PHASE I REPORT
APPLICABILITY OF^RGANIC SOLIDS TO THE
DEVELOPMENT OF NEW TECHNIQUES FOR REMOVING
OXIDES OF SULFUR FROM FLUE GASES
10669-6003-RO-00 31 OCTOBER, 1968
PREPARED FOR:
NATIONAL CENTER FOR AIR POLLUTION CONTROL
UNDER CONTRACT NO. PH22-68-46
TRW
SYSTEMS GROUP
ONE SPACE PARK
REDONDO BEACH, CALIFORNIA
-------
PHASE I REPORT
APPLICABILITY OF ORGANIC SOLIDS TO THE
DEVELOPMENT OF NEW TECHNIQUES FOR REMOVING
OXIDES OF SULFUR FROM FLUE GASES
10669-6003-RO-OO 31 OCTOBER, 1968
PREPARED FOR:
NATIONAL CENTER FOR AIR POLLUTION CONTROL
UNDER CONTRACT NO. PH22-68-46
TRW
enouf
ONE SPACE PARK
REDONDO BEACH, CALIFORNIA
-------
lo669-6003-RO-OO
.T
PHASE I REPORT
APPLICABILITY OF ORGANIC SOLIDS TO THE
DEVELOPMENT OF NEVI TECHNIQUES FOR RE,\10VING
OXIDES OF SULFUR FROM FLUE GASES
By
R. A. Meyers, J. L. Lewis and J. S. Land
Prepared for:
National Center for Air Pollution Control
Under Contract No. PH22-68-46
31 October 1968
Approved by:
fci~
E. A. Burns, Manager
Chemical Research and
Services Department
TRW SYSTEMS GROUP
One Space Park
Redondo Beach, California
-------
10669-6003-RO-OO
CONTENTS
1.0 :rnTRODUCTION AND SUMMARY
.................
2.0 LITERATURE SEARCH - ORGANIC SOLIDS FOR SULFUR DIOXIDE
REMOVAL FROM FLUE GASES. . . . . . . . . . . . . . .. . .
2.1 Organic Solids Which Interact with Sulfur Dioxide. . .
2.1.1
2.1.2
2.1.3
2.1.4
2~1.5
2.1.6
2.1.7
2.1.8
Polymers - Cellulosics. . . . .
. . . .
. . . .
Polymers - Ion Exchange. . . . . . . . . . . .
Polymers - Miscellaneous. . . . . . . . . . . .
Homocyclic Aromatics and Derivatives. . . . . .
Heterocyclic Aromatics and Derivatives. . . .
Hydrocarbons and Derivatives. . . . . . . . .
Telomeric Dyes and Dye Bases. . . . . . . . .
Organo Metallics
. . . . . . .
. . . .
. . . .
2.2 Criteria for Selection of Most Promising Organic
801 i dB . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Most Promising Organic Solids for Removal of
Sulfur Dioxide from. Flue Gases. . . . . . . . . . . .
3.0 PRELIMINARY CHEMICAL SYSTEMS ANALYSIS. . . .
. . . . . . .
3.1 Process Description
. . . .
. . . . . .
. . . . . . .
3.2 Process Model. . . . . . .
3.2.1
3.2.2
. . . . . . .
.......
Derivation of Mathematical MOdel
. . . . . . .
Method of Computer Solution. .
. . . . . . . .
3.3 Process Base Case Conditions. . . . . . . . .
. . . .
3.4 Results of Parametric Analysis.
. . . . . . . . . . .
3.5 Conclusions
. . . . . . . . . . . .
. . . . . . . . .
4.0 APPENDIX - COMPt1rER PROGRAM LISTING. . .
5.0 REFERENCES
.........
. . . .
. . . . . . . . . . . .
. . . . . . . .
Page
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3
4
4
7
9
11
11
11
11
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16
18
21
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26
28
30
36
48
51
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Figure
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2
3
4
5
6
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8
9
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14
15
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17
~.
10669-6003-RO-00
ILLUSTRATIONS
Structure of Ion Exchange Resins.
. . .
. . . . . . .
Change-Transfer/Acid-Base Interaction of
N-vinylcarbazole with S02 .......
.......
Change-Transfer/Acid-Base Interaction of
Pyrolyzed Poly(acrylonitrile) with S02 . . . . . . . .
Addition Reaction of Pyroly~ed Poly(vinylchloride)
wi th 802 . . . . . . . . . . . . . . . . . . . . . . .
Coal Burning Power Plant with S02 Recovery Capability.
Unsteady-Btate Operation of a Packed Bed ,
......
Effect of the Mass Transfer Coefficient on the S02
Sorption Batch Time, . . . . . . . . . . . . . . . .
Effect of the Mass Transfer Coefficient on the
Operating Profit of the S02 Recovery System. . . . .
Effect of the Gas-Solid S02 Equilibrium Constant on
the 802 Sorption Batch Time, . . . . . . . . . . . .
Effect of the Gas -Solid S02 EC,uilibrium Constant on
the Operating Profit of the S02 Recovery System
Effect of Sorption Column Diameter on the S02
Sorption Batch Time. . . . . . . . . . . . .
. . . .
Effect of the Sorption Column Diameter on the
Operating Profit of the S02 Recovery System
.....
Effect of Sorption Column Height on the S02 Sorption
Ba tch Time. . . . . . . . . . . . . . . . . . . . . .
Effect of the Sorption Column Height on the Operating
Profi t of the S02 Recovery System (30 -ft, col.), . . ,
Effect of the Sorption Column Height on the Operating
Profit of theS02 Recovery System (40-ft. col.), , . .
Effect of the weight of Paper per Cubic Foot of Column
and the Column Void Fraction on the S02 Sorption Batch
Time. . . . . . .,. . . . . . . . . . . . . . . . . .
Effect of the Weight of Paper per Cubic Foot of Column
Void Fraction on the Operating Profit of the S02
Recovery System. . . . . . . . . . . . . . . . . . .
Page
8
10
10
10
19
22
37
37
38
38
39
39
40
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40
41
41
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Figure
18
19
20
21
22
23
24
25
26
27
28
29
l0669-6oo3-RO-00
ILLUSTRATIONS (CONTINUED)
Effect of the S02 Mole Fraction in the Feed Flue
Gas on the S02 SOrption Batch Time. . . . . . .
Effect of the S02 Mole Frbction in the Feed Flue
Gas on the Opera~ing Profit of the S02 Recovery
Sys tem . . . . . . . . . . . . . . . . . . . . .
Effect of the S02 Concentration of the Paper at
oatur'ation on the S02 Sorption Batch Time
Effect of the S00 Concentration of the Paper at
Saturation on the Operating Profit of the S02
Recovery System. . . . . . . . . . . . . . . . . . .
Effect of Column Diameter on the Capital Investment
for the S02 Recovery System. . . . . . . . . . . . .
Effect of Column Height on the Capital Investment
for the S02 Recovery System . . . . . . . . . .
Effect of the Cost of Paper on the Operating Profit
of the S02 Recovery System. . . . . . . . . . .
Effect of the Paper Replacement per Batch on the
Operating Profit of the S02 Recovery System. . . . .
Effect of the Paper Replacement per Batch on the
Operating Profit of the S02 Recovery System (Heat
Credit Altered) ...................
Effect of the S02 Credit Value on the Operating Profit
of the S02 Recovery System. . . . . . . . . . . . . .
Effect of the Heat Credit Value on the Operating
Profit of the S02 Recovery System. . . . . . .
Effect of the Cost of a General Sorbent on the
Operating Profit of the S02 Recovery System. . . . .
Page
42
42
43
43
44
44
45
45
45
46
46
47
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TABLE I
TABLE II
LIST OF TABLES
Classification of Organic Solid - S02
Interactions. . . . . . . . . . . .
10669-6003-RO-00
.......
Properties of Most Promising Organic Solids
for S02 Removal. . . . . . ... . . . . . .
. . . .
Page
5
15
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10669-6003-RO-OO
1.0
INTRODUCTION AND SUMMARY
This Phase I comprehensive report describes the work pertormed by TRW
Systems Group tor the National Center tor Air Pollution Control under
Contract No. Ph-22-68-46 during the period of 24 June through 30 September
1968. This work had the following objectives:
8
To perform a detailed library search and selection of most
promising organic solids for removing sulfur dioxide from
flue gas, and
To perform a preliminary chemical systems analysis for can-
didate S02 removal materials.
As a result of a detailed literature search and conceptual analysis,
8
a number of organic solids were identified as having capacity for the bind-
- -
ing of sulfur dioxide. A principal accomplishment of this task was the
identification of a number of waste materials which have high potential for
removal of S02 fran flue gases. Organic materials were selected on the
bas is ot:
8 Known ability to take up sultur dioxide,
8 Price and availability,
8 Thermal stability,
8 Regenerability, and
8 Mechanical properties.
Five organic materials were identified which offered promise for removing
sulfur dioxide from flue gases:
8
Cell ulos ics ,
8
Nigrosin,
8
Poly(N-vinylcarbazole),
Pyrolyzed poly\vinylchloride), and
8
8 Pyrolyzed poly(acrylonitrile).
The specific cellulosics selected are: waste newsprint, sawdust arid cotton.
Although a number of other inexpensive cellulosic based materials ought to
be-evaluated the limitations of Phase II required that the scope be narrowed.
-1-
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10669-6003-RO-OO
The results of the preliminary chemical systems analysis demonstrate
that organic solid sulfur dioxide recovery from flue gases is, in g~neral,
economically feasible where certain criteria are met. The preliminary chemi-
cal systems analysis was keyed to thermal regeneration of the organic solids,
however, in the case of cellulosic materials chemical reaction and conversion
of the products to useful commodities may also be a feasible process. How-
ever, as so little is known as to the parameters involved in these conver-
sion processes at the present time, a consideration of this type of regenera-
tion was not included in the preliminary chemical systems analysis.
-2-
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10669-6003-RO-OO
2.0 LITERATURE SEARCH
ORGANIC SOLIDS FOR SULFUR DIOXIDE REMOVAL FRCM FLUE GASES
A comprehensive literature search through Chemical Abstracts subject
heading for sulfur dioxide was completed from the year 1907 to the present.
All pertinent sub-categories of the heading sulfur dioxide were search in
detail, e.g., reaction of, reaction with, absorption, etc., with special re-
ference to reaction with organic solids. Thirty-three references were found
which dealt with the interaction of sulfur dioxide or nitrogen oxides with
organic solids. Of these, only those concerned with the use of ion exchange
resins addressed themselves to the specific problem of removing sulfur di-
oxide from gas mixtures and none of the ion exchange papers discussed the
temperature region applicable to flue gas stacks (these being 215-300oF
after the preheater region of the flue gas stack and approximately 6oo-650oF
before the preheater region). This lack of high temperature testing of the
ion-exchange resins is probably due to the fact th~t most of the resins con-
tain either pendent amino groups or single-strand organic backbones which
are relatively thermally unstable. Several references provided information
showing that cellulosic materials take up appreciable quantities of S02 at
room temperature. It had originally been hoped that data such as adsorption
and desorption rates of sulfur dioxide, activation energies of organic solid-
gas reactions, etc., at room temperatur~or better flue gas stack temperatures,
would be available from the literature. Unfortunately, where references were.
found to be specific for organic solid-sulfur dioxide interactions, these
studies were conducted almost entirely at temperatures equal to or well be-
low room temperature.
