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CN-117582813-B - Short-process Claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation

CN117582813BCN 117582813 BCN117582813 BCN 117582813BCN-117582813-B

Abstract

The invention discloses a short-process Claus desulfurization and sulfur recovery process of coupling low-temperature catalytic oxidation, which is characterized in that waste gas containing H 2 S is directly fed into a catalytic oxidation reactor taking carbon materials or carbon-carried metals as catalysts after passing through a primary Claus conversion reactor and a condenser, and the low-concentration H 2 S is completely converted into sulfur and recovered under the low-temperature condition by utilizing the low-temperature catalytic oxidation activity of the carbon materials or the carbon-carried metals. Compared with the traditional Claus process, the process route can realize complete removal of H 2 S in sulfur-containing waste gas and sulfur recovery only through a one-stage Claus reaction and a low-temperature catalytic oxidation reaction without a multi-stage Claus conversion reactor and multiple reheating-condensing cycles, and has the advantages of short flow, low system complexity and low energy consumption.

Inventors

  • SUN FEI
  • SHI YAN
  • QU ZHIBIN
  • PI XINXIN
  • BAO JIANMIN

Assignees

  • 哈尔滨工业大学

Dates

Publication Date
20260508
Application Date
20231109

Claims (6)

  1. 1. A short-process claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation, characterized in that the process comprises the following steps: Step one, exhaust gas containing H 2 S sequentially enters a sulfur-making combustion furnace and a sulfur-making waste heat boiler after gas distribution, and partial H 2 S is subjected to conversion reaction to SO 2 and Claus reaction, wherein the concentration of H 2 S in the exhaust gas entering the sulfur-making combustion furnace after gas distribution is 15-30%; step two, cooling furnace gas, entering a first-stage condenser, condensing liquid sulfur and separating from process gas at the temperature of not more than 160 ℃, and recovering obtained liquid sulfur; step three, the process gas at the outlet of the first-stage condenser reaches 240-300 ℃ after being reheated, and enters a first-stage Claus converter to undergo a Claus reaction under the action of a sulfur-producing catalyst; Step four, cooling the process gas at the outlet of the first-stage Claus converter, then cooling the cooled process gas to below 160 ℃ in a second-stage condenser, separating condensed liquid sulfur from the process gas, and recovering the obtained liquid sulfur; step five, the process gas at the outlet of the secondary condenser is subjected to air distribution, cooled and enters a catalytic oxidation reactor, and is subjected to catalytic oxidation reaction under the action of a carbon-based catalyst or a catalyst taking carbon as a carrier to convert H 2 S into sulfur, wherein the concentration of H 2 S in the waste gas entering the catalytic oxidation reactor after air distribution is not more than 5%; Step six, after the catalyst in the catalytic oxidation reactor is saturated, cleaning by adopting an organic solvent, and recovering sulfur which is a catalytic oxidation product of H 2 S; And step seven, washing and regenerating the catalyst after washing and regenerating the catalyst by using an organic solvent, and recovering trace amount of SO 2 to catalyze and oxidize sulfuric acid as a product.
  2. 2. The short-process claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation according to claim 1, wherein the sulfur-producing catalyst is one or a combination of several of natural bauxite, activated alumina and TiO 2 catalysts.
  3. 3. The short-process claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation according to claim 1, wherein the carbon-based catalyst is one or a combination of several of activated carbon, carbon nanotubes and porous graphene.
  4. 4. The short-process claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation according to claim 1, wherein the carbon-supported catalyst is one or a combination of more of activated carbon, carbon nanotubes and porous graphene, and the carbon-supported catalyst is one or a combination of more of Fe, cu, ce, al 2 O 3 、TiO 2 、SiC、MgO、MnO 2 catalyst materials.
  5. 5. The short-process claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation according to claim 1, wherein the catalytic oxidation reaction temperature range is 20-160 ℃.
  6. 6. The short-process claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation according to claim 1, wherein the organic solvent is one or a combination of benzene, acetone and carbon tetrachloride.

