Integrated ethanol and renewable diesel facility

Abstract

An integrated facility for the co-production of ethanol and renewable diesel fuel is provided. Corn oil, an ethanol production by-product, is utilized as a feedstock for a renewable diesel plant operating within the same general facility as the corn ethanol plant. By-products of the renewable diesel plant, such as fuel gas, steam, and/or naphtha, can be utilized in various parts of the ethanol plant to increase the operating efficiency thereof.

I claim: 
     
         1 . An integrated process for the co-production of ethanol and renewable diesel fuel comprising:
 distilling an ethanol-containing beer within distillation apparatus of an ethanol plant to produce an ethanol-rich overhead stream and a solids-containing, whole stillage stream;   recovering a corn oil product from said ethanol plant;   reacting said corn oil product from said ethanol plant with hydrogen in a reaction system of a renewable diesel plant to produce a mixture of reaction products comprising renewable diesel fuel, fuel gas, and naphtha;   directing said reaction products to a distillation system of said renewable diesel plant for separation of said reaction products into a renewable diesel fuel stream, a fuel gas stream, and a naphtha stream; and   combusting at least a portion of said fuel gas stream within one or more devices located within or utilized during the operation of said ethanol plant.   
     
     
         2 . The process according to  claim 1 , wherein said fuel gas comprises one or more members selected from group consisting of butane, propane, ethane, and methane. 
     
     
         3 . The process according to  claim 1 , wherein said renewable diesel plant comprises a reactants heater located upstream of said reaction system, said reactants heater combusting at least a portion of said fuel gas stream to supply heat to said corn oil product and hydrogen entering said reaction system. 
     
     
         4 . The process according to  claim 1 , wherein said corn oil product is recovered from said whole stillage stream within whole stillage processing apparatus of said ethanol plant. 
     
     
         5 . The process according to  claim 4 , wherein said whole stillage processing apparatus comprises a centrifuge for separating said whole stillage stream from said distillation apparatus into a thin stillage stream comprising said corn oil product and a cake, said cake being directed toward drying apparatus comprising a cake dryer and a thermal oxidizer for treatment of a dryer exhaust stream produced by said dryer. 
     
     
         6 . The process according to  claim 5 , wherein said cake dryer is supplied with hot air from an air heater, at least a portion of said fuel gas stream being combusted within said air heater. 
     
     
         7 . The process according to  claim 5 , wherein said thermal oxidizer comprises a burner, at least a portion of said fuel gas stream being combusted within said thermal oxidizer burner. 
     
     
         8 . The process according to  claim 1 , wherein said ethanol plant is supplied with electrical power from a gas turbine, at least a portion of said fuel gas stream being combusted within said gas turbine. 
     
     
         9 . An integrated process for the co-production of ethanol and renewable diesel fuel comprising:
 distilling an ethanol-containing beer within distillation apparatus of an ethanol plant to produce an ethanol-rich overhead stream and a solids-containing, whole stillage stream;   recovering a corn oil product from said ethanol plant;   reacting said corn oil product from said ethanol plant with hydrogen in a reaction system of a renewable diesel plant to produce a mixture of reaction products comprising renewable diesel fuel, fuel gas, and naphtha;   directing said reaction products to a renewable diesel distillation system for separation of said reaction products into a renewable diesel fuel stream, a fuel gas stream, and a naphtha stream;   condensing at least a portion of said ethanol-rich overhead stream to produce an ethanol product stream; and   adding at least a portion of said naphtha stream to said ethanol product stream to produce a denatured ethanol product.   
     
     
         10 . The process according to  claim 9 , wherein said ethanol product stream is dehydrated to form an enriched ethanol product stream, said naphtha stream being added to said enriched ethanol product stream to produce a denatured ethanol product. 
     
     
         11 . The process according to  claim 10 , wherein said denatured ethanol product comprises between about 0.01% to about 5% by volume of naphtha. 
     
     
         12 . The process according to  claim 10 , wherein said enriched ethanol product stream comprises approximately 200 proof ethanol. 
     
