The Engine Manufacturers Association (EMA) has released the results of a study evaluating the economic viability of using urea-based selective catalytic reduction (SCR) to meet the USA's stringent new emission laws.

The study, which was undertaken by TIAX, concludes that it is feasible to provide urea to a large fraction of the trucking industry in a cost-competitive manner.

If the technology was taken up the news could mean SCR technologies scoring extensive market penetration in establishing technology capable of tackling emissions by the 2007/2010 standards.

In completing the study, TIAX examined potential market structures, created cost models, completed a critical path analysis, and examined several business cases.

However, a number of key factors were deemed crucial to the success of SCR: greater than 50 per cent market penetration of SCR technologies, a concerted effort to develop the requisite infrastructure, and a clear and early signal from manufacturers that they intend to provide SCR-equipped vehicles.

To date the American EPA has been speaking in favour of NOx adsorbers-and against urea-SCR-as the NOx reduction strategy for compliance with the 2007/2010 emission standards.