SHEET



DATE:     5-3-72	    SCRUB:   Urea in H20  [231 gm in 1 litre


                                       H20]   3.85 molal
OBJECT:    Absorption of NO
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.   122   °F     Initial pH   3.85	      Final pH   3.9


    H20       10       %     C02 	12	%      02       3	%
         NO:  Na0SO^  —>• Dry  Ice	> NDIR
                              Page  1  of  4
    NO      4-80	ppm     N02 	NA	ppm      S02     NA	ppm



COMMENT:


          (1)  About 15 ppm of NO absorbed (= 3%).

-------
                                 - 190 -
                        NOX SCRUBBING DATA SHEET
DATE:     5-3-72            SCRUB:   Urea in H?0
OBJECT:   Absorption of NO and S02
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.   122   °F     Initial pH 	3.9          Final pH 	
             10	%     C02	12
    NO      490	ppm     N02 	NA	ppm      S02     2154



COMMENT:


          (1)  Basically no absorption of NO.


          (2)  S02 level went nearly to zero and rose slowly.
                               Page  2  of 4

-------
                                  -  191  -
                        NOX SCRUBBING DATA SHEET
DATE:
          5-3-72
                            SCRUB:   Urea in HgO  (solution had already

                                       been used  for NO-S02 absorption)
OBJECT :   Absorption of NO and N02

CONDITIONS: Scrub volume
Pot Temp. 122 °F
H»0 10 %
NO 339 PPm
@ 1000 ml Total Gas Flow (
Initial pH 3.9
CO. 12 %
NO. 390 PPm
3
a 3200 cm per minute
Final pH
0. 3 %
S00 NA PPm
COMMENT :
          (1)  NO absorption * 11%.

          (2)  N02 absorption = 36%.

          (3)  Generated 750 ppm S02 initially, which tappered off
               while running.
                               Page 3 of 4

-------
DATE:
          5-3-72
                                -  192  -
                        NOX SCRUBBING DATA SHEET
SCRUB:   Urea in H20
OBJECT'   Absorption of NO, N02  and  S02
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute
    Pot Temp.    122  Op     Initial pH     3.9	      Final  pH 	
    H20      10	%     C02       12	%     ' 0,       3         %
    NO       323	ppm     N09 	400	ppm
                               '2
                              SO,
2154
       _ppm
COMMENT:
           (1)  No absorption  -  7%.
           (2)  N02  absorption *  38%.
           (3)  S0_  absorption  = 89%  initially;  decreased with  time
                               Page 4 of A

-------
5-4-72
                                  Mg(OH)2 with NO, N02,
pp
0
o
1-1

X

CN

10
1
9
1
8
1
7
i
6
1
5


4
1
3

1
2
I

1
i
o

m

0
o
»H

X

o
5
,
t
I

4

1
1
3
i
1
1

2
1
1
t

1

i

o
i
i

i
(
T





*

2

2

2
1
1
f
1
1
•
1
9

i
6
t
1

3
i
1
o
i
1

^
D

X

CM
o
.n
to —
I
7 —

4 —
-
1 —
8 —
•
5 —

•
2 —
•—

-
—
-

m^^m
*
^^H



BP









9
__. .
— —




—



1



••••••••
0
1



•rtU
pH

^r


Off On
* S02 i

,95 8,

9^0 8^8
\
V \
\

I

1
\
\ i 	 v
\ \
\ 1 \ 1


1 ' ' ' i i i i i i i "™"T^ ~r
10 20 30 ^0 50 60 70 80' 90 100 110 120 130 140 15
Time in Minutes 1











BP
^ _
4

t




^•a








••••
0
                                                                                                         vo
                                                                                                         U)

-------
DATE:     5-4-72
        - 194



NOX SCRUBBING DATA SHEET


    SCRUB:   15 gm Mg(OH>2 in 1000 ml of

              water  (slurry)  	
OBJECT:    NOX-SOX Absorption
CONDITIONS:    Scrub volume & 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   122   °p     Initial pH   9.95	      Final pH   8.4

    H20     10	7.     C02       12	%      02      3	%

    NO     350	ppm     N00 	340	ppm      SO-     2220    ppm
COMMENT:
          (1)  More N02 was scrubbed then NO as would be expected
               (40% NO + 76% N02 absorbed).

