Vegetable oils: Precombustion characteristics and performance as diesel fuels
Vegetable oils show technical promise as alternative fuels for diesel engines and have good potential as emergency fuels. Realistically, vegetable oils cause a number of problems when used in direct-injection diesel engines, generally attributable to inefficient combustion. At least partially responsible for poor combustion of neat vegetable oils are their high viscosity and non-volatility. To improve combustion several somewhat empirical approaches involving both chemical and physical modifications have been investigated by endurance tests in a variety of engines. Using the EMA 200 h engine screening test, several fuels show technical promise. These include methyl, ethyl, and butyl esters; high-oleic oils:diesel blend (1:3); diesel:soybean oil:butanol:cetane improver (33:33:33:1); and microemulsion fuels (diesel:soybean oil:190 proff ethanol:butanol, 50:25:5:20) and (soybean oil:methanol:2-octanol:cetane improver, 53:13:33:1). Using a pressure vessel, fuel injection system, and high speed motion picture camera, fuel injection characteristics of vegetable oils, e.g., soybean, sunflower, cottonseed, and peanut, have been observed in a quiescent nitrogen atmosphere at 480/sup 0/C and 4.1MPa. Their injection and atomization characteristics are markedly different from those of petroleum derived diesel fuels. Heating the vegetable oils to lower their viscosities increased spray penetration rate, reduced spray cone angles, and resulted in spray characteristics resembling those of diesel fuel. Significant chemical changes occurred following injection. Samples collected at about 400 microseconds after the injection event consisted of appreciable quantities of C/sub 4/-C/sub 16/ hydrocarbons, and free carboxyl groups were present.
- Research Organization:
- Northern Regional Research Center, USDA/ARS, 1815 N. Univ. Street, Peoria, IL
- OSTI ID:
- 5667436
- Report Number(s):
- CONF-860425-
- Journal Information:
- Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States), Vol. 31:1; Conference: 191. American Chemical Society national meeting, New York, NY, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
33 ADVANCED PROPULSION SYSTEMS
DIESEL ENGINES
FUEL SUBSTITUTION
PERFORMANCE TESTING
VEGETABLE OILS
COMBUSTION PROPERTIES
ALKENES
BUTANOLS
CHEMICAL PROPERTIES
COTTONSEED OIL
DIESEL FUELS
ESTERS
ETHANOL
FUEL INJECTION SYSTEMS
HIGH TEMPERATURE
MEDIUM PRESSURE
METHANOL
MICROEMULSIONS
OCTANOLS
PEANUT OIL
SOYBEAN OIL
SUNFLOWER OIL
SYNTHETIC FUELS
VISCOSITY
ALCOHOLS
COLLOIDS
DISPERSIONS
EMULSIONS
ENGINES
FUEL SYSTEMS
FUELS
HEAT ENGINES
HYDROCARBONS
HYDROXY COMPOUNDS
INTERNAL COMBUSTION ENGINES
LIPIDS
OILS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PETROLEUM PRODUCTS
TESTING
TRIGLYCERIDES
090110* - Hydrocarbon Fuels- Properties- (1979-1989)
330102 - Internal Combustion Engines- Diesel
330800 - Emission Control- Alternative Fuels