Biodiesel, A New Fuel For Vegetable Growers
August 1, 2007 Most of the current publicity about biofuels is about ethanol made from corn. Unfortunately, this is of only minor interest to vegetable growers since the majority of the fuel they use is diesel fuel and switching to engines that can use ethanol is not a viable alternative.
Biodiesel is relatively new in this country, although its use has been encouraged in Europe for several years. It can be produced from a number of crops such as soybean and canola oils and from some waste items, such as used cooking oil and animal fats. In fact, there have been numerous stories in the press discussing how some people were collecting used cooking oil from restaurants, filtering it, and using it in older diesel automobiles.
Although stories of this type seem to make good press, there were more than a few problems with this approach. Here in California, the California Air Resource Board, commonly known as CARB, is concerned that cars using this type of biodiesel are not meeting the automotive exhaust emissions standards, and there is a possibility that diesel engines will be damaged by this type of biodiesel. At this time, no new diesel powered cars are sold in California because the diesel cars available do not meet CARB emission standards.
The Making Of Biodiesel
Most biodiesel is actually a blend with conventional diesel fuel. The blends are identified by the percentage of biodiesel. For example, B5 is 5% biodiesel while B20 contains 20% biodiesel, and 100% biodiesel is known as B100.
Diesel engine manufacturers are concerned about the quality of biodiesel and impurities in the fuel that could cause engine damage or reduce engine life. Manufacturers require that the B100 biodiesel used in diesel fuel blends meet the American Society of Testing Materials (ASTM) D6751 standard or, in the case of European diesel engine manufacturers, European standard EN14214, before they will approve the blend for use in their engines. As with many standards, D6751 is subject to change and recently a stability specification was added to the standard.
A recent study by the National Renewable Energy Laboratory found that more than 50% of the B100 produced did not meet the ASTM D6751 standard. Interestingly enough, a previous study by the same organization showed only 30% of the fuel produced did not meet the ASTM standard. In other words, the situation appears to be getting worse. The glycerin content did not meet the standard. Glycerin in biodiesel can cause serious damage to diesel engines.
A Changing Situation
At this time, most diesel engine manufacturers are allowing the use of B5 diesel fuel in their engines. However, the situation is constantly changing as manufacturers do more research and testing. For example, Cummins Inc., a maker of diesel and gas engines, announced in late March that B20 was approved for use in a number of its diesel engines, if the B100 used to make the blend met ASTM 6751 standards and the fuel came from a BQ-9000 certified marketer. The BQ-9000 certification is a voluntary standard administered by the National Biodiesel Accreditation Commission and is a combination of the ASTM D6751 standard and a quality systems program including storage, sampling, and other good management practices that are necessary with biodiesel.
In my next column I will discuss more specific recommendations on biodiesel fuel use from the major farm equipment manufacturers.
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