Production of Biodiesel from Vegetable Oils: A Survey

Abstract

The purpose of this work is to investigate biodiesel production processes from vegetable oils. Biodiesel fuel can be made from new or used vegetable oils and animal fats, which are non-toxic, biodegradable, renewable resources. The vegetable oil fuels were not acceptable because they were more expensive than petroleum fuels. Biodiesel has become more attractive recently because of its environmental benefits. With recent increases in petroleum prices and uncertainties concerning petroleum availability, there is renewed interest in vegetable oil fuels for diesel engines. Dilution of oils with solvents and microemulsions of vegetable oils lowers the viscosity, and some engine performance problems still exist. The purpose of the transesterification process is to lower the viscosity of the oil. Pyrolysis produces more biogasoline than biodiesel fuel.

Keywords:

• biodiesel
• economy
• microemulsions
• pyrolysis
• transesterification

Notes

^a Wheat grain oil contains 11.4% of 8:0 and 0.4% of 14:0 fatty acids.

^b Castor oil contains 89.6% ricinoloic acid.

^c Bay laurel oil contains 26.5% of 12:0 and 4.5% of 14:0 fatty acids.

^d Peanut kernel oil contains about 2.7% of 22:0 and 1.3% of 24:0 fatty acids.

^e Coconut oil contains about 46.5% of 12.9 and 19.2% of myristic fatty acids.

^a This specification is the process of being evaluated by ASTM. A considerable amount of experience exists in the U.S. with a 20% blend of biodiesel with 80% petroleum-based diesel. Although biodiesel can be used in the pure form, use of blends of over 20% biodiesel should be evaluated on a case-by-case basis until further experience is available.

^{a b} Or equivalent ASTM testing method.

^c Austrian (Christina Plank) update of USDA test method.

^a Melting point of highest melting, most stable polymorphic form.

^a Only results for one of the biodiesel plants evaluated is reported here.