Reducing the cost of catalytic converters through design, and reducing engine-out emissions using advanced turbocharging and combustion techniques, are the focus of recent U.K.-based research projects spearheaded by two leading technical universities.
At Imperial College, London, Dr. Benjamin Kingsbury, a Research Associate in the Dept. of Chemical Engineering, is heading a project to develop a production process for high volume manufacture of a new catalytic converter aimed at both improving vehicle fuel consumption while offering production cost savings.
And the University of Bath’s Powertrain and Vehicle Research Center (PVRC), which had a significant role in the development of Ford’s 1.0-L I3 EcoBoost engine, is taking part in a £133 million government-and-industry-backed “greener cars” program. The work is being carried out by the new Advanced Propulsion Center (APC), a joint industry and government body established by the U.K. Automotive Council to become a hub of excellence for advanced powertrain technology, including improvements to fuel efficiency and reduction in carbon emissions — and to migrate technologies into products.
Catalyst substrate improvements
Dr. Kingsbury developed the catalytic converter together with Prof. Kang Li and Dr. Zhentao Wu, who are also with Imperial College’s Dept. of Chemical Engineering. Early tests indicate a potential fuel consumption benefit of around 3%, with a complementary reduction in CO2 emissions.
Dr. Kingsbury said the catalytic converter’s design uses up to 80% less precious metals (platinum group), which brings significant cost reduction. The design is also said to suffer less through-life degradation. Typically, rare metals represent up to 70% of the cost of a catalytic converter. Laboratory tests indicate a 4% deterioration over 100,000 km (161,000 mi) for the new system, compared to a claimed 35% deterioration for a regular catalytic converter.
A spokesperson for Imperial College says Kingsbury has been in contact with several auto industry companies regarding the new system. He has initiated an Imperial start-up company to market it.
According to Kingsbury, the fundamental design of automotive "cats" has not significantly changed since the technology became an integral part of light-vehicle emissions control systems in the mid-1970s in the U.S., and in Europe about a decade later. The adoption of closed-loop feedback capability improved the original design by markedly reducing emission of particulates via conversion of NOx into nitrogen and water.
“The prototype I have developed could make cars cheaper to run because they use less fuel," Kingsbury said. "It could potentially help manufacturers to reduce their costs and it could also save on fuel costs and ultimately lead to reduced CO2 emissions.”
He explained that he has advanced an existing manufacturing process to improve the structure of the catalytic converter’s honeycombed substrate. The effect is to increase the surface area, which facilitates the rare metals being distributed more effectively and fewer being required. The increased surface area also results in an enhancement of the system’s chemical reaction process. Exhaust back pressure is also reduced, he claimed.
Dr. Kingsbury has received funding from the Royal Academy of Engineering to take his system to the marketplace, according to a release from Imperial College.
Project ACTIVE with Ford
At the University of Bath, the PVRC has been awarded £1.2m to carry out research as one of Ford’s 11 partners on Project ACTIVE (Advanced Combustion Turbocharged In-line Variable Valvetrain Engine), which centers on the 1.0-L EcoBoost, now powering several of the company’s models.
The basis of the project is to help accelerate the introduction of future generation low-carbon technologies aimed at reducing CO2 via advanced turbocharging and combustion system development, complemented by highly sophisticated variable valvetrain technology.
Dr. Sam Akehurst, Lecturer in Automotive Engineering at the PVRC, explained: “The PVRC's role in the Ford-led ACTIVE program is to investigate the fundamental performance and interactions of a new type of turbocharger with new variable valve timing technology. We will study how the turbocharger interacts with the pulsating flow in the engine exhaust due to the blow-down events that occur from each cylinder as the exhaust valve opens."
This will be done in two ways—on engine and by utilising a unique hot pulsating turbocharger gas stand that the PVRC is developing. Both of these methods will support the validation of advanced simulation techniques aimed at assisting Ford in making decisions on how best to use the new technologies.
"The objectives are to optimise the performance of the engine and turbocharger in unison to achieve best performance in terms of overall engine torque, fuel economy and good transient response,” Dr. Akehurst told Automotive Engineering.
Prof. Gary Hawley, Dean of the Engineering and Design faculty, and Director of the PVRC, added: “Our involvement in this project continues the high impact contribution that we made to the development of the EcoBoost engine.” He said it builds on the University’s capability to emulate the performance and behavior of complex technologies and systems to drive down the car-engine CO2 footprint.
Along with Ford, the ACTIVE project involves four of the U.K.’s leading automotive research universities (Bath, Loughborough, Bradford, and Nottingham), as well as component and equipment suppliers including Continental, Schaeffler, UEES, Cambustion, AP Raicam, and the energy company BP.