Electrochemical reactor for upgrading methane and small alkanes to longer alkanes and alkenes

Patent metadata

Field	Value
Publication number	US-2021164115-A1
Application number	US-201917046611-A
Country	US
Kind code	A1
Filing date	Apr 12, 2019
Priority date	Apr 12, 2018
Publication date	Jun 3, 2021
Grant date	—

Abstract

This application relates to new process that utilizes electrodes that incorporate acids that facilitate upgrading of methane and other low molecular weight alkanes to higher order hydrocarbon molecules, such as paraffins, olefins, and aromatics, at temperatures less than 250° C. A primary focus of the invention includes methane conversion to ethylene. The first step of the process includes acid containing electrodes that facilitate the activation of the alkane in the anode layer of the electrochemical reactor. Subsequent steps include the separation of protons from produced longer chain hydrocarbons followed by subsequent electrochemical reduction of the protons to yield hydrogen at the cathode or protons combined with oxygen at the cathode to yield water. The reaction steps in the anode upgrade methane to higher order hydrocarbon products.

First claim

1 . An apparatus for synthesizing higher order hydrocarbons from low molecular weight alkanes comprising:
(a) an anode; (b) a cathode; (c) an acid electrolyte separator; (d) a catalyst; (e) electrode binders that feature acids in the anode and cathode; (f) a low molecular weight hydrocarbon; (g) wherein the catalysts are comprised of platinum group metals or platinum group metal oxides, or transition metal or transition metal oxides; (h) wherein the anode and the cathode are in electronic communication to allow flow of electrons from the anode to the cathode; (i) wherein the low molecular weight hydrocarbon is in contact with the anode; and, wherein synthesis of a higher order hydrocarbon occurs at a temperature less than 400° C.

2 . The apparatus of claim 1 wherein the low molecular weight alkane is selected from a group consisting of methane, ethane, propane, butane and mixtures of these.

3 . The apparatus of claim 1 wherein the low molecular weight alkane is methane and wherein the higher order hydrocarbon is an alkane, alkene, or aromatic product.

4 - 5 . (canceled)

6 . The apparatus of claim 1 wherein the acid is selected from the group consisting of trifluoroacetic acid, perchloric acid, sulfuric acid, phosphoric acid, chlorosulfonic acid, perchloric acid, hydrofluoric acid, triflic acid, and fluorosulfonic acid.

7 . (canceled)

8 . The apparatus of claim 6 wherein the anode and cathode further comprises an electrically conductive support material, catalyst, and an acid containing ionomer binder.

9 . The apparatus of claim 8 wherein the synthesis reaction occurs at a temperature between 100° C. and 250° C.

10 . The apparatus of claim 9 wherein the cathode and anode comprise a catalyst that is selected from a group consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum metal or the metal in its oxide form.

11 . The apparatus of claim 10 wherein the acid containing ionomer binder comprises a polymer host such as polybenzimidazole, polycations, and blends of polybenzimidazole-polycations.

12 . The apparatus of claim 11 wherein the polycation material is selected from a group consisting of polyaromatic or perfluorinated backbones with tethered cation groups such as quaternary ammoniums, imidazoliums, phosphoniums, or ternary sulfoniums or sulfoxniums, or tethered metal cation centers.

13 . A method for synthesizing higher order hydrocarbons from low molecular weight alkanes comprising:
a. providing an apparatus comprising: i. an anode; ii. a cathode; iii. an acid electrolyte separator; iv. a catalyst; v. electrode binders that feature acids in the anode and cathode; vi. a low molecular weight hydrocarbon; vii. wherein the catalysts are comprised of platinum group metals or platinum group metal oxides, or transition metal or transition metal oxides; viii. wherein the anode and the cathode are in electronic communication to allow flow of electrons from the anode to the cathode; ix. wherein the low molecular weight hydrocarbon is in contact with the anode; and, wherein synthesis of a higher order hydrocarbon occurs at a temperature less than 400° C. b. feeding the low molecular weight hydrocarbon the apparatus; c. applying an electrical current to the anode. d. removing the higher order hydrocarbon synthesized in the apparatus; e. removing hydrogen produced in the apparatus.

14 . The method of claim 13 wherein the low molecular weight alkane is selected from a group consisting of methane, ethane, propane, butane and mixtures of these.

15 . The method of claim 13 wherein the low molecular weight alkane is methane and wherein the higher order hydrocarbon is an alkane, alkene, or aromatic product.

16 . (canceled)

17 . The method of claim 13 wherein a hydrogen molecule is produced at the cathode.

18 . The method of claim 13 wherein the acid is selected from the group consisting of trifluoroacetic acid, perchloric acid, sulfuric acid, phosphoric acid, perchloric acid, hydrofluoric acid, triflic acid, chlorosulfonic acid, and fluorosulfonic acid.

19 . (canceled)

20 . The method of claim 16 wherein the anode and cathode further comprises an electrically conductive support material, catalyst, and an acid containing ionomer binder.

21 . The method of claim 18 wherein the synthesis reaction occurs at a temperature between 100° C. and 250° C.

22 . The method of claim 21 wherein the cathode and anode comprise a catalyst that is selected from a group consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum metal or the metal in its oxide form.

23 . The method of claim 22 wherein the acid containing ionomer binder comprises a polymer host such as polybenzimidazole, polycations, and blends of polybenzimidazole-polycations.

24 . The method of claim 23 wherein the polycation material is selected from a group consisting of polyaromatic or perfluorinated backbones with tethered cation groups such as quaternary ammoniums, imidazoliums, phosphoniums, or ternary sulfoniums or sulfoxniums, or tethered metal cation centers (i.e., metallocenes).

25 . An apparatus for synthesizing ethylene from methane:
(a) an anode; (b) a cathode; (c) an acid electrolyte separator; (d) a catalyst; (e) electrode binders that feature acids in the anode and cathode; (f) methane; (g) wherein the catalysts are comprised of platinum group metals or platinum group metal oxides, or transition metal or transition metal oxides; (h) wherein the anode and the cathode are in electronic communication to allow flow of electrons from the anode to the cathode; (i) wherein the methane is in contact with the anode; and, wherein synthesis of ethylene occurs at a temperature less than 400° C.

26 - 27 . (canceled)

Assignees

• Univ Louisiana State

Inventors

• Arges Christopher George
• Flake John C
• Fang Yuxin

Classifications

• C25B11/089

  Alloys · CPC title

• C25B11/081

  the element being a noble metal · CPC title

• C25B11/077

  the compound being a non-noble metal oxide · CPC title

• C25B11/071

  comprising metal or alloy powder and non-metallic binders · CPC title

• C25B11/052

  Electrodes comprising one or more electrocatalytic coatings on a substrate · CPC title