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NREL's Earl Christensen Honored with Two Awards from National Biodiesel Board

February 16, 2018

Fuel stability research advances innovation and bolsters industry confidence in biodiesel.

Scott Fenwick, Earl Christensen, and Steve Howell.
Earl Christensen (center) receives the Innovation Award from NBB Technical Director Scott Fenwick (left) and NBB Senior Technical Advisor Steve Howell (right) in January 2018. Photo courtesy of the National Biodiesel Board/ZimmComm.

This January, Earl Christensen, a senior scientist at the National Renewable Energy Laboratory (NREL) received his second award from the National Biodiesel Board (NBB) in less than three months.

Christensen was recognized with the Eye on Biodiesel Innovation Award for his work in proving the long-term storage stability of biodiesel. In November, Christensen was also named Biodiesel Researcher of the Year at the Biodiesel Technical Workshop, where the NBB acknowledged that his work provides the confidence risk-averse manufacturers need to introduce the fuel into new markets.

“It’s a pretty big deal to get both of those awards,” said Steve Howell, senior technical advisor for the NBB. “The Eye on Biodiesel Awards go to folks who have had the most impact on the industry, while Researcher of the Year really means you’re in the upper echelon of the research world.”

An article in Biodiesel Magazine said, “Christensen has been instrumental in conducting work related to biodiesel stability that has bolstered confidence in B20 (a blend of 20% biodiesel, 80% petroleum diesel) by both original equipment manufacturers and end-users alike.”

Christensen is part of the Fuels and Combustion Science team at NREL, which has a long history of collaboration with the NBB, answering industry questions and working with manufacturers to help biodiesel evolve from a fledgling industry to a thriving business. Howell noted that NREL research stands out because of a concerted effort to work closely with industry, incorporating their feedback and addressing real world issues. Christensen’s recent research focused on evaluating the effects of long-term storage on biodiesel.

“There’s a lot of concern with biodiesel because it can behave differently from hydrocarbon diesel,” Christensen said. “Biodiesel oxidizes almost in the same way as the fats and oils that it’s made from. It’s a good thing from an environmental perspective, if biodiesel spills it will biodegrade. But from a storage and handling perspective, especially long-term storage, it’s something people worry about.”

It’s well accepted in the industry that biodiesel blends are stable for up to six months, but manufacturers have expressed concern about stability for applications that call for less-frequent use.

“Most diesel fuel doesn’t sit around that long,” Christensen said. “But there are applications that call for less-frequent use like home heating oil, backup generators, infrequently used vehicles, where fuel needs to be stable for well over a year, even up to three years. So, we needed to know, can biodiesel last that long?”

Christensen was twice recognized for proving that yes, it can. By simulating the effects of time on B20 blends, he discovered that fuel samples from around the country are already lasting at least a year in storage. He and the team at NREL also established a protocol for monitoring fuel over time and treating it with an additive, which dramatically elongates the life of the fuel up to three or even four years.

“We’ve got to prove beyond the shadow of a doubt to very conservative engine and fuel companies that this fuel is acceptable in their engines and acceptable to blend with their fuels, so we need to have good data,” Howell said. “That’s why we put our money into NREL programs. We only use the best.”

As a result of Christensen’s findings, the NBB is extending the recommended shelf life of biodiesel from a minimum of six months to one year. The NBB is also providing funding for NREL to take a much deeper dive into the fundamental science of the effects of different antioxidants on biodiesel stability.