ASTM has Real-World Consequences

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Consumers may not care about the parts per million of sodium or percentage of bound glycerin that was in the biodiesel that went into the B5 or B20 they just filled up with. However, if a consumer's vehicle suffers from a clogged filter or excessive engine wear, they won't care that it was one batch of off-spec fuel that caused the problem. It will be a biodiesel problem that they will solve by never buying the renewable fuel again. So, it's little wonder that many of the presentations at the National Biodiesel Conference & Expo held in February in San Antonio dealt with ASTM quality standards for biodiesel and how producers can meet those standards.

In October 2006, the National Renewable Energy Laboratory (NREL) released a report showing that out of 32 biodiesel samples collected nationally, half failed to meet ASTM quality requirements. NREL Principal Engineer Robert McCormick says that doesn't mean half of the biodiesel being produced in the United States is off-spec, but it indicates that there is a potentially serious problem in the industry. "I think it's safe to say that an unacceptably large fraction of the biodiesel on the market is failing to meet spec," says McCormick, who was one of the presenters at the conference.

Biodiesel manufacturers need to know what can go wrong in their manufacturing processes and how that can lead to impurities in the finished product. "Manufacturers have to test their products, and they have to know what they're doing in terms of purifying what I term the 'crude biodiesel' that comes out of the transesterification reaction," McCormick says. "There's not just one approach to doing this. There are probably three or four main ideas on how you go about doing this. Any one of them will get you to a quality product if you're doing it right, but they have to take measurements and test every batch."

ASTM International, formerly the American Society for Testing and Materials, is a voluntary standards organization that develops specifications for everything from steel girders to children's pajamas. Biodiesel producers and marketers are primarily concerned with two standards-ASTM D 975, which covers diesel fuels and may soon include biodiesel blends up to B5, and ASTM D 6751, which sets the minimum standards for B100. ASTM is also considering creating a specification that would cover biodiesel blends from B6 to B20, says Steve Westbrook, chairman of Subcommittee E of the ASTM Committee D02 on Petroleum Products and Lubricants.

Subcommittee E works on specific standards for biodiesel and blends. Current practice just assumes that on-spec diesel and biodiesel can be blended. "There is no written spec for what a B5 or a B6 to B20 [blend] should be," Westbrook says. "The unwritten accepted procedure is that if you take diesel that meets 975 and biodiesel that meets 6751 and blend them together, the resulting blend is a legal fuel. But that's not really a position that the ASTM subcommittee is willing to live with."

Subcommittee E has put the proposed standards for blends of B5 or less and B6 to B20 on hold pending more research into problems with precipitation above the cloud point of the fuels. "Further action is waiting on some studies on low-temperature concerns," Westbrook says. "Once that task force is done, it will make some recommendations, and we'll proceed from there." The task force is scheduled to make its recommendations at the subcommittee's June meeting, he adds.

Legal Issues
"It's important to meet the spec for a whole list of reasons," McCormick says. "Users who get B20 and even B2 that is made from out-of-spec fuel are going to have operational problems. Even if the producers don't say it, consumers are going to assume the biodiesel meets the ASTM spec. By selling out-of-spec biodiesel, you are really committing fraud."

The ASTM D 6751 standard is more than just an assurance that consumers get the product they think they're buying. Engine manufacturers rely on the standards to develop their fuel recommendations for vehicles. The U.S. EPA bases air pollution requirements on vehicles using standard fuels and works to keep nonstandard fuels out of the market.

"Biodiesel that meets the ASTM spec is registered with the EPA as a fuel, and has undergone significant emissions and health effects testing as part of that registration," McCormick says. "Biodiesel that fails to meet that spec isn't included in that registration, so it's not a legal fuel. [The] EPA will come after you if they find you're not selling ASTM-spec fuel. We are aware that [the] EPA is preparing to begin and test to enforce the spec. They're not doing it now, but they're going to be doing it this year."

Finally, biodiesel incentive programs based on tax credits are regulated by the Internal Revenue Service (IRS), and only ASTM D 6751 biodiesel qualifies for those tax credits. "So if someone is selling out-of-spec biodiesel, they're committing tax fraud," McCormick says. "The IRS is already actively enforcing the spec. If you're failing the spec, they're not going to give you a second chance. They're going to padlock your plant."

Start Your Engines
Standards are also necessary to provide engine manufacturers with a consistent fuel that they can test and evaluate for use in their products, says Roger Gault of the Engine Manufacturers Association. "We need a viable standard that can be used by engine manufacturers to qualify their products and define for their customers the impact of the use of biodiesel fuels," Gault says. "It's a daunting task to figure out what's acceptable."

Engine manufactuers are concerned about the variability between biodiesel and other products marketed as alternative fuels and even between biodiesel from different manufacturers, and the different blends of these fuels, Gault says. "Even with the standards, there is still a pretty fair variety of product in that mix," he says. "There is a wide variety of blend levels and a wide variety of interactions with everything under the sun." Most engine manufacturers are comfortable with blends up to B5, Gault says. More work on both the quality standards and the processes to meet those standards has to be done before higher biodiesel blends will be accepted. "The real question is: At what level of blend do you need a stand-alone specification?" he says. "We've taken the approach so far, that up to B5 the applicable petroleum diesel fuel standards are viable and acceptable, given that the B100 meets its requirements. But we think once you get above B5 that becomes problematic."

Outstanding issues with biodiesel standards that remain to be addressed from the perspective of engine manufacturers include: oxidation stability-peroxides, acids and insoluble precipitates; microbial growth; water separator performance; materials compatibility of both plastics and metals; and temperature-related problems, including cold flow and precipitates, Gault says.

Quality First
Achieving and maintaining quality production is critical to the biodiesel industry, says Paul Hoar of Agrifuels LLC, a contractor with the National Biodiesel Board. "The engine manufacturers are trying to be supportive, but until a reasonable number [of biodiesel producers] meet the specifications, they may say they can't support the use of biodiesel above, say, a B5" he says. "Or in the worst case, they might not endorse biodiesel at all."

Hoar says biodiesel producers should strongly consider participating in the BQ-9000 or a similar quality assurance program. BQ-9000 is not a quality standard, but it's a program managed by the National Biodiesel Accreditation Commission (NBAC) to ensure that producers take the steps necessary to produce a product that consistently meets the applicable specifications. "The idea is, if they follow the procedures outlined in BQ-9000, it increases the likelihood substantially that when the fuel reaches the consumer it will meet the standards of ASTM D 6751," he says.

BQ-9000 certificates of analysis follow the products through the marketing system, Hoar says. This will become more important as government regulators step up their enforcement of biodiesel quality standards. "What's interesting in the legislation is that there is a presumed liability through the chain of custody depending on where the noncompliance is found," he says. "Everyone back up to the producer that owns and handles the fuel in the chain of custody is presumed liable. They have to prove they have a quality management system and [that] when the fuel reached their location, it was good to use in their process, they handled it properly, and they passed it downstream in the chain and it was [ASTM D] 6751 at that time. If they don't have a quality management system to fall back on to actually prove that, they could be liable for significant penalties that both the EPA and IRS can enforce."

Jerry W. Kram is a Biodiesel Magazine staff writer. Reach him at [email protected] or (701) 746-8385.