B20 in the freeze
There has always been an issue with heating oil (and diesel) and the winter. And yet, there no shortage of oil furnaces in northern climates. In fact, our industry would never have developed if the issues and handling requirements were extraordinary. Adding biofuel to the mix does change things, but how much?
Several articles and columns in recent issues of the magazine have addressed winter additives and blending relative to Bioheat®. The issue, frankly, is not really the current blend in service, since 2% (B2) or 5% (B5) have cold-weather properties fairly comparable to unblended heating oil or diesel. However, for a variety of market-enhancing reasons there is a strong push to take the fuel to the next level which would be 20%, or B20. So, what are the ramifications?
It might be helpful at this point to note that B20 motor fuel has been used successfully, in some cases for several decades, in very cold environments. As the Iowa Renewable Fuels Association notes, B20 has been used through winter in Yellowstone National Park in Wyoming and Montana since 1996. It has been used in Glacier National Park year-round since 2001. It has similarly been used for years by fleet and resort operators in Colorado, and first responders in Brooklyn Park, Minn. and Boise, Idaho. Harvard University uses it in the winter as well.
Biodiesel does have higher cloud and pour points with typically a narrower (perhaps even much narrower) margin between the two. Results will also vary by feedstock. However, at a B20 blend the difference is not all that great. For example, the difference in pour point between No. 2 fuel oil and B20 is 3-10 degrees Fahrenheit’hardly exotic. As with conventional heating oil or diesel, this challenge can be addressed in some fairly traditional ways.
First, it is strongly suggested that the fuel meet standard ASTM D6751 and that the supplier be BQ9000 certified. The National Biodiesel Board notes that fuel quality is absolutely critical to successful cold flow operation, and that includes the petroleum component as well. After that, blending with kerosene is an option; blending a more sensitive feedstock such as tarrow with soybean oil-based feedstock helps; and finally adjusting the concentration of winter additives to meet the requirements of the specific blended fuel should take care of any concerns.
For those that blend the fuel themselves, and/or operate bulk plants where a higher-concentration Bioheat or pure B100 might be stored, some additional steps are likely required such as the use of tank heaters. For example, NBB notes that B100 stored in cold temperatures must be heated to at least 15 degrees higher than the biodiesel feedstock being used prior to distribution or blending into middle distillates of any grade.
The good news, is that while a significant amount of data has already been developed on how to handle B20 biodiesel blends in colder climates, there is no doubt that the organizations that are actively working to bring this fuel to the heating side’such as NBB and the National Oilheat Research Alliance’will be fine-tuning that established experience for our industry. It appears that a major research focus for NORA after its recent reauthorization is B20, and that would hardly make sense if that fuel could not be used effectively and efficiently in the standard climate in which our industry operates.