Pretreatment of fats and oils in the production of biofuels

Abstract

Methods are disclosed for the treatment of feedstocks comprising a fatty acid- or triglyceride-containing component to remove contaminants that are detrimental to the conversion of such feedstocks to hydrocarbons, and especially biofuel fractions such as diesel or aviation biofuels. Contaminants contributing to the presence of trace elements in animal fats and/or plant oils, as components of feedstocks, hinder the ability to catalytically convert these feedstocks, for example by hydroprocessing, to biofuels.

1 . A method for treating a feedstock comprising a fatty acid- or triglyceride-containing component comprising one or more contaminants, the method comprising contacting the feedstock with an ion exchange resin to provide a treated feedstock having a reduced concentration of at least one of the contaminants. 
     
     
         2 . The method of  claim 1 , wherein the one or more contaminants is an alkali metal, an alkaline earth metal, a transition metal, or a non-metal other than C, H, or O. 
     
     
         3 . The method of  claim 2 , wherein the one or more contaminants is selected from the group consisting of Ca, Fe, Mg, Na, P, and K. 
     
     
         4 . The method of  claim 1 , wherein the fatty acid or triglyceride-containing component is an animal fat, a plant oil, or a mixture thereof. 
     
     
         5 . The method of  claim 4 , wherein the animal fat is selected from the group consisting of lard, tallow, train oil, milk fat, fish oil, grease, sewage sludge, and mixtures thereof. 
     
     
         6 . The method of  claim 4 , wherein the plant oil is selected from the group consisting of rapeseed oil, corn oil, colza oil, canola oil, tall oil, sunflower oil, soybean oil, hempseed oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, jatropha oil, camelina oil, salicornia oil, pennycress oil, algal oil, and mixtures thereof. 
     
     
         7 . The method of  claim 1 , wherein the ion exchange resin is a strong base or weak base anion exchange resin, a strong acid cation exchange resin, or a combination thereof. 
     
     
         8 . The method of  claim 7 , wherein the strong base anion exchange resin has quaternary ammonium functional groups. 
     
     
         9 . The method of  claim 7 , wherein the weak base anion exchange resin has amine functional groups. 
     
     
         10 . The method of  claim 7 , wherein the strong acid cation exchange resin has sulfonic acid functional groups. 
     
     
         11 . The method of  claim 3 , wherein the treated feedstock has a total concentration of Ca, Fe, Mg, Na, P, and K contaminants that is reduced by at least about 35% relative to the feedstock. 
     
     
         12 . The method of  claim 1 , wherein the treated feedstock has a concentration of P that is reduced by at least about 70% relative to the feedstock. 
     
     
         13 . The method of  claim 1 , further comprising contacting the treated feedstock with hydrogen under catalytic hydroprocessing conditions to provide a hydroprocessed product. 
     
     
         14 . The method of  claim 13 , wherein the contacting with hydrogen under catalytic hydroprocessing conditions results in both hydrotreating and hydrocracking reactions. 
     
     
         15 . The method of  claim 13 , further comprising fractionating the hydroprocessed product to recover a hydroprocessed biofuel. 
     
     
         16 . The method of  claim 15 , wherein the hydroprocessed biofuel is a hydroprocessed diesel biofuel or a hydroprocessed aviation biofuel. 
     
     
         17 . A method for making a hydroprocessed biofuel from a feedstock comprising an animal fat, a plant oil, or a mixture thereof, the method comprising:
 (a) contacting the feedstock with a macroreticulated, strong acid cation exchange resin to provide a treated feedstock having a reduced concentration of one or more contaminants selected from the group consisting of Ca, Fe, Mg, Na, P, and K;   (b) contacting the treated feedstock with hydrogen and a hydroprocessing catalyst to provide a hydroprocessed product; and   (c) separating the hydroprocessed product to recover the hydroprocessed biofuel.   
     
     
         18 . The method of  claim 17 , wherein the cation exchange resin is in the hydrogen form. 
     
     
         19 . The method of  claim 17 , further comprising blending the hydroprocessed biofuel with from about 1% to 99% by weight of a petroleum-derived fuel. 
     
     
         20 . A biofuel composition made by the method of  claim 19 .