          (2)  As usual for this type of run, all the S02 was
               scrubbed.
             NO:   Na2S03
      Dry Ice
NDIR

-------
5-5-72
                         Mg(OH)2 with  Hydroquinone (Endurance Run)
i. B
ex a
ex
o
o o
H O
X
X
«M
O O

10 5
1
9 '
1
1
8 4
' ,
7 i
1
1
6 3

i
5 «
1


4 2

i
3 '
i


2 1

1
i !
1

0 0
i
i
§.
ex

o
o
H
X

fM
O
VI
30 —
i -
27 —

i •
24 -
i -
21 _
1
1 '
18 —
i
1 '
15 —

I
1 '
12 __
1
1 -
9 _

1
1 -
6 _
1
1 -
3 _
1
1 '
0 _
i
1











BP
*"*



3?
—

mmm





















•M Hi
0 ]

                                                                                       PH
                                                         7.7
                                                                                                       7.6
                                                                                                            VO
                                                                                                            01
10 60 70 80 90 100
 I   I
140  160   180   200   220

          Time in Minutes
320   340   360
380

-------
                                 - 196 -



                        NOX SCRUBBING DATA SHEET


DATE:     5-5-72	    SCRUB:   15 g Mg(OH)2  plus 1.0 g

                                    Hydroquinone	
OBJECT:   Endurance Run
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.  122    °F     Initial pH 	9.9          Final pH   7.6

    H^O      10        %     CO,,       12          %
                                                           2
    NO      NA	ppm     N02 	675	ppm      SO-     2280    ppm
COMMENT:
          (1)  N02 dropped to zero initially; it came off zero =* 80 min.
               and rose slowly.

          (2)  The S02 dropped to zero and stayed there for the entire
               run.

          (3)  Solution became more yellow as the run progressed.
          NO:   Na2S03 —>  Dry  Ice  	>NDIR

-------
5-9-72
                                         Urea in  H0SO.
                                                   2  4
& a
ft, E cL
ex ex
«M ft
O CM
2! 0 0
2 co
0
000
«H O O
X ^ ^
10 5 30 —
*
1 . 1
9 | 27 —
i i
8 A 24 —
i !
1 « 1
7 j 21-
1 i -
6 3 18-
1 , i •
5i 15 —
I •
' 1 '
A 2 12
, i -
3 | 9 _
1
i •
216 —
1 j

1 J 3 _
1 i
1 1 '


i i


BP
^» '
*» ~* "TF






































no absorption




NO
only









pH = 1.8



















1
I
1
1
1
I
t

i
I
1








BP
r 	 >




















NO + NO















































BP




1
1




*^^m







JL.

0 10 20 30 0 10 20 30
I 1 I




^m




























NO
only







































BP
« 	 ^























E
O
LT*
C")


-------
                                -  198  -





                        NOX SCRUBBING DATA  SHEET



DATE:     5-9-72	    SCRUB:    Urea  in H?SO/f:  1 Kg 10%

                                      urea  soln  +  30  ml 6N H?S04
OBJECT:    To absorb NOX with urea.
                                                                  3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @  3200  cm  per minute


    Pot Temp. __125__°F     Initial pH       1.8           Final  pH  Not Taken


    H n      10        7     rn          12        '/       o        ^         7
    "O                 '°     IjUn         *^-        /o       \Jn       -3         I"
COMMENT:


          (1)  Essentially no absorption of NO.
           NO:  Na2S03 	> Dry Ice 	>- NDIR



                              Page 1 of 6
    NO     520	ppm     N02 	NA	ppm       S02      NA	^ppm

-------
                                 - 199 -
                        NOX SCRUBBING DATA SHEET
DATE:     5-9-72            SCRUB:   Urea in H?S04
OBJECT:
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute




    Pot Temp.   125   °F     Initial pH _ 1.8          Final pH _
           10 _ %     C02 _ 12
                               Page  2  of  6
    NO      340 _ ppm     N02      330 _ ppm      S02     NA _ ppm






COMMENT :




          (1)  Some absorption of NO, - 15%.




          (2)  Some N00 absorbed, = 30%.

-------
                               - 200 -
                        NOX SCRUBBING DATA SHEET
DATE:     5-9-72	    SCRUB:    Urea in H2S04
OBJECT:
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.   125   °F     Initial pH     1.8           Final pH 	
              10	%     C02 	12
                              Page 3 of 6
    NO  	NA	ppm     N02 	680	ppm      SO,,     NA	ppm




COMMENT:


          (1)  N02 absorption - 54%.

