CHICAGO, IL – The Engine Manufacturers Association (EMA) is struggling to carry out a recently unveiled test specification for determining how 20 percent biodiesel blends (B-20) perform in advanced diesel engines, a top official with the group said this week, noting that many technical barriers remain.

Complications in advancing the specifications could impact the California Air Resources Board’s (CARB) upcoming biodiesel policy and general expansion of biodiesel blends statewide and nationally. The biodiesel industry earlier this year pointed to the EMA test specification undertaking as a critical step to bolster acceptance of the fuel.

The South Coast Air Quality District Nov. 7 hosted a forum and roundtable discussion on biodiesel with various biodiesel stakeholders and regulators. The forum included an update from Roger Gault, EMA’s technical director, on the group’s progress in developing biodiesel test specifications, as well as engine operation and warranty issues related to biodiesel.

In June, EMA announced it was seeking the test methods, recognizing that federal and state agencies are aggressively seeking out biodiesel blends as an alternative to petroleum products and to reduce greenhouse gas emissions. EMA said the tests were needed to give engine manufacturers assurance that biodiesel blends are acceptable in terms of safety, engine performance, and emissions.

CARB is expected to soon release a biodiesel policy, which is expected to describe how the board intends to regulate the fuel.

At the Nov. 7 South Coast forum, Gault said because the group has struggled with its B-20 blend specification, it does not anticipate developing test methods for blends above 20 percent. Some of the difficulties encountered during the development of the test specifications relate directly to the overall quality of biodiesel. Regarding technical fuel performance, Gault said EMA is struggling with “water filtration” and “material compatibility issues.”