Document 4JVZ0ezdovOyNBV4yv8oVZjyp

LEAD INDUSTRIES ASSOCIATION, In c . 292 MADISON AVENUE NEW YORK, N.Y. 10017 TELEPHONE-AREA CODE 212 OR 9*6020 SUBJECT; June 10, 1968 CHALLENGE; AIR AND THE AUTOMOBILE To; Board of Directors and Industry Development Committee Please find attached a copy of a booklet entitled CHALLENGE; CLEAN AIR AND THE AUTOMOBILE which has been published by the Petroleum Chemicals Division of Du Pont. We believe you will find it of some interest. The booklet discusses the role of lead antiknock compounds in air pollution beginning on Page 3. Du Pont's development of practical methods to reduce pollutants in vehicle exhausts, their exhaust manifold reactor, as discussed by Mr. Allan Taft at the Directors' Meeting in Montreal-is described on Page 16. If you would like additional copies of the report we shall be glad to supply them. Sincerely yours.  ' s . ' : N 706.01 Progress & problem Everv advance in tecnnoioqv tends to introcluce new problems as well as nenents. This is simpK part or the price ot progress, tor no event, even in technologv. is unattected bv or tails to ariect other events. * Motor vehicles-- autos and trucks --are a case in point. Their convenience and necessitv are unquestioned. Their development has led to physical changes ot the verv luce ot the earth -- and vast changes in the verv nature ot society. But a price we pav tor these benefits is the concern we reel about the emissions from these multitudinous sources. This is a subiect ot increasingly broad and searching inquiry, with particular attention directed to the possible effect on public health and comfort. Du Pont is intimately involved in the investigation of automotive emissions and in the whole subject ot fuels, fuel additives, and engines because ot its position as a maior supplier of chemical additives to the petroleum industry. The investigations center in two important areas of pollution arising from vehicle emissions: the role of lead antiknock compounds in air pollution, and the development of practical methods to reduce pollutants in vehicle exhausts. This booklet presents some recent research findings and activities in these areas. The work described is continuing. Already, significant contributions to better understanding and eventual control of vehicle emissions have been made. A task force approach To tile search tor knowledge about vehicle emissions. Du Pont brings consicieraple resources. Leading the investigation tor the Petroleum Chemicals Division are the 180 scientists and technicians of its Petroleum Laboratory Also participating are the stall ot b5 scientists and technicians or Haskell Laboratorv tor Toxicology and Industrial Medicine and other scientific and technical resources of Du Pont. Further, Du Pont sponsors research into the effects of lead and auto exhausts m manv colleges and universities. This includes, tor example, blood and urine studies in southeastern Peru and the -\ustraiian "outback,'' analyses of ancient bones in Arizona and Nevada, and iead levels in the blood of pregnant women in Pennsylvania. To conduct work in the area of automotive emissions, some extremely sensitive instruments have been assembled. Manv were developed and built bv Du Pont just tor this purpose. These research activities have two principal aims. One is concerned with improving the efficiency, economy and performance of existing fuels. The other is to add Du Pont's scientific resources to those of the oil industry in a common effort to understand the nature of automotive emissions, to determine what may be harmful in these exhausts, and to propose methods and devices to eliminate or substantially reduce these pollutants. Here is what Du Pont has done and what it has round. v -, A :jC-; i-r- Effect of lead antiknocks on exhaust emissions V automotive miieage mounts, so do the cieposib that accumulate in the combustion chamber: this usuallv increases exhaust emissions. Conversely, removal of these deposits reduces these emissions. Do leaded fuels cause greater emissions than unleaded fuels? In an effort to answer this, Du Pont launched the most comprehensive testing program of its kind vet conducted. This was necessary because, after analysis, it was concluded that all previous test procedures proved unsatisfactory in one wav or another. Experiments using engines mounted on laboratory test stands can be misleading; the results Depend upon the method in which the engine is operated. Similarly, road tests, or proving ground tests, with cars driven repetitively over prescribed courses can