Treatment of synthesis gases from a gasification facility

Patent metadata

Field	Value
Publication number	US-9254469-B2
Application number	US-201414551664-A
Country	US
Kind code	B2
Filing date	Nov 24, 2014
Priority date	Nov 25, 2013
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A technology for producing synthesis gas from crude gas from various gasification processes for solid or liquid fuels. To limit the temperatures in a subsequent strongly exothermic CO shift reaction to adjust the H 2 /CO ratio, the crude gas which has been freed of dust flows through two shift reactors arranged in series. The first reactor has a specific reaction-kinetically limited catalyst and the second reactor has a conventional sour gas catalyst. The specific catalyst used in the first reactor limits the exothermic shift reaction to such an extent that the reaction temperatures in the first and second reactors remain so low to avoid thermal damage to the catalysts even without introduction of external steam, and the desired gas composition is achieved.

First claim

The invention claimed is:

1. A process for the treatment of crude gases obtained in gasification of solid or liquid carbon-containing starting materials in an entrained-flow, a fixed-bed or a fluidized-bed gasification, the process comprising:
conducting the treatment of the crude gases at up to pressures of 12 MPa and at temperatures of up to 1900° C.;
using a shift technology for achieving a predetermined H 2 /CO ratio of a synthesis gas, by feeding the crude gas sequentially through at least two shift reactors, wherein the feeding of the crude gas through the first shift reactor is with the crude gas freed of entrained solids, and wherein the first shift reactor contains a reaction-kinetically limited catalyst with mild intrinsic activity; and
the feeding of the second shift reactor is with the partially shifted crude gas fed from said first shift reactor, wherein the second shift reactor contains a catalyst which is not reaction-kinetically limited.

2. The process as claimed in claim 1 , further comprising:
performing the gasification in a gasification reactor; and
directly cooling the hot crude gas leaving the gasification reactor by spraying water at the crude gas in a quenching chamber and then;
passing the crude gas through a heat exchanger system located downstream of the quenching chamber for cooling the crude gas to the inlet temperatures of the first shift reactor of from 200 to 350° C.

3. The process as claimed in claim 1 , further comprising indirectly cooling the hot crude gas leaving a gasification reactor in a waste heat combination comprising radiation and convection coolers connected in series.

4. The process as claimed in claim 1 , further comprising cooling the hot crude gas leaving a gasification reactor by combination of direct and indirect cooling using a partial quench and a convection cooler with steam generation which are connected in series.

5. The process as claimed in claim 4 , further comprising performing the partial quenching is by spraying in a limited amount of water.

6. The process as claimed in claim 4 , further comprising performing the partial quenching by introducing a colder gas.

7. The process as claimed in claim 4 , further comprising performing the partial quenching by chemical quenching comprising introducing further fuel into the hot crude gas leaving the gasification reactor.

8. The process as claimed in claim 1 , further comprising subjecting the crude gas to dust precipitation down to residual contents of 1 mg/m 3 before entering the crude gas into the first shift reactor of the shift technology.

9. The process as claimed in claim 1 , further comprising providing the crude gas at a temperature which is at least 20° C. above the temperature at which water vapor condensation commences before the crude gas enters the first shift reactor of the shift technology.

10. The process as claimed in claim 1 , further comprising the crude gas which has been partially shifted in the first shift reactor, and the first shift reactor that is provided with the reaction-kinetically limited catalyst, does not exceed an outlet temperature of 480° C.

11. The process as claimed in claim 1 , further comprising mixing part of the crude gas fed into the first and the second shift reactors into the partially shifted crude gas from the first shift reactor before the crude gas enters the second shift reactor.

12. The process as claimed in claim 1 , further comprising adding a part of the crude gas which has been partially shifted in the first shift reactor to the fully shifted crude gas downstream of the second shift reactor.

13. The process as claimed in claim 1 , further comprising when the crude gas enters the first shift reactor, setting the steam/gas ratio in the range from 0.1 to 2.5.

