Dehydrogenation of alkanes to alkenes

Patent metadata

Field	Value
Publication number	US-10150715-B2
Application number	US-201515507985-A
Country	US
Kind code	B2
Filing date	Sep 23, 2015
Priority date	Sep 29, 2014
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

Process for dehydrogenation of alkanesor alkylbenzenes by using metal sulfide catalyst under the presence of small amounts of hydrogen sulfide.

First claim

The invention claimed is:

1. A process for the dehydrogenation of alkanes, alkenes and/or alkylbenzenes to the corresponding unsaturated chemical products and hydrogen (H 2 ), comprising:
contacting a carrier gas comprising (1) one of benzene and a benzene-toluene mixture, and (2) alkane, alkene and/or alkylbenzene compounds to be dehydrogenated with a pre-sulfided metallic sulfide (MeS) catalyst, in which the dehydrogenation is conducted in one or more dehydrogenation reactors in the presence of H 2 S without formation of H 2 S as a reaction product, wherein the carrier gas further comprises: (1) 0.5% to less than 10% by volume steam (H 2 O), (2) hydrogen sulfide (H 2 S) at a molar ratio of H 2 S to the alkane, alkene and/or alkylbenzene compounds to be dehydrogenated between 0.1 and 0.2, and (3) an initial molar ratio of hydrogen sulfide to hydrogen (H 2 ) between 0.01 and 0.2, wherein said alkane, alkene and/or alkylbenzene compounds comprise at least one of: (1) ethylbenzene, and (2) methane, ethane, or a combination thereof; and
recovering a product stream comprising unsaturated chemical products.

2. The process according to claim 1 in which the initial molar ratio of hydrogen sulfide (H 2 S) to hydrogen (H 2 ) is 0.05-0.06.

3. The process according to claim 1 , in which Me of the metallic sulfide (MeS) catalyst is selected from Fe, Co, Ni, Mn, Cu, Mo, W and combinations thereof.

4. The process according to claim 1 , in which the process is conducted at temperatures in a range of 500-700° C.

5. The process according to claim 1 , wherein the alkylbenzene compound is ethylbenzene, and styrene is the unsaturated chemical product.

6. The process according to claim 1 , in which unreacted alkanes, alkenes, alkylbenzenes and by-products in the product stream are recycled to the one or more dehydrogenation reactors.

7. The process according to claim 6 , in which the unreacted alkanes, alkenes, alkylbenzenes and by-products in the product stream include methane, ethane, ethylbenzenes, benzene, toluene, and combinations thereof.

8. The process according to claim 1 , wherein said carrier gas further comprises methane, ethane, or combinations of both.

9. The process according to claim 1 , wherein the one or more dehydrogenation reactors are adiabatic reactors with a reheating step and selective oxidation of hydrogen produced in the process between the adiabatic reactors.

10. The process according to claim 1 , in which off-gas containing H 2 and CH 4 produced in the process is used as a part of the carrier gas and selective oxidation of hydrogen is conducted upstream of a first dehydrogenation reactor.

Assignees

• Haldor Topsoee
• Haldor Topsoe As

Inventors

• Højlund Nielsen Poul Erik
• Hansen John Bøgild

Classifications

• C07C2527/047

  with chromium, molybdenum, tungsten or polonium · CPC title

• C07C2521/10

  Magnesium; Oxides or hydroxides thereof · CPC title

• C07C5/46 Primary

  with sulfur or a sulfur-containing compound as an acceptor · CPC title

• C07C2527/043

  with iron group metals or platinum group metals · CPC title

• C07C2527/051

  Molybdenum · CPC title