Abstract
In the present study conversion of vegetable oils to new transportation liquid fuels by pyrolysis and catalytic pyrolysis have been investigated. World annual petroleum consumption and vegetable oil production is about 4.018 and 0.107 billion tons, respectively. Global vegetable oil production increased 56 million tons in 1990 to 88 million tons in 2000, following a below-normal increase. Leading the gains in vegetable oil production was a recovery in world palm oil output, from 18.5 million tons in 1998 to 27.8 million In 2003. Vegetable oils from renewable oil seeds can be use when mixed with diesel fuels. Vegetable oils can be used as fuels for diesel engines, but their viscosities are much higher than usual diesel fuel and require modifications of the engines. Different ways have been considered to reduce the viscosity of vegetable oils such as dilution, microemulsification, pyrolysis, and transesterification. Compared with transesterification, pyrolysis process has more advantages. The liquid fuel produced from pyrolysis has similar chemical components to conventional petroleum diesel fuel. Vegetable oils can be converted to a maximum of liquid and gaseous hydrocarbons by pyrolysis, decarboxylation, deoxygenation, and catalytic cracking processes. Sunflower seed oil has been pyrolized to obtain liquid fuels at atmospheric pressure, a reaction temperature of 560-690 K in the presence zeolite as catalysts. The maximum yields of conversion from pyrolysis of sunflower oil were obtained from 2% zeolite catalytic runs at all temperatures. Then, the yield of conversion decreased with increasing catalyst percentage. The maximum yield of pyrolysis oil was 54% from 2% zeolite catalytic run at 690 K. The liquid fuel produced from pyrolysis has similar chemical components to conventional petroleum diesel fuel.