EPA/AA/CTAB/91-03
                         Technical  Report
              Evaluation Of Camet Resistively Heated
               Metal Monolith Catalytic Converters
             On An M100 Neat Methanol-Fueled Vehicle

                             Part III
                                by
                      Gregory K. Piotrowski
                        Ronald M.  Schaefer
                            July 1991
                              NOTICE

     Technical  Reports do  not necessarily  represent  final  EPA
decisions or positions.    They are intended to present technical
analysis of issues using data which are currently available.  The
purpose  in the  release of such  reports is  to facilitate  the
exchange  of  technical  information and to  inform the  public of
technical developments  which  may  form the basis  for  a final EPA
decision, position or regulatory action.

              U. S. Environmental Protection Agency
                   Office of Air and Radiation
                     Office of Mobile  Sources
               Emission Control Technology Division
           Control Technology and  Applications Branch
                        2565 Plymouth  Road
                       Ann  Arbor, MI  48105

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        UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                     ANN ARBOR. MICHIGAN 48105
                           JUL 30 1991                    OFFICE OF
                                                      AIR AND RADIATION
MEMORANDUM


SUBJECT:  Exemption From Peer and Administrative  Review
FROM:     Karl H. Hellman, Chief
          Control Technology and Applications Branch


TO:       Charles L. Gray, Jr., Director
          Emission Control Technology Division


     The attached report entitled "Evaluation Of Camet Resistively
Heated  Metal  Monolith  Catalytic  Converters  On  An  M100  Neat
Methanol-Fueled Vehicle - Part III"  (EPA/AA/CTAB/91-03)  describes
the evaluation of the  most current generation of quick  light-off
catalytic  converters  now  being  furnished by  the Camet  Co.  to
automobile  manufacturers.    This evaluation  was conducted on  a
methanol-fueled  (M100) vehicle.

     Since this report is concerned only with the presentation of
data and  its  analysis  and does not  involve matters of  policy or
regulation, your concurrence is requested  to waive  administrative
review according to the policy outlined in your  directive of April
22, 1982.
   Concurrence:  (_ ^WhS' f~*J ,/^	Date:  7-
               Charles L. Gray, Jr^ Dir.,ECTD
Nonconcurrence:	Date:.
               Charles L. Gray, Jr., Dir., ECTD

cc:  E. Burger, ECTD

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                        Table of Contents

                                                            Page
                                                           Number

I.   Summary	l

II.  Introduction	2

III. Description of Catalytic Converters 	  3

IV.  Description of Test Vehicle	5

V.   Test Facilities and Analytical Methods	5

VI.  Test Procedures	7

VII. Discussion of Test Results	  8

     A.   QLOC Only, Without Air Assist	8

     B.   QLOC Only, With Air Assist	12

     C.   QLOC + Main Catalyst, With/Without Air Assist. .   . 19

VIII.Evaluation Highlights . 	 26

IX.  Future Efforts	27

X.   Acknowledgments	27

XI.  References	\	29

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I.   Summary

     A low mileage resistively heated catalytic converter of a type
currently furnished by the Camet Co. to automakers was evaluated on
a methanol fueled vehicle.   This  converter was smaller in volume
than typical three-way catalytic converters used on current model
year vehicles of  comparable  engine displacement,  and is designed
specifically as a quick light-off catalyst  (QLOC)  by Camet.

     The QLOC was evaluated  in  three  separate modes.   First, the
QLOC was  placed in  the  exhaust stream  of the test  vehicle and
evaluated without the benefit of  catalyst  air assist  (simulated
oxidation catalyst)  or a larger main  catalyst (MC)  also present
downstream.  Next, the QLOC was tested with resistive heating and
simulated air assist, but without  a MC in the  exhaust.  Finally, a
low  mileage  nonresistively  heated  MC  was  added  immediately
downstream  of  the   QLOC.    This  two-catalyst system  was  then
evaluated with resistive heating applied to the QLOC and catalyst
air assist.  Because the additional air was added in front of the
QLOC, this air assist also affected the operation of the larger MC
positioned downstream.

     With the  QLOC alone and  resistive  heating applied  for 15-
seconds  prior  to  and  40 seconds following  cold start  (15/40
resistive heating) ,  Bag 1 emissions from the Federal Test Procedure
(FTP) cycle were reduced 50 percent from  unheated catalyst levels.
Only a slight reduction  in formaldehyde, and  no change in carbon
monoxide (CO) Bag 1 emission levels were noted when this catalyst
was resistively heated.

     Air was added in front of the catalyst at an average rate of
5 SCFM for short intervals following start  in  Bag 1.  The addition
of air  for 30  seconds to the 15/40  resistively  heated catalyst
decreased Bag 1  methanol emissions a further 54 percent from heated
catalyst only levels,  to 1.83 grams.   Bag 1  formaldehyde levels
were reduced 30  percent when air assist was  provided for  30 seconds
to the resistively  heated catalyst.   CO levels decreased as the
time period of air addition was  increased.   CO was reduced to 12.7
grams over Bag  1  with air addition for  30  seconds to the heated
catalyst, a 33 percent decrease from heated-catalyst-only levels.
CO emissions continued to decrease, to 4.5 grams  in Bag 1 as the
air assist period was  extended  to 120 seconds following start in
Bag 1.

     The addition of the MC behind the QLOC had the  effect of
reducing Bag 1 emissions of methanol,  CO and formaldehyde to very
low levels, while contributing  to only a slight reduction in NOx
emission levels.   The most  efficient configuration of the  two-
catalyst  system  modes evaluated  utilized the 15/40  resistive
heating schedule mentioned above and air addition for 100 seconds
following cold start in Bag 1.   The simultaneous use of  these two
assists decreased Bag 1 methanol emissions to 0.37  grams. This was
down from 7.95 grams measured with no  resistive heat or  air assist
provided to the two-catalyst  system.   Formaldehyde emissions were

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also  reduced,  to 34  milligrams over Bag  1 with  QLOC  resistive
heat/air addition.  This was an 85 percent improvement from the 227
milligrams in Bag 1  measured when the two-catalyst system received
no resistive heating or air assist.

      The largest increase in  catalyst  efficiency when resistive
heating/air assist was provided to the two-catalyst system occurred
for CO control, however.   Almost 16 grams of CO were measured over
Bag 1 with the two-catalyst system, when the QLOC was not supplied
with resistive heating or additional air.  CO was reduced to less
than  two  grams over Bag  1 with 15/40  resistive  heating  and 100
second air addition, a 90 percent reduction.

     Improvements in Bag 1 emission levels generally caused average
FTP emissions to decrease  almost proportionally to the decrease in
Bag 1 levels.  With the resistively  heated and  air assisted two-
catalyst system, OMHCE were reduced to a low 0.07 grams per mile.
Formaldehyde emissions were also very low at only four milligrams
per mile.   The  greatest  percentage  increase in  efficiency from
unassisted catalyst operation,  however,  was in the category of CO
emissions.    The heated/air  assisted  two-catalyst  system  gave
average FTP CO emissions of only 0.2 grams per mile, an increase in
efficiency  of  80  percent  over  unassisted catalyst  operation.
Although  Bag  1  NOx  levels  appeared to  increase slightly  with
increasing air addition times,  the level of FTP NOx emissions was
0.7 grams per mile with the two-catalyst system either unassisted
or assisted with both resistive heating/air addition.

