A non-profit trade organisation has demonstrated that propane-fuelled engines for forklifts in Classes 4 and 5 may meet strict new environmental standards.

The research and development arm of the Washington-based Propane Education & Research Council (PERC) funded a three-year USD1.39-million study at the Southwest Research Institute (SwRI), in San Antonio, Texas.

The research examined existing propane, or liquefied petroleum gas (LPG), forklift technologies and their ability to meet 2007 US Environmental Protection Agency regulations and included recommendations for further study. The 2007 regulations call for large spark-ignition non-road engines to reduce hydrocarbon and nitrogen oxide emissions from three grams per brake horsepower-hour (g/bhp-hr) to two g/bhp-hr and show an increase in useful engine life by 40 per cent.

"We will bring fuel quality funding initiatives to the council" in early October, said Brian Feehan, managing director of PERC's engine fuel programs. "Some are under way already."

SwRI recommendations call for a study to determine the sources of heavy-end deposits, research into deposit formation mechanisms, and an evaluation of heavy-end mitigation methods. SwRI also suggested a study of intake port and intake valve deposit trends with "additised" LPG and development of improved analytical methods to predict the deposit-forming potential of LPG motor fuels.

The program used three-way exhaust catalyst units from three manufacturers in Canada's Ontario province, Nett Technologies Inc, of Mississauga, DCL International Inc, of Vaughan, and Engine Control Systems/ECS, of Newmarket.

Outside research involved 10 Yale forklifts with Mazda 2.0 and 2.2-litre engines operating in a climate-controlled beverage warehouse. SwRI measured and evaluated fuel residue deposits in the engines' vaporisers, said Mike Ross, SwRI program manager.

At SwRI laboratories, three Nissan H20 2.0-litre four-cylinder engines ran simultaneously, and their vaporisers yielded other samples.

Currently propane fuels more than 670,000 forklifts in the US, according to PERC's September 2005 engine fuel roadmap. PERC determined the number from an analysis of forklift sales and conversions, discussions with fuel cell manufacturers and details from forklift training and maintenance programs.

PERC said propane fuelled many engine-driven forklifts because it supported durable engine fuel systems capable of varying engine speeds with low carbon monoxide emissions and low engine maintenance costs, compared to gasoline or diesel systems.

George Maes, of Linde Material Handling, represented the Industrial Truck Association, of Washington, on the PERC project's steering committee.

Among its missions, PERC aims to promote safe, efficient use of propane as an energy source. Current PERC funding, under the 1996 federal Propane Education & Research Act, comes from a levy of five-tenths of one cent per gallon of odorised propane gas. The levy was projected to collect USD50.4 million during 2006 to fund PERC programs and projects.