Production of liquids and reduced sulfur gaseous products from sour natural gas

Patent metadata

Field	Value
Publication number	US-2019210941-A1
Application number	US-201815867902-A
Country	US
Kind code	A1
Filing date	Jan 11, 2018
Priority date	Jan 11, 2018
Publication date	Jul 11, 2019
Grant date	—

Abstract

Aspects of the invention are associated with the discovery of approaches for the conversion of sour natural gas streams, by conversion to liquid hydrocarbons. Particular processes and their associated apparatuses advantageously combine (i) dehydroaromatization (DHA) of methane in a gaseous feedstock, to produce aromatic hydrocarbons such as benzene, with (ii) the reaction of H2S and methane in this feedstock, to produce organic sulfur compounds such as carbon disulfide (CS2) and thiophene (C4H4S). A gaseous product having a reduced concentration of H2S is thereby generated. The aromatic hydrocarbons and organic sulfur compounds may be recovered in a liquid product. Both the gaseous and liquid products may be easily amenable to further upgrading. Other advantages of the disclosed processes and apparatuses reside in their simplicity, whereby the associated streams, including a potential gaseous recycle, generally avoid high partial pressures of H2S.

First claim

1 . A methane dehydroaromatization (DHA) process comprising:
contacting a feedstock comprising methane and H 2 S with a DHA catalyst and recovering a liquid product comprising, as conversion products of the methane and H 2 S, one or more aromatic hydrocarbons and one or more organic sulfur compounds, wherein the methane is present in the feedstock at a concentration of at least about 50 vol-%, and wherein the H 2 S is present in the feedstock at a concentration from about 1 vol-% to about 25 vol-%.

2 . The process of claim 1 , wherein the one or more aromatic hydrocarbons include benzene and the one or more organic sulfur compounds include both carbon disulfide and thiophene.

3 . The process of claim 1 , wherein the feedstock comprises sour natural gas.

4 . The process of claim 3 , wherein the feedstock further comprises a methane-containing gaseous recycle.

5 . (canceled)

6 . The process of claim 1 , wherein the DHA catalyst comprises molybdenum.

7 . The process of claim 6 , wherein the DHA catalyst comprises supported MoS 2 or supported CoMo.

8 . The process of claim 1 , wherein the contacting of the feedstock with the DHA catalyst is carried out under DHA conditions including a temperature from about 800° C. to about 1200° C., an absolute pressure from about 30 kPa to about 2.1 MPa, and a weight hourly space velocity (WHSV) from about 0.05 to about 5 hr −1 .

9 . The process of claim 1 , wherein the recovering of the liquid product is carried out by separating the liquid product from a methane-containing gaseous product.

10 . The process of claim 9 , wherein the DHA catalyst is contained in a DHA reactor, the process further comprising:
withdrawing a DHA effluent from the DHA reactor and feeding at least a portion of the DHA effluent to a separator to perform a separating of the liquid product from the methane-containing gaseous product.

11 . The process of claim 9 , further comprising separating H 2 S from the methane-containing gaseous product to provide an H 2 S-depleted methane product.

12 . The process of claim 9 , wherein the DHA catalyst is contained in a DHA reactor, the process further comprising:
withdrawing a DHA effluent from the DHA rector and feeding at least a portion of the DHA effluent to an ethylene oligomerization (EO) reactor containing an EO catalyst, and withdrawing an EO effluent from the EO reactor and feeding at least a portion of the EO effluent to a separator to perform the separating of the liquid product from the methane-containing gaseous product.

13 . (canceled)

14 . A process for sweetening of a feedstock comprising methane and H 2 S, the process comprising:
(a) in a DHA reaction stage, contacting at least a portion of the feedstock with a DHA catalyst, to provide a DHA effluent; and (b) in a separation stage, separating from at least a portion of the DHA effluent (i) a liquid product comprising, as conversion products of the methane and H 2 S, one or more aromatic hydrocarbons and one or more organic sulfur compounds, and (ii) a methane-containing gaseous product, wherein the DHA reaction stage is carried out at an absolute pressure from about 100 kPa to about 300 kPa, and wherein a conversion of the H 2 S in the feedstock, in a single pass through the DHA reaction stage, is from about 30% to about 95%.

15 . The process of claim 14 , further comprising, prior to step (a), combining a methane-containing fresh feed with a methane-containing gaseous recycle to provide the feedstock comprising methane and H 2 S.

16 . (canceled)

17 . The process of claim 14 , further comprising:
(c) in a gas purification stage, separating H 2 S from the methane-containing gaseous product to provide an H 2 S-depleted methane product.

18 . The process of claim 17 , wherein step (c) further provides a methane-containing gaseous recycle, the method further comprising:
(a) combining a methane-containing fresh feed with the methane-containing gaseous recycle to provide the feedstock comprising methane and H 2 S.

19 - 23 . (canceled)

24 . A process for sweetening of a feedstock comprising methane and H 2 S, the process comprising:
(a) in a DHA reaction stage, contacting at least a portion of the feedstock with a DHA catalyst, to provide a DHA effluent; (b) feeding at least a portion of the DHA effluent to an ethylene oligomerization (EO) reactor and withdrawing an EO effluent from the EO reactor; and (c) in a separation stage, separating from at least a portion of the EO effluent (i) a liquid product comprising, as conversion products of the methane and H 2 S, one or more aromatic hydrocarbons and one or more organic sulfur compounds, and (ii) a methane-containing gaseous product, wherein the DHA reaction stage is carried out at an absolute pressure from about 100 kPa to about 300 kPa, and wherein the H 2 S is present in the feedstock at a concentration from about 1 vol-% to about 25 vol-%.

Assignees

• Gas Technology Inst

Inventors

• Marker Terry
• Wangerow Jim
• Boysen Dane
• Linck Martin B
• Ortiz-Toral Pedro

Classifications

• C10L2290/542

  Adsorption of impurities during preparation or upgrading of a fuel · CPC title

• C07C2523/882

  and cobalt · CPC title

• C07C2/08

  Catalytic processes · CPC title

• C07C2/76 Primary

  by condensation of hydrocarbons with partial elimination of hydrogen · CPC title

• C10L2290/10

  Recycling of a stream within the process or apparatus to reuse elsewhere therein · CPC title