Propane autogas, the vehicular form of the common heating fuel, is usually restricted to spark-ignited light- and medium-duty truck engines, but a propane supplier is poised to introduce a dual-fuel system for Class 8 diesels. It promises to substantially cut fuel costs with a relatively modest investment in equipment, and sales should start in October.
Blossman Services, based in North Carolina and an arm of Blossman Gas, has partnered with BL Energie in Quebec, Canada, to sell a “blended fuel” system made by Prins in Holland. The system injects varying amounts of propane to replace diesel fuel.
“Our goal is 30 to 35 percent” displacement, though it can go as high as 40 percent, said Jessie Johnson, Blossman’s vice president of sales and marketing. Because propane costs half to one-third less than diesel, total dollar savings for fuel would be roughly 10 to 20 percent.
A Blossman-BL Energie system for a Class 8 diesel would cost about $15,000 – less than half a natural gas system’s cost -- he said, partly because a saddle tank is a stout but simple steel vessel that stores propane at 150 to 200 psi. Propane fueling stations likewise cost a small fraction of natural gas stations, though he emphasized that gas makes sense in some operations.
A diesel is not “converted” to propane by the system, he said, because it burns 100 percent diesel fuel at idle and at full power, where the hotter-burning propane might damage it. And the engine reverts to all diesel if the propane tank runs empty.
The Series 60 test engine has been running for six months in a road tractor, Johnson said, and it’s been tested on numerous other heavy and medium-duty truck engines. In Canada there already are 150 to 200 trucks running with the system. It’s meant for retrofits onto existing diesels, though it might be certified for new trucks later.
“This system is technically capable of operating on off-road construction equipment,” said Brent Kiomall, Blossman’s applications engineer. “However, it has not been tested on any applications in that field.”