NREL B20 Survey Results

A brief rundown of NREL's latest survey
By Ron Kotrba | February 18, 2009
Teresa Alleman, senior engineer with National Renewable Energy Laboratory in Golden, Colo., presented results on the 2008 B20 quality survey. Even though a new B6 to B20 specification, ASTM D 7467, now exists, the B20 samples for this survey were taken prior to the release of D 7467.

The survey consisted of 32 samples taken from geographically diverse regions across the United States in late spring, early summer 2008.

The samples were obtained both from fleets using B20, and from pumps specifically labeled "B20." Of the 32 samples taken, 60 percent were nominally B20, meaning within B18 to B22. Two of the 32 samples contained biodiesel percentages much greater than 20 percent, but most off-spec samples contained too little biodiesel, most commonly B2, B5 and B11.

Seventy four percent of the 32 samples passed the new B20 spec's stability test for induction time; 8.4 hours was the average for B20. Alleman said there's an ongoing workshop at ASTM looking at utilizing the Karl Fischer moisture test method in the biodiesel specification.

Even though Alleman said the B20 survey results from 2008 showed improvements from the last B20 spec conducted back in 2004, she cautioned, "You need to be sure that the blend being advertised is the blend being delivered."