Biodiesel Fuel Education Program

During the past decade, the United States has become increasingly dependent on imported oil to meet its energy demands. Nearly 50 percent of United States consumption of petroleum is imported. Several times during the past two decades the country has been reminded of its vulnerability to relying on overseas oil.

The American farmer can help reduce our country's dependence on imported oil by using agricultural crops to produce energy. Some of these crops, produced from many types of vegetable oil plants or tallow from livestock, can be used for what is named BIODIESEL, a fuel to replace some of our domestic use of diesel fuel in agricultural machinery, trucks, and buses. Diversion of only 10 percent of America's cropland to the production of BIODIESEL could provide all the diesel fuel used for U.S. agriculture. However, there may be other users of the environmentally friendly fuel properties, making it more valuable away from agriculture.

ENVIRONMENTAL IMPACT of USING VEGETABLE OILS as FUELS

Gaseous and particulate emissions can be reduced with the use of vegetable oil based fuels. Such fuels are part of the natural cycle (i.e., assimilation of CO₂ by plants for growth and development), and could lead to a zero net gain in oxides of carbon emissions. Vegetable oil contains negligible levels of sulfur and reduces emissions of sulfur dioxide responsible for acid rain. Vegetable oils are also more environmentally friendly in the case of a spill. the fuel is biodegradable, and will quickly break down, preventing long term damage to soil or water.

Production of BIODIESEL is highly efficient since up to 4.2 BTU's of liquid are recovered for each BTU used in its production and processing. Production costs depend on the price of rapeseed, the value of the meal left when the oil is extracted from the seed, the value of glycerol, the price of alcohol, and the government programs for production, research and subsidies.

If farmers were allowed to grow rapeseed as an energy crop on set-aside or CRP acreage, BIODIESEL would be used in agriculture. If the environmental advantages were fully understood, BIODIESEL would become the fuel of choice, even at a higher price, for many environmentally sensitive or pollutant-prone areas.

FUEL PRODUCTION

Rapeseed (Brassica Napus) is grown in northern Idaho as a winter annual. It produces approximately 2,000 pounds of seed per acre from which is extracted about 100 gallons of vegetable oil for fuel, and 1,200 pounds of meal that can be used for energy, livestock feed, or other industrial purposes. All of the oil used in the University of Idaho Studies had been extracted from rapeseed. UI scientists use two small mechanical screw presses donated to the UI by Brocke and Sons, Seedsmen of Kendrick, Idaho. The plant has a capacity of about 200 pounds per hour and generates about 10 gallons of raw rapeseed oil per hour.

Transesterification is necessary before vegetable oil can be used in most diesel engines. This is the process of using an alcohol (methanol or ethanol) in the presence of a catalyst such as sodium hydroxide or potassium hydroxide to chemically break the molecule of the raw rapeseed oil and glycerol. The UI Department of Agricultural Engineering has a 200-gallon batch reactor for producing methyl and ethyl esters. Table 1 shows typical fuel properties:

Table 1

Typical fuel properties of a raw rapeseed oil and methyl and ethyl esters of rapeseed oil in comparison with No. 2 diesel.
Properties	Raw Rapeseed oil	Methyl Ester	Ethyl Ester	Diesel
Heat of combustion btu/lb (gross)	17,370	17,506	17,500	19,652
Flash Point (°F)	525	338	365	176
Cloud Point (°F)	12	26	30	7
Pour Point (°F)	5	6	-5	-18
Viscosity (cs) @ 104 °F	46.7	5.7	6.1	3.51
Sulfur (%, wt)	0.022	less than 0.001	0.008	0.36
Density (lb/gal) @ 70 °F	7.57	7.20	7.31	7.07

Based on analyses of samples sent to Phoenix Chemical Lab, Inc., Chicago, IL;
analyses by Analytical Lab Services and Ag Engineering Analytical Lab, Moscow, ID.

The UI is studying rapeseed oil esterified using ethanol as the alcohol instead of methanol. Benefits of ethyl ester are:

ON-ROAD TEST OF BIODIESEL BLENDS

The UI is working with four diesel-powered pickups in the BIODIESEL tests. A 1992 Dodge pickup is powered by a 5.9 liter turbo-charged and inter-cooled engine. This engine is direct injected and runs on 20 percent methyl ester of rapeseed oil (RME) and 80 percent diesel (D2). A Ford pickup, which has an engine with a pre-combustion chamber, uses 20 percent raw rapeseed oil and 80 percent D2. It is powered by a 7.3 liter, naturally aspirated engine. Engines are not modified, but modifications have been made to the pickups for testing convenience.

UI personnel operate a 1994 Dodge pickup powered by direct injection diesel engine. It is fueled with 100 percent ethyl ester of rapeseed oil (REE). In 1995, Dodge Truck supplied a diesel-powered pickup which is operated by the National Park Service in Yellowstone National Park. It is also using 100 percent REE. The engines in both these trucks are like the Cummins diesel engine in the 1992 Dodge. The engines and fuel systems in the trucks have not been modified in any way.

The fuel delivery systems in the first two trucks have been modified to provide for onboard mixing of the fuel. The vegetable oil fuel is in a 50-gallon fuel tank that is in the bed of each vehicle, and a small mixing tank is mounted to the frame of each vehicle. Vegetable oil at the 20 percent rate and D2 fuel at the 80 percent rate are supplied to this tank by electric fuel pumps. The return line from the diesel injection system also comes into this small tank. Providing for onboard mixing greatly ex tends the range of the vehicle compared to carrying a mixed fuel in the existing tanks.

Since the vegetable oils have a pour point only slightly below freezing, the fuel must be heated in cold weather. A heating system using engine coolant has also been added to the vegetable oil tank in the first two vehicles.