The results of the literature search and conceptual studies are pre-
sented below in three sections:
.
Organic solids which interact with sulfur dioxide,
.
Criteria for selection of most promising organic solids, and
.
MOst promising organic solids for removal of sulfur dioxide
from flue gases.
-3-
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10669 -6003 -RO -00
2.1
ORGANIC SOLIDS WHICH INTERACT WITH SULFUR DIOXIDE
Approximately 32 references were found which delcribed the interaction
of sulfur dioxide with organic solids. The information contained in these
references is summarized in Table I which contains a classification of or-
ganic solid-S02 interactions, together with information generated at TRW
Systems prior to the start of this contract. In this section, each organic
solid will be discussed individually in the following organic solid subdivi-
sions:
.
Polymers - cellulosics,
.
Polymers - ion exchange,
.'
Polymers - miscellaneous,
.
Homocyclic aromatics and derivatives,
.
Heterocyclic aromatics and derivatives,
.
Telomeric dyes and dye bases, and
.
Organ'o-metallics
2.1.1
Polymers - Cellulosics
Cellulose is obtained from and makes up a large part of the structure
of wood, cotton, ceral, straw, hemp and jute among others. Paper: is a major
commercial cellulosic product ~hich consists largely of cellulose that also
1ncl uCes fillers, binders, and pigments. The 1966 total U., S. production of
paper products was 46.5 million tons which included the following major
forms: paper, paperboard and construction paper, while the total newsprint
consumption in the U.S. was 9.1 million tons of which 6.7 million tons were
imported from Canada~
Cellulose is a ladder polymer
J-{.
08 CHIOH
H H I 0 '
H / ~I ""/
C c
/ ""0 OH -V "H
H OH
x
Cellulose
-4-
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TABLE I
CLASSIFICATION OF ORGANIC SOLID - S02 INl'ERACTIONS
I
\J1
I
Organic Solid Type Organic Solid : Interactions ReI'erences
i
POlymer Cellulosics (paper, wood cotton), ; Insertion, change-trans~er 2 - 8
etc.
Ion exchange resins (divinylben- Change-transfer, acid-base 9 - 15
zene~ethylvinylpyridine copolymer
and other amine containing i
polymers)
. Poly(N-vinylcarbazole) Cba nge -trans fer, acid-base 21
Pyrolyzed Poly(acrylonitrile) Change-transfer, acid-base 21
Conjugated double bond containing Addition 22
resins pyrolyzed poly(vinyl-
chloride)
Linear saturated polymers (Teflon, Absorption-Adsorption 16 - 20
poly(propylene), poly(vinyl-
chloride, etc.)
I Homocyclic Aromatics and l\nthrecene Change-transfer 23 - 24
Deri vati ves Hydroquinone Inclusion compound 25 - 26
Coal* Change -transfer, acid-base 27
Heterocyclic Aromatics and Phenothiazine Change -trans fer, acid-base 28
Derivatives Dianin Inclusion compound 29 - 30
Hydrocsrbons and Derivatives Camphor Change-transfer 31
Cyclohexylhydroxylamine. Insertion 32
Telomeric Dyes and Dye Bases Nigrosin Change -transfer, acid-base 21
Copper Phthalocyanine Change -transfer, acid-b:..se 22
Organo Metallics Tri -n -dod~cyl ;,1 uminum Insertion 34
Alkali metal salts of fatty acids Insertion, acid-base 33
Alkali metal salts of ben~oic ~cii
, i
*Coal is u complex mixture of homocyclic and heterocyclic :;ro:::3ti::s.
I-'
o
~
\0
~
o
o
\JJ
I
::0
o
I
o
o
-------
10669-6oo3-RO-OO
which because of this is highly thermally stable. Cellulose materials
generally do not begin rapid thermal decomposition below 500-600oF (1).
Hence, cellulose derivatives from a thermal stability st...ndpoint are appli-
cable to flue gas stack region in the area after and possibly before the
preheater. Take up of sulfur dioxide and other gases by cellulose has
been studied in some detail at or near room temperature.
It has been shown
that cellulose itself absorbs, in order of decreasing volume: sulfur dioxide,
carbon dioxide and oxygen (this is the same order as charcoal) (2). It has
a160 been shown that sulfur dioxide absorption by various cellulose deriva-
tives varies according to the heat pretreatment of the cellulose derivative
(3). At room temperature, hydrophilic cotton absorbs 3~ by weight sulfur
dioxide, filter paper,3.2~ by weight, filter paper heated at 1730C prior to
sorption 4.3~, filter paper heated to 3200C takes up 2.98~, hydrophilic
cotton heat dried at 1500C takes up 13.88% and nitro cellulose takes up
l6.89~. In another paper it is stated that wood takes up more sulfur dioxide
than does cotton (4), and that carbon dioxide is not appreciably absorbed
by wood. Galzova shows that sulfur dioxide is taken up by cotton during a
drying process (5), while. Hudson shows that printing paper takes up very
small amounts of sulfur dioxide from the atmosphere under ambient conditions
(6 - 8).
It is clear from these results that sulfur dioxide is taken up in ap-
preciable quantities, as much as l7~ by weight at room temperature by cellu-
losic materials. This uptake probably occurs by a combination o~ charge-
transfer interactions and insertion reactions.
CHARGE TRANSFER
CELLULOSE + n S02 .. CELLULOSE, (S02)n
K . . = [CELLULOSE' (S02)nl n
equd [CELLULO~E) [S02 ) n
(1)
CHEMICAL REACTION
CELLULOSE +OH)n + nS02 ... CELLULOSE+ OS02H)n
K = (CELLULOSE-t OS02H)n] n
equil (CELLULOSE-t OH)n) (S02) n
(2)
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10669-6oo3-RO-OO
Change transfer interactions (Equation 1) are generally exothermic processes
and the equilibrium constants decreases as temperature increases, as does
ordinary sorption. Thus the higher temperatures encountered in flue gases
will tend to decrease strongly this type of sulfur dioxide uptake. However,
it is hoped that the major part of the 502 uptake is due to the second re-
action, that of insertion (Equation 2). This is a chemical reaction which
will very likely be endothermic and higher temperatures will increase the
equilibrium constant rather than decrease it. Thus, it may be anticipated
that sulfur dioxide uptakes of from 5 to 10~ may be found for at least
some of the cellulosic containing materials at flue gas temperatures of
o
215-300 F. I~deed, a rough feasibility test utilizing a gas stream which
was 30~ 802 w/w in nitrogen showed an uptake of 502 at 2l50F by ground
waste newsprint. There are a number of "regeneration" possibilities for
cellulose materials:
.
Regeneration of cellulose and sulfur dioxide by use of heat,
inert gas, vacuum, solvent extraction (water, amines, etc.)
.
Hydrolysis of cellulose to glucose by action of bound
sulfur dioxide (from flue gas) together with water.
It is very difficult to set absolute prices for these materials as the
prices are highly variable depending on the quality and grade. It has,
however, been ascertaine~ that waste paper can be obtained for roughly
0.3 cents per pound. This compares quite favorably with the price of
activated charcoal of 10 cents per pound. Of course, it is readily appar-
ent that all of the cellulosic materials are extremely inexpensive. relative
to pure chemical compounds or activated charcoal. This brief study, which
will survey a number of other organic solid classes, must limit itself to
a few cellulosics, specifically: sawdust, (approximately 5O~ cellulose),
cotton, (almost lOO~ cellulose), and waste paper specifically newsprint
(roughly 75~ cellulose).
2.1.2
Polymers - Ion Exchange
Ion exchange resins. both cation and anion types have been studied in
some detail with regard to their ability to sorb sulfur dioxide. The
structure of typical cation and anion exchange resins are shown in the
figure below.
-7-
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10669-6003-RO-OO
-CH.-CH-CH.-CH-CH.-CH-CH.-CH- .
I I SOaH I I'
9 0/ 9 9
SOaH CH SOaH
/ '"
-CH-CH2 CH2-CH-CH2-
! I
9 9
SO~H SOaH
CII inn c'(~har.sf" rc"i~
--CH.---CH ---C,,",.-- -CH-CH.,----CH--CH,,-CH-
~ I - I . I . I CH2~(CHa)
(1 (1 (1 o/cr.;)
Ye Ye CtG Y
CH~N(CHah CH2N(CH3h CH .
C1G I '"
CH2-CH-CH2-
CH-CH2 I
r~/I 91
/,/ ~
CH2 e
I CH2N(CHah
GN(CH3)3 C1G
CI8
Anion c~ch~ng(: re~in
Figure 1.
Structure of Ion Exchange Resins
As much as 0.25 gram of sulfur dioxide per gram of ion exchange resin has
been reported to be obtained at room temperature for typical ion exchange' resins
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10669-6003-RO-00
at equilibrium (9) and comparisons have been made between ion-exchange re-
sins and typical inorganic sorbents such as activated charcoal, molecular
sieve and silica gel (9-13) in which the ion exchange resins were shown to
be satisfactory for low temperature sorption but not equivalent to the in-
organics. Clearly, the linear structure of ion exchange resins coupled
with the thermal instability of the pendent acid and base groups limits
their use in actual flue gas environments. It has been shown that ion-
exchange resins based on copolymers of 2-methyl-5-vinylpyridine and p-di-
vin~rlbeQ'l.ene sorb sulfur dioxide from moving gas streams at low temperatures
(600c), and these sorbents may be regenerated by combination of hot air and
ammonia, or sulfur dioxide may be oxidi~ed to sulfur trioxide on the cata-
lytic surface formed by the ion exchange resin, again at relatively low
temperatures (14, 15).
2.L3
Polymers - Miscellaneous
Several researchers have studied the interactions of sulfur dioxide
with various construction materials including plastics at ambient levels
(1 to 100 pphm. voL) and at ambient..temperatures (20-350C) (16-19). These
workers have shown that materials, such as st~inless steel, Teflon, Tygon,
glass, poly(propylene), poly(vinylchloride), etc., sorb small amounts of
sulfur dioxide from the atmosphere. Further, it has been shown that sul-
fur dioxide, nitrogen oxide, etc., catalyze thermal decomposition of poly-
(tetrafluoroethylene) at 450-5000C (20). However, the nature of these
materials and the low degree of sulfur dioxide sorption coupled with rela-
tive thermal instability indicates that they are of little interest with
regard to the problem of removing sulfur dioxide from flue gases.