vield erroneous conclusions, again depending on how the test is accelerated in terms of rate of mileage accumulation and the number ot stops and starts per dav. How, then, can a true test result be obtained? And, further, how can you test cars the wav the public reallv drives them? The answer is to test automobiles under actual road conditions, as thev are reallv driven, bv the people who own and drive the cars. This is the procedure Du Pont followed. A fleet of 122 cars The purpose was to see what effect lead in the gasoline has on exhaust emissions. The method LI AC1c 3fc <! I I I I I J i<> 'ub'icuze the ownem ui 122 iir.md new car' ut late tc't)4 and eariv ini-,3 model' representing the various make' anti models in correct proportion to their national sales. Halt the cars were tueled with six brands ot ieacled gasoline and the remainder with a commercial unleaded premium gasoline. All the cars were driven bv their owners in their normal dailv routine and were maintained in normal fashion. Average mileage per car in each ot the two groups was 12.000 per vear. Sensitive and accurate measurements ot exhaust emissions were made on each car everv two months tor 18 months, emploving the standard Calitornia cvcle technique. It was round that carbon monoxide emissions were essentiallv-equivalent tor the two fleets, so lead, apparently, was no factor here. A difference was found in hydrocarbon emissions, but the cars using leaded fuels emitted only _ per cent more hydrocarbons than those using unleaded fuel. Lead and control devices Since the 1966 model vear, all new cars sold in Calitornia have been equipped with exhaust emission control devices as required bv law. Beginning with the 1968 models, such control devices are required nationwide. The question naturailv arises as to how these devices will arfect the relative performance of leaded and unleaded fuels with respect to exhaust emissions. To check this point as quicklv as possible, Du Pont bought on the open market in California twelve cars of each of the three most popular low-priced models, all factory-equipped with exhaust emission control devices. After careful tune-ups to meet factory specifications, these cars were loaned to 36 families for use as their family cars. Half the cars were tueled with leaded gasoline, the other half with an unleaded 4 L I A01937 Exhaust irum Calhnrnia Cycle type tests is collected in large plastic bags iletti and anakzed tor total hydrocarbons jnd carbo: monoxide b\ eouipmrnt shown above. Concentrations ot spectnc hydrocarbon- are 'ub>equentl\ determined cnromatograpnicaih and calculated bv computers iriehtl. Part ot a typical computer printout is shown below. S***. *' , . " ,v- : ^ 1 I I :j : --* js3 L4|ii.iss -M* M i -4 4 W- s -i ? i t s --4 -a x -4-3- ilJS- -4 2 ---S4-S| 8^il 1< 3<H ^n1i33s15 -"----iiill*!!! i ! -- -* -49 *- rm4sU-rwi-ffS-U5-gs1j*-*i* -- t? *i? i i ii-ia---------44-4 -i 4 4 S LU01938 *' L1401939 gasoline. Each car was methodically switched from one tamilv to another every week. Emission measurements were made on each car every two months ror twelve months. Average mileage accumulation was about 1000 miles per month. Here again, the test was run under conditions the motorist actually encounters. The results show' that the average hydrocarbon emission level with leaded fuel was 6 per cent higher than with unleaded fuel --essentially the same result observed in the 122 car test, mentioned above. Furthermore, the level waned considerably from one make of car to another. There was more difference among the makes of car than there was between leaded and unleaded fuel in anv one make. In tact, only one make produced any significant difference between leaded and unleaded fuel. Carbon monoxide emissions again were not affected by lead antiknocks. Significance of the tests These results led Du Pont researchers to the conclusion that the presence of lead in the gasoline is not significant to the industrywide effort to reduce hydrocarbon emission. Leaded fuels are at onlv a slight disadvantage insofar as hydrocarbon emissions are concerned. More importantly, the effect in absolute terms is proportional to the emission level, although the percentage effect is the same. Thus, a 7 percent lead effect at a future emission level of 100 ppm will be onlv 7 ppm, a very small quantity indeed. Thus, the question is not lead versus no lead. The question and the problem is hydrocarbon emission itself. What is the nature and composition of the hydrocarbon emission, how can the various components be detected and isolated, and how can they be eliminated or significantly reduced? Du Pont has made some important contributions here, and they are discussed on the following pages. 