Oxidative coupling of methane systems and methods

Patent metadata

Field	Value
Publication number	US-2017283345-A1
Application number	US-201615356202-A
Country	US
Kind code	A1
Filing date	Nov 18, 2016
Priority date	May 24, 2012
Publication date	Oct 5, 2017
Grant date	—

Abstract

Systems and methods conducive to the formation of one or more alkene hydrocarbons using a methane source and an oxidant in an oxidative coupling of methane (OCM) reaction are provided. One or more vessels each containing one or more catalyst beds containing one or more catalysts each having similar or differing chemical composition or physical form may be used. The one or more catalyst beds may be operated under a variety of conditions. At least a portion of the catalyst beds may be operated under substantially adiabatic conditions. At least a portion of the catalyst beds may be operated under substantially isothermal conditions.

First claim

1 .- 15 . (canceled)

16 . A system for generating hydrocarbons having two or more carbon atoms (C 2+ hydrocarbons), comprising:
a methane source that provides methane;
an oxidant source that provides an oxidant;
a reaction unit in fluid communication with said methane source and said oxidant source, said reaction unit comprising a catalyst bed that includes at least one oxidative coupling of methane (OCM) catalyst, wherein said OCM catalyst facilitates an OCM reaction using said methane from said methane source and said oxidant from said oxidant source to generate said C 2+ hydrocarbons, and wherein said catalyst bed has an inlet zone that is contacted by a bulk gas mixture formed upon entry of said methane from said methane source and said oxidant from said oxidant source into said reaction unit; and
a control unit operably coupled to said reaction unit, wherein said control unit is programmed to:
(a) maintain a thermal profile across said catalyst bed during said OCM reaction, which thermal profile is characterized by (i) a temperature of said inlet zone being less than about 600° C., and (ii) a maximum temperature within said catalyst bed being greater than about 800° C.;
(b) maintain a pressure within said reaction unit greater than about 15 pounds per square inch gauge (psig); and
(c) maintain said OCM reaction within said catalyst bed at a methane conversion of at least about 6% and a C 2+ hydrocarbon selectivity of at least about 40%.

17 . The system of claim 16 , wherein said catalyst bed comprises at least one nanostructure catalyst that is pressed or formed into at least one shape.

18 . The system of claim 17 , wherein said at least one nanostructure catalyst is selected from the group consisting of a metal oxide, a metal hydroxide, a perovskite, a metal oxyhydroxide, a metal oxycarbonate, a metal carbonate, a metal element from any of Groups 1 through 7, a lanthanide, and an actinide.

19 . The system of claim 17 , wherein said at least one nanostructure catalyst comprises at least one metal dopant that provides said C 2+ hydrocarbon selectivity of at least about 40%.

20 . The system of claim 16 , wherein said control unit is programmed to maintain said OCM reaction within said catalyst bed under substantially adiabatic conditions.

21 . The system of claim 16 , wherein said control unit is programmed to maintain said OCM reaction at a C 2+ hydrocarbon selectivity of at least about 50%.

22 . The system of claim 16 , further comprising at least one heat transfer unit thermally coupled to said methane source, wherein said at least one heat transfer unit is operably coupled to said control unit, and wherein said control unit is programmed to maintain said methane source at a temperature of at least about 400° C. using said at least one heat transfer unit.

23 . The system of claim 16 , further comprising at least one heat transfer unit thermally coupled to said oxidant source, wherein said at least one heat transfer unit is operably coupled to said control unit, and wherein said control unit is programmed to maintain said oxidant source at a temperature of at least about 400° C. using said at least one heat transfer unit.

24 . The system of claim 16 , wherein said control unit is programmed to maintain said OCM reaction at a methane conversion of at least about 10%.

25 . The system of claim 16 , wherein said reaction unit comprises a plurality of serially coupled vessels, wherein each of said serially coupled vessels includes at least one catalyst bed, wherein said control unit is operably coupled to said plurality of serially coupled vessels and is programmed to (i) operate said catalyst bed in each of said plurality of serially coupled vessels under substantially adiabatic conditions and (ii) maintain said OCM reaction at a C 2+ hydrocarbon selectivity of at least 50% within said catalyst bed in each of said plurality of serially coupled vessels.

26 . The system of claim 25 , further comprising a plurality of thermal transfer units, wherein a given thermal transfer unit of said plurality of thermal transfer units is upstream of a given vessel among said plurality of serially coupled vessels and is operably coupled to said control unit, and wherein said control unit is programmed to maintain a bulk gas temperature of at most about 700° C. in an inlet zone of said given vessel using said given thermal transfer unit.

27 . The system of claim 25 , further comprising at least one thermal adjustment unit fluidly coupled between a first vessel and a second vessel of said plurality of serially coupled vessels, wherein said first vessel is upstream of said second vessel, and wherein said thermal adjustment unit performs at least one of (i) remove a portion of an OCM product stream comprising said C 2+ hydrocarbons from said first vessel and directs a remainder of said OCM product stream to said second vessel, (ii) direct said methane or said oxidant to said second vessel, and (iii) transfer heat from said OCM product stream to a coolant.

28 . The system of claim 16 , wherein said control unit is programmed to adjust a proportion between a concentration of said methane and a concentration of said oxidant in said inlet zone to provide a ratio between said methane and said oxidant in said inlet zone such that said oxidant acts as a limiting reagent.

29 . The system of claim 16 , further comprising a temperature sensor positioned within said catalyst bed and operably coupled to said control unit, wherein said temperature sensor provides an output signal to said control unit that is indicative of a temperature of said catalyst bed.

30 . The system of claim 16 , wherein said control unit is programmed to maintain a maximum temperature within said catalyst bed of less than about 900° C.

31 . The system of claim 16 , wherein said control unit is programmed to maintain a pressure within said reaction unit greater than about 45 psig.

32 . The system of claim 16 , wherein said control unit is programmed to maintain a temperature of said inlet zone less than about 500° C.

33 . The system of claim 22 , wherein said control unit is programmed to maintain said methane source at a temperature of at most about 600° C. using said at least one heat transfer unit.

34 . The system of claim 23 , wherein said control unit is programmed to maintain said oxidant source at a temperature of at most about 600° C. using said at least one heat transfer unit.

35 . The system of claim 16 , wherein said control unit is programmed to maintain a temperature gradient through said catalyst bed of at most about 50° C.

Assignees

• Siluria Technologies Inc

Inventors

• Schammel Wayne P
• Wolfenbarger Julian
• Ajinkya Milind
• Mccarty Jon
• Cizeron Joel M
• Weinberger Sam
• Edwards Justin Dwight
• Sheridan David
• Scher Erik C
• Mccormick Jarod

Classifications

• B01J2208/00539

  Pressure · CPC title

• B01J2208/00628

  Controlling the composition of the reactive mixture · CPC title

• C10G2300/1092

  C2-C4 olefins · CPC title

• C10G50/00

  Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation · CPC title

• C07C2/84 Primary

  catalytic · CPC title