A process for manufacturing esters from acid and alcohol and a system thereof are provided, wherein the system includes a reactive distillation column, a sidestream reactor packed with catalyst, and a decanter for conducting the method. The method is carried out by (a) extracting a first mixture of acid and alcohol from the reactive distillation column, for then feeding the first mixture to at least one sidestream reactor packed with catalyst to obtain a reaction product; (b) feeding the reaction product from the sidestream reactor to the reactive distillation column, allowing a second mixture of alcohol, ester and water to be separated from a top end of the reactive distillation column; (c) feeding the second mixture into the decanter to separate an organic phase from an aqueous phase; and (d) separating esters from the organic phase. The method and system allow the esters to be extracted without using a plurality of recovering columns and decanters, and are capable of improving packing/changing catalyst in a single reactive distillation column.