Biorenewable naphtha

Abstract

The present invention generally relates to a method for producing a naphtha product from a renewable feedstock. The method includes hydrotreating the renewable feedstock to produce a hydrotreating unit heavy fraction that includes n-paraffins, and hydrocracking the hydrotreating unit heavy fraction to produce a hydrocracking unit product that includes the naphtha product. The method also includes separating the naphtha fraction and optionally recycling the hydrocracking unit heavy fraction through the hydrocracking unit. The present invention also relates to a biorenewable naphtha product suitable for use as feed stock for steam crackers and catalytic reforming units, and for use as fuel, or fuel blend stock.

1 . A method for producing olefins from biorenewable feedstocks, comprising the steps of:
 a. hydrotreating the biorenewable feedstock to produce a hydrocarbon fraction;   b. hydrocracking the hydrocarbon fraction of step (a) to produce a distribution of hydrocracked hydrocarbons;   c. separating a naphtha fraction from the distribution of hydrocracked hydrocarbons; and   d. subjecting the naphtha fraction to steam cracking in a steam cracker to yield olefins.   
     
     
         2 . The method of  claim 1  wherein a heavy fraction from the distribution of cracked hydrocarbons is recycled to the hydrocracking step (b). 
     
     
         3 . The method of  claim 2 , further comprising the step of recovering from the heavy fraction a middle distillate fraction. 
     
     
         4 . The method of  claim 1 , wherein the biorenewable feedstock comprises monoglycerides, diglycerides, triglycerides, free fatty acids, and combinations thereof. 
     
     
         5 . The method of  claim 4 , wherein the biorenewable feedstock is selected from the group comprising animal fats, animal oils, poultry fat, poultry oil, vegetable fats, vegetable oils, rendered fats, rendered oils, restaurant grease, brown grease, waste industrial frying oils, fish oils, fish fats, and combinations thereof. 
     
     
         6 . The method of  claim 1 , wherein the hydrotreating step operating conditions comprise a reaction temperature of from about 300° F. to about 850° F. and a reaction pressure of from about 300 psig to about 3,000 psig. 
     
     
         7 . The method of  claim 1 , wherein the hydrocracking step operating conditions comprise a reaction temperature of from about 400° F. to about 900° F. and a reaction pressure of from about 250 psig to about 3,000 psig. 
     
     
         8 . The method of  claim 1 , wherein the naphtha product has a boiling point range of from about 70° F. to about 400° F. 
     
     
         9 . The method of  claim 1  wherein the steam cracker coil outlet pressure is about 1.7 bar. 
     
     
         10 . The method of  claim 1  wherein the steam cracker steam-to-hydrocarbon ratio is about 0.45 w/w. 
     
     
         11 . The method of  claim 1  wherein the steam cracker coil outlet temperature is from about 1540° F. to about 1560° F. 
     
     
         12 . The method of  claim 1  wherein the olefins comprise ethylene, propylene, and butadiene. 
     
     
         13 . The method of  claim 12  wherein the combined yield of ethylene, propylene, and butadiene is greater than 50 wt %. 
     
     
         14 . The method of  claim 1  wherein the yield of pyrolysis fuel oil less than 1 wt %. 
     
     
         15 . A method for producing a 100% biorenewable gasoline for automobiles, comprising:
 a. hydrotreating the biorenewable feedstock to produce a hydrocarbon fraction;   b. hydrocracking the hydrocarbon fraction of step (a) to produce a distribution of hydrocracked hydrocarbons;   c. separating a naphtha fraction from the distribution of hydrocracked hydrocarbons; and   d. blending the naphtha fraction with bio-ethanol in concentrations of 1-30%.   
     
     
         16 . The method of  claim 15  wherein a heavy fraction from the distribution of cracked hydrocarbons is recycled to the hydrocracking step (b). 
     
     
         17 . The method of  claim 16 , further comprising the step of recovering from the heavy fraction a middle distillate fraction. 
     
     
         18 . The method of  claim 15 , wherein the biorenewable feedstock comprises monoglycerides, diglycerides, triglycerides, free fatty acids, and combinations thereof. 
     
     
         19 . The method of  claim 18 , wherein the biorenewable feedstock is selected from the group comprising animal fats, animal oils, poultry fat, poultry oil, vegetable fats, vegetable oils, rendered fats, rendered oils, restaurant grease, brown grease, waste industrial frying oils, fish oils, fish fats, and combinations thereof. 
     
     
         20 . The method of  claim 15 , wherein the hydrotreating step operating conditions comprise a reaction temperature of from about 300° F. to about 850° F. and a reaction pressure of from about 300 psig to about 3,000 psig. 
     
     
         21 . The method of  claim 15 , wherein the hydrocracking step operating conditions comprise a reaction temperature of from about 400° F. to about 900° F. and a reaction pressure of from about 250 psig to about 3,000 psig. 
     
     
         22 . The method of  claim 15 , wherein the naphtha product has a boiling point range of from about 70° F. to about 400° F. 
     
     
         23 . The method of  claim 15  wherein the 100% biorenewable gasoline is 85 vol % bio-ethanol. 
     
     
         24 . The method of  claim 23  wherein the 100% biorenewable gasoline has an anti-knock index of about 95. 
     
     
         25 . A product produced from a biorenewable feedstock, comprising a naphtha boiling range hydrocarbon having a boiling range between about 70° F. and about 400° F.; and a specific gravity at 20° C. of from about 0.680 to about 0.740, wherein the product is selected from the group comprising a fuel for industrial burners, turbines, and boilers, a feedstock for steam crackers and catalytic reforming, and an alternative gasoline fuel for combustion engines when blended between 1% and 85% by volume with ethanol.