Recent studies at TRW Systems have shown that TRW processable polyim-
ides ($10-30/lb for prepolymer), poly(N-vinylcarbazole) ($5/lb), and 8-hy-
droxyquinoline-formaldehyde polymer (unavailable commercially) remove sul-
fur dioxide from moving gas streams at 4600F (on fire brick) (21), and
these organic solids are. ther~ally stable according to thermogravimetric
analysis in air at temperatures encountered in flue gas stacks.
However,
the high price of the pOlyimide and relative unavailability of the formal-
dehyde polymer limit their potential. The change-transfer interaction of
N-vinylcarbazole with S02 is shown in Figure 2.
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10669-6003-RO-00
/-
-I
~/.N.'O
V-'#
+
5°2
..
/-0-
0; I ;/5°2
O/N~O
.
Figure 2. Change-Trafisrer/AcLl-Base Interaction of
N-vinylcorbazole with SO?
In addition, subsequent experimental evaluation at TRW Systems has
shown that pyroLyzed poly(acrylonitrile) ($0.60/1b for polyacrylonitrile)
and pyrolyzed poly(vinylchloride) ($0.15/1b for pOly(vinylchloride), how-
ever, as a possible waste product it could cost only the price of transpor-
tion), also takes up sulfur dioxide from moving gas streams (22) probably
via change-transfer or acid-base (Figure 3) and addition reactions
Figure 4) respectively.
5°2
+
'())~/
- I I -
/ N° N~"""""
-
--
Figure 3.
Change-Transfer/Acid-Base Interaction of
Pyrolyzed Poly(acrylonitrile) with 802
n
~
}-;i\"--J1 '", =
Figure 4.
Addition Reaction of Pyrolyzed Poly(vinyl-
chlor-ide) with 802
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10669-6003-RO-00
2.1.4
Homocyclic Aromatics and Derivatives
Anthracene has been shown to sorb sulfur dioxide, nitrogen dioxide and
oxygen all of which produce a marked increase in the surface photoconducti-
vity of anthracene crystals (23, 24). Hydroquinone takes up (by inclusion
compound formation) sulfur dioxide, nitrogen oxide, carbon monoxide and car-
bon dioxide gases at room temperature and reverts to hydroquinone and gas
at approximately 2500F (25, 26), and coal, a complex combination of homo-
cyclic and heterocyclic aromatics has been shown to take up sulfur dioxide
at about 3000C with conversion of some of the sulfur dioxide and chem.:cal
alteration of the coal (27).
2.1. 5
Heterocyclic Aromatics and Derivatives
Phenothiazine forms an equimolar complex with sulfur dioxide in solu-
tion which is regenerable in the solid state by evaporation of sulfur
dioxide at room temperature under vacuum (28). Dianin,(p-3,4-dihydro-2,2,4-
trimethyl-2-H-l-benzopyran-4-yl) phenol, forms inclusion compounds with
sulfur dioxide and other flue gas components. The molecular structure of
these inclusion compounds or clathrates have been studied in detail by
infrclred spectroscopy (29, 30).
2.1.6
Hydrocarbons and Derivatives
Camphor forms 1:1 and 1:2 complexes with sulfur dioxide above -16°c.
Equilibrium pressures of the camphor-sulfur dioxide system were measured at
several temperatures ranging from -380 to +38°C (31). Cyclohexylhydroxyla-
mine reacts with sulfur dioxide at -lOoC to give cyclohexylsulfamic acid
(32) .
2.1.7 Telomeric Dyes and Dye Bases
Recent studies at TRW Systems have shown that nigrosin ($2.75/1b), an
aniline black derivative (21),
()~0)yND:~bN0~bN'O
. H
NH
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10669-6003-HO-00
Gnd copper phthalocyanine (221
OC/N"C 0
.1 I~
C - oN N = C
/ ., \
N . Cu ' N
~ '..' I
C-N N-C
~II I"~
o C'N'C ()
remove sulfur dioxide from moving gas streams at 460°F'.
No mention of
either of these dyes or indeed of any dyes was found in the literature with
regGrd to take up of sulfur dioxide. It appears that these dyes~ which are
highly thermally stable~ take up sulfur dioxide by charge-transfer or pos-
, "
I
sibly acid-base interactions.
2.1.8
Organo Metallics
Alkali metal salts of benzoic and fatty acids add gaseous sulfur di-
oxide at a slow rate in the ratio of approximately 1 mole of sulfur dioxide
to 1 mole of compound at temperatur~s above OOC (33). Tri-n-dodecyl alum-
inum reacts with 3 moles of sulfur dioxide per mole of compound yielding
aluminum trisulfonates which can later be hydrolyzed to sulfamic acids (34).
2.2
CRITERIA FOR SELECTION OF MOST PROMISING ORGANIC SOLIDS
At this point in the progrum, the basic criteria which may be
used for the selection of organic solids for Phase II evaluation for the
removal of sulfur dioxide from flue gas emission stacks, are the following:
.
Ability of sorbent to remove 802 from flue gas at operating
temperatures at. a high rate,
.
Thermal stability of sorbent,
.
Cost and availability of sorbent, and
.
Mechanical properties.
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lo669-6003-RO-OO
It is clear thut the prim~ry requirement of the organic solid for the re-
moval of sulfur dioxide from flue gases is Clbility to remove sulfur dioxide
selectively from moving gas mixtures ~t the flue gas operuting temperatures
and ut a relatively high rate (typical contact times are in the order of a
second). The sorbent must be thermally st~ble at the temper~ture of sul-
fur dioxide uptake (2150F minimum after the preheater region) for at least
several minutes. If the sorbent is to be regenerated thermally, it must
be stable at even higher temperatures (approxim3tely 6000F) for a period
of minutes. The organic solid must be capable of being regenerated or
converted to useful products. Regenerability modes could include heat,
inert gas, vacuum, solvent extraction, catalytic oxidation, or conversion
of the reaction product to a useful commodity chemical. The availability
of inexpensive organic solids in large quantities and without any laborious
modifications is of major importance. Finally, the mechanical properties
of organic solid.must be such that the solid is amenable to use in a sorp-
tion configuration. That is, the organic solid must be either reasonably
porous and finely divided itself or capable of being coated onto a high
surface are8 substrate such as fire brick or activated charcoal.
2.3
MOST PROMISING ORGANIC SOLIDS FOR REMOVAL O)F SULFUR DIOXIDE FROM
FLUE GASES
Seven specific organic solids were selected for Phase II experimental
evaluation on the basis of the criteria stated in Section 2.2. These or-
ganic solids are:
8 Newsprint (paper),
8 Sawdust,
8 Cotton,
8 Nigrosin,
8 Pyrolyzed poly(acryonitrile),
8 Pyrolyzed poly(vinylchloride), and
8 Poly(N-vinylcarbazole).
-13-
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lo669-6003-RO-OO
The properties of these organic solids as related to the criteria for sul-
fur dioxide removal are presented in Table II. The organic solids which
were selected are all known to take up sulfur dioxide, be thermally stable
at flue gas temperatures, to be low in cost, bave good mechanical proper-
ties and have potential for regenerability. Monomeric organic solids even
though known to take up sulfur dioxide were eliminated from this study
(e.g.,3nthracene, phenothiazine, etc.) because of their lack of mechanical
properties, that is, they cannot be coated on inert substrates nor can they
form mechanically sound sorbent particles. The ion exchange resins were
eliminated from this study as they are being evaluated on other NCAPC pro-
grams. Polyimides and 8-hydroxyquinoline-formaldehyde polymers were dis-
carded from further consideration because of their very high price.
-14-
-------
TABLE II
PROPERTIES OF MOST PROMISING ORGANIC SOLIDS FOR S02 REMOVAL
I
t-'
V1
,
I I
Thermal Stability ,
0 I
S02 Uptake Before Pre-heater 550-650 F (Reg. 2) I Cost and Mechanical
Organic Solid After Pre-heater 2l5-300oF (Reg. 1) Regenerability Availability Properties
L Newsprint Known to take Basic constituent (cellulose) Heat, wash or Waste mater- Can be used
(paper up S~ at R.T. stable region 1 chemical conver- ials cost of 8S ls,ground
and prellmin- sion possible t:'ansportatlon or shredded,
2. Sawdust ary results etc.
show take up
3. Cotton at 2l50F by
paper
4. Nigrosin Known to take Stable regions 1 and 2 Heat or wash $2. 75/lb. in Can be coated
up S~ at possible ton quantity
4600
5. Pyrolyzed Poly Known to take Stable regions 1 and 2 Heat or wash Poly(acryloni- Can be coated
(acrylonitrile) up S~ at possible trile) $0.68/
4600F lb in any
quantity
6. Pyrolyzed Poly Known to take Stable region 1 Heat or wash Poly(vlnyl- Can be coated
(vlaylchlorlde) up S~ at possible chloride),
4600F waste material,
, cost of
transportatIon
7. Poly(N-vinyl- Known to take Stable region 1 Heat or wash $5.00/lb in ton Can be coated
carbazole up S02 at I possible quantity
46o~ ~
t-'
o
0\
0\
\0
I
0\
o
o
W
I
=0
o
I
o
o
-------
10669-6003-RO-00
3.0
PRELIMINARY CHEMICAL SYSTEMS ANALYSIS
This section presents the results of a preliminary chemical systems
of processes using organic solids to control sulfur dioxide emissions from
flue gases. It was the objective of the analysis to develop preliminary
process designs capable of estimating the capital investment and operating
costs of systems employing organic solid sorbents and thereby demonstrate
the feasibility of these processes.
A large part of the S02 pollution problem, 46% of the total in 1966,
can be attributed to SO~ emission from electricity generating power stations.
c-
Of the emissions from power stutions in 1966, about 91% came from the com-
bustion of coal and about 9i from oil (35). In view of these factors,
the preliminary analysis was directed toward the development of a process
which could be incorporated into a coal burning power plant. A consider-
ation of the capital expenditure involved in a process capable of handling
the large inventory of organic solid sorbent reQuired to control the S02
emission from an "average" power plant led to the choice of GI fixed-bed
i I
mode of oper~tion. A mathematical model, applicable to polymeric organic
solid sorbents as well as monomeric sorbents, was formulated to simulate
a fixed-bed sorption column, Rnd the model was then translated into a
FORTRAN II computer .[...cogram.
In Section 2.3, candidate organic solids for removal of sulfur dioxide
from flue gases were assessed in terms of system criteria and as a result
seven organic solids were selected for Phase II evaluation. Of these, the
cellulosics appeared to most clearly satisfy the criteria. For example,
the 46.5 million tons of paper products produced in the U.S. in 1966 is in
line with the estimated 28 million tons of S02 per year (approximately 13
million tons of S02 per year can be attributed to power station stack
gases) emitted to the atmosphere in the U.S. (35). The price of waste
. paper, roughly 0.3 cents per pound, compares favorably with the price of
other sorbent materials(waste paper is approximately 1/30th the price of
activated charcoal). In addition, cellulose does not begin rapid thermal
decomposition below 500-6000F and, hence, could be used in the gas stack
region after the
sorb significant
literature.
air preheater.