II.  Introduction

     The  largest portion  of  methanol,   carbon monoxide  (CO),  and
formaldehyde exhaust emissions from a catalyst-equipped MIOO-fueled
vehicle tested over the Federal Test Procedure (FTP)  occur during
the cold start and catalyst warm-up phase in Bag  1. [1]  The same is
generally true for hydrocarbon exhaust emissions from a catalyst-
equipped gasoline-fueled vehicle emission tested over the FTP.[2]
Emissions of oxides of nitrogen  (NOx) at cold start are generally
not as significant  as levels of NOx  emissions  generated later in
the cycle as  they  are  produced  at  higher concentrations  under
greater load after  the engine  has  warmed.   Cold start is defined
here as following a vehicle soak of 12-36 hours at 72-86°F.[3]

     A catalytic converter is generally ineffective for oxidizing
emissions of methanol and  formaldehyde from an MIOO-fueled vehicle
until the converter  has reached catalytically active, or light-off
temperature.   Though this  temperature  varies  for the catalyst
considered, light-off temperatures  for typical three-way converters
of 350°C  have been  recently mentioned  in  the  literature[4]  when
referring to  the performance of an  electrically  heated catalyst
(EHC).  Resistively heating the substrate and thereby the catalyst
to light-off  temperature  at cold  start reduces  the  time during
which the catalyst  remains ineffective because of insufficient

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warming  by the relatively  cold exhaust  gas.    This  accelerated
warmup would also have the advantage of occurring when the engine
is cold and producing higher levels of unburned fuel and CO because
of operation under relatively richer conditions.

     EPA has been interested in catalyst preheating for some time
and  has  conducted   evaluations  of  resistively heated  catalyst
technologies supplied  by Camet  Co.[1,5,6,7,8,9]   This  work has
involved both methanol  and  gasoline-fueled vehicle applications.
Other  sources,   both  government  and industry,  have  conducted
evaluations    of    this    technology    and   published    test
results.[4,10,11,12,13]    These   other   efforts  have  involved
primarily gasoline-fueled test vehicles.

     The  Camet  catalysts  previously evaluated  by  EPA were  a
prototype design, consisting of a resistively heated segment and a
slightly  larger  nonresistively heated main  catalyst.   These two
segments were placed in close proximity to each other in the same
converter shell.  The end of the shell containing the resistively
heated  segment  was  placed  upstream  in   the exhaust during the
previous  EPA  evaluations.     A complete description  of  these
prototype converters was provided in an earlier report published by
Camet; details are also given here below in the section providing
a description of the catalysts evaluated.

     The  current generation  of EHC  now  furnished  by  Camet  to
automakers for evaluation consists of a single resistively heated
segment.  This unit  is designed specifically as a quick light-off
catalyst,  to  oxidize excess  emissions of  unburned fuel  and  CO
following  cold  start.[14]     Camet  suggests  that  a  standard
underfloor  catalytic converter system may also be necessary  to
reduce unburned fuel and CO  emissions from most vehicles to very
low levels.  Camet supplied EPA with a current-generation EHC for
evaluation on an MIOO-fueled vehicle.  This catalyst was evaluated
by  EPA  as part  of  an effort to  identify  and  determine  the
effectiveness of novel emission control technologies.  The details
of  the technology evaluated  and  the test procedures  are given
below.   All  of  the testing  referred to here  consists of  an
evaluation of fresh, unaged catalysts.

III. Description Of  Catalytic Converters

     The catalytic converter of primary interest in this evaluation
is referred to hereafter as  the quick light-off catalyst (QLOC).
The QLOC uses a  single-segment,  resistively heated stainless steel
foil substrate,  configured into a honeycomb (Figure 1).  The total
volume of the honeycomb was approximately 200 cm3,  and the energy
for heating was supplied from a dedicated 12-volt,  115 amp-hour,
deep cycle battery.  The QLOC evaluated here was a fresh, unaged
catalyst.   A solid-state power controller,  normally  supplied  by
Camet to regulate the high current involved, was not used in this
evaluation.  Instead, a switch and  engine  starter motor relay were
used to supply energy from the dedicated battery when desired.   A
typical three-way catalyst formulation was used; Table 1 contains
more detailed specifications of the QLOC.

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                             Figure  1

                Camet Resistivelv Heated Catalyst
                             Table 1

                 Detailed Specifications Of Quick
                   Light-Off  Catalyst  Evaluated
Camet Model Number

Catalyst Volume

Rated Power Usage (Camet Data)

Approx. Heating Time To 650°F

Substrate Material

Back Pressure At 55 mph

Length Between Edges Of End Pipes

Catalyst
          Specification

                  10-15

                216 cm3

            2,800 watts

             14 seconds

   Stainless steel foil

          230 mm of H20

                 107 mm

5:1 Pt:Rh, 1.41 g/liter
Battery Used To Supply Resistive Heating         Action Pack, 12V
                                       Deep Cycle/Marine Battery,
                                                       115 Amp-Hr

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     The Camet  QLOC tested  here  may not  be  a substitute  for  a
larger volume main  catalyst  (MC).  A MC was added in series with
the QLOC in order to reduce emission levels over the remainder of
the FTP to  the low levels experienced with a conventional three-way
catalyst.  The simulated MC was a two-segment Camet EHC prototype
previously evaluated by EPA.

     This simulated MC (Figure 2)  consisted of resistively heated
and nonresistively heated segments canned  in very close proximity
to each other in a common shell.  No  resistive heating was applied
to the EHC portion  of  this  simulated main  catalyst during any of
the testing conducted as part of the current evaluation.  Table 2
contains detailed specifications of this catalyst.

IV.  Vehicle Description

     The test vehicle  was a  1981  Volkswagen Rabbit 4-door sedan,
equipped with automatic transmission, air conditioning, and radial
tires.  The 1.6-liter engine had a rated maximum power output of 88
horsepower  at  5,600 rpm,  when using neat methanol fuel.   The
vehicle  was  tested at 2,500 Ibs  inertia  weight and  7.7 actual
dynamometer horsepower.  This vehicle was  loaned to the U. S. EPA
by Volkswagen of America.

     A detailed  description  of the  vehicle and special methanol
modifications were provided in an earlier report.[9]

V.   Test Facilities And Analytical Methods

     Emissions testing at EPA was conducted on a Clayton Model ECE-
50 double-roll chassis dynamometer, using a direct-drive variable
inertia flywheel unit and road load power control unit.  The Philco
Ford constant volume  sampler has  a  nominal capacity of 350 CFM.
Exhaust HC emissions were measured with a Beckman Model 400 flame
ionization detector (FID).   CO was measured using a Bendix Model
8501-5CA infrared CO analyzer.  NOx emissions were determined by a
Beckman Model 951A chemiluminescent NOx analyzer.

     Exhaust  formaldehyde was  measured using a  dinitrophenyl-
hydrazine  (DNPH)  technique.[15,16]   Exhaust  carbonyls including
formaldehyde  are reacted with DNPH solution  forming  hydrazine
derivatives; these derivatives are separated from the DNPH solution
by means of high  performance  liquid chromatography (HPLC),  and
quantization is accomplished by spectrophotometric analysis of the
LC effluent stream.

     The procedure  developed for  methanol  sampling and presently
in-use employs water-filled  impingers through  which are pumped a
sample  of  the  dilute exhaust or evaporative  emissions.    The
methanol in the sample gas dissolves  in  water.  After the sampling
period is complete,  the solution in the impingers is  analyzed using
gas chromatographic (GC)  analysis.[17]

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                             Figure  2

                  Main Catalyst Used in Program
                             Table 2

               Detailed  Specifications  Of  Simulated
               	Main  Catalyst*	
Garnet Model

Dimensions;

     Frontal Area


     Length


     Cells/cm2


     Weight


Catalyst Type/Loading




Designed Power Rating
                Specifications
                     Prototype
                     Model 513
          54 cm2 heated brick,
         57 cm2 unheated brick

          8.9 cm heated brick,
         8.9 cm unheated brick

            20, heated segment
          50, unheated segment

         240 g, heated segment
       345 g, unheated segment

     Heated segment 3:1 Pt:Pd,
                  1.06 g/liter
Unheated segment, 6.7:1 Pt:Rh,
                  1.41 g/liter

                   3,000 watts
     From  Reference 4,  no  heat  applied  to resistively  heated
     segment during current testing.