The instrument panel in each test vehicle cab has been modified. An hour meter was added to provide more information on engine operation. Other meters indicate that the fuel mixing system is working properly. An extra fuel gauge warns the operator that it is time to start looking for a station with BIODIESEL. The goal is to operate each vehicle about 25,000 miles per year, and to reach 100,000 miles in about four years.

OIL SAMPLING

Oil samples are taken at each oil change, which is every 3,000 to 4,000 miles, and are analyzed at Western States Cat. Tests include analysis for wear metals and physical tests for antifreeze, fuel dilution, water and viscosity. An infrared analysis of the oil checks for soot, sulfur, nitration, and oxidation.

DYNAMOMETER TESTING

All three vehicles are tested on a chassis dynamometer every 10,000 to 15,000 miles at Western States Cat in Spokane, Washington. The dyno is computer controlled and provides a printout of horsepower to the wheels, torque, fuel consumption, fuel tempera ture, inlet air temperature, coolant temperature, exhaust temperature, engine blow by, engine rpm, and turbo boost pressure. An opacity meter measures the amount of smoke in the exhaust.

At each dynamometer test the vehicles undergo two or three tests: one with the 20/80 percent mix and one with the 100 percent D2 and the ester fueled vehicles are tested on 100 percent methyl or ethyl ester. The injectors are removed from the engines at intervals to check for deposits and to measure engine compression.

CHECK VEHICLE

Three other pickups are used as check vehicles. Two have the 5.9 liter direct injection engine, and the other has a 7.3 liter engine with pre-combustion chamber. These vehicles are operated on 100 percent D2 fuel and serve as comparisons. Oil samples for analysis are taken at the owners discretion and are analyzed by the sa me laboratory. When possible, these vehicles are also tested on the Dynamometer at Western States Cat in Spokane, Washington.

PROGRESS REPORT

As of January 1995, the on-road vehicle tests are progressing very well. No major mechanical difficulties have occurred. The two 1992 on-road vehicles, one fueled with 20 percent RME and one 20 percent raw rapeseed oil have reached 55,400 miles and 46,5 00 miles respectively.

Reduced fuel filter life had been a problem in the 20 percent RME blend fueled vehicle. Rust in the heated, steel tanks was observed and the tanks were replaced with stainless steel.

Continuous improvements to the onboard mixing system have been made in order to obtain a more accurate mixture. The tank heating system performed well during the cold winter months keeping the BIODIESEL at 50 F.

At the 16,000 mile dynamometer test, the 1994 pickup fueled with the 100 percent REE had a 30 percent decrease in opacity and a 7.8 percent reduction in horsepower compared to D2. The 1992 pickup operated on 20 RME, at the 50,000 mile dynamometer test, h ad horsepower changes of -1.5 and-2.9 percent and opacity changes of -9.4 and -25.6 percent when fueled with 20 percent RME blend and 100 percent RME respectively (Table 2).

The injectors and compression were tested at each dynamometer inspection. Injector valve opening pressures (VOP) varied as much as 100 psi. No differences were noted between the cylinder compression tests.

EMISSIONS TESTS WITH RAPE ESTERS IN COMPARISON WITH DIESEL

In 1994, UI personnel conducted a series of chassis dynamometer emissions tests in cooperation with the Los Angeles County Metropolitan Transit Authority. The test vehicle was a 1994 Dodge 2500 pickup with a Cummins 5.9 liter, turbocharged and inter-cooled diesel engine.

Emissions data generated in this program included all regulated emissions: total hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NO_x), and particulate matter (PM) (see graph).

Two test cycles were used. First was an arterial cycle, which consisted of eight replications of accelerating to 40 mph and decelerating to 0 mph and took 758 seconds. Second was the dynamometer driving schedule for heavy duty vehicles (Code of Federal Regulations 40, Part 86, Appendix I, Cycle D), a 1060 second test.

Several fuels were tested including both methyl and ethyl esters of rapeseed oil produced by UI Agricultural Engineering. The D2 fuel used in the tests was Phillips D2, low sulfur control fuel.

Data from the tests included 20 percent REE, which is a blend of 20 percent REE and 80 percent D2 control fuel, 50 percent REE, which is a blend of 50 percent REE and 50 percent D2 control fuel; and 100 percent REE.

COAST-TO-COAST ON-ROAD TEST

In summer 1994, personnel from UI Agricultural Engineering drove the 1994 Dodge 2500 pickup 8,742 miles at an average of 18.7 mpg, fueled only with 100 percent ethyl ester of rapeseed oil. All of the REE fuel was carried onboard. The vehicle currently a s traveled over 28,000 miles on 100 percent REE.

TRUCK IN THE PARK

The UI, along with the Montana Department of Environmental Quality, Wyoming Department of Commerce, Dodge Truck, and J.R. Simplot Company are exploring the market for BIODIESEL in the tourism industry and other environmentally sensitive applications. The Dodge Truck Division of Chrysler Corporation supplied a 1995 4x4 diesel pickup, to be fueled with 100 percent REE and operated by the National Park Service in Yellowstone National Park through 1996. This project's goal is to encourage industrial producti on and use of BIODIESEL in the region.

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BIODIESEL (methyl or ethyl ester of plant oils or animal fats) is a new fuel which is being tested under a wide range of conditions including both neat and blended with petrodiesel. Users of this fuel should be aware, however, that currently there is no fuel specification for BIODIESEL and, therefore, engine manufacturers cannot fully recognize it as equivalent to diesel. Users of this fuel or any fuel not meeting manufacturers' published fuel specification requirements assume warranty liability for failure of components or emissions certification traceable to the fuel. Nonfuel related warranty issues are not affected by the use of BIODIESEL.