     
         13 . An integrated process for the co-production of ethanol and renewable diesel fuel comprising:
 distilling an ethanol-containing beer within distillation apparatus of an ethanol plant to produce an ethanol-rich overhead stream and a solids-containing, whole stillage stream;   recovering a corn oil product from said ethanol plant;   reacting said corn oil product from said ethanol plant with hydrogen in a reaction system of a renewable diesel plant to produce a mixture of reaction products comprising renewable diesel fuel, fuel gas, and naphtha;   directing said reaction products through a heat exchanger to cool said reaction products and generate steam;   directing said cooled reaction products to a renewable diesel distillation system for separation of said reaction products into a renewable diesel fuel stream, a fuel gas stream, and a naphtha stream; and   directing said steam to a steam distribution header for providing steam to said ethanol plant.   
     
     
         14 . The process according to  claim 13 , wherein said corn oil product is recovered from said whole stillage stream within whole stillage processing apparatus of said ethanol plant. 
     
     
         15 . The process according to  claim 14 , wherein said whole stillage processing apparatus comprises a centrifuge for separating said whole stillage stream from said distillation apparatus into a thin stillage stream comprising said corn oil product and a cake, said ethanol plant further comprising a multiple effect evaporator, said thin stillage stream being directed through said multiple effect evaporator to remove moisture therefrom and form a syrup, said steam distribution header being operably connected to a first effect of said multiple effect evaporator and delivering at least a portion of said steam to said first effect. 
     
     
         16 . The process according to  claim 13 , wherein said ethanol-rich overhead stream has been condensed and is directed through an overhead heat exchanger that is operably coupled with said steam distribution header, at least a portion of said steam being directed through said overhead heat exchanger thereby said ethanol-rich overhead stream and forming an evaporated ethanol-rich stream. 
     
     
         17 . The process according to  claim 16 , wherein said vaporized ethanol-rich stream is directed to a dehydration unit wherein substantially all of the water comprising said ethanol-rich overhead stream is removed to produce an enriched ethanol stream. 
     
     
         18 . An integrated facility for the co-production of ethanol and renewable diesel fuel comprising:
 an ethanol plant comprising
 distillation apparatus operable to separate an ethanol-containing beer into an ethanol-rich overhead stream and a solids-containing, whole stillage stream; and 
 corn oil recovery apparatus operable to produce a corn oil stream; and 
   a renewable diesel plant comprising
 a reaction system operably coupled with said corn oil recovery apparatus to receive at least a portion of said corn oil stream and produce a reaction product stream comprising renewable diesel fuel, naphtha, and fuel gas; and 
 a distillation system operable to separate said reaction product stream into a renewable diesel fuel stream, a naphtha stream, and a fuel gas stream, 
   said fuel gas stream being operably coupled with one or more fuel gas-combusting devices located within or utilized during operation of said ethanol plant.   
     
     
         19 . The integrated facility according to  claim 18 , wherein said renewable diesel plant includes a reactants heat exchanger disposed downstream of said reaction system and upstream of said distillation system and operable to generate steam that is directed to a steam distribution header. 
     
     
         20 . The integrated facility according to  claim 18 , wherein said corn oil recovery apparatus comprises whole stillage processing apparatus operable to produce said corn oil stream and dried distillers grain with solubles (DDGS). 
     
     
         21 . The integrated facility according to  claim 20 , wherein said whole stillage process apparatus comprises a centrifuge operable to separate a whole stillage stream from said distillation apparatus into a thin stillage stream and a cake, and a multiple effect evaporator operable to produce a syrup from said thin stillage stream, said steam distribution header being operably coupled with a first effect of said multiple effect evaporator, steam generated by said reactants heat exchanger being directed to said first effect. 
     
     
         22 . The integrated facility according to  claim 20 , wherein said ethanol plant comprises an overhead heat exchanger operable to receive at least a portion of said ethanol-rich overhead stream and evaporate at least a portion thereof, said overhead heat exchanger being operably coupled with said steam distribution header, steam generated by said reactants heat exchanger being directed to said overhead heat exchanger. 
     
     
         23 . The integrated facility according to  claim 19 , wherein said ethanol plant comprises a dehydration unit operable to remove water from said ethanol-rich overhead stream and produce an enriched ethanol product stream, at least a portion of said naphtha stream from said renewable diesel plant being directed toward and combined with at least a portion of said enriched ethanol product stream to produce a denatured ethanol product. 
     
     
         24 . The integrated facility according to  claim 19 , wherein said one or more fuel gas-combusting devices are selected from the group consisting of:
 (a) a thermal oxidizer burner operably connected to thermal oxidizer apparatus receiving a cake dryer exhaust gas stream;   (b) a cake dryer air heater operably connected with a cake dryer; and   (c) a gas turbine; and   (d) a boiler.