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     Most of the emission results in this report are computed using
the methods outlined in the "Final Rule For Methanol Fueled Motor
Vehicles And  Motor Vehicle Engines," which was  published in the
Federal  Register  on  Tuesday,  April 11,  1989.    Because  these
specialized  procedures  and   calculation   methods   are  not  in
widespread use, we have also included a hydrocarbon result which is
what would be  obtained if  the exhaust was  treated as if the fuel
were gasoline.  This is done as a convenience for the readers and
users  of the  report  who  may  be  more familiar  with hydrocarbon
results obtained this way.

VI.  Test Procedures

     This program had  as its goal the evaluation of a QLOC provided
by  Camet  Co.  for  the  reduction  of  unburned  fuel,  CO  and
formaldehyde emissions from a methanol-fueled vehicle.

     The evaluation consisted  of  three  distinct  phases which are
discussed separately  in the following section.   The first phase
consisted of  a preliminary  evaluation  of  the QLOC on the test
vehicle.  All emissions testing was conducted over the FTP cycle,
and resistive heating was limited to different schemes during the
cold start portion of  Bag 1.  All of the  testing in this evaluation
was conducted at 72-73°F conditions.

     The next phase of the evaluation involved  the addition of air
during resistive heating to assist the oxidation  of unburned fuel,
CO and  formaldehyde.   This air addition allowed the catalyst to
function as an oxidation catalyst; the catalyst formula, however,
was a  typical three-way variety.   The  QLOC alone  was evaluated
during this phase.  Testing was conducted  over the  FTP cycle and
resistive heating/air addition was again limited  to the cold-start
portion of Bag 1.

     The final phase of the evaluation had the QLOC employed as a
true warm-up  catalyst.  A main catalyst was added  underfloor in
series behind the QLOC.  The purpose of the main converter was to
provide sufficient catalyst volume and activity  to reduce emissions
to very  low  levels over  a wide variety  of  engine speed and load
conditions following catalyst warm-up.

     Air  addition in  front  of the QLOC,   as  well  as resistive
heating,  were  utilized  in  Bag   1  during this phase  of  the
evaluation.  Because  the QLOC was located  upstream  from the main
catalyst, any excess air added  in front of it would also affect the
operation of the main catalyst.   The air assist  was utilized for
only limited periods following key-on, however;  it was thought that
limiting the addition  of air to these brief  periods would limit the
effect on any  possible increase in oxides  of nitrogen due to the
converter.

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VII. Discussion Of Test Results

     A.   QLOC Only. Without Air Assist

     This evaluation consisted of three separate phases.  The first
phase,  commented  on  in  this  section,  consisted  of  a  brief
evaluation of  the QLOC  without  the benefit  of air assist  or a
larger main catalyst.

     During all phases of  this  evaluation,  resistive heating and
air assist were restricted to the  cold-start  portion of Bag 1 of
the FTP.  The first 505 seconds of  the FTP is commonly referred to
as Bag 1;  the cold-start portion consists of  the initial minutes of
Bag  1  during  which  the  engine  and exhaust  system  heat  to a
relatively steady-state  temperature.   The following  discussion
comments  on differences  in exhaust emission levels  which  may be
related to oxidation catalyst operation,  catalyst resistive heating
or both.  Bag  1 emission  levels are given  in  grams of emissions
over the  test  segment  (Bag 1)  except for formaldehyde,  which are
presented in milligrams  over Bag  1.   Composite FTP emissions are
given in  tabular  form  in grams  per mile except for formaldehyde,
which are presented in milligrams per mile.

     Figure 3  presents Bag 1 methanol  emission levels during the
first   phase   of   the  evaluation.     Several  catalyst  heating
conventions were  tried to  gauge the effectiveness  of  changes in
heating strategy.  The notation used in  Figure  3 and thereafter to
denote the heating convention utilizes two numbers separated by a
slash.    The  first number refers to  the  number  of  seconds of
catalyst  resistive heating applied prior to key-on (start)  in Bag
1; the  second  number refers to the number of seconds of resistive
heating applied immediately following  cold start.   All heating
conventions  involved  3-15 seconds  of  heating  prior  to  start.
Fifteen seconds of  heating prior  to key-on  may be impractical in
order to  accommodate  the driver's  desire for  a quick start/drive
sequence, as well as for  possible  catalyst durability concerns.  A
15-second heating period prior  to  start,  however, ensured a warmed
substrate and  surroundings for these laboratory experiments.

     Bag  1 emissions of  methanol were  reduced almost  50 percent
from  baseline  levels by  the  small QLOC,  without  the  aid of
resistive heating.    Resistive  heating, even  in the  absence of
additional air to promote  oxidation,  increased the efficiency of
the catalyst significantly.  Heating the catalyst for 90 seconds
following start reduced methanol emissions from unheated catalyst
levels  almost  50 percent.  It is less clear, however, how changes
in the catalyst heating convention affected emissions when compared
to levels from 3/90 catalyst heating.  Increasing the time interval
of  resistive   heating  prior to key-on  appeared to  increase the
heated  catalyst's effectiveness.  The three conventions which had
15-second heat periods prior to key-on had Bag 1 emission levels of
methanol  roughly  20  percent  lower   than   the  3/90  heating
configuration.  Extending  catalyst heating after key-on for modes
utilizing 15-second heating periods prior to start gave mixed

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                           Figure 3
                 QLOC Only, No Air Assist
            Methanol  Emissions, Bag 1 Of FTP
  EHC Resistive Heating

               Baseline

               No Heat

                 3/90*

                  5/40

                 15/20

                 15/40

                 15/60
                     19.14
         10.69
  5.26

  5.52
4.27

3.95

4.34
* Heat 3 Seconds Prior To Start,
90 Seconds Following Start
                              5      10     15     20
                             Exhaust Methanol (grams)
                           25
                           Figure 4
                 QLOC Only, No Air Assist
          Formaldehyde Emissions, Bag 1  of FTP

  EHC Resistive Heating

               Baseline

               No Heat

                 3/90*

                  5/40

                 15/20

                 15/40

                 15/60

                       0  200 400  600  800 1000120014001600
                          Exhaust Formaldehyde (milligrams)
* Heat 3 Seconds Prior To Start,
90 Seconds Following Start

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                                10

results.   The methanol  emissions  from the  60-second post-start
heating period, 4.34 grams  over Bag  1,  were  slightly higher than
levels obtained with 20- and 40-second post-start heating periods.
Although  three tests  were  conducted  in  each  mode,  it may  be
necessary to conduct more tests, using modal analysis, to correlate
average  Bag  1  emissions  with catalyst  resistive heating  time
intervals.

     Figure  4 presents  Bag  1 formaldehyde  emissions when  the
catalyst heating  conventions referred  to in Figure  3  were  used.
Resistive heating in the absence of  any excess  air assist to the
catalyst appeared to increase catalyst  efficiency,  though not to
the extent noted with unburned fuel (methanol)  emissions.  The most
efficient scheme was 3/90 heating, which provided an approximately
30  percent  decrease  in  formaldehyde  emissions  from  unheated
catalyst levels.  Catalyst efficiency improved very slightly over
the modes using 15-second prestart heating,  when post-start heating
times were increased.  The decrease in formaldehyde emissions was
only 8 percent as post-start heating  was increased from 20 seconds
to 60 seconds.