-------
                                - 201 -
                        NOX SCRUBBING DATA  SHEET
DATE:      5-9-72	    SCRUB:   Urea in H2SC-4
OBJECT:
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm3 per minute




    Pot Temp.  125    °F     Initial pH       1.8         Final pH 	
              10	%     C02 	12     7.
    NO      NA	ppm     N02 	700	ppm      SO      2190    ppm






COMMENT:




           (1)  NO - absorption =  40%.




           (2)  SO  absorption *  21%.
                              Page 4 of 6

-------
                                 -202 -
                        NOX SCRUBBING DATA SHEET
DATE:     5-9-72            SCRUB:   Urea in H2S04
OBJECT:
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp.   125   °F     Initial pH 	1.8          Final pH	
    H20       10       %     C02 	12
    NO     - 350     ppm     N02 	700	ppm      S02     2190    ppm



COMMENT:
           (1)  N02 absorption ~ 44%.


           (2)  S02 absorption * 21%.


           (3)  NO absorption * 18%.
                                Page 5 of 6

-------
                                 -  203  -
                        NOX SCRUBBING DATA SHEET
DATE:     5-9-72	    SCRUB:    Urea in
OBJECT:
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute


    Pot Temp. __H5__°F     Initial pH      !•*          Final pH 	
              10	TL     C02       12
    NO      466	ppm     N02 	NA       ppm      S02      740    ppm



COMMENT:

          (1)   NO absorption was zero.


          (2)   S02 absorption * 10%.


          (3)   Information not on graph.
                               Page 6 of 6

-------
                                  - 204 -
                        NOX SCRUBBING DATA SHEET
DATE:     5-15-72           SCRUB:   Na2S, 2.1 molal
OBJECT:   Sulfide scrubbing, Analyze dissolved NO-,
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   125   °p     Initial pH     —	      Final pH    —
               .10	%     C02       12	%      02
    NO  	™	ppm     N02 	670	Ppm      S02     —	ppm


COMMENT:

          (1)  AN02 -  100%, with 23 ppm NO produced.

          (2)  Unable to analyze solution because of spectrophotometric
               interference.
               NO:   Na2S03—>>  Dry  Ice	>• NDIR

-------
6-22-72
                                (NH4)2S03-NH4HS02 Mixture
ppm
x 100
tN CS
o o o
& 'K U)
10 5 30 —
9 1 27 —
' i -
8 4 24 —
1 , i -
7 1 01

i i -
6 3 18 —
1 , i -


1 ' i -
4 2 12 —
1 i -
i
3 • i 9 -
i
1 '
216 —
1 , i •
1 ' 3 —
i
j
000 —
1 1
! 1


BP
f" ~4

.....





















•M^M
0
\



pH = 6.3



-22%
^"'

















^^^^^^^^^^^^^^^^^^^^^^^H
1 1
10 20 30
1


BP
t- ->
, pH =
	 —





















m^^_
30
1



6.3



f\ / m
-24%
















	 -97%
-JOTT" • — -•
40 50 60


BP
6—

	























                                                                                                         NJ
                                                                                                         o
                                                                                                         Ul
                                   Time in Minutes

-------
                                  -  206  -
                        NOX SCRUBBING DATA SHEET
DATE:     6-22-72           SCRUB:   NH^HSO^ Mixture
OBJECT:   Study Influence of Sulfate
                                                                 3
CONDITIONS:    Scrub volume @ 1000 ml    Total Gas Flow @ 3200 cm  per minute

    Pot Temp.   128   °F     Initial pH 	6.3           Final pH    6.3

    H20 	10       7.     C02       12	%      02      3	%

    NO      450	ppm     NO. 	500	ppm      SO-      2860    ppm
COMMENT:
          (1)  AN02 was  100%; AS02 was  97%; and ANO was  24% after 1
               hour.

          (2)  Ball sticking in the NO meter caused slight fluctuations
               in readings.
          (3)  Scrubbing solution consisted of 11.2 wt.
               14.6 wt.  % (NH4)2S03,  16.6 wt.  % (NH4)2 S04,  and
               57.6 wt.  % water.   Specific gravity was 1.24.

          (4)  Presence  of sulfate had no discern able effect.
          NO:   Na2S03—^ Dry Ice —^ NDIR

-------