By Hank Hogan

What comes after two and before four? The answer is B6 to b20, according to a just-released update to ASTM International’s D396 standard specification for fuel oils. For those selling diesel fuel for heating, having a Specification for blends of 6% to 20% biodiesel, or B6 to B20, could be good news. Importantly, these biodiesel blends are on par in terms of carbon footprint with natural gas, a chief competitor.

The release of the new specification could be just the start. On the horizon is the looming challenge of significant reductions in the carbon footprint of heating oil. For instance, in the northeast United States there are policy goals to reduce the carbon footprint of heating buildings by 80% by 2050, according to Steve Howell, chairman of the ASTM Biodiesel Task Force. That target can be achieved with biodiesel, he said.

“In the heating oil area, we’re really looking to go all the way to B100. At that point, you will have an 80% carbon reduction,” said Howell, who is based in Kansas City, Mo., U.S.A. and a partner at MARC-IV Consulting.

The use of 5% biodiesel in the No. 1 and No. 2 grades of D396 was approved in 2008. Those two grades are for domestic and small industrial burners. D396 also has heavier grades, Nos. 4, 5 and 6, with these being used in more industrial settings. There was no grade No. 3. The latest update to D396, issued in the first quarter of 2015, adds the new B6-B20 grade, which is for domestic and small industrial burners, between grades No. 2 and 4. Steven Westbrook is chairman of the ASTM Subcommittee on Burner, Diesel, Non-Aviation Gas Turbine and Marine Fuels, the subcommittee where any changes to the standard are considered. He explained that the process of changing an ASTM standard is by consensus. That makes it difficult to get unanimous approval for any significant item of business, such as the addition of B6-B20. Thus, at the December 2014 ASTM D02 meeting in San Diego, Calif., U.S.A., the negative ballots were adjudicated first before the subcommittee and again before the full committee.

“In the end, the voting members found the negative votes on the item not persuasive. So the item passed,” Westbrook said.

Seven years elapsed between the approval of B5 and B6-B20 in the heating oil specs. During that time, industry and government agencies developed data on the effects of B6-B20 in heating equipment, particularly on long-term pump durability, elastomer and seal compatibility. Surveys were also sent to those who had experience using these fuels.

One such company is Worley & Obetz, which is headquartered in Manheim, Penn., U.S.A. Owner Seth Obetz said the company has been marketing what he characterized as high quality biodiesel blends, from B20 up to B100, since 2001. The company’s service technicians report cleaner heat exchangers and cleaner fuel systems in heating systems burning biodiesel blends, Obetz said.

“Biodiesel’s solvent qualities serve to clean the tank and fuel system, and the more complete burning characteristics of bio blends along with the greatly reduced particulate matter lead to cleaner systems and less problems overall,” he said.

Another reason for the decrease in heating system issues is that long-term pump durability studies showed that the biodiesel blends had less pump leakage than with conventional heating fuel, Howell said.

The data set generated during the seven-year collection process is one of the most extensive he has ever seen in 20 years, Howell said. Westbrook noted that ASTM members want data to support a proposed specification change and that the amount needed depends on the nature of the proposed change.

The information collected built on the data already generated by on- and off-road engines running B6 to B20. It was the total picture that played a role in getting the revision approved.

The heating fuel industry was one of the groups behind the movement to modify D396, pushing for this because it wanted to change the public’s perception of its products, according to Howell. On- and off-road vehicles have moved to ultra-low sulphur diesel, which is below 10 or 15 parts per million (ppm) sulphur. In contrast, heating oil still contains thousands of ppm sulphur.

The update to D396 is important in changing the image of heating oil. “They want to turn heating oil into a 21st century fuel where it goes to ultra-low sulphur and ultra-low carbon,” Howell said of the industry’s goal.

The cost of such efforts is not known, but industry groups have stated that they have invested millions of dollars in research, outreach and education. The funding comes from heating oil dealers, biodiesel producers and soybean growers.

Howell predicted that the release of the updated specification will spur the acceptance of the new fuel and help drive growth in its use. The B6-B20 heating oil specs are designed so that heating and vehicle applications can use the same pool of distillate fuel, which will simplify the supply chain.

As for the future, there is B100, which may be necessary to meet stricter carbon footprints. According to the U.S. Environmental Protection Agency (EPA), lifecycle greenhouse gas emissions can be cut by anywhere from 55% to 85% by switching from petroleum diesel to B100, depending on the biodiesel feedstock. Different feedstocks have different degrees of greenhouse gas (GHG) emissions. Among the feedstock tracked by the EPA, biodiesel from waste grease offers the highest GHG emissions reduction of 85%. No matter the feedstock, the savings by switching to 100% biodiesel will be substantial. The advantage of a fuel-centered approach is that it doesn’t require changes in equipment technology.

B100 would bring other benefits, Howell said. Among those, biodiesel has a higher flash point than petroleum diesel, which makes it safer to store at home. In addition, “The 2050 policy goals, you can meet those today if you just wanted to go to B100 in your home heating oil unit. Then you’d have a biodegradable, non-toxic fuel.”