Global trends on the processing of bio-fuels

The aim of the present paper is to investigate bio-fuels produced from biomass materials by thermochemical and biochemical methods and the utilization trends of the products in the world. Bio-fuels are liquid or gaseous fuels made from plant matter and residues, such as agricultural crops, municipal wastes and agricultural and forestry by-products. Liquid bio-fuels being considered world over fall into the following categories: (a) vegetable oils and biodiesels; (b) alcohols; and (c) biocrude and synthetic oils. Bioethanol can be produced from cellulose feedstocks such as corn stalks, rice straw, sugar cane bagasse, pulpwood, switchgrass, and municipal solid waste. Conversion technologies for producing bioethanol from cellulosic biomass resources such as forest materials, agricultural residues and urban wastes are under development and have not yet been demonstrated commercially. Biodiesel fuel can be made from new or used vegetable oils and animal fats, which are non-toxic, biodegradable, renewable resources.The problems with substituting triglycerides for diesel fuels are mostly associated with their high viscosities, low volatilities and polyunsaturated character. Different ways have been considered to reduce the high viscosity of vegetable oils.