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CN-121986066-A - Hydrocarbon pyrolysis process

CN121986066ACN 121986066 ACN121986066 ACN 121986066ACN-121986066-A

Abstract

A process for producing a hydrogen-containing gas stream containing hydrogen sulfide and simultaneously producing a low sulfur carbonaceous material comprises the steps of (i) providing a hydrocarbon feed gas stream containing sulfur compounds, (ii) supplying carbonaceous particles to a reactor and subjecting the feed gas stream to pyrolysis in the reactor over a moving bed of carbonaceous particles, (iii) recovering the hydrogen-containing gas stream containing hydrogen sulfide, and (iv) recovering the low sulfur carbonaceous particles. The sulfur eventually exists as hydrogen sulfide that is harmless to the selected downstream application or is purposefully used for the selected downstream application or can be readily removed from the hydrogen stream. There is no need to perform a desulfurization step prior to thermocatalytic conversion of the sulfur-containing hydrocarbon feedstock.

Inventors

  • MUENSTER INGO
  • D. VOLLICKER
  • F. Schaff
  • D. RICK
  • KONS GERMAIN
  • S. SCHULTZ

Assignees

  • 巴斯夫欧洲公司

Dates

Publication Date
20260505
Application Date
20241001
Priority Date
20231006

Claims (13)

  1. 1. A process for producing a hydrogen-containing gas stream containing hydrogen sulfide and simultaneously producing a low sulfur carbonaceous material, the process comprising the steps of: (i) Providing a hydrocarbon feed gas stream comprising sulfur-containing compounds; (ii) Supplying carbonaceous particles to a reactor and subjecting the feed gas stream to pyrolysis in the reactor on a moving bed of the carbonaceous particles; (iii) Recovering a hydrogen-containing gas stream containing hydrogen sulfide, and (Iv) Recovering the low sulfur carbonaceous particles.
  2. 2. The method of claim 1, wherein the initial sulfur concentration of the supplied carbonaceous particles is c (S) 0 and the sulfur concentration of the recovered low sulfur carbonaceous particles is c (S) R less than or equal to c (S) 0 .
  3. 3. The method of claim 1 or 2, further comprising (V) Directing the hydrogen-containing gas stream to a gas separation unit to obtain a hydrogen-depleted gas and a hydrogen stream containing hydrogen sulfide, and (Vi) The hydrogen-depleted gas is recycled back to the reactor.
  4. 4. The method of claim 1 or 2, comprising removing hydrogen sulfide from the hydrogen sulfide-containing gas.
  5. 5. A method as set forth in claim 3 comprising removing hydrogen sulfide from the hydrogen sulfide-containing hydrogen stream.
  6. 6. The method of claim 1 or 2, comprising directing the hydrogen-containing gas containing hydrogen sulfide to a sulfur-insensitive hydrogen-consuming reaction, hydrogen sulfide production, catalyst sulfiding operation, or selective sulfur poisoning of a catalyst.
  7. 7. A method as set forth in claim 3 comprising directing the hydrogen sulfide-containing hydrogen stream to a sulfur-insensitive hydrogen-consuming reaction, hydrogen sulfide production, catalyst sulfiding operation, or selective sulfur poisoning of the catalyst.
  8. 8. The process of claim 6 or 7, wherein the sulfur-insensitive hydrogen-consuming reaction is a refinery hydrotreatment, preferably Hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and/or Hydrodearomatics (HDA).
  9. 9. The method of claim 6 or 7, wherein the catalyst sulfiding operation is sulfiding a hydrotreating catalyst.
  10. 10. The method of claim 6 or 7, wherein the selective sulfur poisoning is a selective sulfur poisoning of a fischer-tropsch catalyst.
  11. 11. A method according to any one of the preceding claims, wherein the solid material particles are selected from carbonaceous materials, metals, ceramics and mixtures thereof.
  12. 12. A method according to any one of the preceding claims, comprising applying a voltage across at least a portion of the moving bed to provide direct resistive heating.
  13. 13. The method according to any one of the preceding claims, wherein the pyrolysis is performed at a temperature in the range of 1000 ℃ to 1600 ℃.