Description

Short-process Claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation Technical Field The invention relates to a process for purifying waste gas containing H 2 S, in particular to a short-process Claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation. Background Sulfur and hydrogen are basic elements in nature, and H 2 S gas composed of them is widely present in industrial gases such as petroleum cracking gas, natural gas, biogas, blast furnace gas, coke oven gas, converter gas, etc. H 2 S has strong toxicity and corrosiveness, can cause serious threat to human health and ecological environment, and can seriously corrode production equipment and gas conveying pipelines. With the rapid development of industry, development of high-efficiency removal technology of hydrogen sulfide is becoming an important issue of concern in the field of energy environment. The claus process, in which the waste gas containing high concentrations of H 2 S is first fed to a burner to convert about one third of the H 2 S to SO 2(H2S+O2→SO2+H2 O, is currently the most common and most classical H 2 S removal and recycling process. Then H 2 S is selectively converted into elemental sulfur (H 2S+SO2→Sx+H2 O) by a normalization reaction between H 2 S and SO 2. However, the Claus reaction is exothermic, the thermodynamic equilibrium and the sulfur recovery dew point limit, and the single-stage Claus reaction has lower conversion rate (60-70%). Therefore, practical claus processes often have multiple claus reaction converters and sulfur condensation recyclers configured, wherein H 2 S undergoes multiple reaction-condensation-reheat cycles, long process runs, and high energy consumption. In order to meet the ultra-low emission requirement, the conventional Claus process also needs to be provided with a tail gas burning and absorbing device, so that the energy consumption and the cost of the system are further increased. The low-temperature selective catalytic oxidation of H 2 S is a technology suitable for the resource conversion of low-concentration H 2 S. Unlike the claus reaction, H 2 S low-temperature catalytic oxidation (H 2S+O2→Sx+H2 O) is not limited by thermodynamic equilibrium, and in theory H 2 S can be converted into sulfur in a 100% conversion by recycling, researchers have tried to combine the H 2 S catalytic oxidation process with the claus process to efficiently convert the low concentration tail gas at the outlet of the claus reactor into sulfur. However, the present catalytic oxidation technology of H 2 S matched with the Claus process uses Fe-based materials, tiO 2 -based materials and the like as catalysts, and the materials are extremely easy to be subjected to sulfation reaction with SO 2 to be deactivated. To avoid this problem, the H 2 S catalytic oxidation technology currently applied to claus processes often needs to be combined with a high-temperature hydrogenation reduction device, and the system is complex and consumes a large amount of additional energy. Moreover, the current claus system coupled with the catalytic oxidation of H 2 S still needs to be provided with two-stage to three-stage claus conversion reactors, and the problems of long flow and high energy consumption of the current claus process are not solved. Disclosure of Invention Aiming at the problems of long flow, complex system and high energy consumption faced by the traditional Claus desulfurization and sulfur recovery process, the invention provides a short-flow Claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation, so as to simplify the flow of the traditional Claus reaction and realize the conversion of H 2 S into sulfur with low energy consumption. Compared with the traditional Claus process, the process route can realize complete removal of H 2 S in sulfur-containing waste gas and sulfur recovery only through a one-stage Claus reaction and a low-temperature catalytic oxidation reaction without a multi-stage Claus conversion reactor and multiple reheating-condensing cycles, and has the advantages of short flow, low system complexity and low energy consumption. The invention aims at realizing the following technical scheme: A short-process Claus desulfurization and sulfur recovery process coupled with low-temperature catalytic oxidation is characterized in that after passing through a first-stage Claus conversion reactor and a condenser, waste gas containing H 2 S directly enters a catalytic oxidation reactor taking carbon materials or carbon-supported metals as catalysts, and the low-concentration H 2 S is completely converted into sulfur and recovered under the low-temperature condition by utilizing the low-temperature catalytic oxidation activity of the carbon materials or the carbon-supported metals, and the process comprises the following steps: Step one, exhaust gas containing H 2 S sequentially enters a