Fatty acid reduction of feedstock and neutral and acidic alkyl ester

Abstract

Processes and compositions reduce free fatty acid (FFA) in oils and fats and in neutral or acidic alkyl ester. The oils and fats or alkyl ester is heated to temperatures from 90° F. to 150° F., and lower numbered alcohol and dilute caustic are added. The mixture is stirred moderately, and allowed to settle into two phases—a FFA phase and a second low FFA phase, containing either oils and fats or alkyl ester. The two phases are separated. The recovery of both glycerin and lower numbered alcohols is increased. Some compositions for reducing FFA comprise lower numbered alcohol and dilute caustic. The processes and compositions reduce FFA levels to meet fuel standards.

1 . A process for refining, the process comprising:
 providing a first mixture comprising free fatty acid, alkyl ester, and mixed fatty glycerides, wherein the amount of mixed fatty glycerides is no more than 5% wt/wt;   providing lower numbered alcohol;   providing dilute caustic; and,   adding the lower numbered alcohol and the dilute caustic to the first mixture resulting in a second mixture.   
     
     
         2 . The process of  claim 1 , wherein the first mixture further comprises glycerin, the process further comprising separating glycerin from the first mixture. 
     
     
         3 . The process of  claim 2  further comprising centrifuging the first mixture prior to separating glycerin from the first mixture. 
     
     
         4 . The process of  claim 1  further comprising heating the first mixture to a temperature from 90 degrees F. to 150 degrees F. 
     
     
         5 . The process of  claim 1  further comprising heating the first mixture to a temperature from 120 degrees F. to 150 degrees F. 
     
     
         6 . The process of  claim 1  further comprising heating the first mixture to a temperature from 140 degrees F. to 150 degrees F. 
     
     
         7 . The process of  claim 4  wherein the first mixture is heated to temperature before the lower numbered alcohol and the dilute caustic are added to the first mixture. 
     
     
         8 . The process of  claim 7  further comprising agitation of the second mixture. 
     
     
         9 . The process of  claim 8  wherein the agitation is a low-shear mixing. 
     
     
         10 . The process of  claim 9  further comprising allowing the second mixture to settle into a first phase upper component and a second phase lower component. 
     
     
         11 . The process of  claim 10  wherein the settling occurs at temperature. 
     
     
         12 . The process of  claim 10  wherein the settling occurs at room temperature. 
     
     
         13 . The process of  claim 9  wherein the second mixture settles into a first phase upper component and a second phase lower component. 
     
     
         14 . The process of  claim 11  wherein the first phase comprises alkyl ester, and the second phase comprises alcoholic aqueous soap. 
     
     
         15 . The process of  claim 11  further comprising separating the first phase from the second phase. 
     
     
         16 . The process of  claim 1  wherein the first mixture is neutral. 
     
     
         17 . The process of  claim 1  wherein the first mixture is acidic. 
     
     
         18 . The process of  claim 1  wherein the lower numbered alcohol is selected from a group comprising: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, propylene glycol, ethylene glycol, and butylene glycol. 
     
     
         19 . The process of  claim 1  wherein the dilute caustic is selected from a group comprising: NaOH and KOH. 
     
     
         20 . The process of  claim 1  wherein the lower numbered alcohol and the dilute caustic are added simultaneously. 
     
     
         21 . The process of  claim 1  wherein the lower numbered alcohol and the dilute caustic are added sequentially. 
     
     
         22 . The process of  claim 21  wherein the lower numbered alcohol is added before adding the dilute caustic. 
     
     
         23 . The process of  claim 15  wherein:
 the amount of dilute caustic provided is from stoichiometric to the amount of free fatty acid in the first mixture to 20% excess of the stoichiometric amount; 
 the concentration of the dilute caustic provided is from 2% to 15% wt/wt; and, 
 the amount of lower numbered alcohol provided is from 1% to 20% wt/wt. 
 
     
     
         24 . The process of  claim 15  wherein:
 the amount of dilute caustic provided is from stoichiometric to the amount of free fatty acid in the first mixture to 10% excess of the stoichiometric amount; 
 the concentration of the dilute caustic provided is from 3% to 6% wt/wt; and, 
 the amount of lower numbered alcohol provided is from 2% to 5% wt/wt. 
 
     
     
         25 . The process of  claim 15  wherein:
 the amount of dilute caustic provided is from stoichiometric to the amount of free fatty acid in the first mixture to 5% excess of the stoichiometric amount; 
 the concentration of the dilute caustic provided is from 4% to 5% wt/wt; and, 
 the amount of lower numbered alcohol provided is from 2.5% to 3.5% wt/wt. 
 
