Motor vehicle emission control

The development of catalytic reactors for cleaning the exhaust gases of motor vehicles has been stimulated enormously by Californian legislation. In 1959 and 

1960 laws on motor vehicle emission standards were enacted which would become operative when at least two different devices were developed which could measure these standards. This gave a large impetus for the research. However, in the mid- 60s, the car industry announced that engine modifications were successful and that the standards could be met without catalytic converters. This delayed further research in the development of catalytic converters. In the late 60s a further tightening of the standards was announced and catalytic research increased considerably. The Clean Air Act of 1970 set standards that went well beyond existing technology and it was clear that catalytic mufflers would be essential. 

1 the activity for NO reduction is high, but not for the oxidation of CO and hydrocarbons. At X 1 the reverse is the case. A special control system had to be developed to guarantee the desired exhaust gas composition. The control system appears to be more critical than the catalyst itself. 

The catalysts in use contain Pt and Rh as major constituents. A converter typically contains 1-2 g Pt and 0.2-0.3 g Rh. The design of the reactor has received a lot of attention. Beads were also applied initially, but nowadays monolithic honeycombs are used almost exclusively. 

The introduction of catalytic converters has had a tremendous impact on the composition of gasoline. The catalysts used became poisoned by small amounts of impurities in particular the lead compounds present in high octane gasoline were detrimental. Processes which produce high octane number compounds were therefore stimulated. First, cracking and reforming increased in importance. More recently, the aromatics content is also expected to have to decrease and alternative processes are in use or under way, e.g. the production of MTBE (methyl tertiary-butyl ether). 

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S. Albu, "California s Regulatory Perspective on Alternate Euels," 13th North American Motor Vehicle Emissions Control Conf (Tampa, Fla., Dec. 11—14, 1990), Mobile Source Division, California Air Resources Board, El Monte, Calif. 

For a description of some of the issues involved in motor vehicle emissions control, see Calvert et al. (1993), for those involving diesel emissions, see Walsh (1995), and for motorcycle emisions compared to passenger cars, see Chan et al. (1995). 

The federal government also preempted the motor vehicle emission control. California alone, among all the states, was able to receive waivers of federal preemption of motor vehicle control. This was permitted because California was able to prove that it had a pressing need for vehicle emission standards more stringent than those adopted by the federal government for the remainder of the country. 

W. Berg, Evolution of Motor Vehicle Emission Control Legislation Leading to the Catalyst Car , SAE 850384. 

For a report on the current status of motor vehicle emission control, see M.V. Twigg (2003) Platinum Metals Review, vol. 47, p. 157. 

See also Batteries Capacitors and Ultracapacitors Electric Motor Systems Emission Control, Vehicle Environmental Problems and Energy Use Flywheels Fuel Cells Fuel Cell Vehicles Flybrid Vehicles Materials Transportation, Evolution ofEnergy Use and. 

U.S. Environmental Protection Agency. (2000). Control of Air Pollution from New Motor Vehicles Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements. Federal Register 65 6698-6870. 

Serious research in catalytic reduction of automotive exhaust was begun in 1949 by Eugene Houdry, who developed mufflers for fork lift trucks used in confined spaces such as mines and warehouses (18). One of the supports used was the monolith—porcelain rods covered with films of alumina, on which platinum was deposited. California enacted laws in 1959 and 1960 on air quality and motor vehicle emission standards, which would be operative when at least two devices were developed that could meet the requirements. This gave the impetus for a greater effort in automotive catalysis research (19). Catalyst developments and fleet tests involved the partnership of catalyst manufacturers and muffler manufacturers. Three of these teams were certified by the California Motor Vehicle Pollution Control Board in 1964-65 American Cyanamid and Walker, W. R. Grace and Norris-Thermador, and Universal Oil Products and Arvin. At the same time, Detroit announced that engine modifications by lean carburation and secondary air injection enabled them to meet the California standard without the use of catalysts. This then delayed the use of catalysts in automobiles. 

Motor vehicle emissions catalysis for, 24 57-125 see also Exhaust gases, automotive Federal control requirements, 24 60, 61 MP2 method, 42 135 MS, see Multiple scattering MSD... 

Barth, D. S. Federal motor vehicle emission goals for CO, HC, and NOx based on desired air quality levels. J. Air Pollut. Control Assoc. 20 519-523, 1970. 

In Sweden, three-way catalysts have been required on all cars since 1989, and tax incentives were offered to purchase such vehicles in the 1987 and 1988 model years. Figure 16.34 shows the CO and hydrocarbon exhaust emissions as a function of model year of gasoline-powered cars, measured using a remote-sensing technique (Sjodin, 1994). There is a large decrease in the emissions from 1987 to 1988 and 1989, supporting the effectiveness of these motor vehicle exhaust controls. 

Hence, a feasible control strategy should be the use of fuels with smaller mass emissions, reduced reactivity of the emissions, or both. We discuss briefly some of the chemical implications of the use of some of these alternate fuels. For a more comprehensive treatment of the advantages and disadvantages of alternate fuels and technologies, see the National Research Council report (1991), and for a discussion of a variety of issues associated with motor vehicle emissions, see Cadle et al. (1996, 1997a, 1997b) and Chang et al. (1991). 

The Mulford-Carrell Act of 1967 dissolved the Motor Vehicle Pollution Control Board in California and created the Air Resources Board that was provided with broad powers and authority and with the ultimate responsibility of controlling air pollution in California. The California Air Resources Board divided the State into eleven air basins, areas with similar meteorological, topographical, and air pollution problems. Ambient-air quality standards were adopted which apply to all of these basins. The enforcing of these standards is still primarily a function of local go /emment, but emission control programs of local agencies have to be s ibmitted to and approved by the State Board. 

In 1977, this Act was amended to extend the deadline of meeting the motor vehicle emissions standards. These amendments also made a first attempt to control stratospheric ozone and created the New Source Review, which required older grandfathered facilities to install pollution control technologies as they modernized. 

EPA-Gasoline-RIA. Regulatory impact analysis—Control of Air pollution from new motor vehicles Tier 2 motor vehicle emissions standards and gasoline sulfur control requirements. US Environmental Protection Agency, Air and Radiation. EPA420-R-99-023, December 1999. 

The aim of the experimental tests performed on the overall power train is the evaluation of efficiency and the individuation of the basic energy management strategies necessary to assure proper vehicle operation. The experimental investigation is performed in dynamic conditions on two different urban driving cycles, the R47 and R40, considered by the European regulations on vehicle emission control. In Fig. 6.21a and b, the two cycles are reported in terms of motor speed versus time. 

In general, requirements must be so framed that they do not prevent innovation they must not present unrealistic or arbitrary standards. It must be borne in mind that however necessary the control of motor vehicle emissions and noise may be - and no one would deny the necessity - there are other considerations, such as safety, cost, reliability, which also have to be balanced. 

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