Integrated Process of Algae Cultivation and Production of Diesel Fuel from Biorenewable Feedstocks

Abstract

An integrated process has been developed for producing diesel boiling range fuel from renewable feedstocks such as plant and animal fats and oils and for cultivating algae or greenhouse plants. The process involves catalytically treating a renewable feedstock by hydrogenating and deoxygenating to provide a hydrocarbon fraction useful as a diesel boiling range fuel. A selective separation may be used to remove at least the carbon dioxide from the first zone effluent.

1 . An integrated process for producing a paraffin-rich diesel boiling range product from a renewable feedstock and for cultivating algae, said integrated process comprising:
 a) treating the renewable feedstock in a reaction zone by hydrogenating and deoxygenating the feedstock using at least one catalyst at reaction conditions in the presence of hydrogen to provide a reaction zone product stream comprising hydrogen, carbon dioxide, water and a paraffins having from about 8 to about 24 carbon atoms;   b) cooling the reaction zone product stream and separating to provide:
 i) a gaseous component comprising at least hydrogen and carbon dioxide; 
 ii) a hydrocarbon product comprising the paraffins; and 
 iii) a water component; 
   c) recovering the hydrocarbon product;   d) separating the gaseous component comprising at least hydrogen and carbon dioxide into a stream comprising hydrogen and a stream comprising carbon dioxide; and   e) passing the stream comprising carbon dioxide to an algae cultivation operation and using the carbon dioxide stream to cultivate algae.   
     
     
         2 . The process of  claim 1  wherein the separating step 1(d) is at essentially the same pressure as the reaction pressure and at a temperature that is at least about 1° C. above the separation temperature of step (b), and comprises passing the gaseous component though at least one amine absorber zone to produce the hydrogen stream and the carbon dioxide stream. 
     
     
         3 . The process of  claim 2  wherein the amine absorber zone comprises an aqueous solution of methyldiethaolamine and piperazine. 
     
     
         4 . The process of  claim 1  wherein the algae cultivation operation is selected from the group consisting of an open pond, a covered pond, a raceway pond, a bioreactor, a photobioreactor, and combinations thereof. 
     
     
         5 . The process of  claim 2  wherein the amine is an aqueous solution of a polyoxypropylene triamine having the formula: 
       
         
           
           
               
               
           
         
       
       where R′ represents a methylene group and R″ represents hydrogen or methyl or ethyl and wherein the sum of X+Y=Z is a positive integer having a value of from about 4 to about 6. 
     
     
         6 . The process of  claim 2  wherein the gaseous component further comprises hydrogen sulfide and the amine absorber zone contains an amine that removes both carbon dioxide and hydrogen sulfide, said process further comprising
 regenerating the amine that removes both carbon dioxide and hydrogen sulfide to generate an acid gas stream containing carbon dioxide and hydrogen sulfide;   passing the acid gas stream through a second amine absorber zone containing an amine selective to hydrogen sulfide to generate a carbon dioxide stream;   regenerating the amine selective to hydrogen sulfide to generate a hydrogen sulfide stream; and   recycling at least a portion of the hydrogen sulfide stream to reaction zone.   
     
     
         7 . The process of  claim 6  wherein the amine absorber zone and the second amine absorber zone comprises aqueous solutions of methyldiethanolamine and piperazine. 
     
     
         8 . The process of  claim 2  wherein the amine absorber is a flexible amine absorber. 
     
     
         9 . The process of  claim 1  wherein a portion of the hydrocarbon product is recycled to the reaction zone is at a volume ratio of recycle to feedstock in the range of about 2:1 to about 8:1. 
     
     
         10 . The process of  claim 1  wherein the reaction conditions in the reaction zone include a temperature of about 40° C. to about 400° C. and a pressure of about 689 kPa absolute (100 psia) to about 13,790 kPa absolute (2000 psia) and the separating of step 1 b) is at a pressure that is no more than 1034 kPa absolute (150 psia) less than the pressure of the reaction zone. 
     
     
         11 . The process of  claim 1  wherein at least a portion of the hydrogen of step (a) is generated by algae. 
     
     
         12 . The process of  claim 1  further comprising treating a petroleum derived hydrocarbon in the reaction zone with the renewable feedstock. 
     
