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California Seeks Near-Zero Emissions in CNG Trucks

In California earlier this month, the South Coast Air Quality Management District (SCAQMD) board voted to petition the federal government to adopt tougher emission standards for large trucks to help the region meet its clean air goals. Heavy-duty trucks are the largest source of smog-forming emissions in the four-county air district.

"The technology for these reductions is available," said SCAQMD Chairman William Burke."The federal government needs to step up and require near-zero emission standards for all new trucks nationwide."

SCAQMD officials point out that the district has led an effort the past three years to develop near-zero emission CNG engines for refuse-hauling trucks. The 8.9-liter engine, produced by Cummins Westport Inc., recently won certification from the California Air Resources Board (CARB) (see Daily GPIOct. 8, 2015).

The air regulatory district is currently working with Cummins Westport and others to develop a larger, near-zero emission engine that it thinks will be appropriate for goods-moving trucks. SCAQMD urged the federal Environmental Protection Agency to do what CARB is about to do -- establish a near-zero emissions standard for heavy-duty trucks.

Meanwhile, last week two Rice University engineering researchers, citing recent reports of methane leakage in the natural gas supply chain, advised using natural gas for power plants, but not to replace gasoline or diesel fuel in vehicles. The two said replacing gasoline and diesel in vehicles with natural gas results in no significant reduction in greenhouse gas (GHG) emissions.

The two, Daniel Cohan and Shayak Sengupta, said their study, "Net Greenhouse Gas Emissions Savings from Natural Gas Substitutions in Vehicles, Furnaces and Power Plants, "looked at the full fuel cycle and found "the greatest emission reductions can be achieved by replacing existing coal-fired power plants or fuel oil furnaces," Substitution of natural gas in light-duty natural gas vehicles (NGV) and transit buses in the vehicle sector did not make the grade.

They based their claim on reports by other researchers that have found that leaks in the natural gas delivery chain to get CNG and liquefied natural gas (LNG) to end-users in transportation can offset gas' climate change advantages in the transportation sector (see Daily GPIMay 20, 2015).

In other actions, the California Energy Commission (CEC) last Wednesday approved $4.3 million in grants for projects aimed at increasing the efficiency of natural gas technology in transportation and several other sectors. These include funds to the city of Petaluma north of San Francisco to design and operate an anaerobic digestion system to produce 150,000 gasoline gallon equivalents (GGE) of renewable natural gas (RNG) from food and beverage waste and use fueling refuse trucks in the city.

A second CEC grant for $1 million was awarded to the Gas Technology Institute to develop and demonstrate an advanced NGV engine to be installed in 18 vehicles, ranging from delivery trucks to school buses. The engine is part of the SCAQMD's efforts to improve air quality in Southern California.

In expanding the use of RNG, Newport Beach, CA-based Clean Energy Fuels Corp. said that Texas-based Dillon Transport has committed to using its brand of RNG, Redeem, in its trucks. The initial supplies will come from Clean Energy's Irving Boulevard station in Dallas. Dillon also will use Redeem when fueling its vehicles in San Antonio, Midland/Odessa, and Houston.

Dillon currently operates 262 NGV trucks, mostly Paccar (Kenworth and Peterbilt) vehicles. Six are fueled with LNG, and the rest use CNG. A little less than half of Dillon's vehicles were fueled by CNG last year, but CNG accounted for 60% of the miles driven, the company told Fleets & Fuels newsletter.

In the marine sector, at least two boatbuilders now are offering CNG options, including a hybrid variant. Intrepid Powerboats and Dusky Marine are among the boat makers now offering the Blue Gas Marine CNG systems as an option on their boats.

A factory installation of a Dusky 252FC fisherman's boat was displayed in February at the Miami International Boat Show. Blue Gas Marine has indicated that it is accelerating its work on CNG for boats with gasoline engines, prompting a bi-fuel upfit that can cut costs with a dual fuel gasoline-CNG "advanced hybrid CNG system," using fuel tanks from Hexagon Lincoln.

Recent Articles by Richard Nemec