     Figure 5 contains Bag  1 data from  the FTP  on CO levels with
the QLOC  over the  same resistive heating modes.    Generally no
change  in  emissions  of  CO  of the magnitude  experienced  with
unburned fuel was noted when the catalyst was resistively heated.
CO emissions from the 15/20 and 15/40 heating schemes were similar
to levels obtained without catalyst heating.  CO was measured at a
higher level when the  catalyst was tested using the 5/40 heating
sequence than  without  any catalyst  resistive heating.   Although
slightly  lower CO  emissions were noted  with  the  3/90  heating
convention, other heating modes which involved significant amounts
of resistive heating did not substantially  reduce CO from unheated
catalyst levels, in the absence of air assist.

     Table  3  is  a  summary  of  Bag   1  levels for  other  emission
categories as  well  as  the three previously discussed  here.   NOx
emissions did not appear to be  significantly affected by catalyst
resistive heating possibly because the heating occurred during the
period of engine  warmup  to hotter, near steady-state temperature
conditions.

     Because Bag 1 emissions of unburned fuel,  CO, and formaldehyde
are comparatively greater than those from other segments of the FTP
for   a   typical  three-way  catalyst   equipped   M100  vehicle,
improvements in Bag 1 emissions due to catalyst resistive heating
should also be seen  in FTP composite emission  averages.  Table 4 is
a summary of FTP weighted average emissions over  the first phase of
this evaluation.  Generally, the weighted average emissions reflect
Bag 1 emissions  trends  noted  above.   For example,  FTP average
methanol emissions  were approximately  21  percent  lower  with the
15/40  catalyst  heating  convention  than  the  3/90  mode;  the
difference  in Bag  1  emissions between tests with the  same two
resistive heating modes was  25  percent.

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                                 11
                               Figure 5
                     QLOC Only, No Air Assist
             Carbon Monoxide Emissions, Bag 1 of FTP
        EHC Resistive Heat Configuration

                             Baseline
                             No Heat

                               3/90*

                                5/40

                               15/20

                               15/40

                               15/60
      * Heat 3 Seconds Prior To Start,
      90 Seconds Following Start
                                    0    10   20   30  40   50
                                   Exhaust Carbon Monoxide (grams)
                              Table  3

          Testing Limited  To Current-Generation  Catalyst
                        Bag 1 Of FTP Cycle
                     No Air Assist To  Catalyst
NMHC HC* CH3OH HCHO OMHCE CO NOx
Category g g g rag g g g
Baseline
No Heat/No
Air
3/90 Heat
5/40 Heat
15/20 Heat
15/40 Heat
15/60 Heat
1.55
0.56
0.27
0.35
0.17
0.17
0.19
7.33
4.10
2.03
2.21
1.62
1.51
1.66
19.14
10.69
5.26
5.52
4.27
3.95
4.34
1298
534
360
467
434
421
397
10.00
5.50
2.77
3.02
2.28
2.13
2.34
37.3
19.0
17.0
20.2
18.9
18.9
17.6
6.9
3.7
3.5
3.5
3.6
3.7
3.7
*    Gasoline-fueled vehicle measurement procedure with a  propane
     calibrated FID.

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                                12
                             Table 4

          Testing Limited  To  Current-Generation  Catalyst
                  FTP Composite Emission Levels
                    No Air Assist To Catalyst
NMHC HC* CH3OH HCHO OMHCE CO NOx
Category g/mi g/rai g/mi mg/mi g/mi g/mi g/mi
Baseline
No Heat/No
Air
3/90 Heat
5/40 Heat
15/20 Heat
15/40 Heat
15/60 Heat
0.28
0.04
0.03
0.04
0.02
0.03
0.01
1.17
0.31
0.18
0.21
0.17
0.16
0.18
2.93
0.80
0.46
0.49
0.43
0.36
0.51
323
61
47
59
57
51
66
1.63
0.42
0.26
0.29
0.24
0.22
0.27
7.3
1.7
1.4
1.7
1.6
1.6
1.5
1.6
0.8
0.7
0.8
0.8
0.8
0.8
     Gasoline-fueled vehicle measurement procedure with a propane
     calibrated FID.
     In summary,  even  without air assist to  the QLOC,  resistive
heating significantly  decreased  emission  levels of methanol over
the FTP.   Only marginal improvement  in average FTP formaldehyde
emissions  was  noted with  resistive  heating,  and  no substantial
lowering of CO levels was noted with resistive heating alone.  NOx
emissions  over the FTP  were relatively unaffected  by  resistive
heating.

     B.   QLOC Only. With Air Assist

     Even  if a catalyst  is resistively heated during cold start,
its effectiveness may  be  lessened  by the absence of  sufficient
oxygen in the  exhaust to bring the desired oxidation reactions to
completion.  In some cases,  a lack  of oxygen  may promote partial
combustion to undesired intermediate products.  Air  addition before
the catalyst may  supply  sufficient  oxygen to  the relatively rich
exhaust to promote the  desired oxidation  of unburned  fuel  and
intermediate products (formaldehyde and CO) . Alternatively, a flow
of ambient air through an  EHC may have the undesirable  effect of
hindering NOx reduction activity and cooling the resistively heated
substrate.

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                                13

     Catalyst air  assist was used in a previous  effort by EPA to
reduce CO  levels  from a gasoline-fueled vehicle  at lower ambient
temperatures with  an  EHC.[7]   In  this case,  additional air proved
useful as  an assist  for EHC  performance.   Other EPA  work with
methanol-fueled vehicles has indicated,  however, that  air assist to
contemporary  platinum:rhodium catalysts   caused  a  significant
increase in Bag l  emissions  of formaldehyde.[18]

     Air assist  before the  EHC was  tried here as a strategy to
improve catalyst  efficiency.   The  air  was  added  only during the
initial portions  of Bag 1 following  key-on,  in order to minimize
any production of formaldehyde  or increases  in oxides of nitrogen.

     Air was added from a shop air hose, rather  than from a belt or
electrically driven air pump.   A regulator  was placed in the air
line to decrease the air flowrate to approximately 5.0 ft3/minute.
An airflow meter was also added to determine the effect  of changes
in exhaust flowrate on the flowrate of air in to the  exhaust.  The
air addition began  with key-on, and continued for  intervals of 30
to 120 seconds.

     Figure 6 contains  unburned fuel emissions data  in  grams over
Bag  1,  when air  assist  is  provided to   the electrically heated
catalyst.  Baseline (no  catalyst)  and  no-heat/no-air emissions data
are also given  in Figure 6 for comparison.   All  catalyst heating
conducted  during  this phase of the evaluation  utilized the 15/40
heating strategy.
                              Figure 6
                    QLOC Only, With Air Assist
                 Methanol Emissions, Bag 1 Of FTP

        EHC Resistive Heat/Air Addition

                            Baseline

                       No Heat, No Air

                           Heat Only

                       60 Sec Air Only

                     Heat,  30 Sec Air*

                      Heat, 60 Sec Air

                     Heat,  120 Sec Air

                                   0    5    10    15   20   25
                                     Exhaust Methanol (grams)
      * Heat 15 Seconds Prior  To/40 Seconds
      Following Start, 30 Seconds Air
      Addition Following Start

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                                14

     As previously shown in Figure  3, resistive heating alone over
the  15/40  heating convention provided  better than a  60 percent
reduction in unburned fuel emissions from unheated catalyst levels.
The addition of air  for  60  seconds following start in Bag 1 also
reduced methanol emissions, yet these levels were almost twice as
high as those noted when the catalyst was resistively heated.  Air
f lowrate over the  catalyst did not vary much because of changes in
the flowrate of exhaust;  fluctuations of only 0.1-0.2 ft3/minute of
air were noted.

