American Society for Testing and Materials International (ASTM) has released a new standard for biodiesel that will help ensure that biodiesel blends of up to 20 percent will be compatible with future diesel exhaust emissions technology, according to information from the National Biodiesel Board (NBB).
The new standard, D 6751-06a, adds new limits on calcium and magnesium, which can be introduced during the biodiesel manufacturing process. The new changes address the potential of small levels of calcium and magnesium on particulate traps. Previous changes to limit sodium and potassium, used as catalysts in the biodiesel manufacturing process, passed earlier this year. Particulate traps are needed to meet Environmental Protection Agency (EPA) 2007 emissions standards, which reduce particulate matter by more than 90 percent from new diesel engines.
Although the changed specification covers pure biodiesel, the majority of original equipment manufacturers (OEMs) view the adoption of an ASTM blended fuel specification as a key component for full, universal acceptance of B20, according to NBB .
The board information said that a subcommittee vote on an ASTM B20 specification is scheduled for December. Depending on the results, final approval for biodiesel blend specifications could come as early as the spring or summer of 2007.