     
         13 . An integrated process for producing a paraffin-rich diesel boiling point range product from a renewable feedstock and for cultivating algae, said integrated process comprising:
 a) treating the renewable feedstock in a reaction zone by hydrogenating and deoxygenating the feedstock using at least one catalyst at reaction conditions in the presence of hydrogen to provide a reaction zone product stream comprising hydrogen, carbon dioxide, water, and paraffins having from about 8 to about 24 carbon atoms;   b) selectively separating the reaction zone product stream into a gaseous stream comprising hydrogen and at least a portion of the water and carbon dioxide from the reaction zone product stream and a remainder stream comprising at least the paraffins;   c) recycling a first portion of the remainder stream comprising at least the paraffins to the reaction zone;   d) combining the gaseous stream and a second portion of the remainder stream to form a combined stream and separating the combined stream to provide:
 a. a gaseous component comprising at least hydrogen, water, and carbon dioxide; 
 b. a hydrocarbon product; and 
 c. a water component; 
 and recovering a portion of the hydrocarbon product and recycling a portion of the hydrocarbon product to the reaction zone; 
   e) selectively separating the gaseous component using at least one amine absorber zone to produce at least a stream comprising carbon dioxide and a stream comprising at least hydrogen and depleted in carbon dioxide; and   f) passing the stream comprising carbon dioxide to an algae cultivation operation and using the carbon dioxide to cultivate algae.   
     
     
         14 . The process of  claim 13  wherein the amine absorber zone contains an amine selective to carbon dioxide, and the stream containing at least hydrogen and depleted in carbon dioxide further comprises hydrogen sulfide. 
     
     
         15 . The process of  claim 14  wherein the amine is an aqueous solution of a polyoxypropylene triamine having the formula: 
       
         
           
           
               
               
           
         
       
       Where R′ represents a methylene group and R″ represents hydrogen or methyl or ethyl and wherein the sum of X+Y=Z is a positive integer having a value of from about 4 to about 6. 
     
     
         16 . The process of  claim 13  wherein gaseous component further comprises hydrogen sulfide and the amine absorber zone comprises an amine selective to carbon dioxide and hydrogen sulfide, said process further comprising
 regenerating the amine selective to carbon dioxide and hydrogen sulfide to generate an acid gas stream containing carbon dioxide and hydrogen sulfide;   passing the acid gas stream through a second amine absorber zone containing an amine selective to hydrogen sulfide to generate the stream comprising carbon dioxide;   regenerating the amine selective to hydrogen sulfide to generate a stream comprising hydrogen sulfide stream; and   recycling at least a portion of the stream comprising hydrogen sulfide stream to reaction zone.   
     
     
         17 . The process of  claim 16  wherein the amine absorber zone and the second amine absorber zone comprise aqueous solutions of methyldiethanolamine and piperazine. 
     
     
         18 . The process of  claim 13  wherein the selectively separating in step 13(b) is performed using a hot high pressure hydrogen stripper operated at a temperature of about 40° C. to about 300° C. and a pressure of about 689 kPa absolute (100 psia) to about 13,790 kPa absolute (2000 psia). 
     
     
         19 . The process of  claim 13  wherein the separating in step 13(d) is performed using cooling followed by phase separation. 
     
     
         20 . The process of  claim 13  wherein the amine absorber is a flexible amine absorber. 
     
     
         21 . The process of  claim 13  wherein the first portion of the remainder stream is recycled to the reaction zone at a volume ratio of recycle to feedstock in the range of about 2:1 to about 8:1, and wherein the reaction conditions in the reaction zone include a temperature of about 40° C. to about 400° C. and a pressure of about 689 kPa absolute (100 psia) to about 13,790 kPa absolute (2000 psia). 
     
     
         22 . The process of  claim 13  further comprising introducing a third portion of the remainder stream to a second reaction zone to contact an isomerization catalyst at isomerization conditions to isomerize at least a portion of the n-paraffins into branched paraffins and generate the said second portion of the remainder stream. 
     
     
         23 . The process of  claim 22  further comprising treating a petroleum derived hydrocarbon in the reaction zone with the renewable feedstock. 
     
     
         24 . A process for producing a branched paraffin-rich diesel product from a renewable feedstock comprising;
 a. treating the feedstock in a first reaction zone by hydrogenating and deoxygenating the feedstock using a catalyst at reaction conditions in the presence of hydrogen and at least one sulfur containing compound to provide a first reaction zone product stream comprising hydrogen, hydrogen sulfide, carbon dioxide, and a hydrocarbon fraction comprising n-paraffins useful as a diesel boiling range fuel;   b. selectively separating, in a hot high pressure hydrogen stripper, a gaseous stream comprising hydrogen, hydrogen sulfide, and at least a portion of the water and carbon dioxide from the first reaction zone product stream and introducing a remainder stream comprising at least the n-paraffins to a second reaction zone to contact an isomerization catalyst at isomerization conditions to isomerize at least a portion of the n-paraffins and generate a branched paraffin-rich stream;   c. combining the branched-paraffin-rich stream and the gaseous stream to form a combined stream and separating:
 i. a gaseous component comprising at least hydrogen and carbon dioxide; 
 ii. a hydrocarbon component; and 
 iii. a water component 
   and recovering at least a portion of the hydrocarbon component;   d. selectively separating the gaseous component using in a first amine solution absorber zone to produce a stream comprising at least hydrogen and depleted in carbon dioxide and a stream comprising carbon dioxide and hydrogen sulfide;   e. selectively separating the stream comprising carbon dioxide and hydrogen sulfide in a second amine solution absorber zone to produce a stream comprising at least hydrogen sulfide and depleted in carbon dioxide and a stream comprising carbon dioxide;   f. recycling at least a portion of the stream comprising at least hydrogen and depleted in carbon dioxide and at least a portion of the stream comprising at least hydrogen sulfide and depleted in carbon dioxide to the first reaction zone.   
     