     The combination of air addition and resistive heating appeared
to improve the efficiency of the EHC substantially with respect to
methanol emissions.    This  improvement  did  not continue  as the
length of time the air addition occurred was lengthened, however.
A roughly 50 percent improvement in efficiency was noted when air
was added for  30  seconds to the heated catalyst (15/40 heating).
The  level  of methanol  emissions rose slightly  when  air addition
time was increased to 60 seconds; a similar increase in the level
of methanol  emissions  was  noted at 120  seconds of air addition.
Additional testing  would have  to  be  conducted to determine the
statistical significance of  the rise  in methanol  emissions noted
when the length of air addition was increased to 60 seconds.

     Figure 7 presents the levels of formaldehyde emissions noted
when air assist was used.  The addition of air,  in the absence of
catalyst heating,  caused formaldehyde  levels to  increase above
nonresistively-heated catalyst levels.  In this first case, air was
added for 60 seconds following start in Bag 1.  When the catalyst
was  resistively  heated, and  air  was added  for only  30 seconds
following start, Bag 1 formaldehyde emissions were reduced to 286
milligrams.  As the air flow was extended over longer time periods,
up to 120 seconds following start,  formaldehyde levels increased.
At the  level  of  2  minutes  of  air addition,  in  spite  of 15/40
catalyst heating, formaldehyde  levels  increased to exceed levels
from no heat/no air catalyst testing.

     It is interesting to note that the single heat/air scheme at
which formaldehyde  levels  were lower  than heated catalyst only
levels involved air addition for only 30 seconds following start.
The heating scheme used here,  15/40 involved resistive heating for
40 seconds following start.   The other two heat/air configurations
had air addition times  that exceeded the period of catalyst heating
(40 seconds).  It is not known  how significant  the period of air
addition in the absence  of  catalyst heat is to  the production of
aldehydes  during  Bag  1.   Given the  15/40 heating  scheme,  more
testing,  preferably  using  modal   analysis,  would  have  to  be
conducted to  determine a more  optimum  air  flowrate  and addition
period.

     In previous  testing on  a  gasoline-fueled vehicle  at lower
temperatures, a significant decrease in CO emissions was noted when
air addition was used with a resistively heated catalyst. [7]  Other
researchers have noted an improvement in CO efficiency from a

-------
                             15
                           Figure 7
                QLOC Only, With Air Assist
          Formaldehyde Emissions, Bag 1 Of FTP
  EHC Resistive Heat/Air Addition
                        Baseline
                  No Heat, No Air
                       Heat Only
                  60 Sec Air Only
                 Heat, 30 Sec Air*
                  Heat, 60 Sec Air
                 Heat, 120 Sec Air
                 1298
  421
286
   468
                                0     400    800   1200   1600
                              Exhaust Formaldehyde (milligrams)
* Heat 15 Seconds Prior To/40 Seconds
Following Start, 30 Seconds Air
Addition Following Start
                           Figure 8
                QLOC Only, With Air Assist
        Carbon Monoxide Emissions, Bag 1 Of FTP
  EHC Resistive Heat/Air Addition
                        Baseline
                  No Heat, No Air
                       Heat Only
                  60 Sec Air Only
                 Heat, 30 Sec Air*
                  Heat, 60 Sec Air
                 Heat, 120 Sec Air
                                0     10    20    30   40   50
                              Exhaust Carbon Monoxide (grams)
• Heat 15 Seconds Prior To/40 Seconds
Following Start, 30 Seconds Air
Addition Following Start

-------
                                16

gasoline-fueled EHC-equipped vehicle when air addition is used.[2]
The  addition of  air  in  front  of the  catalyst evaluated  here
provided a  very significant enhancement  of EHC activity  for CO
removal.

     Figure 8 provides Bag 1 CO emissions data for the EHC with air
addition.   As mentioned above,  catalyst heating alone provided
virtually no benefit  for  CO  beyond unheated  catalyst emission
levels.  Sixty seconds of air addition following start reduced CO
to approximately 12.7 grams, a 33 percent decrease from no-heat/no-
air catalyst operation.

     Catalyst heating with  increasing lengths of  air addition time
provided significant  increases  in  CO conversion efficiency.   The
15/40 heating scheme,  with  30 seconds  of air  addition following
start, gave the  same level of Bag 1 CO, 12.7  grams, as the addition
of air only  for  60 seconds.  Increasing the time of air addition to
a full 60 seconds with catalyst heating decreased CO by  roughly 50
percent to 5.9 grams.  (This convention involved air addition for
approximately 20 seconds following the end  of catalyst heating.)
When the period of  air addition was  increased  to  120  seconds,  a
further substantial  decrease in  CO emissions  resulted.   While it
appears  from these  tests  that  catalyst resistive heating  may
provide a useful assist to  an  oxidation catalyst for CO control,
more tests would have to be  conducted to quantify the contribution
of the heating.   Different heating  conventions could also be tried
to determine a  scheme that  would more effectively complement the
air addition strategy selected.

     Bag 1 emissions data is summarized in Table 5.  OMHCE trend in
the same general  direction  as the  heaviest organic  component by
total weight actually measured  (methanol).   A slight increase in
NOx emissions was noted as air addition over  the three-way catalyst
was increased to 120 seconds.  This increase was minimized by the
limitation of catalyst air  assist  to relatively short periods of
time of excess CO/unburned fuel emissions following cold start.

     Table 6 presents the average  FTP results for each emissions
category.    Because  the Bag  1  emissions  of  the pollutants of
interest here are  such  a  significant  component of  average  FTP
emissions of these pollutants, it was expected that any improvement
in Bag l emissions would be manifest in FTP emissions.  This indeed
was noted in most cases.

     Though  it  is  not possible  to  select an  optimum catalyst
operating strategy  based upon  the limited  testing  commented on
here, the 15/40 heating/30  second air addition strategy  appears to
be relatively effective.  Air addition time is kept to  a minimum,
reducing any cooling effect on the heated substrate.  Excess

-------
                                17
                             Table 5

         Testing  Limited To  Current-Generation  Catalyst
                        Bag 1 Of  FTP Cycle
                     Air Assist  To Catalyst
NMHC HC* CH3OH HCHO OMHCE CO NOx
Category g g g mg g g g
Baseline
15/40 Heat/
No Air
30 Sec Air /No
Heat
60 Sec Air/No
Heat
120 Sec
Air/No Heat
15/40 Heat/
30 Sec Air
15/40 Heat/
60 Sec Air
15/40 Heat/
120 Sec Air
1.55
0.17
0.13
0.05
0.14
0.10
0.01
0.01
7.33
1.51
3.01
2.70
2.44
0.74
0.72
0.75
19.14
3.95
8.71
7.54
6.94
1.83
2.15
2.16
1298
421
634
735
853
286
468
673
10.00
2.13
4.25
3.67
3.59
1.07
1.18
1.29
37.3
18.9
17.8
12.7
12.2
12.7
5.9
4.5
6.9
3.7
4.0
3.9
4.2
3.6
4.0
4.3
*    Gasoline-fueled vehicle measurement procedure with a propane
     calibrated FID.

-------
                                18
                             Table 6

         Testing  Limited  To  Current-Generation Catalyst
                  FTP Composite Emission Levels
                     Air  Assist To  Catalyst
NMHC HC* CH3OH HCHO OMHCE CO NOx
Category 9/mi 9/roi 9/mi mg/mi g/mi g/mi g/mi
Baseline
15/40 Heat/
No Air
30 Sec Air/No
Heat
No Heat/ 60
Sec Air
No Heat/ 120
Sec Air
15/40 Heat/
30 Sec Air
15/40 Heat/
60 Sec Air
15/40 Heat/
120 Sec Air
0.28
0.03
0.01
0.00
0.01
0.02
0.01
0.00
1.17
0.16
0.26
0.23
0.23
0.13
0.13
0.14
2.93
0.36
0.76
0.69
0.66
0.30
0.37
0.38
323
51
84
91
98
50
67
83
1.63
0.22
0.38
0.35
0.35
0.18
0.20
0.21
7.3
1.6
1.8
1.4
1.3
1.3
1.0
0.8
1.6
0.8
0.9
0.8
0.8
0.8
0.8
0.9
*    Gasoline-fueled vehicle measurement procedure with a propane
     calibrated FID.

