New Guidelines Issued for Blending Biodiesel with Cold Diesel Fuel; Study’s Findings Will Give Marketers Added Confidence

August 22, 2005 — By National Biodiesel Board

JEFFERSON CITY, Mo. — In light of greater demand for biodiesel and a growing number of petroleum distributors getting into the biodiesel business, an industry-established Cold Flow Blending Consortium recently issued results of a cold weather blending study. This project was formed to address biodiesel blending procedures in the winter and employed experts in biodiesel and petrodiesel industries, including distributors, rack blenders and pipeline companies as well as energy experts from academia and the U.S. and Canadian governments.

Biodiesel is a renewable diesel fuel that is made from domestic resources such as soybean oil or other domestic fats and vegetable oils. It can be used in any diesel engine with few or no modifications and can be blended with petroleum diesel at any level. Biodiesel significantly cuts harmful environmental emissions, promotes greater energy independence and boosts our economy.

The National Biodiesel Board (NBB) coordinated this study because petroleum blenders and distributors wanted more data on the most cost effective means to achieve a homogenous, or consistent, biodiesel blend in cold weather. The passage of a bill in Minnesota that requires all on-highway diesel fuels to contain at least 2 percent biodiesel, was the primary factor for the heightened interest from the petroleum industry.

It is well known that biodiesel blends of B20 (fuel that is a 20 percent biodiesel and 80 percent regular diesel blend) and lower can be used in cold climates if the finished blend has appropriate cold flow properties for the time of year and geography where it is used. This study addressed questions from the petroleum industry about how to achieve that stable blend in cold weather, especially for a B2 blend, when the temperature of the diesel fuel is colder than the point at which the pure biodiesel starts to freeze and become cloudy (known as cloud point).

According to the report, successful homogenous blending of B2 will occur if the biodiesel is incorporated into the diesel stream as it is going from a storage tank to a truck and if the temperature of the biodiesel is a minimum of 10 F above the cloud point. The temperature of the diesel fuel did not matter as long as its temperature was above its cloud point. This type of in-line blending is similar to the way conventional diesel fuel additives are incorporated.

“Many blenders have requested guidelines which detail processes and temperatures that could be implemented to reduce operational issues of getting a good biodiesel blend,” said Paul Nazzaro, coordinator of this study and petroleum liaison to NBB. “The collective efforts of this diversified group of experts have generated a comprehensive body of work which has taken the guess work out of storage and blending of B2 and will help ensure consistency and reliability."

Additives Systems Incorporated of Broken Arrow, Oklahoma, the firm selected to conduct the study, blended biodiesel with diesel fuel at a variety of temperatures, including those seen in the wintertime in Minnesota. The testing utilized a small blending test rig designed to simulate splash blending and proportional (or in-line) blending at the terminal. Unadditized No. 1 and No. 2 diesel fuels were selected, along with three biodiesels with a range of cold flow properties. The fuels were selected to represent the highest and lowest freezing temperatures expected of petrodiesel and biodiesel in the U.S. and Canadian market. All testing focused on preparing two percent volume biodiesel blends (B2).

To ensure quantitative data was obtained for in-line blending, differential pressure drop measurements were collected. These measurements compared the pressure drop of neat diesel fuel through a filter with the pressure drop created by B2 blends at various temperatures. The visual results from the splash blend testing were qualitative in nature, so the report came to no definitive conclusions regarding splash blending of B2 with cold diesel fuel.

“With the Cold Flow Blending Study now completed, petroleum organizations and downstream blenders can move forward with their planning for B2 distribution,” said Nazzaro.

Biodiesel, used in hundreds of fleets, is nontoxic and biodegradable. Biodiesel has the highest energy balance of any transportation fuel. The U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA) in 1998 performed the prevailing life cycle study of the energy balance of biodiesel. It found that for every one unit of fossil energy used in the entire biodiesel production cycle, 3.2 units of energy are gained when the fuel is burned, or a positive energy balance of 320 percent.

Users of biodiesel include governmental and commercial fleets, personal passenger vehicle owners and farmers. Farmers have invested millions of dollars in bringing biodiesel into commercial success through the soybean checkoff.

The full study can be accessed by visiting www.biodiesel.org/resources/reportsdatabase/reports/gen/20050728_Gen-354.pdf. Readers can learn more about biodiesel by visiting www.biodiesel.org.

Contact
Jenna Higgins
National Biodiesel Board
800-841-5849

National Biodiesel Board
3337A Emerald Ln.
P O Box 104898
Jefferson City, MO 65110-4898
(573) 635-3893 phone
(800) 841-5849
(573) 635-7913 fax
www.biodiesel.org