Removal of impurities from oils and/or fats

Abstract

Disclosed is a process for removing solids, metals, phosphorus compounds and other impurities from low quality triglyceride containing feedstock. The final treated triglyceride containing feedstock may be converted to fuel range hydrocarbons via hydrotreating process.

1 . A process comprising:
 (a) providing a feedstock comprising at least one triglyceride and one type of impurities;   (b) admixing an organic solvent with said feedstock for a contacting time to form a mixture;   (c) settling said mixture for a retention time to form a layer of treated feedstock, a layer of impurities, and a layer of organic solvent; and   (d) recovering said layer of treated feedstock from said mixture, wherein said treated feedstock comprises less than 50% of the amount of said impurities than which is in said feedstock.   
     
     
         2 . The process in accordance with  claim 1  further comprising the step of
 (e) contacting said treated feedstock with a hydrotreating catalyst in a reaction zone under a condition sufficient to produce a reaction product containing diesel boiling range hydrocarbons, wherein said condition includes a pressure of less than about 2000 psig and a temperature in the range of from about 260° C. to about 430° C. 
 
     
     
         3 . The process in accordance with  claim 1 , wherein said triglyceride is selected from the group consisting of vegetable oils, animal fats, and any combination thereof. 
     
     
         4 . The process in accordance with  claim 1  wherein said impurities is selected from the group consisting of phosphorus, metals, solids, proteins and bone materials, and any combinations thereof. 
     
     
         5 . The process in accordance with  claim 1  wherein said organic solvent is polar organic solvent, wherein said treated feedstock comprises less than 80% of the amount of said impurities than which is in said feedstock. 
     
     
         6 . The process in accordance with  claim 5  wherein said polar organic solvent is ethylene glycol. 
     
     
         7 . The process in accordance with  claim 1  where in the amount of said organic solvent is in the range from 0.1 to 50 wt %, calculated on the weight of triglyceride. 
     
     
         8 . The process in accordance with  claim 1 ,
 wherein the temperature of said feedstock is kept in the range of the lowest temperature at which said mixture remains as a liquid to 150° C. for at least 1 minute prior to admixing with said solvent;   wherein the temperature of said mixture is kept in the range of the lowest temperature at which said mixture remains as a liquid to 150° C. during said step b; and   wherein the temperature of said mixture is kept in the range of the lowest temperature at which said mixture remains as a liquid to 150° C. during said step c.   
     
     
         9 . The process in accordance with  claim 1  wherein said contacting time is at least 1 minute; and wherein said retention time is at least 1 minute. 
     
     
         10 . The process in accordance with  claim 1  further comprising a step of recycling said layer of organic solvent after step c. 
     
     
         11 . The process of  claim 2 , wherein said hydrotreating catalyst comprises nickel and molybdenum. 
     
     
         12 . The process of  claim 2 , wherein said hydrotreating catalyst comprises cobalt and molybdenum. 
     
     
         13 . A process comprising:
 (a) providing a feedstock comprising at least one triglyceride and one type of impurities;   (b) subjecting said feedstock to a first separation device to remove at least 25% of said impurities from said feedstock and to produce a first effluent stream;   (c) admixing an acid or acid anhydride with said first effluent stream for a first contact time to form a first mixture;   (d) admixing water with said first mixture for a second contact time to form a second mixture;   (e) subjecting said second mixture to a second separation device to form an aqueous phase and oil phase; and   (f) subjecting said oil phase to a third separation device to remove another portion of said impurities from said oil phase to produce a treated feedstock.   
     
     
         14 . The process in accordance with  claim 13  further comprising the step of
 g) contacting said treated feedstock with a hydrotreating catalyst in a reaction zone under a condition sufficient to produce a reaction product containing diesel boiling range hydrocarbons, wherein said condition includes a pressure of less than about 2000 psig and a temperature in the range of from about 260° C. to about 430° C. 
 
     
     
         15 . The process in accordance with  claim 13 , wherein said triglyceride is selected from the group consisting of vegetable oils, animal fats, and any combinations thereof. 
     
     
         16 . The process in accordance with  claim 13  wherein said impurities is selected from the group consisting of phosphorus, metals, solids, proteins and bone materials, and any combinations thereof. 
     
     
         17 . The process in accordance with  claim 13  wherein said acid or acid anhydride having a pH of from 0 to 6 as measured at 20° C. in a one molar aqueous solution. 
     
     
         18 . The process in accordance with  claim 13  wherein said acid is phosphoric acid. 
     
     
         19 . The process in accordance with  claim 13  wherein an aqueous solution of said acid containing 0.1 to 99.9% of the acid in H 2 O is used. 
     
     
         20 . The process in accordance with  claim 13  wherein the amount of water added is in the range from 0.1 to 10 wt %, calculated on the oil. 
     
     
         21 . The process in accordance with  claim 13  wherein said first contacting time is at least 0.1 minute, and where in said second contacting time is at least 1 minute. 
     
     
         22 . The process in accordance with  claim 13  wherein the temperature of said first mixture is maintained in the range of the lowest temperature at which said first mixture remains as a liquid to 150° C. during said first contacting time. 
     
     
         23 . The process in accordance with  claim 13  wherein said first separation device is a filter with a pore size of at least 0.1 μm. 
     
     
         24 . The process in accordance with  claim 13  wherein said first separation device is a filter with a pore size from 2 to 7 μm, where in said filter removes at least 50% of said impurities from said feedstock to produce said first effluent stream; 
     
     
         25 . The process in accordance with  claim 13  wherein said second separation device is a centrifuge. 
     
     
         26 . The process in accordance with  claim 13  wherein said third separation device is a filter with pore size of at least 0.1 μm. 
     
     
         27 . The process of  claim 14  wherein said hydrotreating catalyst comprises nickel and molybdenum. 
     
     
         28 . The process of  claim 14 , wherein said hydrotreating catalyst comprises cobalt and molybdenum.