Fin?lly, the ability of cellulose to
amounts of sulfur dioxide has been reported in t!~'"'
-16-
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10669-6003-1\0-00
A process, based on a regenerative fixed-bed 802 sorption system with
sulfur recovery capability, was specifically designed for a cellulose
(paper) sorbent. A computer program, written to evalu8te the capital and
opcr8ting costs of the proposed cellulose - 802 sorption process, was com-
bined vrith the fixed-bed computer program and then utilhed to determine
the cost sensitivities of the selected independent pur8meters.
The com-
puter program output, Hhich included operating owl capital costs', as well
88 process condition information (sorption batch time, amount of 802 sorbed
on paper, etc.), is presented in graphical form aud can be used to identiIY
operating regions which Hill result in the maximum profit.
The graphs are
also an aid in evaluating the effect of a process parameter on the process
operating cost.
The results of the preliminary analysis indicates that the proposed
cellulose - 80~ recovery process is economically feasible. In particular,
~
the computer simulation of tne proposed process, operating at the selected
base case conditions, calculated that a profit of' $941,000 would be netted
per year (42 cents/ton coal). The total capital requirement would be
$2,770,000.
A further consequence of the preliminary chemical system analysis was
the development of 1:1 computer capability, applicoble to a Hide range of
problems involving 802 removal and recovery, which can be adapted to any
solid sorbent material operated in batch manner. Only minor revisions in
tne proposed 802 recovery system would be required if organic solids
(e.g., nigrosin, pyrolyzed polyacrylonitrile, pyrolyzed polyvinylchloride)
were to replace paper as the 802 sorbent. Some indication of the effect of
sorbent .:~ost on the process operating profit for a 802 recovery system
equivalent to the proposed system but using a general sorbent material is'
included in this report.
The results of this study are described under the following five cate-
gories below:
. Process Description
. Process Model
8 Process Base Conditions
8 Results of Parametric Analysis
8 Conclusions
The computer program is presented in the Appendix (Section 4.0).
-17-
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10669-6003-RO-00
3.1
PROCESS DESCRIPI'ION
A process for removing and recovering S02 from flue gas streams has
been developed utilizing the S02 sorption capability of cellulose (paper).
Figure 5 is the flowsheet of the proposed process as it might be incorpora-
ted into a coal-burning power plant (or with minor changes to an oil-burn-
ing power plant). There are wide variations between power plants with re-
gard to boiler configuration, the arrangement of heat-recovery equipment,
and the temperatures at various positions in the plant, and therefore, the
optimum configuration could vary from the one selected here to illustrate
the gener8l characteristics of the proposed S02 recovery system in a power
plant. Although the following process description will apply directly to
the paper - SO,) recovery system of Figure 5, only slight modifications
"-
would be required if another organic solid sorbent is used. The major
equipment items in the recovery system are three carbon steel sorption
columns, a paper shredder, and an induced draft fan.
It is believed that
three columns may be necessary to assure adequate time to regenerate and
replace the paper between each sorption run.
Because of the large quantity
of sorbent material which must be handled to control the S02 emission from
a power plant, it was determined that the lowest capital expenditure would
result from a fixed-bed mode of operation.
If the amount of required
sorbent could be significantly reduced below current estimates, a system
using fluidi~ed beds or rotating disc contactors may prove economically
advantageous.
The location of the induced draft fan will be dependent on
operating conditions of a particular system and, for this reason, is shown
in two possible positions in Figure 5.
The operdtion of the S02 recovery system, as illustred in Figure 5,
cons ists' of three phases:
.
Sorption of S02 by the paper.
Regeneration of ~he paper and recovery of the 802'
.
.
Replacement of the spent paper.
The hiGh SO... .content flue gas, after passing through the power plant I s
l:
dust collector and spark eliminator, enters the fixed-bed sorption column,
pacl~ed with shredded paper.
The 802 in the flue gas is sorbed on the paper,
-18-
-------
S02 RECOVERY SECTION
S02 TO CATALYTIC OXIDIZER:
AND ABSORBER FOR I
SULFURIC ACID I
MANUFACTURE
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I-'
\0
I
FLUE GAS:
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I INDUCED
I DRAFT FAN
I PAPER
I
I
I
I
I
I
I
I
PAPER
SHREDDER
S02 LEAN FLUE GAS
STACK
Figure 5 .
PAPER MAKE-UP
PAPER
ADDITION REGENERATION SORPTION
STEAM
AIR
PREHEA TER
\ ~PARK
I iliMINATORS
I FLUE
I DUST GAS
I COLLECTOR
I
I
I
~""-.
, ~~
L:.~
OPTIONAL
INDUCED
DRAFT FAN
SPENT PAPER TO BURNERS
Coal Burning Power Plant with 502 Recovery Capability
nr1q
LJ II I I STEAM
AND
lJ II 19000F
LJ
FORCED
DRAFT
FAN
BURNER-
BOILER
AIR
SUPERHEA TERS
REHEA TERS
COAL
I-'
g
0\
\D
~
o
w
:k
o
I
8
-------
10669-6003-RO-00
und the flue geG, Qlter exiting from the column, is sent to the pmler
plant t s stack.
dust collector.
The paper also entrains any fly ash that passes through the
The column operates in this mode
until the 802 content of
specified pollution limits.
of S02' the flue gas
the flue gas exiting from this column exceeds the
\.lhen the paper no longer sorbs an adequate amount
streum is fed to one of the other columns.
After completion of the sorption mode, the paper in the column under-
goes regeneration by passing hot flue gas (600°F) through the column, CClUS-
ing the S02 on the paper to desorb. The hot fLue Gas is drawn from the
line separating the economizer (water preheater) :.Jnd the air preheater.
The 802 rich gas leaving the COl.umn during the regeneration mode is sent
to a catalytic oxidizer and converted to S03' The S03 then undergoes
further processing to sulfuric acid.
After regeneration of the paper is completed, some 01' the p2.per at
the bottom of the column is withdrdWTI ond sent to the burners as fuel.
Fresh puper makeup is conveyed from the shredder and e.dd.ed at the top of
the colu:nn.
The column is then ready to begin the sorption mode aguin.
Stability problems during upsets in the flue gas generating device
\'lere not apparent in the proposed process.
For example, a temperature
runaway in the power plant's boiler would be partially damped in the econo-
mi~er and air preheater.
The flue gas must also pass through spark elim-
inators which have the capability of spraying water into the gas stream.
Even if a fire did occur in a column, the flue gas stream could be diverted
to the stack and the fire quickly quenched by Q water spray system in the
column.
Another problem which could arise is a boiler tube rupture which
would send a large amount of steam and water into the system. The water
and steam should not cause any serious deterioration or' the paper. Along
a similor line, an oxygen deficiency in the boiler or a failure of the
dust collector, reSUJ. ting in large amounts of carbon entering the S02 re-
covery system, should not adversely affect the paper and, in fact, the paper
would entrain the solid pClrticles in the flue gas.
No major st8bility problems relating to the SO" recovery system it-
- c
sell' .rere uncovered. Paper tronsfer \'lithin the columns \olil.l tal<:e p:L8ce
,:,,20-
-------
lOGG)-000]-RO-OO
by internal vibration.
If complete blockage of the paper should occur,
manual replocement of the paper would be possible until the problem is recti-
fied.
A water spray system will be built into the system as a precaution
against fires, and even if a fire does occur in a column, it should not
cause extensive damage to the equipment.
Since the spent paper is used as fuel in the boiler, the sorbent does
not cause secondary pollution problems. The only secondary pollution should
be that encountered in a modern sulfuric acid plbnt provided the recovered
I
I
I.
I
802 is converted to sulfuric acid.
3.2
PROCESS MODEL
3.2.1
Derivation of 1~~hematical Model
A mathematical model containing technical and economic variables of
interest was formulated for the proposed 802 recover~y process. Since the
sorption columns are the major cost items in the process, the technical
portion of the model was developed to simulate the unsteady-state operation
of a packed bed.
The economic portion of the model, utilizing information
provided by the technical study, estimates the capital and operating costs
of the proposed S02 recovery process.
The technical section of the model has the capability of determining
the composition of the sorbable component in both the solid and fluid phases
as a function of time and position in the column.
The description of the
technical model deals specificQlly with an 802-paper sorption column, but
the approach is of a general form and would apply to the unsteady-state
operation of any fluid-solid fixed bed column.
Consider a. sorption column in which 802 is transferred from the gas
phase to the solid phase (in this case paper). with reference to Figure 6,
let
ft3
G = superficial flue gas flow rate, (hr - ftC empty column cross section)
concentration in feed flue gas (moles 802/ft3)
C
o
= SO
2
CG = 802 concentration in flue gas at position Z in the column and
at time t, (moles S02/ft3)
-21-
-------
-L
dZ
T
z
1
10669-6003-RO-OO
FLUE GAS TO STACK WITH
S02 MOLE FRACTION s Y FINAL
PROPERTIES OF PAPER PACKING
P, E, Q
i,'" r~~T~~E~~~\~~~A~ WITH 502
. AND SUPERFICIAL FLOW RATE G
Figure 6. Unsteady-8tate Operation of a Packed Bed
-22-
-------
1 0669 -6003 -RO -00
Cp = 802 concentration in the paper at position Z in the column and
at time t, (moles 802/lb paper).
Q = saturated 802 concentration of paper, (moles 802/lb paper.
Y a residual 802 mole ratio of the flue gas, CG/Co.
X = residual 802 mole ratio of paper, cplQ.
p = density of paper, (lbs paper/ft3 column).
€ = void fraction of column (ft3 act~al vOlume/ft3 empty column).
t = time, hr.
Z = column height, ft.
k a mass transfer coefficient,
g 2 3
moles/(hr)(ft transfer area) (moles/ft ).
a = area for mass transfer per unit volume, (ft2 transfer area/rt3
column).
Ci = 802 concentration at fluid-solid interface, (moles 802/ft3).
H = equilibrium constant, Ci = HCp.
It will be assumed that Co' Q, p, E, kg' a, and H are constant, that plug
flow exists within the column, and that axial diffusion of 802 is negligi-
ble. Composition gradients within the paper will be neglected, and mass
transferred by diffusion as the result of solid-solid contact will be ig-
nored.
A material balance on the 802 contained in an element of unit cross
section and of height dZ is
Ra te of input:
GCG = GCoY
aCG
G(CG + az
dZ)
= GCo(Y + ~~ dZ)
Rate of output:
Rate of accumulation: o~ [E CG + pCp] dZ = ~ [EC oY + oQ.XJ dZ
The 802 material balance is then
aY ~Y aX
- = E C ~t + pQ :::.t
dZ 0 u u
- GC
o
(1)
-23-
-------
10669-6003-RO-00
or
a!. E a!. + ~
aZ + G;t OC
o
a! =0
at
(2)
The term
- OC
o
~~ accounts for the concentration change of S02 caused by
flue gas flow
E C oY
o at
accounts for the S02 concentration change in the gas
hold-up in the voids
~
pQ at
accounts for the concentration change of the S02 sorbed
on the paper
Each term has units of moles/hr-ft2 empty column cross section.