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                                19

formaldehyde and NOx formation are also minimized by reducing the
air  addition  time,   and   the   lowest   rates  of  methanol  and
formaldehyde emissions were noted  with this  catalyst  operating
procedure.  It should  be recalled,  however,  that this QLOC has a
small  volume  and  it  requires  the  assistance  of a  larger main
catalyst, according to the manufacturer, Camet  Inc.   Therefore,
although  the  small  QLOC  was  generally  more  efficient  when
resistively heated and operated  in the oxidation  catalyst mode, it
would still be necessary to use a  larger main catalyst to ensure
better performance.  The lowest formaldehyde emission level noted
here, 50 milligrams/mile far exceeded the California standard of 15
milligrams/mile over the FTP,  even at low mileage.

     C.   OLOC + Main Catalyst.  With/Without Air Assist

     The QLOC evaluated here  used a small substrate  in order to
minimize the power requirements  for  catalyst  heating.  The smaller
volume also  ensures ease  of  location,  wherever  desired,  in the
exhaust  system.   According to  Camet,   it  is necessary  to equip
vehicles with a larger, nonresistively heated catalyst in order to
reduce pollutant emissions  to  very low levels over the entire FTP.

     A metal monolith catalyst,  described earlier in Section III,
was installed immediately following the QLOC underfloor to simulate
a QLOC assisted by a main catalyst.  The larger main catalyst also
had the capability of being resistively heated, however,  at no time
during the testing commented upon here  was any resistive heating
applied  to the  main catalyst.   Catalyst heating of the QLOC was
limited  to the  15/40  convention, and air  addition occurred over
100-second intervals.

     Three separate catalyst configurations are  referred to  in the
remaining Figures.  Configuration "A" refers to the electrically
heated catalyst  only,  without  benefit  of a  main catalyst  in the
exhaust.  This data is  from the catalyst  testing  with 15/40 heating
and  air  addition  for  30   seconds.    Configuration  "B"  refers to
testing  conducted with the main  catalyst  only present  in  the
exhaust  stream.   No resistive  heating  or air  addition was used
during this testing.  Configuration "C"  is the QLOC with the main
catalyst close  coupled downstream.   Resistive  heating  here was
limited to 15/40, and air  addition occurred  in front of the QLOC.
This  additional  air   was   added  for intervals  of  100  seconds
following start in Bag 1.   Because the MC was coupled immediately
downstream of  the QLOC,  the  activity  of the  MC would also be
affected by the supplemental air.

     Figure 9 presents emissions data from the QLOC + MC testing,
compared with  other  selected  test results  of  single  converter
systems.   The  catalyst system  denoted "A" is  a  mode of QLOC
operation discussed previously  that appeared more efficient with
respect  to other  QLOC  operating conventions  evaluated.   Catalyst
system "B" refers to the evaluation of the MC without the QLOC in
the exhaust.

-------
                                20
                              Figure 9
                   QLOC & MC, W/WO Air Assist
                 Methanol Emissions, Bag 1 Of FTP

        Catalyst/Heat/Air Configuration

                           Baseline

                     A, 15/40, 30 Air*

                   B, No Heat, No Air**

                    C, No Heat, No Air

                    C, No Heat, 100 Air

                    C, 15/40, No Air***

                     C, 15/40. 100 Air

                                  0    5    10   15   20   25
                                     Exhaust Methanol (grams)
      •A (EHC Only), 15/40 Heat, 30 Sec Air
      -*B (MC Only), No Heat, No Air
      ***C (EHC+MC), 15/40 Heat, No Air
     The QLOC  alone,  in Configuration "A," provided good methanol
conversion efficiency in spite of  its limited size.  The simulated
MC  alone,   however,  was not  nearly  as  efficient  for  methanol
conversion.  The Bag 1 emission level  of 10.02 grams of methanol
was  comparable  to  the smaller  QLOC's performance  (10.69 grams,
Figure 3) in the unheated, no air  assist  mode.  Adding the  QLOC in
front of the MC  did not improve methanol  emissions to much  below 8
grams/Bag 1.   Even with the addition  of  air for 100 seconds,  the
decrease in  emissions to 6.08 grams was  only a small improvement
from the 7.54  grams noted  with the addition of air for 60  seconds
over the QLOC  only (Figure 6).

     Heating the QLOC + MC configuration,  in the absence of excess
air, significantly lowered methanol emissions from levels obtained
with the heated QLOC only.  1.46  grams of methanol in Bag 1  were
noted with the two-catalyst system and the QLOC heated 15/40 in Bag
1.  This is a 63 percent decrease from the 3.95  grams measured  with
QLOC alone heated  over the 15/40 convention (Figure 3).  With 100
seconds  of  excess  air  added  in  front  of  the  two-catalyst
configuration,   methanol  emissions   were  reduced   again   very
significantly  to 0.37 grams/Bag 1.

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                                 21

     The use of a MC also significantly assisted the conversion of
formaldehyde  emissions.   Roughly similar  levels of  formaldehyde
emissions  from Bag 1  were measured  from the heated/air  assisted
QLOC only (Configuration A) and the unassisted MC, Configuration B;
this  data  is  presented  in  Figure  10.    Substantial  successive
decreases  in  aldehyde emissions  were noted with  the  two-catalyst
configuration  (C)  when air  only,  then  heat  only,  and  finally
resistive  heat/air assist  were  utilized.   While the  final  two-
catalyst   configuration  tested  yielded  a  very  efficient  34
milligrams of  formaldehyde in Bag 1,  more additional testing would
have  to  be  conducted  to  determine  a  more  optimum  resistive
heating/air addition  strategy.
                              Figure 10
                   QLOC & MC, W/WO Air Assist
               Formaldehyde Emissions, Bag 1 Of FTP
        Catalyst/Heat/Air Configuration

                            Baseline

                      A, 15/40, 30 Air*

                   B, No Heat, No Air"

                     C, No Heat, No Air

                    C, No Heat, 100 Air

                     C, 15/40, No Air««

                      C, 15/40, 100 Air
1298
                                   0     400    800   1200   1600
                                  Exhaust Formaldehyde (milligrams)
      •A (EHC Only), 15/40 Heat, 30 Sec Air
      ••B (MC Only), No Heat, No Air
      »«C (EHC+MC), 15/40 Heat, No Air

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                                22

     Figure 11 presents  CO emissions over Bag 1 for Configuration
C.  Though not shown there,  it should be  recalled that the QLOC
alone,  with  120   seconds  air  assist,  gave  very low  Bag  1   CO
emissions  of  only  4.5 grams (Figure 8).
                              Figure 11
                   QLOC & MC, W/WO Air Assist
             Carbon Monoxide Emissions, Bag 1 Of FTP
        Catalyst/Heat/Air Configuration

                           Baseline

                      A, 15/40, 30 Air*

                   B, No Heat, No Air**

                    C, No Heat, No Air

                    C, No Heat, 100 Air

                    C, 15/40, No Air***

                      C, 15/40, 100 Air
                 37.3
     12.7

     13.1;

       15.9
1.7
                                  0    10    20    30   40   50
                                 Exhaust Carbon Monoxide (grams)
      •A (EHC Only), 15/40 Heat, 30 Sec Air
      ••B (MC Only), No Heat, No Air
      ***C (EHC+MC), 15/40 Heat, No Air
     CO emissions rose slightly above MC only levels, when the QLOC
was placed  in  front of it in the  exhaust stream (no resistive heat
or air assist  utilized).   No reason for this unexpected occurrence
is given  here.  No  unusual  driving conditions or  engine problems
were  noted during  this testing  that  might  have  contributed
substantially  to this unexpected result.

