Systems and methods for esterification and transesterification of fats and oils

Abstract

Esterification and transesterification of fats and oils is conducted using one or more heterogeneous solid catalysts in the presence of an alcohol and a cosolvent. In one example, esterification of free fatty acids in fats and oils feedstock is conducted by contacting the feedstock with a solid catalyst having acidic groups. Transesterification of triglycerides in the feedstock is conducted by contacting the feedstock with a solid catalyst having basic groups. Single train continuous plant designs are described for near complete conversion of fats and oils by sequentially contacting the feedstock with heterogeneous acidic solid catalyst and basic solid catalyst.

1 . An ester production system, comprising:
 a first reaction vessel comprising a first substantially insoluble solid catalyst that comprises acidic groups, the first solid catalyst adapted to catalyze conversion of free fatty acids to esters;   a second reaction vessel comprising a second substantially insoluble solid catalyst that comprises basic groups, the second solid catalyst adapted to catalyze conversion of tricglycerides to esters, the second reaction vessel in fluid communication with the first reaction vessel; and   a pump configured to drive a mixture of an oil or fat feedstock and an alcohol sequentially through the first reaction vessel and the second reaction vessel.   
     
     
         2 . The system of  claim 1 , further comprising one or more additional reaction vessels comprising the first solid catalyst in fluid communication with the first reaction vessel. 
     
     
         3 . The system of  claim 1 , further comprising one or more additional reaction vessels comprising the second solid catalyst in fluid communication with the second reaction vessel. 
     
     
         4 . The system of  claim 1 , wherein fluid communication between the first reaction vessel and the second reaction vessel is provided by a pipe connection between the first reaction vessel and the second reaction vessel. 
     
     
         5 . The system of  claim 1 , wherein the first solid catalyst comprises a cation exchange resin. 
     
     
         6 . The system of  claim 1 , wherein the second solid catalyst comprises an anion exchange resin. 
     
     
         7 . The system of  claim 1 , wherein the first reaction vessel comprises a column reactor, a fixed packed bed, a fluidized bed, a bubbling bed, a boiling bed, a moving bed, an elutriated bed, a circulating bed, an agitated bed, or a combination thereof. 
     
     
         8 . The system of  claim 1 , wherein the second reaction vessel comprises a column reactor, a fixed packed bed, a fluidized bed, a bubbling bed, a boiling bed, a moving bed, an elutriated bed, a circulating bed, an agitated bed, or a combination thereof. 
     
     
         9 . The system of  claim 1 , further comprising a heat exchanger configured to heat or cool fluid flowing into at least one of the first reaction vessel and the second reaction vessel. 
     
     
         10 . The system of  claim 1 , further comprising a first heat exchanger configured to heat or cool fluid flowing into the first reaction vessel and a second heat exchanger configured to heat or cool fluid flowing into the second reaction vessel, wherein the heat exchangers are configured to provide fluid to the first reaction vessel at a temperature different from that of fluid provided to the second reaction vessel.