Advanced oxidative coupling of methane

Abstract

The present disclosure provides a method for generating higher hydrocarbon(s) from a stream comprising compounds with two or more carbon atoms (C 2+ ), comprising introducing methane and an oxidant (e.g., O 2 ) into an oxidative coupling of methane (OCM) reactor that has been retrofitted into a system comprising an ethylene-to-liquids (ETL) reactor. The OCM reactor reacts the methane with the oxidant to generate a first product stream comprising the C 2+ compounds. The first product stream can then be directed to a pressure swing adsorption (PSA) unit that recovers at least a portion of the C 2+ compounds from the first product stream to yield a second product stream comprising the at least the portion of the C 2+ compounds. The second product stream can then be directed to the ETL reactor. The higher hydrocarbon(s) can then be generated from the at least the portion of the C 2+ compounds in the ETL reactor.

1 . A method for generating higher hydrocarbon(s) from a stream comprising compounds with two or more carbon atoms (C 2+ ), comprising:
 (a) introducing methane and an oxidant into an oxidative coupling of methane (OCM) reactor that has been retrofitted into a system comprising an ethylene-to-liquids (ETL) reactor, wherein said OCM reactor reacts said methane with said oxidant to generate a first product stream comprising said C 2+  compounds;   (b) directing said first product stream to a pressure swing adsorption (PSA) unit that recovers at least a portion of said C 2+  compounds from said first product stream to yield a second product stream comprising said at least said portion of said C 2+  compounds;   (c) directing said second product stream to said ETL reactor; and   (d) generating said higher hydrocarbon(s) from said at least said portion of said C 2+  compounds in said ETL reactor.   
     
     
         2 . The method of  claim 1 , further comprising:
 recovering a light stream comprising (i) hydrogen and (ii) carbon monoxide (CO) and/or carbon dioxide (CO 2 ) from said PSA unit and recycling said light stream to said OCM reactor;   directing at least a portion of said light stream into a methanation unit that reacts said hydrogen and said CO and/or CO 2  to produce a methanation product stream comprising methane; and   directing said methanation product stream into said OCM reactor.   
     
     
         3 . The method of  claim 1 , further comprising recovering C 2  and/or C 3  compounds from said second product stream and directing said C 2  and/or C 3  compounds to said OCM reactor. 
     
     
         4 . The method of  claim 1 , wherein said OCM reactor further comprises a post-bed cracking (PBC) unit. 
     
     
         5 . A method for generating compounds with two or more carbon atoms (C 2+  compounds), comprising:
 (a) directing oxygen (O 2 ) and methane (CH 4 ) into an oxidative coupling of methane (OCM) reactor that reacts said O 2  and CH 4  in an OCM process to yield a product stream comprising (i) C 2+  compounds including ethylene (C 2 H 4 ) and (ii) carbon monoxide (CO) and/or carbon dioxide (CO 2 ); and 
 (b) directing said product stream from said OCM reactor into a separations system that employs a refrigeration unit having a refrigerant that includes methane from said product stream, to enrich said C 2+  compounds in said product stream. 
 
     
     
         6 . The method of  claim 5 , wherein said product stream is directed into said separations system through one or more additional units. 
     
     
         7 . The method of  claim 5 , further comprising separating methane from said product stream for use in said refrigeration unit. 
     
     
         8 . The method of  claim 5 , further comprising directing CO and/or CO 2  from said product stream to a methanation reactor that reacts said CO and/or CO 2  to yield a methanation product stream comprising methane. 
     
     
         9 . The method of  claim 8 , further comprising directing at least a portion of said methane in said methanation product stream to said OCM reactor. 
     
     
         10 . The method of  claim 5 , further comprising separating said product stream into (i) an ethylene product stream comprising ethylene and (ii) a C 3+  product stream comprising compounds with three or more carbon atoms (C 3+  compounds). 
     
     
         11 . The method of  claim 5 , further comprising directing ethane from said product stream to said OCM reactor. 
     