Similarly, a material balance on the S02 in the solid phase is
Rate of input: kga (CO - Ci) dZ
Rate of output: 0
Rate of accumulation:
o~ (p Cp) dZ
the material balance is then
oC
\~a (CO -Ci) =p ~
(3)
This equation was derived assuming that the diffusion of S02 from the bulk
of the flue gas to the solid-gas interface is the rate controlling step
of the overall reaction of S02 and paper.
The assumption is also made that an equilibrium
tween the S02 at the solid-gas interface and the S02
this condition can be expressed by the relationship
condition exists be-
in the paper and that
C i = HCp
Substituting in (3)
oC
kga (CO - HCp) = p ~
(4)
Rearranging (4) in terms of X and Y
oX k a C Y k a H
at = g 0 - ~
pQ p
X
(5)
-24-
-------
10669-6003-RO-OO
Several boundary and initial conditions were added to complete the
technical model. If the composition of the entering flue gas is maintained
constant
Y = 1 for Z = 0, t ~ 0
Also, no change in S02 concentration will occur at any point in the packed
bed until the entering flue gas has had time to flow down to that point.
This condition can be expressed as
x = 0 for Z > 0,
t> S Z
-L
t > ~ Z
-L
Y = 0 for Z > 0,
where the paper initially has been assumed to have essentially zero S02
concentration. B,y specifying the height of the column (Zfinal) and the
maximum allowable S02 mole fraction in the exit flue gas (Yfinal)' the
final boundary becomes
Y ~ Yfinal at Z = Zfinal' E > 0
Equations (2) and (5) along with the above conditions completely de-
fine the transient behavior of the fixed-bed sorption column. Solution of
this protion of the mathematical model will yield concentration of S02 in
either the gas or solid phase for any Z or t.
The economic portion of the model estimates the capital and operating
costs of the proposed process. The cost-capacity values used to determine
the total plant capital cost were obtained by curve fitting data provided in
"Cost Engineering in the Process Industries," C. H. Chilton, 1960. All
costs were updated to 1968 using the ENR Index and multiplied by their ap-
propriate installation cost factors. For example the equation for deter-
mining the sorption column cost is.:
COLCST = (2.515 x 10-6D4_8.99 x 10-4D3 + 0.1182D2 - 1.079D + 82.09)
Zfinal x 2.93 x 2
/
where
COLCST = installed cost of a single tower
D = tower diameter in inches
Z~i 1 = tower height in feet
I na
-25-.
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10669 -6003 -RO-OO
2.93 = updating factor
2.0 = installation factor
The operating costs are calculated assuming that the S02 recovery system
requires two operators per shift and three shifts per day.
3.2.2 Method of Computer Solution
The mathematical model was translated into a FORTRAN II computer pro-
gram which was then utilized to determine cost and operational sensitivities
of various independent parameters. A description of the method used to ob'-
tain a solution to the technical portion of the model, comprised of
E~uation (3) and (5) along with the corresponding initial and boundary con-
ditions is given below.
Equation (3) can be simplified by the change of variables:
S = (€/L)Z
oS - ~
oZ - G
e=t-(.f z)
G
iJe
- - =1
ot
08 - €
oZ - - G
then
QI - Q! ~
oZ - oS oZ
oY (J e
+ - -
00 oZ
- Q! ~ -
- oS G
oY S.
08 G
and
oY = Q! ~ + Q! oS
ot 08 at at ot
- ~
- 08
Similarly,
oX
ot
oX
= -
08
Substituting the above into Equation (3) and (5) yields
€ oY €
G oS - G
"Y €
Iol.:.. + -
08 G
2!. + ~
08 GC
o
oX = 0
08
-26-
-------
,c,.:;..;-'
which simplifies to
oY pQ
-+-
08 €C
o
~ =0
06
and
k aC k aH
Q! -.L..£ Y -~ X
o 6 - pQ p
The boundary conditions become
Y = 1 at 8 = 0
Y = 0 at () = 0
() ~ 0
8>0
Y So Yfinal
X = 0
at 8 = Stinal
at 6 = 0
6 > 0
8>0
l. 0669 -6003 -RO-OO
(6)
(7)
Equations (6) and (7) were solved on a 8DA 940 computer using a finite
difference approach known as the "modified Euler's method" or "Henn's first
method" (36). The program pertaining to the technical model was written
so that the following parameters could be varied:
flue gas flow rate at standard conditions (1 atm, 6o°F)
mole fraction of 802 in feed flue gas
maximum allowable residual 802 mole ratio
saturated S02 concentration on paper, Q
weight of paper per unit column volume, p
void fraction of the column, €
mass transfer coefficient, k a
g
equilibrium constant, H
.
, cross -sectional area of the column
height of column
.
.
average column pressure
average column temperature
.
.
.
.
.
.
.
.
.
in exit 'flue gas, Y
finill
The technical. program outputs the batch time and the total moles of
S02 which are sorbed on the paper during one batch. The time at which the
mole fraction of 802 in the exit flue gas exceeds the specified maximum
allowable S02 mole fraction determines the batch time. Since the moles of
802 sorbed on the paper at each sub-interval of height is know, the total
moles of 802 are calculated by using Simpson's rule to integrate over the
height of the column.
,4
-27-
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10669-6003-RO-00
The computer program for the economic model allowed the following
parameters to be varied:
.
paper cost
S02 credit value
heat credits
.
.
The output form the economic portion of the model includes:
3.3
.
total plant capital cost
hourly operating cost
hourly S02 credit
hourly paper credit
.
.
.
.
yearly paper usage
yearly amounts of S02 recovered
total plant yearly cost
.
.
PROCESS BASE CASE CONDITIONS
A study of the proposed S02 recovery system was conducted specifically
for the case in which cellulose (paper) is the organic solid employed. Each
of the technical and economic variables of the computer program was assigned
a value, either from known experimental data or from best estimates of
parameter, for the base case of operation. References relating to the base
conditions are given when possible.
The selected base conditions are:
1.
Column diameter = 30 feet
Column height, Zfinal = 60 feet
Average pressure in column, P = 14.9 psi
Average temperature in column, T = 3000F
Flue gas flow rate at standard conditions
87.3 million cubic feet per houri
MOle fraction of S02 in feed flue gas. 0.003 (4)
Maximum allowable residual S~ mole ratio in exit flue gas, YfinalD
0.1 mols S02 leaving column per mole S02 in feed (3)
Saturated S0:2 concentration on paper, Q a 0.1 lb S02/lb paper (5)
2.
3.
4.
5.
(1 atm, 60oF) =
6.
7.
8.
1
The flue gas flow rate corresponds to an 800-megawatt power plant burning
280 tons coal/hour (37).
-28-
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10669-6003-R~
9.
Weight of paper per unit column volume, p = 7 lbs paper/ft3
columnl
Void fraction of column, E = 0.1 actual volume/column volumel
10.
11.
Mass transfer coefficient, k a = 20,000 mOles/(hr)(ft3
(moles/ft3) g 1 SO /ft3
mo es 2 gas
Equilibrium constant, H = 0.001 moles S02/1b paper
Cost of paper = 0.3 cents/lb (Reference 5)
2
Credit for S02 recovered = 0.5 cents/lb S02
Heat credit = 50 cents/MM Btu (37, 38).
column)
12.
13.
14.
15.
Two percent of the paper in the column is replaced after each sorption
run. The percentage is low, because as paper replacement increases, it be-
comes exceedingly more difficult to provide an adequate amount of paper to
supply the power plant. The heat of combustion attributed to the spent
paper is 7560 Btu/lb paper.
The power plant is assumed to burn 280 tons of 4% sulfur coal per hour
and to operate at 90% efficiency (330 days/yr). Essentially all of the S02
sorbed is removed from the paper during the regeneration step.
The heat required to desorb the S02 from the paper was assumed to be
of the same order of magnitude as the S02 heat of solution in water, and by
using this value and a heat cost of 50 cents/MM Btu, the cost of regenera-
ting the paper was estimated at approximately 0.01 cents/lb S02. Since the
cost of regenerating the paper would have little effect on the S02 credit
value (0.5 cents/lb S02 in the base case), it was assumed negligible.
The S02 credit value represents the net worth of the S02 as a raw
material feed gas. It does not include the cost of converting the S02 to
a marketable product (i.e., sulfuric acid).
lThe density of paper was considered a constant at 70 lbS/ft3 (39).
2The S02 credit was evaluated based on a ioo~ sulfuric acid selling price
of $20/ton (1.5 cents/lb S02). It is equated to the market value of 1.5
cents/lb S02 less the cost of upgrading the S02 to sulfuric acid.
-29-
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10669 -6003 -RO -00
PROCESS COSTS FOR BASE CONDITIONS
The computer simulation of the cellulose-S02 recovery system operating
at the base conditions described previously produced the following results:
.
Batch time
Paper usage
= 0.51 hours
= 46,200 tons/year
= 162,600 tons/year
= $2,770,000
= $1l9/hour
$0.42/ton coal
$941,000/year
.
.
S02 recovered
Total capital cost
Operating Profit
.
.
3.4 RESULTS OF PARAMEl'RIC ANALYSIS
Figures 5 through 29 show the results of the parametric analysis of
the paper-S02 recovery system conducted by perturbing a selected parameter
while maintaining all other variables in the base case conditions. In
Figures 7 through 21., the following variables
Weight of paper per unit column volume (p) - void fraction (€)l
Mole fraction of S02 in feed flue gas
Saturated 802 concentration on paper, Q
were plotted as functions of sorption batch time and as functions of opera-
ting profits. The operating profit in terms of MM $/yr is calculated as-
suming that the power plant operates at 90iefficiency (330 days/yr) and
the operating profit in $/ton coal assumes that the power plunt burns 280
tons coal/hr. The curves are constructed for S02 credit values of 1.0 cents/
lb and 0.5 cents/lb.
.
Mass transfer coefficient - k a
g
.
Equilibrium constant - H
Column diameter
Column height
.
.
.
.
.
lIf the density of paper (DEN) is constant, the weight
column volume (p) and the column void fraction (€) are
e>q>ression:
of paper per unit
related by the
DEN = p / (1 - € )
-30-
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10669-6oo3-RO-OO
Figures 22 and 23 show the effects of column diameter and height on
the overall capital costs of the 502 recovery system. Figure 24 illus-
trates the effect of the paper cost on the operating profit of the system.
Figures 25 and 26 are graphs of the system's operating profit vs the per-
centage of paper makeup per sorption cycle, plotted for two 502 credit
values and two heat credit values. Figure 21 is a plot of the operating
profit vs the 502 credit value and Figure 28 shows the operating profit as
a function of the heat credit value.
Figure 29 is a plot showing the effects of a general sorbent cost in
$/hr on the operating profits of the system. Since the heat credit was as-
sumed zero in the construction of this plot the curves apply to a sorbent
which is discarded after releasing the sorbed S02'
;'ilien applicable, the value of the base case is indicated on the figure.
