The CRT™ combines a catalyst with proprietary Johnson Matthey catalytic coating with a bare filter

Johnson Matthey's CRT™ won the Royal Academy of Engineering's MacRobert Award for Engineering Achievement in 2000

Cities around the world are increasingly restricting access to only the cleanest commercial vehicles

In the second half of this decade a significant new market for catalytic emissions control systems for heavy duty diesel engines will be evolving and Johnson Matthey with its world leading Continuously Regenerating Trap (CRT™) technology is very well positioned to benefit from this important growth opportunity.

In the 25 years that have passed since the first autocatalysts were sold for use in passenger car applications in the United States and Japan there has been enormous growth in the market for emission control catalysts for light duty cars and trucks. This has been driven by the spread of emissions legislation around the world and increasingly tougher emissions standards in new, as well as existing, markets.

Autocatalysts have undoubtedly brought important environmental and health benefits. With passenger car exhaust emissions now at very low levels, governments around the world are increasingly turning their attention to tackling pollution from other major types of vehicles including trucks and buses.

Heavy duty diesel vehicles are a conspicuous source of smoke particles and other pollutant emissions, particularly in urban areas. The particulates and oxides of nitrogen (NOx) contained in emissions from these vehicles give rise to major health concerns. This is encouraging governments to act at a local and national level to implement policy initiatives to clean up emissions from trucks and buses. Over the next few years these initiatives will create a second major market for catalytic emission control systems, a market for catalysts and filters to effectively control the emissions from heavy duty diesel engines used in trucks and buses.

New trucks and buses are already subject to quite stringent emissions legislation in Europe and the US, although this actually applies to the engine rather than to the vehicle. Standard engines tend to be fitted to a wide variety of vehicle types, from trucks and buses to fire engines, trains and cranes. To date, emissions regulations for these engines have been met without the need for catalytic exhaust aftertreatment. However, initiatives by government, local authorities and fleet operators to clean up emissions, particularly in city centres where air quality concerns are greatest, have resulted in the growth of significant markets for retrofit technology for heavy duty diesel engines. These utilise alternative fuels such as natural gas and liquid petroleum gas or what are commonly termed clean diesels, which operate on low sulphur diesel fuel and employ catalytic exhaust aftertreatment systems. Tests have shown these vehicles to be significantly cleaner than their conventional counterparts, creating a two-tier market. In response, emissions legislation for the European Union, United States and Japan, to take effect from 2005 through 2007, will push all new heavy duty diesel engines to achieve the same high levels of environmental performance.

Johnson Matthey, with nearly thirty years of experience at the leading edge of catalytic vehicle emission control technology, is a world leader in the development and supply of catalysts for engines operating on the full range of fuels. Its patented CRT™ is the market leading particulate trap system for heavy duty diesels. Developed to trap and burn the soot found in diesel exhaust as well as removing carbon monoxide and unburned hydrocarbons, the CRT™ has proven itself in widespread use around the world to be the first truly reliable way of removing soot particles from diesel exhaust, effectively cleaning up heavy duty diesels. The market for retrofit of CRT™ technology started in Europe, particularly in Scandinavia, Germany and the UK, but has since grown to include major programmes in the United States and Japan. CRT™ is now entering the South East Asian market via Hong Kong. The main enabler for the adoption of catalytic exhaust aftertreatment systems like the CRT™ has been the growing availability of ultra low sulphur and sulphur free diesel fuel. This is often prompted by government tax incentives to encourage the use of these more environmentally friendly fuels. Wherever ultra low sulphur diesel fuel has gone the CRT™ has followed and vice-versa, as the benefits from CRT™ use have helped initiate a move to these cleaner fuels in many locations. As the result of these developments the world's major heavy duty diesel engine and vehicle manufacturers now have a great deal of experience and data from the day to day operation of CRT™ systems. In addition to undertaking generic research on the CRT™, Johnson Matthey has been working closely with engine manufacturers to support their CRT™ test programmes. Many of the world's leading manufacturers now see the CRT™ as a fundamental part of their strategy for achieving legislated emissions targets.

However, this is by no means the end of the story. New systems based on enhanced CRT™ technology are being developed to meet the challenges of future heavy duty diesel emissions legislation. These include new products that have CRT™ catalyst technology packaged with sophisticated electronic emissions management systems that allow filter regeneration to be optimised across the full range of operating conditions. New systems are also under development that will allow the control of NOx, a major technological hurdle for diesel emission control. This can be achieved either by trapping the NOx and subsequently catalytically reducing it to benign nitrogen or, as in the case of Johnson Matthey's combined particulate/NOx system, the SCRT™, by using a reductant such as urea to reduce NOx to nitrogen. In both cases, Johnson Matthey will be supplying dedicated catalysts for these important technologies.

Johnson Matthey is working in partnership with heavy duty diesel engine and vehicle manufacturers around the world to optimise CRT™, SCRT™ and other innovative emission control technologies for use with their products. It is estimated that the market for catalytic systems for heavy duty diesel emission control will be over 600,000 units a year. This may sound small in comparison with the more than 50 million cars equipped with catalysts each year. However, the larger size of the engines used in trucks and buses means that the volume of catalyst used by this application is an order of magnitude greater than that used on a car. This coupled with the sophistication of the systems results in a very exciting opportunity for growth in the company's global vehicle emission control catalyst business.