| abstract |
A method of converting vegetable-based organic acids into corresponding lower alcohol esters. According to the present method, the raw material which comprises organic acids is brought into contact with a lower alcohol in the presence of an acidic catalyst in order to esterify the acids. In the present invention, a reaction mixture is formed of the raw material, which comprises organic acids, and of lower alcohol, and this reaction mixture is brought into conditions under which the mixture cavitates in order to esterify the organic acids and to lower the acid number of the raw material to a value which is at maximum 20 % of the original acid number. With the present invention, it is possible by using esterification to produce, for instance from organic acids of tall oil, such as fatty acids, an inexpensive biodiesel fuel. |