     
     
         26 . The process of  claim 15  wherein the second mixture settling into a first phase upper component and a second phase lower component is achieved by centrifuging the second mixture. 
     
     
         27 . The process of  claim 15  wherein the separating comprises removing the lower component from second mixture. 
     
     
         28 . The process of  claim 15  wherein the separating comprises decanting the upper component from the second mixture. 
     
     
         29 . The process of  claim 27  wherein the lower component comprises alcoholic aqueous soap. 
     
     
         30 . The process of  claim 29  further comprising reacting acid with the alcoholic aqueous soap. 
     
     
         31 . The process of  claim 30  wherein the acid is selected from a group comprising:
 hydrochloric acid, acetic acid, citric acid, phosphoric acid, sulfuric acid, and methanesulfonic acid. 
 
     
     
         32 . The process of  claim 30  further comprising recovering free fatty acids formed by the reaction. 
     
     
         33 . The process of  claim 30  further comprising removing alcoholic water. 
     
     
         34 . The process of  claim 15  wherein the separating comprises removing the upper component from the second mixture and wherein the removed upper component comprises a third mixture. 
     
     
         35 . The process of  claim 34  wherein the third mixture comprises alkyl ester having total acid number less than or equal to 0.5. 
     
     
         36 . The process of  claim 35  further comprising:
 washing the third mixture with soft water to form a resultant mixture, wherein the resultant mixture comprises soap water and wet ester; and, 
 removing the soap water from the resultant mixture. 
 
     
     
         37 . The process of  claim 35  further comprising removing residual lower numbered alcohol from the third mixture to form a fourth mixture. 
     
     
         38 . The process of  claim 37  wherein the fourth mixture comprises a purified alkyl ester, and trace amounts of monoglycerides, soap, residual lower numbered alcohol. 
     
     
         39 . The process of  claim 38  further comprising washing the fourth mixture with soft water resulting in a fifth mixture, wherein the fifth mixture comprises two components. 
     
     
         40 . The process of  claim 39  wherein the fifth mixture comprises a wet ester component and a soap water component. 
     
     
         41 . The process of  claim 40  further comprising removing the soap water component from the fifth mixture. 
     
     
         42 . The process of  claim 41  further comprising:
 removing the wet ester component from the fifth mixture; and, 
 drying the wet ester component. 
 
     
     
         43 . The process of  claim 41  further comprising adding acid to the removed soap water component to form a sixth mixture. 
     
     
         44 . The process of  claim 43  wherein the acid is selected from a group comprising hydrochloric acid, acetic acid, citric acid, phosphoric acid, sulfuric acid, and methanesulfonic acid. 
     
     
         45 . The process of  claim 43  wherein the sixth mixture comprises re-formed fatty acids and waste water, the process further comprising recovering the free fatty acids. 
     
     
         46 . The process of  claim 45  further comprising removing the waste water from the sixth mixture. 
     
     
         47 . A composition for refining, the composition comprising:
 a lower numbered alcohol, wherein the lower numbered alcohol is selected from a group comprising: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, propylene glycol, ethylene glycol, and butylene glycol;   a dilute caustic, wherein the dilute caustic is selected from a group comprising NaOH and KOH; and   a crude biodiesel product, wherein the crude biodiesel product comprises:
 free fatty acid at a concentration of not more than 10% wt/wt; 
 monoglycerides at a concentration of not more than 5% wt/wt; 
 glycerin at a concentration of not more than 1% wt/wt; 
 alcohol at a concentration of not more than 10% wt/wt; and 
 alkyl ester at a concentration of not more than 95% wt/wt. 
   
     
     
         48 . The composition of  claim 47  wherein the crude biodiesel product comprises products of transesterification of triglycerides. 
     
     
         49 . The composition of  claim 47  wherein the crude biodiesel product comprises products of combined esterification/transesterification reactions. 
     
     
         50 . The composition of  claim 47  wherein:
 the amount of the dilute caustic is from stoichiometric to the amount of free fatty acid in the crude product to 20% excess of the stoichiometric amount; 
 the concentration of the dilute caustic is from 2% to 15% wt/wt; and 
 the amount of lower numbered alcohol is from 1% to 20% wt/wt. 
 
     
     
         51 . The composition of  claim 47  wherein:
 the amount of the dilute caustic is from stoichiometric amount to the amount of free fatty acid in the crude product to 10% excess of the stoichiometric amount; 
 the concentration of the dilute caustic is from 3% to 6% wt/wt; and 
 the amount of lower numbered alcohol is from 2% to 5% wt/wt. 
 
