Continuous process for converting natural gas to liquid hydrocarbons
View Patent ↗A method comprising: providing an alkyl halide stream; contacting at least some of the alkyl halides with a coupling catalyst to form a product stream comprising higher hydrocarbons and hydrogen halide; contacting the product stream with a solid reactant to remove at least a portion of the hydrogen halide from the product stream; and reacting the solid reactant with a source of oxygen to generate a corresponding halogen.
1. A system comprising:
a coupling reactor comprising a coupling catalyst for receiving an alkyl halide stream and contacting at least a portion of the alkyl halide stream with the coupling catalyst to form a product stream comprising higher hydrocarbons and hydrogen halide, wherein the coupling catalyst comprises a fluorinated alumina, a dealuminated ZSM-5 zeolite, erionite, ferrierite, ALPO-5, MAPO-36, ZSM-12, ZSM-57, ZSM-23, ZSM-22, or MCM-22;
a separator unit for separating at least some of the product stream from the hydrogen halide, wherein the separator unit comprises an absorption column;
an oxidation reactor comprising an aqueous solution comprising a metal capable of forming multiple stable oxidation states for receiving a source of oxygen and at least a portion of the hydrogen halide from the separator unit and generating a corresponding halogen and water; and
a second separator unit for receiving a gas stream of hydrocarbon products recovered from the absorption column, wherein the second separator unit operates by distillation, pressure swing adsorption, or membrane separation.
2. The system of claim 1 wherein the metal capable of forming multiple oxidation states in the oxidation reactor comprises at least one metal selected from the group consisting of: Cu, Fe, Sb, Mn, V, As, Ru, and a combination thereof.
3. The system of claim 1 wherein the aqueous solution in the oxidation reactor has a pH less than about 7.0.
4. The system of claim 1 wherein the oxidation reactor is at a temperature from about 65° C. to about 300°.
5. The system of claim 1 wherein the oxidation reactor is at a pressure from about 0.1 atm to about 40 atm.
6. The system of claim 1 wherein the oxidation reactor comprises at least one reactor type selected from the group consisting of: a continuous stirred tank reactor, a plug flow reactor, a packed column reactor, a fixed bed reactor, and a fluidized bed reactor.
7. The system of claim 1 further comprising a product separator for receiving the products of the oxidation reactor and separating the corresponding halogen and the water.
8. The system of claim 1 further comprising a halogenation reactor for receiving a halogen stream and an alkane stream and generating the alkyl halide stream.
9. The system of claim 1 wherein the halogen is bromine.
10. The system of claim 1 , wherein the coupling catalyst comprises the erionite, the ferrierite, the ALPO-5, the MAPO-36, the ZSM-12, the ZSM-57, the ZSM-23, the ZSM-22, or the MCM-22.
11. The system of claim 1 , wherein the coupling catalyst comprises the fluorinated alumina.
12. The system of claim 11 , wherein the fluorinated alumina is a support for a catalytic material.
13. The system of claim 1 , wherein the coupling catalyst comprises the dealuminated ZSM-5 zeolite.
14. The system of claim 1 , wherein the absorption column is a packed column or a tray column.
15. The system of claim 1 ,
wherein the metal capable of forming multiple stable oxidation states comprise selenium, tellurium, antimony, arsenic, or ruthenium.
16. The system of claim 15 , wherein the metal capable of forming multiple stable oxidation states comprise selenium or tellurium.
17. A system comprising:
a coupling reactor comprising a coupling catalyst for receiving an alkyl halide stream and contacting at least a portion of the alkyl halide stream with the coupling catalyst to form a product stream comprising higher hydrocarbons and hydrogen halide, wherein the coupling catalyst comprises a fluorinated alumina, a dealuminated ZSM-5 zeolite, erionite, ferrierite, ALPO-5, MAPO-36, ZSM-12, ZSM-57, ZSM-23, ZSM-22, or MCM-22;
a separator unit for separating at least some of the product stream from the hydrogen halide, wherein the separator unit comprises an absorption column;
an oxidation reactor comprising an aqueous solution comprising a metal capable of forming multiple stable oxidation states for receiving a source of oxygen and at least a portion of the hydrogen halide from the separator unit and generating a corresponding halogen and water; and
a liquid-liquid splitter for receiving liquid hydrocarbon products recovered from the absorption column.
18. A system comprising:
a coupling reactor comprising a coupling catalyst for receiving an alkyl halide stream and contacting at least a portion of the alkyl halide stream with the coupling catalyst to form a product stream comprising higher hydrocarbons and hydrogen halide, wherein the coupling catalyst comprises a fluorinated alumina, a dealuminated ZSM-5 zeolite, erionite, ferrierite, ALPO-5, MAPO-36, ZSM-12, ZSM-57, ZSM-23, ZSM-22, or MCM-22;
a separator unit for separating at least some of the product stream from the hydrogen halide, wherein the separator unit comprises a distillation column; and
an oxidation reactor comprising an aqueous solution comprising a metal capable of forming multiple stable oxidation states for receiving a source of oxygen and at least a portion of the hydrogen halide from the separator unit and generating a corresponding halogen and water.