A description of each of the graphs vollows.
Figure]
This plot shows the S02 sorption batch time in hours vs the mass trans-
fer coefficient, k a, 'in units of moles/(hr)(ft3 column) (moles/ft3). The
g
range extends from 10,000 to 10,000. All other variables were at their
k a
g
respective base case conditions.
Figure 8
The effects of a variance in k a on the o~rating profit of the recov-
g
ery system is shown in this figure. The range of k a is 10,000 to 70,000
moles/(hr)(ft3 column) (moles/ft3) and the base cas~ k a is 20,000. Curves
g
are plotted for S02 credit values of 0.5 cents/lb and 1.0 cents/lb.
Figure 9
In this figure, the S02 sorption batch time is plotted against the
solid-gas interfacial equilibrium constant (H). The equilibrium constant
is defined by the expression
Ci = HC
. p
where Ci is the S02 concentration at the fluid-solid interface which is in
equilibrium with Cp' the moles of S02 per lb of paper. The units for this
constant are (moles's02/ft3 gas)/(moles S02/1b paper).
-31-
-------
10669-6003-RO-00
The batch time was evaluated for H values ranging from 10-2 to 10-5
and, as shown, the batch time increases as the value of H decreases in mag-
nitude.
All other variables were at base case conditions.
Figure 10
This figure is a plot of the equilibrium constant, H, vs oper~ting
profit in terms of r~ $/yr and $/ton coal. The base case condition in 0.001
(moles 802/ft3 gas)/(moles 802/1b paper).
Figure 11,
The effect of sorption column diameter on the 802 sorption batch time
is illustrated in Figure 11. As expected, the batch time increases as the
column diameter becomes larger. The base case diameter is 30 ft.
I :
Figure 12
Figure 12 shows the effect of column diameter on the overall operating
profit of the 802 recovery system. Curves are plotted for 802 credit value
of 1.0 cents/lb and 0.5 cents/lb. All other values are at the base case
operating conditions.
I '
For the proposed 802 recovery system, the batch time decreases as the
column height becomes smaller (Figure 11) but the amount of paper required
by the sorption process becomes larger. Because the fuel credit value ex-
ceeds the initial cost, rising operating profits are realized as the amount
of paper burned for fuel increases. Therefore, a trade-off results for,
although the shorter column returns a larger margin of profit, problems re-
lated to obtaining a sufficient supply of paper and to regenerating the
paper in the given time period will likely arise.
Figure 13
[
[
I:
Figure 13 shows the effect of column height on the sorption batch time
for columns having diameters of 30 feet and 40 feet. Besides indicating
that batch time increases proportionately with column height, the plot also
shows that the rate of increase in batch time (represented by the slope of
the curves) is greater for the column 40 feet in diameter.
-32-
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10669-6003-RO-00
Figure 14
The effect of column height on the operating profit for a column 30
feet in diameter is shown in this figure. As shown, the operating profit
decreases as the column height increases. With the substitution of column
height for column diameter, the discussion presented for Figure 8 would
also apply here.
Figure 15
This plot is similar to Figure 14 except that the curves correspond
to a column 40 feet in diameter.
Figure 16
The effect of the weight of paper per cubic foot of column and void
fraction (ft3 actual vOlume/ft3 empty column) on the sorption batch time is
illustrated in Figure 16. The density of the paper (lbs paper/ft3 paper)"
is assumed constant and thus the weight of paper per cubic foot "of column
and the fraction (values in parentheses) are related by
DEN = p / (1 - € )
when
As expected,
increases.
DEN = lb./paper/rt3 paper
n = lb paper/ft3 column
€ = ft3 actual volume/rt3 empty column
the batch time increases as the amount of paper
in the column
Figure 11
Operating profit vs the weight of paper per cubic foot of column and
void fraction are plotted in Figure 11. The numbers in parentheses along
the abscissa of Figure 11 represent values for the void fraction. Accord-
ing to the plot, the weight of paper per unit column volume (and the void
fraction) does not significantly affect the operating profit over the range
analyzed.
Figure 18
Figure 18 shows the effect of the mole fraction of 802 in the flue
gas being fed to the sorption column on the sorption batch time. As can be
-33-
-------
10669-6003-RO-00
seen from the curve, the mole fraction of 802 in the feed flue gas has a
significant effect on the batch time.
Figure 19
This is a plot of the mole fraction of 802 in feed flue gas vs the
operating profit. The operating profits do increase as the 802 feed mole
fraction'becomes larger because the revenue from 802 recovery also increases.
Although the operating profits improve with a high 802 mole fraction in the
feed flue gas, batch time favors a low value for this parameter.
Figure 20
In Figure 20, the 802 sorption batch time is shown to increase as the
802 concentration of the paper (lbs 802/lb paper) at saturation conditions
also increase.
Figure 21
Figure 21 illustrates curves relating the saturated 802 concentration
of the paper to the operating profit of the proposed system. Again, the
operating profits are highly dependent on the 802 credit value.
Figure 22
Figure 22 indicates the effect of an increase column diameter on the
capital investment of the proposed 802 recovery process. All parameters,
except column diameter, were at their respective base conditions.
Figure 23
The effect of column height on overall capital investment is shown in
this figure. Two curves corresponding to the column diameters of 30 feet
and 40 feet are plotted.
Figure 24
Figure 24 shows the inversely proportional relationship between the
operating profit of the proposed 802 recovery process and the cost of
paper. According to the plot, a process operating at the base case condi-
tions will show a profit if the paper cost is less than 1.3 cents/lb.
-34-
-------
10669-6003-RO-00
Figure 25
This figure is a plot of the operating profit vs the percentage of
paper replacement per sorption cycle. In the base case, 2% of 'the paper is
replaced prior to 802 sorption. As the percentage of paper replacement in-
creases, the practical problem of obtaining and handling sufficient amounts
of paper becomes magnified. The slopes of the curves are positive because
the base case operating conditions result in a paper fuel credit that ex-
ceeds the paper cost.
Figure 26
I
[
I'
II
I'
I
I'
!
I;
Figure 26 is similar to Figure 25 except that the heat credit hus been
altered from the base case condition of 50 cents/l~ Btu to 25 cents/MM Btu.
In this case, the fuel credit of the paper no longer exceeds the initial
cost of the paper, and therefore the slopes of the curves are negative. If
all other parameters except the heat credit are at their base case values,
the proposed process will show a profit if the paper replacement per sorp-
tion cycle is less than 16%. The curves in both Figures 21 and 22 were
calculated using 7560 Btu/lb paper as the heut of combustion of paper.
Figure 2_7
Figure 27 illustrates the effect of the 802 credit value on the opera-
ting profit of the 802 recovery system. The 802 credit value represents
the net worth of 802 as a raw material fuel gas but does not include the
cost of converting it to a salable product (i.e., sulfuric acid). A pro-
cess operating at the base-case conditions will operate at a profit if the
802 credit value is greater than 0.2 cents per pound. If looi sulfuric
acid can be marketed at $20/ton (1 cent/lb of sulfuric acid or 1.5 cents/
lb of 802)' a profit can be realized if the cost of, upgrading the 802 to
sulfuric acid is less than 1.3 cents/lb of 802 (assuming all of the 802
sorbed on the paper is converted to sulfuric acid.
Figure 28
This figure is a plot of the heat credit value (cents/MM Btu) vs the
operating profit. These curves are for the base case condition in which 2%
of the paper in the column is used as fuel during each sorption cycle. The
slope of the curve would increase if the percentage of paper replacement
-35-
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10669-6003-RO-00
per sorption cycle was increased. The values of the operating profit were
calculated assuming that the heat of combustion of paper is 7560 Btu/lb.
Figure 29
The curves in Figure 29 apply to a 802 recovery system employing a
general sorbent material but otherwise similar to the proposed system.
In
this graph, the operating profit is plotted as a function of sorbent cost
($/hr). Zero heat credit was given to the sorbent in determining the curves
and, therefore, the sorbent cost applies directly to a material which is
discarded upon replacement. If the spent sorbent does have some economic
worth, the value on the abscissa corresponds to the difference between the
initial cost of the sorbent and any credit which can be assigned to the
spent sorbent.
3.5 CONCLUSIONS
The results of the preliminary chemical systems annlysis demonstrate
that the proposed cellulose - 802 recovery process is. economically feasi-
ble. Specifically the analysis computed that the process, operating at
the selected base case conditions, will show a profit of $941,000 per year
(42 cents/ton coal). This is a preliminary analysis of the proposed sys-
tem and a more thorough determination of the values of the process para-
meters (probably by laboratory experimentation) is needed to substantiate
these results.
-36-
-------
1-
a::
:I:
I
W
~
I-
:I:
U
I-
<
cD
z
o
I-
Q..
a::
o
V\
d" 0.4
V\
0.7
10669-6003-RO-00
0.6
0.5
0.3
10
w ~ ~ ~ ~
k a x (103) - MOLS/(HR) (FT3 COLUMN) (MOLES/FT3)
9
70
Figure 7.
.... 1.00
«
o
u
Z 0.90
o
$
I 0.80
t:
...
o
g; 0.70
C>
Z
~ 0.60
'"
w
o 0.50
Figure 8.
Effect of the Mass Transfer Coefficient
on the S02 Sorption Batch Time
1.20
-
- S02 CREDIT VALUE = 1.0 /LB -::
- -
- -
- -
-
-
S02 CREDIT VALUE = 0.5 /LB -
-
I I I I I
2.6
2.4
2.2
0
."
m
2.0 '"
>
::!
Z
1.8 C)
."
'"
o
1.6 ."
::;
I
~
1.4 ~
....
-......
-<
1.2 '"
1.0
0.8 ":
1. 10
0.40
0.30
10
20 30 40 50 60
k 0(101) - MOLES/ (HR) (fT3 COLUMN) (MOLES/fT3)
9
70
Effect of the Mass Transfer Coefficient
on the Operating Profit of the S02 Recovery
System
-37-
-------
10669-6oo3-RO-OO
0.6
0.1
O.S
""
:I:
, 0.4
~
o
~ 0.3
Z
o
;::
...
~
st 0.2
o
10-S
10-4 10-3
H - iMOlS S0i"TJ GAS)/(MOlES SO/lB PAPER)
10-2
Figure 9.
Effect of the Gas-Solid S02 Equilibrium
Constant on the S02 Sorption Batch Time
2.B
1.20
2.6
1.10
S02 CREDIT VALUE = 1.0./lB
2.4
~
8 1.00
Z
o
$ 0.90
o
2.2 ~
~
2.0 Z
C\
...
1.8 Q
::;
o
!::
o O.BO
~
C)
~ 0.70
3
~ 0.60
1.6 !
