Method and apparatus for preparing alkyl ester fatty acid using fatty acid

A method for preparing fatty acid alkyl ester for bio-diesel fuel comprising the step of carrying out a counter current type esterification reaction of fatty acid and alcohol in each tray of a counter current column reactor at a temperature of 200 to 350° C. and a pressure of 10 to 35 bar,

• wherein a raw material of the fatty acid is fed to an upper part of the counter current column reactor and alcohol is fed to a lower part of the counter current column reactor;
• wherein the counter current column reactor has a number of trays which are installed horizontally to have a number of vertical compartments;
• wherein each of a number of trays has an opening part at one end thereof to communicate one compartment with an adjoining compartment;
• wherein the opening parts of two adjoining trays are alternately installed with each other:
• and
• wherein the raw material of fatty acid is fed to a top compartment at the upper part of the counter current column reactor and then is transferred to lower compartments in order, and the alcohol is fed to a bottom compartment at the lower part of the counter current column reactor and then is transferred to upper compartments in order.