The goal of this project was to evaluate locally developed yellow mustard cultivars to determine their suitability as low cost feedstock for biodiesel. Rapeseed, canola, and yellow mustard are particularly well-adapted alternative crops for the Palouse of northern Idaho and eastern Washington. In addition, genetic modifications of these oils to produce a feedstock that has particularly advantageous properties for biodiesel is entirely possible. One of these varieties, Ida Gold, was selected based on the recommendations of the plant breeder. Other yellow mustard oils were also used in some of the tests. Oil extraction and biodiesel production efficiencies have been somewhat less for the yellow mustards than for rapeseed and canola. Extraction averaged only 58 percent compared to 78 to 80 percent for rapeseed and canola. Biodiesel production had a yield of 7 percent less than when rapeseed and/or canola were used.
Fuel characterization parameters according to the American Society of Agricultural Engineers EP 552 and the interim American Standards for Testing Materials (ASTM) standard for biodiesel are being evaluated. The data collected thus far indicates that the yellow mustard oil is fairly consistent with rapeseed and canola as far as its use as a fuel is concerned.
A 1999 Cummins-powered Dodge diesel pickup truck was used for on-road testing. The truck was operated for 23,980 miles on yellow mustard biodiesel (mustard ethyl ester or MEE). It averaged 15.23 mpg, which was quite good considering a considerable portion of the use was pulling a trailer to deliver alcohol and biodiesel. The truck was tested on a chassis dynamometer comparing operation on MEE and diesel fuel. No operational problems have been noted with the test vehicle. Oil analysis results from samples of the engine oil are normal. Test results showed a 6.4 percent reduction in power and an increase of 1.6 percent in fuel use when operated on MEE compared to diesel. Injector cutout tests conducted on this vehicle were normal.
A 2001 Volkswagen 1.9 L diesel new beetle was obtained for demonstration with yellow mustard biodiesel. The vehicle fuel was changed to yellow mustard biodiesel at 492 miles and a total of 5,109 miles has been run since then. The vehicle is being used to demonstrate the feasibility of using biodiesel in smaller vehicles and for urban use. The “Idaho Mustard Bug” has been used in numerous demonstrations, schools, field days, open houses, and was on display at the Renewable Energy Fair in Sun Valley and the Ethanol Conference at West Yellowstone. It has been particularly effective in teaching K-12 students about the advantages of alternative fuels.
Stationary engine tests, including a 200-hour Engine Manufacturers Association (EMA) durability test, are in progress. As part of this project, the University of Idaho (UI) test facility was upgraded with a new computer system and new instrumentation. A new 24 hp, 3 cylinder, direct injection engine was obtained and is currently under test on a biodiesel fuel produced from Ida Gold yellow mustard. During the durability startup tests, MEE power averaged 6.0 percent lower; fuel consumption was 2.2 percent higher and Brake Specific Fuel Consumption (BSFC) (hp-hrs/gal) was 8 percent higher than when operated on diesel. We had available a machine vision system for scoring the results of the injector coking. This facility was made operational and upgraded to reduce the variability between readings with a particular injector. It has been used for both MEE testing and tests with used vegetable oil.
In August and September of 2001, a series of chassis dynamometer emissions tests were run with a 1994 Dodge Cummins diesel powered pickup. UI’s recently upgraded 602 SuperFlow Dynamometer was used to correlate emissions readings from a portable five-gas analyzer with emissions readings obtained in 1997 at the Los Angeles Mass Transit Authority testing facility with the same truck. Results of these these tests show that only the nitrous oxide (NOx) data may be comparable. The sensitivity of the analyzer was insufficient for carbon monixide (CO) comparisons, and the erratic nature of the data for hydrocarbons (HC) made it difficult to compare. Additional tests are suggested comparing biodiesel feedstocks to determine if the NOx data would follow trends developed earlier.