| abstract |
A process for esterifying a mixture comprising between 10% and 20% by weight of free fatty acids (FFAs), said process comprising the steps of: (i) providing at least a first portion of the mixture to at least a first container reaction; (ii) heating the first portion of the mixture to a reaction temperature for esterification, the reaction temperature being between 71 ° C and 76 ° C; (iii) introducing esterification conditions into the first reaction vessel, comprising adding an esterification catalyst and an alcohol to the reaction vessel, the esterification catalyst being sulfuric acid; (iv) stop heating the first portion of the mixture; (v) recirculating the first portion of the mixture by withdrawing it from the first reaction vessel and returning it to the first reaction vessel; and (vi) esterifying the FFAs in the first portion of the mixture; wherein the recirculation of the first portion of the mixture is configured to maintain a suitable reaction temperature for the esterification of the FFAs in the first portion of the mixture, the reaction temperature being between 71 ° C and 76 ° C; and wherein the mass of the esterification catalyst used relative to the% by weight of the FFAs in the mixture before the esterification is from 26 kg of catalyst per% by weight of FFAs to 32 kg of catalyst per% by weight of FFAs, so that the amount of FFAs in the mixture is reduced to 3% by weight or less. |