Description

Hydrocarbon pyrolysis process The present invention relates to a hydrocarbon pyrolysis process. Hydrogen can be produced from hydrocarbon fuels by both oxidative and non-oxidative conversion processes. Oxidation processes include Steam Reforming (SR) and Partial Oxidation (POX). For methane, steam reforming proceeds according to the following main reactions: CH4 + H2O → CO + 3H2 similar reactions will occur with other hydrocarbons. Typically, in the presence of a catalyst for steam reforming, the following water gas shift reaction also occurs: CO + H2O → CO2 + H2 these reactions are endothermic, generally requiring the reactor outlet to reach high temperatures above 800 ℃. Partial oxidation is a non-catalytic process in which sub-stoichiometric amounts of oxygen are allowed to react with carbonaceous materials (like natural gas), liquid feeds (like fuel oil, gas oil) and/or coal at high temperature to obtain synthesis gas containing hydrogen and carbon monoxide. For methane, the partial oxidation proceeds according to the following main reactions: 2CH4 + O2 → 2CO + 4H2 For the partial oxidation reaction, the carbonaceous feed is mixed with air, oxygen-enriched air and/or molecular oxygen and introduced into a high temperature partial oxidation reactor of at least 1200 ℃ and thermally reacted in the absence of a catalyst. Non-oxidative pathways include thermal decomposition of hydrocarbons into hydrogen and carbon, also known as decomposition or pyrolysis. For methane, pyrolysis proceeds according to the following main reactions: CH4 → C + 2H2 The process is moderately endothermic (about 37 kJ/mole H 2). As is apparent from the above reaction equation, in methane pyrolysis, the release of carbon dioxide is prevented. Thus, where the desired energy source is derived from a renewable resource, methane pyrolysis is a CO 2 -free (i.e., clean) technology that can achieve zero emissions of hydrogen. Methane pyrolysis is a one-step process that produces large amounts of hydrogen. Carbon is a valuable byproduct produced in the process. There is an increasing demand for low sulfur carbonaceous materials. Such carbonaceous materials may be used, for example, in aluminum and steel production, tire manufacturing, electrode manufacturing, polymer blending, additives for building materials, carbon devices (like heat exchangers), soil conditioning, or storage. Conventional catalytic reforming and partial oxidation processes require the feedstock to be desulphurised to the ppm level. Sulfur compounds are strong poisons for catalysts used in steam reforming processes. Likewise, catalytic methane pyrolysis processes using solid phase catalysts such as nickel (Ni), iron (Fe), molybdenum (Mo), or cobalt (Co) are sensitive to sulfur impurities in the feed. Thus, the feed gas needs to be pre-desulphurised prior to pyrolysis. Desulfurization of hydrocarbons is typically accomplished by catalytic Hydrodesulfurization (HDS), wherein the organosulfur species are converted to H 2 S. Conversion to hydrogen sulfide is typically accomplished by reaction with hydrogen over a non-noble metal sulfided catalyst, particularly a Co/Mo or Ni/Mo containing catalyst. In a gas processing unit, H 2 S is readily removed from desulfurized hydrocarbons by adsorption or absorption. The necessity of catalytic hydrodesulfurization increases the cost of producing hydrogen from hydrocarbons. US 7,157,167 B1 describes a process for producing hydrogen and carbon by thermocatalytically decomposing a hydrocarbon fuel under the influence of a carbon-based catalyst in the absence of air and/or water. When sulfur is present in the hydrocarbon feedstock, it will eventually be present in the form of elemental sulfur that can condense. It has now been found that the presence of sulfur in a hydrocarbon feedstock is not only harmless when hydrocarbon thermocatalytic conversion is carried out on a moving bed of carbonaceous particles, but the pyrolysis of moving carbon hydrocarbons virtually completely replaces the hydrodesulfurization unit. This means that no costly desulfurization step is required prior to the thermocatalytic conversion of the sulfur-containing hydrocarbon feedstock. The sulfur eventually exists as hydrogen sulfide that is harmless to the selected downstream application or is purposefully used for the selected downstream application or can be readily removed from the hydrogen stream. Furthermore, it has been found that carbonaceous materials deposited on carbonaceous particles by such thermocatalytic conversion simultaneously have a high purity, in particular a low sulfur concentration. Accordingly, the present invention relates to a method comprising the steps of: (i) Providing a hydrocarbon feed gas stream comprising sulfur-containing compounds; (ii) Pyrolysis of a feed gas stream in a reactor on a moving bed of solid material particles, and (Iii) Recovering a hydrogen-containing gas stream comprising hydrogen sulfide. In particular, the present in