By Ron Kotrba

During an educational session on the first day of the 2010 National Biodiesel Conference & Expo in Grapevine, Texas, the National Biodiesel Board’s technical director, Steve Howell, spoke about potential future adjustments to the ASTM quality specification for biodiesel, D6751.

Since D6751 is supposed to be process and feedstock neutral, Howell said emerging biodiesel conversion techniques may force an adjustment to the specification. The example he gave was LS9 Inc.’s process that uses microorganisms to convert sugars—not fats and oils—to methyl esters. D6751 specifies fats or oils as feedstocks to produce alkyl esters. “We may have to change the scope of the definition of biodiesel,” Howell said.

He also raised the question of whether minor components found in a sugar-derived biodiesel would be covered in the current ASTM specification.

In addition, Howell told the audience that up to 5 parts per million of biodiesel in the jet fuel spec has been approved by engine makers, which is being balloted in D1655. Jet fuel, and the obvious sensitivities of potential contamination from methyl ester trailback, is one of the major reasons biodiesel is not transported in pipelines. Some believe 5 ppm biodiesel contamination in jet fuel is not high enough, and Howell said a large program is underway to approve up to 100 ppm biodiesel in jet fuel.

The biodiesel industry may also see the addition of separate specifications for winter-grade and summer-grade methyl esters, much like petroleum diesel has No. 1 and No. 2 grades. “It’s one option being discussed by the filter clogging group,” Howell said. “If I were a betting man, I’d say it will be balloted this spring.”

Finally, ASTM will ballot a measure this spring to include the Cognis Quality Trait Analysis system, Ck2-09, which can analyze several parameters in only minutes with one drop of fuel. The American Oil Chemist Society passed the new test method already. According to Howell, “The wet chemistry tests will be maintained as the referee methods. Once this makes it through the complete balloting process and is an official option in D6751, the National Biodiesel Accreditation Commission will accept Congnis QTA system results for BQ-9000 compliance.”