The present invention provides a method and apparatus for reacting a natural oil with a short chain alcohol in the presence of alkaline catalyst, in which a mixture of natural oil, short chain alcohol and alkaline catalyst is fed in one direction along a pipe reactor under transitional or turbulent conditions, so th...

A method of esterifying free fatty acid in natural oil comprises heating the natural oil (2) to a first temperature above a reaction temperature, feeding the heated natural oil into an acid resistant pipe reactor (5), providing a mixture of acid catalyst (6) and short chain alcohol (8) at a second temperature below ...