1.4 .~
1.2
O.SO
S02 CREDIT VALUE = O.S./lB
1.0
0.40
10-S
104 1~3
H - (MOLES S0i"TJ GAS) / (MOlES SO/lB PAPER)
O.B
10-2
Figure 10. Effect of the Gas-Solid S02 Equilibrium Constant on
the Operating Profit of the S02 Recovery System
-38-
-------
1.6
Co:: 1.4
J:
I
W
~ 1.2
I-
J:
U
I- 1.0
~
z
Q 0.8
I-
0...
Co::
0 0.6
V)
N
0
V) 0.4
...J
..c.
o 1.00
u
z
o
" 0.90
...
,
~ 0.80
o
""
...
~ 0.70
S
~ 0.60
o
10669-6003-RO-00
1.8
0.2
o
20
30 40
SORPTION COLUMN DIAMETER-FT
50
Figure 11. Effect of Sorption Column Diameter on
the S02 Sorption Batch Time
1.30
2.8
1.20
2.6
S02 CREDIT VALUE = 1.0. /L8
1. 10
2.4
2.2
o
...,
2.0 ~
....
Z
1.8 CI
...,
'"
o
1.6 ~
I
1.4 !
~
'"
1.2
502 CREDIT VALUE = 0.5. /1..8
1.0
0.40
0.8
0.30
20
0.6
50
30 40
SORPTION COLUMN DIAMETER - FT
Figure 12. Effect of the Sorption Column Diameter on the
Operating Prorit of the S02 Recovery System
. -39-
-------
10669-6003-RO-00
1.6
1.4
..
X
1.2
t
~ 1.0
i 0.8
Z
o
t= 0.6
'"
~
~N 0.4
0.2
o
40
60
HEIGHT OF SORPTION COLUMN - FT
80
Figure l~. Effect of Sorption Column Height on the SO~ Sorption Batch Time
S~fON cO&.......". DlAMfnt. JO n ,..
1.20
,..
1,10
U
.
0 1.00 U 0
u ;a
~ E
S 0.90 . 2.0 i
~ 0." I.' ;I
~
r ~
~ 0.70 - I.' !
~ 0.'0 ...
o
0,50 U
1.0
0."
0.30 ..
.. ..
HUGHY Of SOI"ION COlUMN. n
Figure 14.
Effect of the Sorption Column Height on the
0P,er~ting Profit of the S02 Recovery System
(30 -I t. col.)
1.20
,..
1,10
'.'
100
~ 0.90 .
u
Z
S 0.10
~02 elmn VAlIA. I.O'l'U
a ..20
r
~ 0." .
~ 0."
o
'0 ~
. 1.1 i
C\
. I., ~
"
- ::: !
....
I..
0.'
..20
..
..
HUGHT Of SOI"ION COlUMN - n
..
Figure 15.
Effect of the Sorption Column Height
Operating Profit of the S02 Recovery
(Ito-ft. col.)
-40-
on the
System
-------
10669-6003-RO-00
1.6
1.4
0<
:I:
..:. 1.2
~
;:
is
....
<{
<0
Z 1.0
o
;:
...
0<
o
VI
ON 0.8
VI
0.6
0.4
7, (0.9) 14, (0.8)
WEIGHT OF PAPER PER CUBIC FOOT OF COLUMN
VOID FRACTION (FT3 ACTUAL VOLUME/FT3 EMPTY COLUMN)
21, (0.7)
Figure 16.
Effect of the Weight of Paper per Cubic Foot
of Column and the Column Void Fraction on the
S02 Sorption Batch ~ime
1.20
I- S02 CREDIT VALUE = 1.04/lB -
.... -
.... -
-
....
-
....
-
I-
-
I-
S02 CREDIT VALUE = 0.5 4/LB -
I- I
2.6
1.10
2.4
-'
~ 1.00
u
Z
o
, 0.90
...
I
~ 0.80
o
~
~ 0.70
Z
;::
~
~ 0.60
o
2.2 0
...
2.0 ~
.....
Z
G'I
1.8 ...
'"
o
."
1.6 ::;
I
1.4 !
~
'"
1.2
0.50
1.0
0.40
7, (0.9)
14, (0.8)
WEIGHT OF PAPER PER CUBIC FOOT OF COLUMN
VOID FRACTION (Fr3 ACTUAL VOLUME/FT3 EMPTY COLUMN)
0.8
21, (0.7)
Figure 1'7.
Effect of the Weight of Paper per Cubic Foot
of Column and the Column Void Fraction on the
Operating Profit of the S02 Recovery System
-41-
-------
..
:I:
I
...
~
;::
:I: 0.6
u
....
~
z
Q
t: 0.4
..
o
'"
N
o
'"
Figure 19;.
"
.
10669-6003-RO-00
1.0
0.8
0.03
0.2
o
o
0.01 0.02
MOLE FRACTION OF S02 IN FEED FLUE GAS
Figure 18.
Effect of the S02 Mole Fraction in the Feed
Flue Gas on the 502 Sorption Batch Time
7.0
15
6.0
13
12
5.0 II
;;J, 0
o 10 ...
u ~
Z 4.0 9
o z
$ Q
, 8 ...
.,
0- Q
~ 3.0 7 ::;
... '
C> 6 ~
Z
;:: 5 3
~ 2.0
0 4
1.0
o
-1
0.015
0.001
0.005 0.01
MOLE FRACTION S02 IN FEED FLUE GAS
Effect of the S02 Mole Fraction in the Feed Flue Gas
on the Operating Profit of the S02 Recovery System
-42-
-------
10669 -6003 -RO -00
0.9
(5
I-
~
z
Q
I-
~
~
o
VI
NO.6
o
VI
0.7
0.8
~
::I:
I
au
~
I-
0.2 0.3
SATURATED S02 CONCENTRATION OF PAPER
(MOLES SO/LB PAPER SATURATFD) .
0.4
Figure ;~O.
Effect of the S02 Concentration of the Paper at
Saturation on the S02 Sorption Batch Time
1.2
- 2.6
502 CREDIT VALUE = I. 04/lB
1. If-
- 2.4
~ 1.01-
U
. z.
e 0.91-
....
I
~ 0.8 I-
o
'"
a-
C> 0.71-
Z
>=
~ 0.61-
a-
o
- 2.2
°
."
- 2.0 ~
....
z
- 1.8 G)
."
'"
°
- 1.6 ;;;
I
~
- 1.4 ~
~
- 1.2 '"
0.5 I-
0.41-
0.1
- 1.0
502 CREDIT VALUE = 0.54/lB
I I 0.8
0.2 0.3 0.4
SATURATED 502 CONCENTRATION OF PAPER
. (MOLES 5°08 PAPER SATURATED)
Figure 21.
Effect of the S02 Concentration of the Paper at Saturation On
the Operating Profit of the S02 Recovery System
-43-
-------
!-
....
~
~
I
~
z
w
~
~
~ 3.0
>
Z
...J
<
t:
a.
<
U
10669-6003-RO-00
4.0
2.0
20
Figure 22.
30 40
COLUMN DIAMETER - FT
Effect of Column Diameter on the Capital
Investment for the S02 Recovery System
50
1
4.5
4.0
,
.... 3.5
Z
~
....
'"
>
~
~ 3.0
~
2.5
60
HEIGHT OF COLUMN - FT
80
Figure 23.
Effect of ColUmn Height on the Capital
Investment for the S02 Recovery System
-44-
-------
10669-6003-RO-00
I.'"
J.'
...
...
'.'
. ',J
0.91'
...
~ ....
00.'"
S
~ a,UtI
p ou,
i .
iio.300
a.ln
I.'
"
I.' ,
I,. i
a
uil
Q
1.0 ~
... I
0.. ~
. 0,4
.....
...
.o.~
-D.IH
..
'.'
'.'
...
I,D 1,1
'..,u con ItA.1
..
J.'
Figure 24.
Effect of the Cost of Paper on the Operating
Profit of the S02 Recovery System
. 0
u
..t""l Clt011 Of ,"'". ~/MM 'T\)
,.c
'.0
;(
o
v
Z
o
"
"7 '.~
~
"
~ 1,0
:
o
'.0 S
E
z
C\
~ 3:0 ~
!
'.0 3
1.0
o.
o
10
'"
30
.. 50 00
'BaNT "'I'B IEPlACEMENT '0 IATOt
10
II)
90
o
100
Figure 25.
Effect of the Paper Replacement per Batch on the
Operating Profit of the S02 Recovery System
'.0
HEAT om" 01 ,...m. 13. IMM 8TU
1.5 -
g -o.s
"
! -1,0
~
~ .\,5
'.0
.
o
~ 0.5
o
So.
~
~
o ~
C\
J
~
. ."o!
3
.'.0
-1,0
-7.5.
10
'"
30
~.
'0 ..0 0'10
'£lC£Nf '","[I 1£p\A.C(M(Nf PO: aAlCH
10
-. I
..
90
'6,0
100
Figure 26.
Effect of the Paper Replacement per Batch on the
Operating Profit of the S02 Recovery System
(Heat Credit Altered)
-45-
I,
-------
10669-6003-RO-00
3.4
1.50
. 3.2
1.40
3.0
1.30
2.8
~ 1.20
u 100
~ .
~
':' 0.80
I::
~ 0.60
If
CJ
j!; 0.40
i
~ 0.20
2.4
o
...
2.0 ~
....
Z
1.6 ~
Q
1.2 ::;
,
0.8 !
~
0.4
o
o
-4
-8
-so
o
0.5
1.0
1.5
502 CREDIT VALUE (4/lB)
Figure 27.
Effect of the S02 Credit Value on the
Operating Profit of the S02 Recovery System
1.175
~ 1.025
o
u 0950
z .
o
5 0.875
I
~ 0.800
o
:: 0.725
C)
~ 0.650
~
~ 0.575
o
1.100
0.500
0.425
0.350
0.275
o
25 50
HEAT CREDIT VALUE- 4/MM BTU
Figure 28.
Effect of the Heat Credit Value on the
Operating Profit of the S02 Recovery System
-46-
2.8
2.6
2.4
2.2 0
"V
2.0 ~
.....
z
C')
1.8 "V
""
o
...
1.6 ::;
I
ui
~
""
1.2
0.8
0.6
75
-------
t
+-
-..J
I
-------
10669-6003-RO-00
4.0 APPENDIX - COMPurER PROGRJ'.M LISTIK:
DIMENSI0N X(20112)IY(20112)IFX(201)
10 ACCEPT 151 AREAIZFINALIPITEMPIFSCIS02PCIYFINALIOSATIOFNIEIXKGAIH
15 F0kMAT (4EI2.6)
C0 = S02PC * P/(10.73 * (TEMP + 460.»
Q = QSAT/64.
G = FSC * 14.7 * (TEMP + 460.)/(P * 520. * AREA)
SFINAL = r*ZFINAL/G
TYPE 201 SFI:'-JAL
20 F0RMAT(/EI2.61//I!.INPUT - ISIIFLAG~I/)
ACCEPT 251 ISIIFLAG
25 F0RMAT (214)
AH = SFINAL/IS
AK = 1./60.