     The  addition  of air and  the use  of QLOC resistive  heating
separately  had a beneficial effect on catalyst performance.   The
use of 100  seconds  of air addition alone reduced Bag 1 CO emissions
by  50  percent to  7.4 grams, over  no  heat/no air  emission levels
with  the two-catalyst system.   QLOC  heating in  the  absence of
additional  air also  reduced CO,  to approximately  10  grams/Bag 1.
This   was  a   35   percent   improvement  from  the   two-catalyst
configuration  which did not  rely on QLOC resistive heating.  This
improvement was not noted when the QLOC was heated in the absence
of  a MC  (Figure 5).

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                                23

     A  very big  assist for  CO control  to  Configuration  C  was
provided by combined  QLOC resistive heating and  the  addition of
excess air.  Bag  1 emissions of CO were  reduced  to  1.7  grams,  a
very  significant  decrease  from  levels  measured  when  either
resistive heating  or  excess  air was  employed  alone.   Again, more
testing would have to be conducted, however,  to obtain an optimum
resistive heating/air addition strategy for CO.

     A  summary  of Bag  1  emissions from  the  two-catalyst system
testing is given below in Table 7.  Although much of the data there
has been discussed above,  one new observation which may be made is
that the addition  of the main catalyst did not cause a significant
decrease in NOx emissions  in  Bag  1.  The MC by itself was effective
as a  NOx  removal  catalyst,  yet  its  additional catalyzed surface
area did not substantially lower Bag 1 NOx emissions when added
behind the  QLOC.   Slight trends toward  increased NOx efficiency
with  catalyst   heating and  decreased  NOx efficiency  with  air
addition were  noted with the QLOC + MC  configuration.   Reduced
levels  of  other  emissions,  caused  by  the increased conversion
efficiency of the  heated/air  assisted QLOC, may  play a significant
role  in the ability  of the  MC to  reduce  NOx emissions.   More
detailed work would have to be conducted to quantify the effects of
the  reduction  of  other  emission  levels  caused  by  catalyst
heating/air assist on NOx conversion efficiency, however.

     Table  8 presents FTP average emissions  from the QLOC  + MC
evaluation.  The  very low Bag 1 CO  levels  from the  two-catalyst
system using both  resistive heating and air addition significantly
lowered  CO  over  the  FTP.    The  configuration  utilizing  15/40
resistive heating  and 100 seconds of  air addition was  the most
effective configuration tested overall.  While the CO levels of 0.2
grams per mile were very low, emissions of formaldehyde were also
measured at only four  milligrams per mile  with this configuration,
well under  the  level  of California standard of 15 milligrams per
mile.  It must  be  pointed  out that these 4 mg/mi emission levels
were achieved at low mileage.

     In the configuration suggested by  Camet  (QLOC  assisting  a
larger main catalyst)  the addition  of air  and the  use of resistive
heating appeared to be successful strategies to improve the overall
efficiency  of   the catalysts.   When  the no-heat/no-air  assist
configuration   is  compared   with   the  heated/air   assisted
configuration,  every FTP emission level except NOx  is substantially
lower with  the  assisted catalysts.  OMHCE, formaldehyde,  and CO
were lowered by approximately 75 percent.  NOx emissions over the
FTP were essentially  unchanged,  in spite  of the addition of air.
Further lowering of emission  levels could  depend upon a refinement
and better  integration of resistive heat/air addition strategies,
as well as  a more appropriate selection of active catalysts for the
application.

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                                24
                             Table 7

            Quick Light-Off And Main Catalyst Testing
                        Bag  1 Of FTP Cycle
   Category
NMHC   HC*   CH3OH  HCHO  OMHCE   CO    NOX
  g     g      g     mg      g     g     g
Baseline
15/40 Heat/No
Air/No Main
Catalyst
No Heat/ 60 Sec
Air/No Main
Catalyst
15/40 Heat/30
Sec Air/No Main
Catalyst
Main Catalyst
Only/No Heat/No
Air
QLC + Main No
Heat/No Air
QLC + Main
No Heat/ 100 Sec
Air
QLC + Main
15/40 Heat/No
Air
QLC + Main
15/40 Heat/100
Sec Air
1.55
0.17
0.05
0.10
0.21
0.19
0.07
0.04
0.02
7.33
1.51
2.70
0.74
3.51
2.83
2.09
0.57
0.17
19.14
3.95
7.54
1.83
10.02
7.95
6.08
1.46
0.37
1298
421
735
286
279
227
181
108
34
10.00
2.13
3.67
1.07
4.72
3.79
2.83
0.78
0.22
37.3
18.9
12.7
12.7
13.1
15.9
7.4
10.2
1.7
6.9
3.7
3.9
3.6
3.7
3.3
3.4
3.1
3.4
*    Gasoline-fueled vehicle measurement procedure with a propane
     calibrated FID.

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                                25
                             Table 8

            Quick Light-Off And Main Catalyst Testing
                  FTP Composite Emission Levels
NMHC HC* CH3OH HCHO OMHCE CO NOx
Category g/mi g/mi g/mi mg/mi g/mi g/mi g/mi
Baseline
15/40 Heat/No
Air/No Main
Catalyst
No Heat/ 60 Sec
Air/No Main
Catalyst
15/40 Heat/30 Sec
Air/No Main
Catalyst
Main Catalyst
Only/No Heat/No
Air
QLC + Main No
Heat/No Air
QLC + Main
No Heat/ 100 Sec
Air
QLC + Main 15/40
Heat/No Air
QLC + Main 15/40
Heat/100 Sec Air
0.28
0.03
0.00
0.02
0.01
0.02
0.01
0.01
0.00
1.17
0.16
0.23
0.13
0.26
0.21
0.17
0.08
0.06
2.93
0.36
0.69
0.30
0.73
0.57
0.47
0.19
0.14
323
51
91
50
22
16
13
9
4
1.63
0.22
0.35
0.18
0.35
0.28
0.23
0.10
0.07
7.3
1.6
1.4
1.3
0.8
1.0
0.5
0.7
0.2
1.6
0.8
0.8
0.8
0.8
0.7
0.6
0.6
0.7
*    Gasoline-fueled vehicle measurement procedure with a
     calibrated FID.
propane

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                                26

VIII.     Evaluation Highlights

     1.   Catalyst resistive heating alone reduced Bag 1 methanol
emissions by 50 percent from unheated catalyst levels with the QLOC
only in the exhaust.   (Several heating conventions were evaluated;
the most efficient convention was 15/40 heating.  This convention
was  only  slightly more  efficient  than  the  others  evaluated,
however.)

     Only  a slight reduction  in Bag  1 formaldehyde  levels  was
gained by resistively heating the QLOC in the  absence of additional
air.  Bag 1 CO was unaffected by catalyst resistive heating without
air assist.

     2.   Adding  air  in  front  of  the  resistively heated  QLOC
significantly improved its efficiency of methanol conversion.  Air
was added at an average rate of  5.0 SCFM; Bag  1 methanol emissions
were reduced approximately  50  percent  to two grams when  air was
added  for  30 seconds after  start.   Formaldehyde  emissions were
reduced approximately 30 percent from heated catalyst levels when
air was added for only 30  seconds in  front of  the heated catalyst.
Extending  the  time  of   air  addition   past  30  seconds  caused
substantial increases  in formaldehyde emissions.  Formaldehyde more
than doubled to 673 milligrams when air addition was increased to
120 seconds from the 286 milligrams in Bag  1 with air addition for
only 30 seconds.

