Considering Biodiesel for Your Construction Equipment

Fuel costs and the United States’ reliance on foreign fuel sources is a constant concern for many construction owners whose businesses are heavily dependent on machinery that requires diesel. Many alternate energy sources have been discussed, researched and used in the past but, for equipment, the primary form of alternate fuel has become biodiesel.Biodiesel is created from renewable agricultural resources, grown domestically (primarily soybeans in the U.S.). It is not the same as raw vegetable oil, it is produced by a chemical process that removes the glycerin present in raw oil. The primary way biodiesel is used is as a part of a biodiesel blend-a blend of biodiesel fuel with petroleum-based diesel fuel. The mix rations are designated by BXX, where XX represents the volume percentage of biodiesel fuel in the blend. Most major construction equipment companies have approved and fitted their machinery to use up to a 20 percent biodiesel/80 percent diesel fuel mix (also called B20) without further alterations to the existing diesel engines.

John Deere has been researching biodiesel for use in construction equipment for more than 10 years, although Joe Mastanduno, product marketing manager, engine/drivetrain, for John Deere Construction and Forestry Division admits that those efforts have gained more attention in recent years. “As diesel fuel prices go up, people look for alternatives. In 2008, when prices skyrocketed, many people started looking at biodiesel as an alternative.”

The government has also played a role in biodiesel’s increasing popularity and use. Mastanduno point out, “The government has a lot of incentives to make us more energy independent.”

Although biodiesel holds appeal as a renewable resource, there are concerns too. Mastanduno notes, “Biodiesel reduces particulate matter but increases NOx. It’s not as fuel efficient as diesel, but it’s coming from our country, our crop, putting us in control of our fuel supply.”

Mastanduno stresses the importance of doing your research on both the company you are buying the biodiesel from and how you manage the fuel purchase. He warns, “You really have to be careful about the quality, handling and storage of biodiesel.”

Biodiesel performs the same as diesel in cold weather and can be treated for winter use in the same ways that No. 2 diesel is treated.

The National Biodiesel Board (NBB) has guidelines and information on biodiesel, including manufacturers, benefits, FAQs, handling and storage available on their website at biodiesel.org. NBB’s vision for the future is, “that by 2015, biodiesel will be viewed as an integral component of a national energy policy which increasingly relies on clean, domestic, renewable fuels. Positive market dynamics coupled with federal counter-cyclical policy will support a significant and stable market. Sales, primarily in the form of low level biodiesel blends, will replace 5 percent of diesel demand by 2015. Energy security and environmentally driven uses, such as B20, remain a significant and visible source of demand.”

Environmental and Safety Information 

Acute Oral Toxicity/Rates

Biodiesel is nontoxic. The acute oral LD50 (lethal dose) is greater than 17.4 g/Kg body weight. By comparison, table salt (NaCL) is nearly 10 times more toxic.

Skin Irritation -Humans

A 24-hr. human patch test indicated that undiluted biodiesel produced very mild irritation. The irritation was less than the result produced by a 4 percent soap and water solution.

Aquatic Toxicity

A 96-hr. lethal concentration for bluegill of biodiesel grade methyl esters was greater than 1000 mg/L. Lethal concentrations at these levels are generally deemed “insignificant” according to NIOSH (National Institute for Occupational Safety and Health) guidelines in its Registry of the Toxic Effects of Chemical Substances.

Biodegradability

Biodiesel degrades about four times faster than petroleum diesel. Within 28 days, pure biodiesel degrades 85 to 88 percent in water. Dextrose (a test sugar used as the positive control when testing biodegradability) degraded at the same rate. Blending biodiesel with diesel fuel accelerates its biodegradability. For example, blends of 20 percent biodiesel and 80 percent diesel fuel degrade twice as fast as #2 diesel alone.

Flash Point

The flash point of a fuel is defined as the lowest temperature at which the vapor above a combustible liquid can be made to ignite in air. Biodiesel’s flash point is over 200° Fahrenheit, well above petroleum based diesel fuel’s flash point of around 125° Fahrenheit. Testing has shown the flash point of biodiesel blends increases as the percentage of biodiesel increases. Therefore, biodiesel and blends of biodiesel with petroleum diesel are safer to store, handle, and use than conventional diesel fuel.  

Source: National Biodiesel Board 

Construction Business Owner,  August 2010