     
     
         52 . The composition of  claim 47  wherein:
 the amount of the dilute caustic is from stoichiometric to the amount of free fatty acid in the crude product to 5% excess of the stoichiometric amount; 
 the concentration of the dilute caustic is from 4% to 5% wt/wt; and 
 the amount of lower numbered alcohol is from 2.5% to 3.5% wt/wt. 
 
     
     
         53 . A composition for reducing free fatty acid, the composition comprising:
 a lower numbered alcohol,   a dilute caustic; and,   wherein:
 the lower numbered alcohol is selected from a group comprising: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, propylene glycol, ethylene glycol, and butylene glycol; 
 the dilute caustic is selected from a group comprising: NaOH and KOH. 
   
     
     
         54 . The composition of  claim 53  further comprising at least one feedstock, wherein the feedstock is selected from a group comprising: distiller's corn oil, castor oil, soybean oil, jatropha oil, algae oil, yellow grease, brown grease, lard, and beef tallow. 
     
     
         55 . The composition of  claim 53  further comprising a crude product of combined esterification/transesterification of triglycerides, wherein the crude product comprises:
 free fatty acid at a concentration not more than 10% wt/wt; 
 monoglycerides at a concentration not more than 5% wt/wt; 
 alcohol at a concentration not more than 10% wt/wt; and 
 alkyl ester at a concentration not more than 95% wt/wt. 
 
     
     
         56 . The composition of  claim 53  wherein the crude product further comprises glycerin at a concentration not more than 1% wt/wt. 
     
     
         57 . The composition of  claim 55  wherein:
 the amount of the dilute caustic is from stoichiometric to the amount of free fatty acid in the crude product to 20% excess of the stoichiometric amount; 
 the concentration of the dilute caustic is from 2% to 15% wt/wt; and 
 the amount of lower numbered alcohol is from 1% to 20% wt/wt. 
 
     
     
         58 . The composition of  claim 55  wherein:
 the amount of the dilute caustic is from stoichiometric to the amount of free fatty acid in the crude product to 10% excess of the stoichiometric amount; 
 the concentration of the dilute caustic is from 3% to 6% wt/wt; and 
 the amount of lower numbered alcohol is from 2% to 5% wt/wt. 
 
     
     
         59 . The composition of  claim 55  wherein:
 the amount of the dilute caustic is from stoichiometric to the amount of free fatty acid in the crude product to 5% excess of the stoichiometric amount; 
 the concentration of the dilute caustic is from 4% to 5% wt/wt; and 
 the amount of lower numbered alcohol is from 2.5% to 3.5% wt/wt. 
 
     
     
         60 . A composition for refining, the composition comprising alkyl ester and alcoholic aqueous soap. 
     
     
         61 . The composition of  claim 60  further comprising two non-emulsified phases, wherein the first phase comprises the alkyl ester, and the second phase comprises the soap. 
     
     
         62 . The composition of  claim 61  wherein the first phase further comprises soap, free fatty acid, glycerin, alcohol, monoglycerides, wherein the amount of:
 free fatty acid is from 0.1% to 0.3% wt/wt; 
 glycerin is not detectable; 
 alcohol is from 1% to 2% wt/wt; 
 monoglycerides is no more than 1.5% wt/wt; and, 
 alkyl ester is at least 94% wt/wt. 
 
     
     
         63 . The composition of  claim 61  wherein the second phase further comprises alkyl ester, glycerin, wherein the amount of alkyl ester is no more than 10% wt/wt, and the amount of glycerin is no more than 2% wt/wt. 
     
     
         64 . A composition for refining, the composition comprising alkyl ester, soap, free fatty acid, glycerin, and alcohol, wherein the amount of:
 free fatty acid is from 1.75% to 2.75% wt/wt;   glycerin is from 0.05% to 0.15% wt/wt;   alcohol is from 1% to 2% wt/wt; and,   alkyl ester is at least 93% wt/wt.   
     
     
         65 . The composition of  claim 64  wherein the amount of the alkyl ester is from 85% to 97% wt/wt. 
     
     
         66 . The composition of  claim 64  wherein the concentration of:
 free fatty acid is not more than 4% wt/wt; 
 glycerin is not more than 0.5% wt/wt; 
 alcohol is not more than 3% wt/wt; and, 
 alkyl ester is at least 85% wt/wt. 
 
