Vancouver, BC-based Westport Innovations led a series of engine advances for natural gas vehicles (NGV) that were unveiled in September, introducing its newest proprietary technology, a first generation of an enhanced spark-ignited (ESI) natural gas engine aimed at the medium-duty truck market.
"Using 100% natural gas as fuel, Westport's new technology optimizes the combustion and thermal efficiencies of the engine by taking advantage of the positive properties of natural gas," the company said. It is aimed at vehicle and engine original equipment manufacturers (OEM).
Westport's ESI technology -- offered by the company on a standalone basis for the first time -- is targeted at sub-9 liter engines for Class 6 and 7 truck applications, and it is also adaptable to sub-2 liter applications for use in both automotive and non-automotive applications.
The offering represents improvements in combustion and thermal management, compared to typical spark-ignited NGV engines, Westport said. Most of the Westport Innovation products are high-pressure, direct-ignition, except for some ESI engines it markets in joint ventures, such as Cummins Westport.
"This is designed to provide up to 10% improvement in power and torque over basic diesel engines," the company said, adding that higher performance from the ESI natural gas technology compared with diesel engines is potentially possible for 4 liter NGV engines to replace a 6 liter diesel engine.
"As gasoline and diesel engines progress, it is critical that OEMs offer natural gas engines that retain their expected performance while providing the environmental and economic benefits of natural gas," said Jack Keaton, Westport executive vice president for global spark-ignited direct-injection technology.
Separately, Columbia, SC-based Skygo Fuel Systems announced a newly certified dual-fuel system related to Cummins ISX engines, and Bend, OR-based Onboard Dynamics has developed a system to allow NGV engines to produce compressed natural gas (CNG) while they are operating.
Skygo officials said their system has been certified by the U.S. Environmental Protection Agency and is available for aftermarket upgrades to the 2007-2009 Cummins ISX engines.
The dual-fuel system designed for multiple applications delivers what Skygo is touting as "very compelling" financial and environmental returns on investment. Originally aimed at trucking applications, the conversion system now is also looking at transit, utility and stationary power applications.
"You can't tell it's running on natural gas," said Skygo President Michael Kilbourne. "The vehicle drives exactly the same as it did before the truck was converted."
In Oregon, Onboard has developed an engine to run on part of its cylinders while the other cylinders are used to compress its fuel into CNG. "Fuel can be drawn from low-pressure [natural gas] lines with no need for a costly CNG fueling station," the company said. With $3.6 million funding from federal government and private sector sources, Onboard has completed a proof-of-concept vehicle using a 5.9-liter Cummins engine converted to spark-ignition and one of its six cylinders used as a compressor, it said. "You've eliminated the infrastructure problem," said Onboard co-founder Jeff Witwer.
The next version of the technology will be an eight cylinder engine in which four of them will be used as a compressor.
The U.S. Department of Energy through its advanced research projects funds provided $2.88 million of the project's funding so far.
In Colorado, new CNG stations are in the development process for an under-served southern portion of the state and at Denver International Airport CNG is included among a shift to alternative fuel vehicles, including propane and electric hybrids.
Oklahoma City-based Sparq said it plans to build two new CNG stations, which will be the first public access NGV fueling in the area that includes Trinidad and Pueblo, CO. The Trinidad station hosted at an existing Shell gasoline station, will be built first, and both will be along Interstate Highway 25 connecting Denver and Albuquerque, NM.
Sparq expects to invest $1.1 million in Trinidad and $1.3 million in Pueblo, according to Sparq CEO Norman Herrera.
At the Denver Airport and elsewhere, ThyssenKrupp Elevator is making the switch to NGVs and other alternative vehicles as part of an effort to lower petroleum use in its national 3,200 vehicle fleet. The fleet operator of trucks and vans reported that it has cut its gasoline use by 710,000 gallons and diesel use by another 115,000 gallons since 2010.