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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.

D.

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

ratio.

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

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96-470 - 73 - pt. II - 32

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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
this it is apparent that the emission of particulate matter due
to attrition is practically non-existent. It is interesting to
note that lead emissions from a vehicle using ordinary leaded fuel

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

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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

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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
are non-existent or very faint. Supporting data for the above

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

Process

Haensel, Vice President Science and Technology and Mr. Melvin J.
Sterba, Assistant to the Vice President of Development
Division, of Universal Oil Products Company. This statement focuses
attention to the energy problem with regard to emission control.

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ANSWER: About two years ago our platinum bearing catalyst (P2-195) was

exhibiting a fair amount of shrinkage and subsequent attrition.
A study was made to see at what temperature this occurred and what
could be done about it. Exhibit D attached hereto shows the data
for that catalyst and shows that at 1600° F bed temperatures there
was a 25% catalyst loss with only 51 cycles of operation. A new
catalyst was developed (PZ-216) and at tests run at the same tempera-
ture it ran twice as long with no catalyst loss. The exhibit also
shows that the stabilized catalyst at 1900° F showed only a 3% loss

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as compared to the previous 25%.

The stabilization technique used for this catalyst (PZ-216) was
one that was brought about by the incorporation of a compound in
the catalyst which prevents the shift from gamma alumina to alpha.
This is the shift in alumina structure which brings about shrinkage,

smaller surface area and less strength.

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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.
July 30, 1973

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