36-CAR TEST EQUILIBRIUM EMISSION LEVELS LEADED V UNLEADED 400---------------------------------------------------------------- CAR A CAR B There is very little dillerence in hydrocarbon emission ievels between cars using leadea and unleaded rue/s. CAR C ^ '' V !?N. w. L I A 91 Q a 0 ' - ,-Mvi\ Hydrocarbon detection -- one part per billion in exhaust gas One minute in aiI the minutes since the vear 1 A.D. -- this is what one part per billion means. That also is the degree of sensitivitv of a gas chromatographic technique developed be Du Pont tor detecting hydrocarbons. It is now in daily service analyzing exhaust gases of Du PontT lest cars. Because there are hundreds ot different kinds ot hydrocarbons in exhaust gas, each with varying reaction rates in forming photochemical smog, it is essential to obtain specific information about the concentration of each individual kind of hydrocarbon before one can calculate the smog potential of exhaust gas. The problem of identification and detection is further complicated because some ot the hydrocarbons occur in very low concentrations. The gas chromatographic method developed by Du Pont has, in addition to a sensitivitv of one part per billion, a capability ot identifying and determining the concentration of more than 130 individual hydrocarbons in a single exhaust gas sample. The method employs two columns to determine the full range of CrC,j hydrocarbons in exhaust. A packed column is used at room temperature to determine C,-C2 components, while a capillary column separates the C3-C12 hydrocarbons as the temperature is varied from -70C to -t-120C. The columns are valved together and share a single flame-ionization detector. The hydrocarbon 1 I *.: samples m exhaust in vrijii plastic hag are analyzed lor specific hydrocarbon> bv gas chromatography. The ultra sensitive technique uses a 150-toot capillary column (below). In the chromatogram (above! each peak represents an individual hvdrocaroon 7 8 BPS L IZ 0 1 9 4 1 peak areas are automatically measured bv an electronic integrator as the chromatogram is recorded. Total analysis time is onlv J5 to .50 minutes. Equally difficult. and often more trustrating, has been the ettort to develop obiective and accurate methods tor collecting exhaust samples The problem is to send to the analyzer the same sample that is taken trom the exhaust pipe. Hydrocarbons at low concentration are easily lost through reaction with oxygen, or bv photochemical reaction with nitrogen oxides, or through absorption or adsorption on the walls ot containers, or in countless other baffling wa\s. Knowledge gained in overcoming these obstacles is being made available to industry and government laboratories. A 'wfcfwVJ.ai*! . - . - .....- -s- %'<--' . r . ' ` 4 (topi Draitai inteurator suppnemtormata o tor computing concentration*. ot each h\arocarbon. ibottom left) ipecial proportional iampler e designed to ootuin representa tive exhaust simple trom car operation on the bigfnvjv where collection ot total exhaust is impractical. s> 10 Li 1019A3 Equipment ttop) is in the control room ot the six-car pro grammed chassis dynamometer. The operation ot a car on the chassis rolls is controlled bv a magnetic tape which is made bv recording the operation or a car on the h/ghwav and citv streets. Thus, the car on the rolls duplicates the operation ot the car on the highway. Gasoline composition -- its effect on unburned hydrocarbons in the exhaust Can the amount and kind ot unburned hydrocarbon m the exhaust be altered b\ cnanges in tuel composition? Because ot that question's importance to Du Pont s customers, an extensive search tor the answer was undertaken. Sixteen tuels were prepared, statistically designed and blended to cover tuel compositions and yolatililies now marketed or which might be marketed in the future. The^e 16 tuels were evaluated in a car equipped with an air-injection exhaust emission control system using the California cvcle technique tor measuring total hydrocarbon emissions. In addition, throughoutthe tests gas chromatographic analyses were made ot the exhaust. The results showed that fuel composition had little eftect on total hydrocarbon emissions, or even on the photochemical reactivity of the unburned hydrocarbons. This was true tor the whole range or fuel compositions. The program has been expanded now- to include even more fuels and more cars: standard cars without exhaust emission control: cam equipped with air-injection systems: cars equipped with engine modification systems- and. finally, a car equipped with the new- Du Pont exhaust manifold reactor giving verv low emissions (page 16). The work is well along. The data analyzed so far show- that the specific hydrocarbons round in the exhaust depend on the specific hydrocarbons in the fuel. On the other hand, the research data show that the fuel composition has little effect on the quantity ot hydrocarbons in the exhaust, or on their photochemical reactivity. LI*01944 k LIA01945 Exhaust particulates -- a difficult sampling technique resolved Air pollution is a broad term encompassing not onlv gaseous material but also manv different kinds ot solid particles, or particulates. While quite a bit is known about these particles, more intormation is needed about their behavior --their size, their shape, their weight, their aerodvnamic characteristics, their airborne life, and their dura bility. One reason tor this apparent ignorance is the host of-experimental difficulties encountered in trapping, identifying, and studying these extremely minute bits of matter. As part of the investigation into the nature ot automotive exhausts, it is necessary to studv the quantity and size of exhaust particulates over extended periods of cvclic vehicle operation. Further, it must be learned how manv of the particles stav suspended in the air, and tor what periods of time. All of this demanded special equipment including a 50-toot long, 22-inch diameter insulated tunnel which the engineers and technicians call the "rocket launcher." This "instrument" is attached to a six-car chassis dynamometer, which, under the direction ot a programmed magnetic tape, operates a test car exactly as a driver would operate his car on the open highway or in crowded city streets. Its basic program tor studying particulates, however, is the Particulates in exhaust are determined bv several techniques. The 50-toot tunnel (left) is used to dilute exhaust samples prior to analysis. 15 qub *01 i s}z*-*' 14 i..' 11., LIA01947 - - ~ w*,..*.. ^rr n mftii>i>ini*iMrt*i T test schedule specified in the Federal Register tor certification tests of emission control devices. Exhaust gases trom the car flow through a short pipe into the end of the tunnel. There, thev mix with fresh air being drawn through the entire length ot the tunnel bv a large tan. The problems involved in mixing these gases and in attaining umtorm velocities across the diameter ot the tunnel were substantial but, alter extensive tests and modifications, all were overcome. Exhaust gases can now be diluted bv 1000-to-one. or even 10,000-to-one, and still provide a trulv propor tional sample tor physical and chemical anaKsis. With these testing techniques and instruments now refined and operating, attention can turn to the next step: identifying and describing the kinds of particles that tend to stav airborne. Some of these particles are as small as a traction of a micron. The next step is to investigate methods ot tailoring the ingredients ot automotive tuels so that the particles coming out ot the tailpipe will settle more rapidly. Large cylindrical tillers are used to collect total par ticulates in exhaust in dynamometer tests. Paniculate sample at several magnifications, ibelowi WCV*' m u p.1 --y - --- LIA0194B 15 To remove pollutants from the exhaust -- an important new development Perhaps one of the most promising developments in the right against automotive exhausts is Du Pont's work with the exhaust manifold reactor, pictured at the right and below. The product of the combined talents of dozens of physicists, chemists, engineers and technicians, this noncatalvtic device has achieved the best control of exhaust emissions to date bv anv svstem known.- In principle, the reactor provides a high tem perature zone in which auto exhaust components are oxidized to carbon dioxide and water before thev pass out through the exhaust svstem. The reactor is mounted on the engine and replaces the conventional exhaust manifold. As the illustration on page 19 indicates, the reactor 1(> t- Uoi 9 49 1* LIA01950 m iniirt i rirtMIlfcirh h i II consists ot an insulated outer shell in which is mounted a tubular core. Exhaust gases, mixed with air supplied bv a conventional air injection svstem, tirst enter the tubular core; battles at each end divert the gases trom the ends back to the center, thus prolonging their stay in the hightemperature zone and speeding their breakdown into