14. The process as claimed in claim 1 , further comprising before the crude gas enters the first shift reactor setting the CO concentration of the crude gas in the range from 40 to 90% by volume based on the dry gas.

15. The process as claimed in claim 1 , further comprising the support material of the reaction-kinetically limited catalyst used in the first shift reactor is selected from the group consisting of aluminum oxide, silicon oxide, magnesium oxide, manganese oxide, zinc oxide, titanium oxide, metal aluminates and mixtures thereof.

16. The process as claimed in claim 1 , further comprising the reaction-kinetically limited catalyst having catalytically active components is formed by molybdenum and cobalt and mixtures thereof, wherein the concentration is in the range from 1 to 6% by mass.

17. The process as claimed in claim 1 , further comprising the reaction-kinetically limited catalyst having catalytically active components is formed by cobalt and nickel and mixtures thereof, wherein the concentration is up to 1.0% by mass.

18. The process as claimed in claim 1 , further comprising the reaction-kinetically limited catalyst having a specific surface area in the range from 50 to 400 m2/g.

19. The process as claimed in claim 1 , further comprising the reaction-kinetically limited catalyst is a specific catalyst having the designation ShiftMax ® 821.

20. The process as claimed in claim 19 , further comprising sulfiding the reaction-kinetically limited catalyst having the designation ShiftMax ® 821 before feeding the crude gas to the first reactor .

21. The process as claimed in claim 19 , further comprising sulfiding the reaction-kinetically limited catalyst having the designation ShiftMax ® 821 outside the reactor before feeding the crude gas to the first reactor.

22. The process as claimed in claim 19 , further comprising sulfiding the reaction-kinetically limited catalyst having the designation ShiftMax ® 821 in the shift reactor before feeding the crude gas to the first reactor.

23. The process as claimed in claim 1 , further comprising the partially shifted crude gas leaving the first reactor which contains the reaction-kinetically limited catalyst, wherein the partially shifted crude gas has a CO content of from 35 to 50% by volume (based on the dry gas) and feeding the partially shifted crude gas with this content to the second shift reactor which contains a catalyst which is not reaction-kinetically limited.

24. The process as claimed in claim 1 , wherein the shifted crude gas at the outlet of the second shift reactor does not exceed a temperature of 480° C.

25. The process as claimed in claim 1 , further comprising feeding the shifted crude gas leaving the second shift reactor to a chemical or physical scrub to remove interfering gases.

26. The process as claimed in claim 1 , further comprising continuing the shift reaction until a pure synthesis gas having an H2/CO ratio in the range from 1.9 to 2.4 is formed after the removal of CO2 and other interfering gases.

27. The process as claimed in claim 1 , further comprising feeding the synthesis gas produced by the specific shift process to a synthesis of methanol.

28. The process as claimed in claim 1 , further comprising feeding the synthesis gas produced by the specific shift process to a Fischer-Tropsch synthesis.

29. The process as claimed in claim 1 , further comprising producing olefins using the synthesis gas produced by the specific shift process.

30. The process as claimed in claim 1 , further comprising feeding the synthesis gas produced by th

Assignees

• Siemens Ag
• Clariant Int Ltd

Inventors

• Cai Yeping
• Faris William M
• Görsch Christian
• Hannemann Frank
• Klostermann Doris
• Marx Robert
• Schingnitz Manfred
• Wang Justin
• Xu Ling

Classifications

• B01J8/0005 Primary

  Catalytic processes under superatmospheric pressure (non-catalytic processes B01J3/00) · CPC title

• B01J8/0285

  Heating or cooling the reactor (for tubular reactors in furnaces B01J8/062) · CPC title

• B01J8/18 Primary

  with fluidised particles {(combustion apparatus with fluidised bed in general F23C10/00; furnaces with fluidised bed F27B15/00)} · CPC title

• C01B2203/0877

  by direct injection of fluid · CPC title

• B01J2208/027

  Beds · CPC title