     
         25 . The process of  claim 24  wherein the isomerization conditions in the second reaction zone include a temperature of about 40° C. to about 400° C. and a pressure of about 689 kPa absolute (100 psia) to about 13,790 kPa absolute (2000 psia) and wherein the hot high pressure hydrogen stripper is operated at a temperature of about 40° C. to about 300° C. and a pressure of about 689 kPa absolute (100 psia) to about 13,790 kPa absolute (2000 psia). 
     
     
         26 . The process of  claim 24  further comprising treating a petroleum derived hydrocarbon in the reaction zone with the renewable feedstock. 
     
     
         27 . An integrated process for producing a paraffin-rich diesel product from a renewable feedstock and for cultivating algae, said integrated process comprising:
 a) generating hydrogen using an algae cultivation operation;   b) treating the feedstock in a reaction zone by hydrogenating and deoxygenating the feedstock using at least one catalyst at reaction conditions in the presence of the hydrogen generated in step (a) to provide a reaction zone product stream comprising hydrogen, carbon dioxide, water and a paraffins having from about 8 to about 24 carbon atoms;   c) cooling the reaction zone product stream and separating to provide:
 i. a gaseous component comprising at least hydrogen and carbon dioxide; 
 ii. a hydrocarbon product comprising the paraffins; and 
 iii. a water component; and 
   d) recovering the hydrocarbon product.   
     
     
         28 . The process of  claim 27  further comprising separating the gaseous component comprising at least hydrogen and carbon dioxide into a stream comprising hydrogen and a stream comprising carbon dioxide and passing the stream comprising carbon dioxide to an algae cultivation operation and using the carbon dioxide stream to cultivate algae. 
     
     
         29 . The process of  claim 27  further comprising treating a petroleum derived hydrocarbon in the reaction zone with the renewable feedstock. 
     
     
         30 . An integrated process for producing a paraffin-rich diesel boiling range product from a renewable feedstock and for cultivating plants in an enclosed greenhouse, said integrated process comprising:
 f) treating the renewable feedstock in a reaction zone by hydrogenating and deoxygenating the feedstock using at least one catalyst at reaction conditions in the presence of hydrogen to provide a reaction zone product stream comprising hydrogen, carbon dioxide, water and a paraffins having from about 8 to about 24 carbon atoms;   g) cooling the reaction zone product stream and separating to provide:
 i) a gaseous component comprising at least hydrogen and carbon dioxide; 
 ii) a hydrocarbon product comprising the paraffins; and 
 iii) a water component; 
   h) recovering the hydrocarbon product;   i) separating the gaseous component comprising at least hydrogen and carbon dioxide into a stream comprising hydrogen and a stream comprising carbon dioxide; and   j) passing the stream comprising carbon dioxide to an enclosed green house and using the carbon dioxide stream to cultivate plants growing the enclosed greenhouse.   
     
     
         31 . An integrated process for producing a paraffin-rich diesel boiling range product from a renewable feedstock and for separating at least two components by supercritical extraction, said integrated process comprising:
 a. treating the renewable feedstock in a reaction zone by hydrogenating and deoxygenating the feedstock using at least one catalyst at reaction conditions in the presence of hydrogen to provide a reaction zone product stream comprising hydrogen, carbon dioxide, water and a paraffins having from about 8 to about 24 carbon atoms;   b. cooling the reaction zone product stream and separating to provide:
 i. a gaseous component comprising at least hydrogen and carbon dioxide; 
 ii. a hydrocarbon product comprising the paraffins; and 
 iii. a water component; 
   c. recovering the hydrocarbon product;   d. separating the gaseous component comprising at least hydrogen and carbon dioxide into a stream comprising hydrogen and a stream comprising carbon dioxide; and   e. passing the stream comprising carbon dioxide to a supercritical extraction operation and using the carbon dioxide stream as the extractant in the supercritical extraction operation to separate at least a first component from a second component in a mixture.