carbon dioxide and water. Although the work on this reactor is still labeled "developmental," experimental models have been made available to petroleum companies, automobile manufacturers and government agencies. Scientists point out that the principle behind this device is sound and well established; what are still undetermined are the questions of materials to be used, the most efficient size and the feasibility of producing it at the least possible cost to the automobile owner. But Du Pont is confident that this type of reactor will be developed into a commercial realitv with w ide acceptance. DUPONT EXHAUST MANIFOLD REACTOR PERFORMANCE OF DUPONT EXHAUST MANIFOLD REACTOR i8 20 25 30 35 MILES. THOUSANDS (abovel Drawings show path ot exhaust through manifold reactor and installa tion ot reactor on an engine. (chart) In a 50,000 mile test, reactors maintained exhaust emissions at tow levels. LIA01952 *. ' V. 1 Reactor' mu,'/ withstand high temperatures and ero'ivc atmosphere' tor long periods. Picture (right) is pros'section os an experimental coated metal showing distribution or elements alter test as determined bv an electron microprobe instrument, (below) Experimental reactor undergoing a durability test, (right) A rig used to simulate exhaust manifold conditions in search tor durable metals. The test specimens are mounted on a doc rotating at high speed in the burner dame. 3* Lead in the environment Because somewhat more than 50 per cent of the lead in the antiknock compounds that are added to gasoline mav be discharged in the vehicle exhaust, concern has been voiced about the effect of this lead on the environment. Du Pont has a vital interest in this question, and for this reason has been in the forefront of research directed towards scientific answers. Its studies have been published in scientific journals and have added considerable know ledge to the subject. Even though the overwhelming evidence shows that no present hazard exists, the investigation is continuing. An early concern -- and it is a continuing one -- was for the health of the people who make the lead antiknock. The Company has applied its knowledge to this area since first starting the manufacture of antiknock compounds. And over the years has compiled extensive knowledge concerning the effect of lead on a large bodv of people in daily contact with it. A recent study comparing the health histories of a large group of workers making lead antiknocks with similar groups not having this exposure to lead shows that there Is no discernible difference between the two groups, even though the worker group under went industrial exposure in addition to everyday community exposure. Du Pont has sponsored other studies to com pare the lead levels found in the blood of urban and rural people. To conduct this research, scien tists collected blood samples from as far away as the jungles of Brazil and the wilderness of New Guinea. No appreciable difference was found in the distribution of lead values among all these groups and those of urban populations, indicating that factors other than vehicle emissions are probably at work here. This view is further reimorced bv a thorough review of all the published data on this subject which shows no change in the lead concentration of widespread groups of Europeans and North Americans over the last 36 years. Investigations continue. One studv sponsored bv Du Pont is taking soil cores rrom the bottom of Crater Lake, in Oregon, to examine the soil content and atmospheric fallout in that area for the last 2000 years. Crater Lake is 2000 feet deep and is uniquely suited for providing these data, since it is watertight. The only loss of water is through evaporation; therefore anv airborne particles that fall on the lake eventually settle to the bottom. Du Pont's specific interest here is to see if there is a difference in lead content between present-day surface soil and the soil of 150 B.C. and of the intervening years as well. < L IA01955 Pedigreed ran are used to study effects of lead ingestion on health of siirus'/ie generation'. In these test' pathological studio* are made on JS ti"ue t\pes trom each rat. trighti Core- nom the bottom 01 Crater Lake. Oregon, are being analyzed to determine whether there are differences between lead at the bottom and top of the core, which would indicate fallout of airborne particulates, ibelowi Blood specimens trom primitive people are analyzed for lead for compari son with blood levels from populous areas. i LI* 01956 mrm ELUjri Itmj ri'lJW) '1' L 1401957 LIAQ1958