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Replacement is a simple operation involving draining and
replacing the pellets using a procedure that is as quick
and simple as adding or changing oil. With Monolithic
catalysts, there is no way to touch-up the converter or
remove just the catalyst. The entire catalyst including the stainless steel container must be removed and replaced.
This would be more expensive and the cost would probably
range from $50 to $100.
What discoveries has UCP made in reducing oxides of nitrogen?
ANSWER: Oxides of nitrogen can be reduced by using a two bed system,
the first of which is a reducing catalyst and must be run
rich of stoichiometric. The second bed is an oxidizing
catalyst and has air injected just before it. We have run
tests on thousands of catalyst samples in our Research
Department and have run about 300 tests in our Automotive
Research Laboratories on these catalysts. The developments are such that these catalysts do a good job of reducing NOx
but do not have good durability.
We believe that three-component control systems are far more
promising than dual-bed catalyst systems. Three component control systems are based on the well established fact that
if the air/fuel ratio is maintained at the stoichiometric
ratio, about 14.7 to 1, the composition of exhaust gases
leaving the engine will be such that a single bed catalyst
can be used to simultaneously eliminate all three pollutants.
Laboratory test data shows NOx reductions of 80% to 90% are consistently available on well designed, three-way catalysts. This is adequate to achieve NOx emissions at about the levels required by the 1976 Standards. Work completed in May by the
Bartlesville Energy Research Center of the Bureau of Mines
confirms some of ou
observations. Steady state tests
conducted by them on a UOP three-way control catalyst at
60 mph road load showed conversions of NOx as high as 93% when
air/fuel ratios were accurately controlled.
Using present types of carburetion, the only way known of
maintaining the air/ fuel ratio through all engine modes is
through the use of a feedback control loop. A sensor in the
exhaust line is used to analyze exhaust gas composition
continuously and feed information back to the carburetor
concerning corrections needed to maintain the stoichiometric
The technological gap remaining to be closed to develop a
mass producible sensor is at least as small as that re
maining to develop a reducing catalyst having satisfactory durability and certainly is smaller than the time required
96-470 - 73 - pt. II - 32
E. Do pelleted catalyst produce particulate matter due to attrition and
do they emit carcinogenic matter?
ANSWER: In four (4) 50,000 mile tests of pelleted catalyst, which have
previously been reported to the EPA, we found that an average loss of the Noble Metal was 0.6 micro-grams per mile. In all
of these tests the weight of the catalyst after the test was
more than the weight of catalyst going into the test. From
at 3 grams per gallon emit 50,000 times the weight of lead as we
would expect converters to emit platinum. Even when the lead
level in the fuel is reduced to .05 grams per gallon, lead emissions will still be 500 times greater than platinum emissions. Both lead metal and lead salts are known to have toxic effects
whereas platinum metal is not known to have toxic effects.
With regard to the second part of the question, catalytic
converters have been found to be 95% effective in removing polynuclear aromatic hydrocarbon (PNAH) tars from automobile exhausts. Typical automobile exhaust emits about ten milligrams of these tars in one hour. This compares to eighteen milligrams contained in the smoke from one cigarette. After passing through a catalytic converter, the same amount of exhaust would
contain only 0.5 milligrams of tar. This means that all of the
exhaust from a vehicle equipped with a catalytic converter would
have to be inhaled for 36 hours before exposing the body to the
same amount of tar contained in one cigarette.
F. What is the effectiveness of a catalytic converter with regard to reduction
of emissions and odor from a diesel engine?
ANSWER: Our tests have shown that a pelleted catalyst system will reduce
diesel engine emissions of hydrocarbons and carbon monoxide about
70%. With regard to odor emissions, tests have indicated that the
catalyst is very effective in reducing odors to a level where they
statements are contained in Exhibits A and B attached hereto.
G. What is the energy loss in producing sufficient quantities of lead-free
fuel to run catalyst supplied vehicles?
ANSWER: Catalytic systems have been proven to increase the performance
and efficiency of vehicles which previously had been tuned for maximum pollution control. This increase in performance and gas mileage is due to several factors among which are the modifications of the air/fuel mixture and spark advance. Attached to this
statement as Exhibit C is a statement prepared by Dr. Valimir
Haensel, Vice President Science and Technology and Mr. Melvin J.
ANSWER: About two years ago our platinum bearing catalyst (P2-195) was
exhibiting a fair amount of shrinkage and subsequent attrition.
as compared to the previous 25%.
The stabilization technique used for this catalyst (PZ-216) was
smaller surface area and less strength.
The above cited data were collated on a single cylinder engine. The credibility of that data was improved by running durability tests on the stabilized (PZ-216) and unstabilized (PZ-195) catalyst in a 1971 vehicle to determine catalyst loss. Exhibit E sets forth these tests and verifies the single cylinder data showing a strong improvement in reducing catalyst loss due to shrinkage.
W. R. Price, Jr.