     
         12 . The method of  claim 5 , further comprising, prior to directing said product stream into said separations system, compressing said product stream. 
     
     
         13 . A method for generating compounds with two or more carbon atoms (C 2+  compounds), comprising:
 (a) directing oxygen (O 2 ) and methane (CH 4 ) into an oxidative coupling of methane (OCM) reactor that reacts said O 2  and CH 4  in an OCM process to yield a product stream comprising (i) C 2+  compounds including ethylene (C 2 H 4 ) and (ii) carbon monoxide (CO) and/or carbon dioxide (CO 2 ); and 
 (b) directing said product stream from said OCM reactor into a separations system that employs a complexation unit having a complexation catalyst that forms pi complexes with said ethylene in said product stream, to enrich said C 2+  compounds in said product stream. 
 
     
     
         14 . The method of  claim 13 , wherein said product stream is directed into said separations system through one or more additional units. 
     
     
         15 . The method of  claim 13 , further comprising using said complexation unit to remove one or more impurities from said product stream, wherein said impurities are selected from the group consisting of CO 2 , sulfur compounds, acetylenes, and hydrogen. 
     
     
         16 . The method of  claim 13 , wherein said complexation catalyst includes one or more metals selected from the group consisting of silver and copper. 
     
     
         17 . The method of  claim 13 , further comprising directing CO and/or CO 2  from said product stream to a methanation reactor that reacts said CO and/or CO 2  to yield a methanation product stream comprising methane. 
     
     
         18 . The method of  claim 17 , further comprising directing said methane in said methanation product stream to said OCM reactor. 
     
     
         19 . The method of  claim 13 , further comprising separating said product stream into (i) an ethylene product stream comprising ethylene and (ii) a C 3+  product stream comprising compounds with three or more carbon atoms (C 3+  compounds). 
     
     
         20 . The method of  claim 13 , further comprising directing ethane from said product stream to said OCM reactor. 
     
     
         21 . The method of  claim 13 , further comprising, prior to directing said product stream into said separations system, compressing said product stream. 
     
     
         22 . A method for generating compounds with two or more carbon atoms (C 2+  compounds), comprising:
 (a) directing oxygen (O 2 ) and methane (CH 4 ) into an oxidative coupling of methane (OCM) reactor that reacts said O 2  and CH 4  in an OCM process to yield a product stream comprising (i) C 2+  compounds including ethylene (C 2 H 4 ) and (ii) carbon dioxide (CO 2 ); and 
 (b) directing said product stream from said OCM reactor into a separations system that employs a CO 2  separation unit to separate said CO 2  from said product stream, to enrich said C 2+  compounds in said product stream, which CO 2  separation unit employs (i) sorbent or solvent separation of CO 2 , (ii) membrane separation of CO 2 , or (iii) cryogenic or low temperature separation of CO 2  having an operating temperature greater than a boiling point of methane and less than a boiling point of CO 2 . 
 
     
     
         23 . The method of  claim 22 , wherein said product stream is directed into said separations system through one or more additional units. 
     
     
         24 . The method of  claim 22 , wherein said sorbent or solvent separation of CO 2  employs an amine based absorption system, a Benfield process, diethanolamine, glycol dimethylether, propylene carbonate, Sulfinol, a zeolite, or active carbon. 
     
     
         25 .- 31 . (canceled) 
     
     
         32 . The method of  claim 22 , wherein said CO 2  separation system comprises a membrane CO 2  separation system. 
     
     
         33 . The method of  claim 22 , wherein said membrane separation of CO 2  employs a polymeric membrane, metallic membrane, ceramic membrane, poly ionic liquid membrane, supported ionic liquid membrane, polyetherimide membrane, or hybrid membrane comprising a membrane supporting a solvent or sorbent. 
     
     
         34 .- 39 . (canceled) 
     
     
         40 . The method of  claim 22 , further comprising directing said CO 2  from said product stream to a methanation reactor that reacts said CO 2  to yield a methanation product stream comprising methane. 
     