     
     
         67 . A process for reducing free fatty acid in a parent oil, the process comprising:
 providing a parent oil, wherein the parent oil comprises free fatty acid, wherein the concentration of the free fatty acid is at least 0.5% wt/wt;   providing lowered numbered alcohol;   providing dilute caustic; and,   adding the lower numbered alcohol and the dilute caustic to the parent oil to form a parent oil mixture.   
     
     
         68 . The process of  claim 67  wherein the lower numbered alcohol is selected from a group comprising: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, propylene glycol, ethylene glycol, and butylene glycol. 
     
     
         69 . The process of  claim 67  wherein the parent oil is selected from a group comprising distiller's corn oil, castor oil, soybean oil, jatropha oil, algae oil, yellow grease, brown grease, lard, and beef tallow. 
     
     
         70 . The process of  claim 69  further comprising
 heating the feedstock to form a heated feedstock from 90 degrees Fahrenheit to 150 degrees Fahrenheit; 
 continuously stirring the parent oil mixture for a period from 10 minutes to 2 hours; and, 
 allowing the parent oil mixture to settle to form a neat liquid with two phases, wherein:
 the first phase comprises feedstock and free fatty acid, wherein the free fatty acid is at a concentration not more than 0.4% wt/wt; 
 the second phase comprises alcoholic aqueous soap; and 
 the lower numbered alcohol and the dilute caustic are added to the heated feedstock to form the parent oil mixture. 
 
 
     
     
         71 . The process of  claim 70  wherein the lower numbered alcohol and the dilute caustic are added simultaneously. 
     
     
         72 . The process of  claim 70  wherein the lower numbered alcohol and the dilute caustic are added sequentially. 
     
     
         73 . The process of  claim 72  wherein the lower numbered alcohol is added before adding the dilute caustic. 
     
     
         74 . The process of  claim 70  wherein the stifling is a low-shear mixing. 
     
     
         75 . The process of  claim 70  wherein:
 the feedstock is heated to a temperature from 120 degrees Fahrenheit to 150 degrees Fahrenheit; 
 the stifling period is from 10 minutes to 1 hour; 
 the amount of dilute caustic provided is from stoichiometric to the amount of free fatty acid in the feedstock to 20% excess of the stoichiometric amount; 
 the concentration of the dilute caustic provided is from 2% to 15% wt/wt; 
 the amount of lower numbered alcohol provided is from 1% to 20% wt/wt. 
 
     
     
         76 . The process of  claim 70  wherein the dilute caustic is selected from a group comprising: NaOH and KOH. 
     
     
         77 . The process of  claim 70  wherein:
 the feedstock is heated to a temperature from 140 degrees Fahrenheit to 150 degrees Fahrenheit; 
 the stifling period is from 10 minutes to 30 minutes; 
 the amount of dilute caustic provided is from stoichiometric to the amount of free fatty acid in the feedstock to 10% excess of the stoichiometric amount; 
 the concentration of the dilute caustic provided is from 3% to 6% wt/wt; 
 the amount of lower numbered alcohol provided is from 2% to 5% wt/wt. 
 
     
     
         78 . The process of  claim 77  wherein:
 the amount of dilute caustic provided is from stoichiometric to the amount of free fatty acid in the feedstock to 5% excess of the stoichiometric amount; 
 the concentration of the dilute caustic provided is from 4% to 5% wt/wt; 
 the amount of lower numbered alcohol provided is from 2.5% to 3.5% wt/wt. 
 
     
     
         79 . The process of  claim 70  wherein the parent oil mixture is allowed to settle at room temperature. 
     
     
         80 . The process of  claim 70  wherein the parent oil mixture is allowed to settle at temperature. 
     
     
         81 . The process of  claim 70  wherein the parent oil mixture is allowed to settle for a period of 60 minutes to 4 hours. 
     
     
         82 . The process of  claim 70  wherein the parent oil mixture separates into a first upper phase and a second lower phase. 
     
     
         83 . The process of  claim 82  wherein the first upper phase comprises:
 parent oil from 91.5% to 99.2% wt/wt; 
 free fatty acid from 0.15% to 0.45% wt/wt; 
 soap from 0.05% to 0.2% wt/wt; and, 
 lower numbered alcohol from 0.15% to 0.30% wt/wt. 
 
     
     
         84 . The process of  claim 82  wherein the second lower phase comprises:
 soap from 8% to 20% wt/wt; 
 water from 50% to 80% wt/wt; and, 
 parent oil from 2% to 5% wt/wt. 
 
     
     
         85 . The process of  claim 82  further comprising extracting the first upper phase by decanting. 
     
     
         86 . The process of  claim 70  further comprising providing more than 1 parent oil.