Process for producing glycerin

Abstract

A process for producing glycerin is comprised of the steps of: (1) contacting a fat with water at a temperature and pressure sufficient to produce hydrolyzed fat and a sweet water stream comprised of water, fat and glycerin; (2) introducing the sweet water stream into a vertical constant temperature zone and heating the sweet water stream to a temperature of at least 200 ° C.; (3) allowing sweet water stream of step (2) to separate into a top layer comprised of fat and a bottom layer comprised of glycerin and water while maintaining a temperature of the two layers of at least about 200 ° C. for a period of time sufficient to deactivate the prions; (4) separating the glycerin from the water.

What is claimed is:  
     
         1 . A method for producing glycerin comprising the steps of (1) contacting a prion-contaminated fat with water at a temperature and pressure sufficient to produce hydrolyzed fat and a sweet water stream comprised of water, fat and glycerin; (2) introducing the sweet water stream into a vertical constant temperature zone and heating the sweet water stream under pressure to a temperature of at least 200°C.; (3) allowing the sweet water stream of step (2) to separate into a top layer comprised of fat and a bottom layer comprised of glycerin and water while maintaining a temperature of the two layers of at least about 200° C. under pressure for a period of time sufficient to substantially deactivate the prions; (4) separating the glycerin from the water.  
     
     
         2 . The method of  claim 1  wherein the prion-contaminated fat is beef tallow.  
     
     
         3 . The method of  claim 1  wherein the vertical constant temperature zone is a vertical column.  
     
     
         4 . The method of  claim 1  wherein the pressure in steps (2) and (3) is up to about 300 psig.  
     
     
         5 . The method of  claim 1  wherein the temperature in steps (2) and (3) is up to about 422° F.  
     
     
         6 . The method of  claim 1  wherein the period of time in steps (2) and (3) is at least 20 minutes.  
     
     
         7 . A method for producing glycerin comprising the steps of (1) contacting a prion-contaminated beef tallow with water at a temperature and pressure sufficient to produce hydrolyzed fat and a sweet water stream comprised of water, fat and glycerin; (2) introducing the sweet water stream into a vertical column and heating the sweet water stream to a temperature of about 422° F. and under pressure of about 300 psig; (3) allowing the sweet water stream of step (2) to separate into a top layer comprised of fat and a bottom layer comprised of glycerin and water while maintaining a temperature of about 422° F. and a pressure of about 300 psig for at least 20 minutes to substantially deactivate the prions; (4) separating the glycerin from the water.  
     
     
         8 . Glycerin which is the product of the process comprising the steps of (1) contacting a prion-contaminated fat with water at a temperature and pressure sufficient to produce hydrolyzed fat and a sweet water stream comprised of water, fat and glycerin; (2) introducing the sweet water stream into a vertical constant temperature zone and heating the sweet water stream under pressure to a temperature of at least 200° C.; (3) allowing the sweet water stream of step (2) to separate into a top layer comprised of fat and a bottom layer comprised of glycerin and water while maintaining a temperature of about 422° F. and a pressure of about 300 psig for a period of time sufficient to substantially deactivate the prions; (4) separating the glycerin from the water.  
     
     
         9 . A method for deactivating prions in an aqueous glycerine mixture comprising the steps of (1) providing an aqueous mixture comprising glycerin wherein the glycerin is contaminated with prions; (2) heating the aqueous mixture to a temperature of at least about 200° C. and maintaining the temperature under pressure for a period of time sufficient to substantially deactivate the prions.  
     
     
         10 . The method of  claim 9  wherein the pressure in step (2) is up to about 300 psig.  
     
     
         11 . The method of  claim 9  wherein the temperature in step (2) is up to about 422° F.  
     
     
         12 . The method of  claim 9  wherein the period of time in step (2) is at least 20 minutes.