     Bag  1 CO  emissions  steadily  decreased  as the time  of  air
addition was increased  at a constant rate of catalyst resistive
heating.  At 60 seconds of  air  addition following start,  without
catalyst heating, CO was measured at almost 13 milligrams in Bag 1.
This  emission  level  was reduced  by  more   than half,  to  5.9
milligrams when 15/40  catalyst resistive heating and 60 seconds of
air  assist were used.   CO emissions appeared  to decrease  at  a
slower rate as the time  of  air addition was extended  beyond 60
seconds.

     3.   Very low Bag 1 emissions of methanol, formaldehyde and CO
were measured when a main  catalyst was added to  the exhaust system
immediately following the QLOC.   Overall, the lowest emissions of
all three pollutants were obtained when resistive heating and air
assist to the QLOC were used simultaneously.  The main catalyst was
not resistively heated.

     The QLOC resistive heating/air addition convention used during
the two-catalyst system evaluation was 15/40 heating and air assist
for 100 seconds following  start  in Bag 1.  The simultaneous use of
these two assists decreased Bag 1 methanol emissions to 0.37 grams.
This was down  from 7.95 grams measured  with  no  resistive  heat or
air  assist provided  to  the two-catalyst  system.   Formaldehyde
emissions  were  likewise  affected;   formaldehyde  emissions  were
reduced to  34 milligrams over Bag 1 with QLOC resistive heat/air

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                                27

addition.    This  was  an  85  percent  improvement  from the  227
milligrams in Bag l measured when the two-catalyst system received
no resistive heating or air assist.

     The  largest  increase in catalyst efficiency  when resistive
heating/air assist was provided to the two-catalyst system occurred
for CO control, however.   Almost 16 grams of CO were measured over
Bag 1 with the two-catalyst system, when the QLOC was not supplied
with resistive heating or additional air.   CO was reduced to less
than two  grams over Bag  1  with 15/40 resistive heating  and 100
second air addition, a 90 percent reduction.

     Improvements in Bag 1 emission levels generally caused average
FTP emissions to decrease roughly proportionally to the decrease in
Bag 1 levels.   With the  resistively  heated and air assisted two-
catalyst system, OMHCE were reduced to a low 0.07 grams per mile.
Formaldehyde emissions were also very low at only four milligrams
per mile.   The greatest  percentage  increase  in efficiency from
unassisted catalyst operation, however, was in the category of CO
emissions.    The  heated/air  assisted two-catalyst  system  gave
average FTP CO emissions of only 0.2 grams per mile, an increase in
efficiency  of  80  percent  over unassisted  catalyst  operation.
Although  Bag  1  NOx levels  appeared to  increase slightly  with
increasing air addition times, the level of FTP NOx emissions was
0.7 grams per mile with the two-catalyst system either unassisted
or assisted with both resistive heating and air addition.

IX.  Future Efforts

     Future  efforts will  be  made to  quantify the  relationship
between catalyst heating/air addition and real time emission rates
of individual  pollutants.   These efforts will  be  concerned only
with the period of time during which resistive heating and/or air
addition is occurring.

     A Horiba modal analysis system has been installed at the EPA
Motor Vehicle Emissions Laboratory; this analyzer will be used to
map  the effects  of changes  in  catalyst  resistive  heating/air
addition on emissions.  While it is not possible to obtain methanol
or formaldehyde analysis,  CO, NOx,  and FID-measured hydrocarbons
emission levels will be determined.

X.   Acknowledgments

     The catalysts evaluated in  this  test program were supplied by
Camet Co.,  located  in  Hiram,  Ohio.  Camet is  a manufacturer and
sales agent for W.  R. Grace and  Company.  The methanol-fueled test
vehicle was supplied by Volkswagen of America.

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                                28

     The authors  appreciate  the efforts of James  Garvey,  Steven
Halfyard, Robert  Moss,  Rodney Branham, and Ray  Ouillette  of the
Test and Evaluation Branch, ECTD, who conducted the driving cycle
test  and prepared the  methanol  and  formaldehyde  samples  for
analysis.   The authors also  appreciate the efforts  of Jennifer
Criss and Leslie  Cribbins  of  CTAB,  ECTD,  for  word processing and
editing support.

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                                29

XI.  References

     1.   "Evaluation   of   Resistively  Heated   Metal  Monolith
Catalytic Converters On An M100  Neat Methanol-Fueled Vehicle, Part
II," Piotrowski, Gregory K., EPA/AA/CTAB/89-09, December 1989.

     2.   Air  Injection To  An  Electrically-Heated  Catalyst For
Reducing Cold Start Benzene Emissions  From Gasoline Vehicles," SAE
Paper 902115, Heimrich, Martin J., 1990.

     3.   1975 Federal Test Procedure, Code of Federal Regulations,
Title 40, Part 86.

     4.   "Recent  Developments  In   Electrically  Heated  Metal
Monoliths," SAE Paper 900503, Whittenberger, W. A.  and J. E. Kubsh,
February 1990.

     5.   "Resistive   Materials  Applied   To  Quick   Light-Off
Catalysts," SAE Paper 890799, Hellman, Karl H.,  et  al., March 1989.

     6.   "Recent  Results From Prototype  Vehicle And  Emission
Control  Technology Evaluation  Using Methanol  Fuel," SAE Paper
901112, Hellman, Karl H., and G. K. Piotrowski, May 1990.

     7.   "A  Resistively  Heated  Catalytic Converter  With  Air
Injection For Oxidation Of  Carbon Monoxide And  Hydrocarbons At
Reduced   Ambient    Temperatures,"    Piotrowski,    Gregory   K.,
EPA/AA/CTAB/89-06, September 1989.

     8.   "Evaluation  Of  A  Resistively-Heated  Metal  Monolith
Catalytic Converter  On A  Gasoline-Fueled  Vehicle,"  Piotrowski,
Gregory K.,  EPA/AA/CTAB/88-12, December 1988.

     9.   "Evaluation  of  A  Resistively-Heated  Metal  Monolith
Catalytic Converter On A M100 Neat Methanol-Fueled  Vehicle," Blair,
D. M., and G. K. Piotrowski, EPA/AA/CTAB/88-08, August 1988.

     10.  "Evaluation of Metallic And  Electrically Heated Metallic
Catalysts On A Gasoline Fueled  Vehicle,"  SAE Paper 900504, R. G.
Hurley, et al., February 1990.

     11.  "Electrically Heated  Metal Substrate Durability," SAE
Paper 910613, Whittenberger,  W. A., and J.  E. Kubsh, February 1991.

     12.  "Electrically Heated Catalyst System Conversions On Two
Current-Technology Vehicles," SAE Paper 910612, Heimrich, M. J., et
al., February 1991.

     13.  "Formaldehyde Emission Control Technology For Methanol-
Fueled Vehicles," SAE Paper 902118, L. R.  Smith, et al.,  1990.

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                                30

     14.  Sales   Literature,   Electrically   Heated   Catalytic
Converter. Camet Co., Hiram, OH.

     15.  Formaldehyde  Measurement In  Vehicle Exhaust  At MVEL,
Memorandum, Gilkey, R. L., OAR, QMS, EOD, Ann Arbor, MI, 1981.

     16.  "Formaldehyde  Sampling  From  Automobile  Exhaust:    A
Hardware Approach," Pidgeon, W., EPA/AA/TEB/88-01, July 1988.

     17.  "Sample Preparation  Techniques For Evaluating Methanol
and  Formaldehyde  Emissions  From   Methanol-Fueled  Vehicles  and
Engines," Pidgeon,  W.,  and M.  Reed,  EPA/AA/TEB/88-02, September
1988.

     18.  "Catalysts  for Methanol  Vehicles,"  SAE  Paper  872052,
Piotrowski, G. K., and J. D. Murrell, November 1987.

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