IMPROVEMENTS IN OR RELATING TO A METHOD FOR TRANSESTERIFYING VEGETABLE OILS

摘要

The invention relates to a method for producing Diesel grade fuel of plant origin by transesterifying a refined vegetable oil with a C1-C4 alkanol in the presence of a catalyst whereupon a polar phase and an apolar phase is formed, removing the polar phase comprising glycerol by-product, and subjecting the apolar phase comprising the fuel to a refining procedure. According to the method of the in-vention refined vegetable oil is transesterified in a homogeneous phase in the presence of at least 0.2 parts by volume, related to unit volume of refined vegetable oil, of an aliphatic hydrocarbon solvent with a boiling point of 40-200<°>C to form a mixture comprising a polar phase and an apolar phase, if necessary, the apolar phase which also comprises non-transesterified vegetable oil beside aliphatic hydro-carbon solvent and transesterified product, obtained after removing the separated polar phase comprising glycerol by-product, is reacted in a further step with a C1-C4 alkanol in the presence of a catalyst until a transesterification conversion of 95-98 % is attained, the separated polar phase comprising glycerol by-product is removed, and the apolar phase comprising the fuel is refined wherein, if desired, at least a portion of the aliphatic hydrocarbon solvent is retained in the product