Process for producing bio-derived fuel with alkyl ester and iso-paraffin components

Abstract

A process for producing a diesel fuel of biological origin. The process includes a biological component to be trans-esterified into a fatty acid alkyl ester. A fraction of the fatty acid alkyl ester is hydrodeoxygenated and hydroisomerized to produce an iso-paraffinic hydrocarbon. The fatty acid alkyl ester and the iso-paraffin components are combined into a middle distillate product suitable for direct use as diesel or jet fuel.

1 . A process for producing a diesel fuel of biological origin, comprising:
 providing a biological component to be trans-esterified into fatty acid alkyl ester,   subjecting a fraction of the fatty acid alkyl ester to hydro-deoxygenation and hydro-isomerization to produce an iso-paraffinic hydrocarbon, and   combining the fatty acid alkyl ester and the iso-paraffin components into a middle distillate composition suitable for direct use as diesel or jet fuel.   
     
     
         2 . The process of  claim 1  wherein the biological component comprises vegetable oils, animal fats, and combinations thereof. 
     
     
         3 . The process of  claim 1  wherein the fraction of fatty acid alkyl ester subjected to hydro-deoxygenation and hydro-isomerization is recovered by distillation. 
     
     
         4 . The process of  claim 1  wherein the fraction of fatty acid alkyl ester subjected to hydro-deoxygenation and hydro-isomerization is recovered by crystallization. 
     
     
         5 . The process of  claim 1  wherein an alcohol used for trans-esterification is methanol. 
     
     
         6 . The process of  claim 1  wherein the trans-esterification is carried out at a temperature of about 80° F. to about 200° F. 
     
     
         7 . The process of  claim 1  wherein the trans-esterification catalyst is potassium hydroxide, sodium hydroxide, or sodium methoxide. 
     
     
         8 . The process of  claim 1  wherein the hydrodeoxygenation pressure is about 500 psig to about 2,500 psig and the temperature is about 400° F. to about 800° F. 
     
     
         9 . The process of  claim 1  where in the hydrodeoxygenation catalyst is a supported NiMo, NiW, or CoMo catalyst, the support being alumina, or alumina with phosphorous or silicon oxides. 
     
     
         10 . The process of  claim 1  wherein the hydroisomerization pressure is about 500 psig to about 2,000 psig and the temperature is about 500° F. to about 800° F. 
     
     
         11 . The process of  claim 1  wherein the hydroisomerization catalyst contains one or more of Pt, Pd, Ni, on amorphous or crystalline supports containing one or more of alumina, fluorided alumina, silica, ferrierite, ZSM-12, ZSM-21, ZSM-22, ZSM-23, SAPO-11, SAPO-31, and SAPO-41. 
     
     
         12 . The process as in any one of  claims 1 - 11  wherein a glycerol byproduct of trans-esterification is subjected to hydro-deoxygenation. 
     
     
         13 . The process as in any one of  claims 1 - 11  wherein the fraction of fatty acid alkyl ester is combined with a biological component rich in free fatty acids before being subjected to hydro-deoxygenation. 
     
     
         14 . The process of  claim 13  wherein the biological component rich in free fatty acids is rendered fat, restaurant grease, waste industrial frying oil, tall oil fatty acid, and combinations thereof. 
     
     
         15 . The process of  claim 14  wherein a glycerol byproduct of trans-esterification is used to wash the biological component rich in free fatty acid before this biological component is subjected to hydro-deoxygenation.