C0NY = (C0 * XKGA)/(DEN * Q)
C0NX = (XKGA * H)/DEN
C0NST = (XKGA * H * Q)/(E * C~)
TYPE 301 AKIAHIC0NYIC0NXIC0NST
30 F0~MAT(//5(EI0.412X)//)
IT = 1
IS=IS+1
THETA = O.
00 100 N=111S
100 X(NI1) = O.
Y<1~» = 1.
De 150 N=211S
150 Y(Nll) = (I.
200 S=O.
Ijj=1
Y(112) = 1.
Xl = X(111)
UX1 = CANY * '1'(111) - C0NX * X(111)
DX=DXI
202 X(112) = X(111) + DX . AK
IF«X(112)-X1) - 1.E-2)20412041203
203 DX2 = C0NY * Y(1,2) - C0NX * X(112)
OX = 0.5 * (OXI + DX2)
Xl = X<1,2)
G0 T0 202
204IF(X(112)-1.)2101205,205
205 X(112)=I.
Y(112)=I.
210 IF(IFLAG)2251225,215
215 IF(IT-30)225,220,220
220 TYPE 275, Y(1,2»)X(112)IS
225 D0 280 M=2IIS
Xl = X (fYII 1 )
Y 1 = 'I' (i"i- 112 )
DXl = C0NY * Y(MI1) - C0NX * X(M,l)
DYI = -(XKGA/E * Y(M-112) - CONST * X(M-112»
-14-8-
I,
-------
i
, ,
DX=DX1
DY=DY1
230 XCM,2) = XCM,l) + DX * AK
YCM,2) = 'yCM-1,2) + DY * AH
IFCCXCM,2) - Xl) - 1.E-2)235,235,240
235 IFCCYCM,2) - Y1) ~ 1.[-2)245,245,240
?40 DX2 = C0NY * YCM,2) - C0NX * XCM,2)
DY2 = -CXKGA/E * Y(M,2) - C0NST * X(M,2»
DX = 0.5 * (DX1 + DX2)
DY ~ 0.5 * (DY1 + DY2)
Xl = X(M,2)
Y1 = Y(M,2)
G0 T0 230
245 IFCXCM,2) - 1.)255,250,250
?~O XCM,2) = 1.
YCM,2) = YCM-l,2)
255 S=S+AH
IIJ=ID+1
IF(IFLAG)280,280,260
260 IF(IT-30)280,265,265
265 IF(ID-10)2~0,280,270
270 Z = S * G/E
TYPE 275, YCM,2),X(M,2),Z
275 F0RMAT C/3(lPE12.6,3X»
IIJ=l
280 C0i\1TINUE
THETA = THETA + AK
IF(IT-30)320,300,300
300 T = THETA + E/G * ZFINAL
TYPE 310, Y(IS,2),X(IS,2),T
310 FeRMAT (/1PE12.6,3X,lPE12.6,18X,l~E12.611)
IT = 0
320 IF(Y(IS,2) - YFINAL)330,400,400
330 D0 340 J=l,IS
X(J,l) = X(J,2)
340 Y(J,l) =Y(J,2)
IT = IT+l
G0 T0 200
400 T = (TH~TA - AK) + E/G * ZFINAL
IF(IFLAG)430,430,410
410 ZH=O.
SH=O.
D0 420 IA=I,IS,10
TYPE 275, 'y(IA,l),X(IA,l),ZH
SH = SH + (AH * 10.)
420 ZH = SH * G/E
TYPE 310, Y(lS,I)~X(IS,I),T
430 1J0 500 JA=I,IS
500 FX(JA) = X(JA,I) * Q * DEN * AREA
AZ = ZFINAL/IS
TS02 = o.
-49-
10669-6003-HO-OCJ
-------
lo66y-6003-RO-OO
F'X(IS+l)=U.
JS=(IS+l)/2
JS=2*JS
D0 510 KA=31J512
510 T502 = TS02 + (FX(KA) + 4.* F'X(KA-l). + FX(KA-2» * AZ/3.
VeL = AREA * ZFINAL
PAPER = DEN * veL
TYPE 5201 V0LIPAPERITITS02
520 F0RMAT(llllfV0L ABS0~BER - FT3~15XIIP[12.~III~LBS PAPER
1$114XIIPEI2.6111$BATCH TIME - HR$18XIIPfI2.6111~S02 REM0VED
2 - M0LS$15XIIPEI2.6111)
4000 TYPE 5000
5000 F0RMAT(III$INPUT PAPER C0STI 502 VALUfl HEAT C0ST~/)
ACCEPT 5010lPAPT0NIS02VALIHTCST
5010F0kMAT(3F'14.4)
IDIA=O
D=(AREA*4./3.1416)**0.5
D=0-1<12.
11'(0-200.)60201602016010
6010 DA=D
D=200.
IDIA=1
6020 C0LCST=««D*2.515E-06-8.899E-04)*D+0.1182)*D-l.079)*D+82.09)
I*ZFINAL*2.93*2.0
IF(IDIA)60301604016030
6030 C0LCST=C0LCST*«DA/D)**0.67)
6040 PAPCST=PAPER*PAFT0N/2000./T
PAPCR=PAPER*7560.*HTCST/l.0E+06/T/100.
T0TCAP=3.5*C0LCST+3.5E+04
CAPHR=0.2*T0TCAP/7920.
S02CR=TS02*64.066*S02VAL/I00./T
~'PER=25.25
REGEN=TS02*64.066*1000.*HTCST/l.0E+06/T/100.
0PC0ST=PAPCST+CAPHR+REGEN+0PER-PAPCR-S02CR
T0TYR=0PC0ST*7920.
PA~YR=PAPER*7920./2000./T
S02YR=TS02*64.066*7920./2000./T
TYPE 6000lT0TCAPI0PC0STIS02CRIPAPCRIT0TYRIPAPYRIS02YR
6000 F0RMAT(IIIII$SUMMARYS:II$T0TAL CAPITAL C0ST = $13XIIPEI4.61
1/$0PERATING C0ST $9H($/HR) = 11PE14.611JS02 CREDIT $9H($/HR) = 1
24XIIPEI4.611$PAPER CREDIT $9H($/HR) = 12XIIPEI4.611$T0TAL YEARLY
3C0ST = $14XIIPEI4.611$PAPER USAGE
-------
,
.,
8.
I 9.
1 10.
1l.
12.
20.
10669-6003-RO-00
5.0 REFERENCES
1.
S. L. Madorsky, "Thermal Degradation of Organic Polymers,"
Interscience Publishers, New York (1964).
2.
B. Oddo, Gass. chim. ital. ~ II, 127-39 (1919).
3. D. Costa, Ann. chim. applicata, ~ 636-47 (1926).
4.
N. H. Grace and O. Maas, J. Phys. Chem., ~ 3046 (1932).
5.
6.
E. S. Galzova, Khlopchatobumazhnaya Prom. ~ No.9, 24-6 (1938).
F. L. Hudson and W. D. Milner, Paper Technol. ~ 155-61 (1961).
F. L. Hudson, R. L. Grant, and J. A. Hockey, J. Appl. Chem. ~ (10),
444 - 7 (1964).
7.
C. J. Edwards, F. L. Hudson, J. A. Hockey, J. Appl. Chern. 1968,
18(5), 146-8.
R. Cole and H. L. Shulman, Ind. Eng. Chem. ~ 859-60 (1960).
E. Krejcar, Chem. Prumysl, 15(2), 77-9 (1965).
L. Szepesy and A. R. Giona, Chim. Ind. 47(6), 588-92 (1965).
L. I. Vinnikov, I. P. Mukhlenov, and I. G. Lesokhin, Zh. Prikl. Khim.
40(9), 1895-901 (1967).
13. .K. Ketjen, Dutch Patent 55,207, Sept. 15, 1943.
14.
J. F. Yanes, C. I. Fernandez, and A. M. Santos, Spanish Patent 302,492,
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French Patent 1,356,116, March 1964.
15.
16.
H. C. Wohlers, N. M. Trieff, H. Newstein and W. Stevens, Atmos.
Environ. ~(2), 121-30 (1967).
17.
H. C. Wohlers, H. NewsteiD, and D. Daunis, J. Air Pollut. Contr. Ass.
17(11), 753-6 (1967).
18.
L. R. Burdick and J. F~ Barkley, U.S. Bur. Mines, Circ. No. 7064, 9 pp.
(1939)
19.
Org. Dielektriki Tru
2-9j Khim Referat. Zhur.
J. D. Michaelsen and L. A. viall, J. Research N..;. tl. Bur. Standards, ~
327 - 31 (1957).
-51-
-------
~
ly
10669-6003-RO-00
21.
TRW Proposal 10669.000, "Applicability of Organic Solids to the
Development of New Processes for Removing S02 from Flue Gases,"
17 November 1967.
22.
R. A. Meyers, .Unpublished data, April 1968.
I. O. Gorislavets, J. Phys. Chem. ~ 97-101 (1943).
23.
24.
W. G. Schneider and T. C. Wuddington, J. Chem. Phys., ~ 358 (1956).
25.
M. Gilford and S. Gordon, U.S. Dept. Com. Office Tech. Servo P.B.
Rept. 145, 517, 23 pp. (1960).
H. G. McAdie, Can. J. Chem. 44(12), 1373-85 (1966).
26.
27.
28.
R. G. Partington and R. Sidebottom, J. Inst. Fuel, ~ 597-601 (1959).
J. B. J. Zaba, British Patent 768,454, February 20, 1957.
29.
30.
M. Davies and W. C. Child, Jr., Spectrochim. Acta, 21(7), 1195-206 (1965).
W. Baker and J. F. W. McOmie, Chemistry & Industry, 1955, 256.
31.
F. Ishikawa, S. Mitsui and T. Murooka, Science Repts. Tohoku Imp. Univ.,
1st Sere g, 852-70 (1935).
32.
G. Soder and H. Schnell, German Patent 950,369, October 11, 1956.
F. Ephraim and C. Aellig, Helvetica Chim. Acta, ~ 37-53 (1923).
33.
34.
K. Ziegler, F. Krupp, K. Weyer and W. Larbig, Ibid. 251-6.
35.
A. M. Squires, "Air Pollution: The Control of S02 from Power Stacks,"
. Chem. Eng., 260, (1967).
36.
Digital Computation for Chemical Engineers, Lapidus, Leon, McGraw-Hill
Book Co., Inc., New York (1962).
37.
s. Katell, "An Evaluation of Dry Processes for the Removal of Sulfur
Dioxide from Power Plant Flue Gases," presented at the 59th National
Meeting A.I.Ch.E., Columbus, Ohio, Mby 15-18, 1966.
38.
Personal Communication from E. Marjohn to R. A. Meyers, "General Guide-
Lines for the Process Economic Evaluations of the Nine Area Surveys for
S02 Removal," October 1968.
N. A. Lange, Handbook of Chemistry, lOth Ed., McGraw-Hill Book Co., Inc.
New York, N.Y. (1961).
39.
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