California’s Air Resource Board lists biodiesel as lowest-carbon fuel

In the US, California's Air Resources Board (ARB) has listed biodiesel as the lowest-carbon fuel in the state’s revised Low Carbon Fuels Standard (LCFS).

The new standard affirms biodiesel reduces greenhouse gas emissions by at least 50% and often by as much as 81% when compared with petroleum, giving biodiesel the best carbon score among all liquid fuels.

As part of the state's LCFS, which requires a 10% reduction by 2020 in the carbon intensity of transportation fuels, the ARB has quantified the carbon intensity of conventional and alternative fuels through a seven-year comprehensive lifecycle analysis.

‘This program is a key element of California’s plans to enact Governor Brown’s executive order mandating a 50% cut in petroleum use by 2030,’ says ARB chair Mary D. Nichols.

California's lifecycle model incorporates all the impacts for producing a fuel's raw materials, including conversion and transportation.

The model also includes the indirect economic impacts of growth in global agriculture, making it one of the most thorough and rigorous evaluations to quantify the environmental footprint of biofuels.

According to Don Scott, director of sustainability at NBB, the national trade association representing the biodiesel industry in the US, biodiesel is the most sustainable fuel on the planet.

‘California's analysis, which has been validated by independent academic review, provides confidence that biodiesel is, without question, a more sustainable alternative for transportation fuel.  The commercial success of the growing biodiesel industry suggests goals to further reduce greenhouse gases and displace imported petroleum are appropriate and achievable.

‘With a focus on carbon reduction and the national policy to support it, biodiesel could reduce carbon emission by 36 million tonnes annually,’ says Scott. 

The estimates provided by ARB for likely fuel pathways include (in grams of CO₂ equivalent per megajoule of fuel):

ULSD (standard diesel)	102.76g/MJ
Petrol	99 (CaRFG) g/MJ
Corn ethanol	80.09g/MJ
Compressed natural gas	79.46g/MJ
Soyabean biodiesel	51.83g/MJ
Used cooking oil biodiesel	19.87g/MJ
Tallow biodiesel	32.83g/MJ
Canola biodiesel	50.23g/MJ
Corn oil biodiesel	28.68g/MJ

 

Weighting these scores by the amount of each feedstock used in the US in 2014 suggests that the average biodiesel in the market has a carbon intensity of 38.4 g/MJ, NBB says.

This would give biodiesel the lowest carbon intensity of any category of liquid or gaseous fuel, and make it competitive with electric vehicles as a carbon mitigation strategy.