Barry John Cooper

Optimising the Low Temperature Performance and Regeneration Efficiency of the Continuously Regenerating Diesel Particulate Filter (CR-DPF) System

An electrooptical scanning device which can detect the relative position of register mark applied to a moving web, either serially on a single track or in two parallel, side-by-side tracks which extend in the direction of movement of the web. Light from a light source positioned some distance above the web is split into three light beams and the light beams are reflected downwardly towards the web. Lenses are positioned to receive and direct the light beam at an oblique angle onto the marks on the track or tracks. The lenses are aligned with the tracks and the light beam passing through a given lens is directed to the opposite track to illuminate three positions, two on the first track and one position on the second track. Light impinging on the web at these positions is scattered. Vertically upwardly scattered light is captured by the lens overlying the particular illuminated position and hence directed via suitable optics to photo-detectors which generate output signals that can be used to determine the relative locations of the marks to thereby detect any misalignments of the web.

Aspects of Automotive Catalyst Preparation, Performance and Durability

The development of legislative controls on petrol engined passenger cars in the USA and Western Europe is reviewed. The application of catalytic control strategies to these requirements is discussed. The principle components of modern exhaust emission control catalysts are identified. They comprise (a) a ceramic substrate, (b) a high surface area wash coat, (c) base metal promoters and/or stabilisers and (d) platinum group metals either singly or in combination. The functional role of these components is discussed and their interaction reviewed from the materials technology standpoint. Aspects of catalyst performance and durability influenced by preparation factors are discussed with particular reference to factors (b), (c) and (d).

OPERATIONAL CRITERIA AFFECTING THE DESIGN OF THERMALLY STABLE SINGLE-BED THREE-WAY CATALYSTS

The successful utilization of single-bed three way catalysts is dependent upon high initial catalyst activity and maintenance of this activity after exposure to a wide range of exhaust composition and temperature. A review of performance after aging under a variety of engine dynamometer and thermal cycles indicates high temperature aging is particularly detrimental to CO conversion while HC conversion is most sensitive to chemical poisoning. Results on individual Platinum Group Metal Catalysts show Platinum has good chemical poison resistance, but is sensitive to thermal deactivation. Palladium shows good thermal stability, but exhibits more deactivation by chemical poisoning. Rhodium is significantly deactivated by lean high temperature aging. These results have been used to compare and contrast the deactivation of bimetallic and trimetallic catalyst formulations. A new generation of catalysts has been developed utilizing the above information. These catalysts exhibit substantially improved performance and thermal stability.

Catalytic Control of Mutagenic Exhaust Emissions from Gasoline Passenger Cars

Extracts of exhaust emissions from passenger cars equipped with conventional and lean-burn gasoline engines were tested for PAHs, NPAHs and mutagenicity. When installed with an appropriate three-way or oxidation catalyst very large reductions in each of these measurements were observed. Engine exhaust emissions contain hydrocarbons which are potentially hazardous to human health. Although there is an extensive database on the levels of mutagenic hydrocarbons in diesel particulate, much less data are available for modern gasoline engines. The study discussed in this paper addresses this with particular reference to the effect of exhaust catalysts on potentially harmful hydrocarbon species emitted by conventional and lean-burn gasoline engines. The effects over the European Extra-Urban Cycle are also addressed.

Catalyst Formulations 1960 to Present

The primary topic of this paper is the evolution of the early oxidation catalysts of the 1960s to present day sophisticated three-way catalysts. Early catalyst formulations are described, along with the chemistry of catalytic emission control for automobiles. The evolution in catalyst formulations and engine control strategy is discussed at length. Precious metal supply and world emission regulations are discussed briefly. The scope of this paper is primarily limited to the U.S. automotive industry and the U.S standards

The use of catalysts with ambient temperature activity for the control of cold-start automotive emissions

Abstract A combination of engine management and catalyst technology has been utilized to greatly reduce HC emissions from a 1994 production vehicle. The key to the catalyst technology is its activity for CO and H2 oxidation at ambient temperature, allowing excellent pollutant control from a cold start.