     
         41 . The method of  claim 40 , further comprising directing said methane in said methanation product stream to said OCM reactor. 
     
     
         42 . The method of  claim 22 , further comprising separating said product stream into (i) an ethylene product stream comprising ethylene and (ii) a C 3+  product stream comprising compounds with three or more carbon atoms (C 3+  compounds). 
     
     
         43 . The method of  claim 22 , further comprising directing ethane from said product stream to said OCM reactor. 
     
     
         44 . The method of  claim 22 , further comprising, prior to directing said product stream into said separations unit, compressing said product stream. 
     
     
         45 . A method for generating compounds with two or more carbon atoms (C 2+  compounds), comprising:
 (a) directing water into an electrolysis unit that electrolyzes said water to yield oxygen (O 2 ) and hydrogen (H 2 ); 
 (b) directing said O 2  from said electrolysis unit and methane (CH 4 ) into an oxidative coupling of methane (OCM) reactor that reacts said O 2  and CH 4  in an OCM process to yield a product stream comprising (i) C 2+  compounds, including ethylene (C 2 H 4 ) and (ii) carbon monoxide (CO) and/or carbon dioxide (CO 2 ); 
 (c) directing at least a portion of said CO and/or CO 2  from said product stream and said H 2  from said electrolysis unit into a methanation reactor that reacts said H 2  and said CO and/or CO 2  to yield CH 4 ; and 
 (d) directing at least a portion of said CH 4  from said methanation reactor to said OCM reactor. 
 
     
     
         46 .- 48 . (canceled) 
     
     
         49 . A method for generating compounds with two or more carbon atoms (C 2+  compounds), comprising:
 (a) directing oxygen (O 2 ) and methane (CH 4 ) into an oxidative coupling of methane (OCM) reactor that reacts said O 2  and CH 4  in an OCM process to yield a product stream comprising (i) C 2+  compounds including ethylene (C 2 H 4 ) and (ii) carbon dioxide (CO 2 ); 
 (b) directing said product stream from said OCM reactor into a separations system that employs a CO 2  separation unit that separates said CO 2  from said product stream to enrich said C 2+  compounds in said product stream; and 
 (c) directing at least a portion of said CO 2  separated in (b) to said OCM reactor. 
 
     
     
         50 . (canceled) 
     
     
         51 . A method for generating compounds with two or more carbon atoms (C 2+  compounds), comprising:
 (a) directing oxygen (O 2 ) and methane (CH 4 ) into an oxidative coupling of methane (OCM) reactor that reacts said O 2  and CH 4  in an OCM process to yield a product stream comprising C 2+  compounds including ethylene (C 2 H 4 ) and heat; 
 (b) using an evaporator to transfer at least a portion of said heat from said product stream to an organic working fluid in a closed fluid flow cycle as part of an organic Rankine cycle (ORC) system, to evaporate said organic working fluid, which closed fluid flow cycle includes said evaporator, a turbine, a condenser, and a pump; 
 (c) directing said organic working fluid evaporated in (b) to said turbine to generate power; 
 (d) directing said organic working fluid from said turbine to said condenser that condenses said organic working fluid; and 
 (e) directing said organic working fluid condensed in (d) to said pump. 
 
     
     
         52 . (canceled) 
     
     
         53 . (canceled) 
     
     
         54 . A method for generating compounds with two or more carbon atoms (C 2+  compounds), comprising:
 (a) directing oxygen (O 2 ) and methane (CH 4 ) into an oxidative coupling of methane (OCM) reactor that reacts said O 2  and CH 4  in an OCM process to yield a product stream comprising (i) C 2+  compounds including ethylene (C 2 H 4 ) and heat; 
 (b) transferring at least a portion of said heat from said product stream to a thermoelectric power generator; and 
 (c) with the aid of said heat, using said thermoelectric power generator to generate power. 
 
     
     
         55 . (canceled) 
     
     
         56 . (canceled)