System and methods for making bioproducts

A system for making a fatty acid alkyl ester, comprising:

• a pretreatment system configured to
• receive water and a mixture comprising a fatty acid glyceride, fatty acid and at least one component selected from the group consisting of a gum, a suspended solid, a dissolved metal, and combinations thereof;
• reduce the amount of at least one component from the mixture while the amount of fatty acid relative to the amount of fatty acid glyceride in the mixture is substantially the same to produce a pretreated mixture;
• a first fixed bed reactor comprising a supported heterogeneous acid catalyst;
• wherein the first fixed bed reactor is configured to
• receive the pretreated mixture and an alcohol;
• perform esterification of fatty acids and transesterification of fatty acid glycerides to produce a first reaction mixture comprising a fatty acid alkyl ester;
• a second fixed bed reactor comprising the supported heterogeneous acid catalyst, wherein the second fixed bed reactor is configured to
• receive at least a portion of the first reaction mixture and an alcohol,
• perform esterification of fatty acids and transesterification of fatty acid glycerides to produce a second reaction mixture comprising a fatty acid alkyl ester, unreacted alcohol, and glycerin;
• wherein the acid number of the second reaction mixture is less than about 0.5, 0.4, 0.3, 0.2, or 0.1;
• wherein said heterogeneous acid catalyst comprises one or more metals selected from the group consisting of molybdenum (Mo), iron (Fe), cobalt (Co) and chromium (Cr).

A system for making a fatty acid alkyl ester, comprising

• a pretreatment system configured to
• receive water and a mixture comprising a fatty acid glyceride, fatty acid and at least one component selected from the group consisting of a gum, a suspended solid, a dissolved metal, and combinations thereof;
• reduce the amount of at least one component from the mixture while the amount of fatty acid relative to the amount of fatty acid glyceride in the mixture is substantially the same to produce a pretreated mixture;
• a first reactor comprising a heterogeneous acid catalyst;
• wherein the first reactor is configured to
• receive the pretreated mixture and an alcohol;
• perform esterification of fatty acids and transesterification of fatty acid glycerides to produce a first reaction mixture comprising a fatty acid alkyl ester;
• and
• a second reactor comprising the heterogeneous acid catalyst;
• wherein the second reactor is configured to
• receive at least a portion of the first reaction mixture and an alcohol;
• perform esterification of fatty acids and transesterification of fatty acid glycerides to produce a second reaction mixture comprising a fatty acid alkyl ester;
• wherein said heterogeneous acid catalyst comprises one or more metals selected from the group consisting of molybdenum (Mo), iron (Fe), cobalt (Co) and chromium (Cr).