Claus process H2S acid gas catalytic combustion method

Abstract

The invention relates to a Claus process H2S acid gas catalytic combustion method, and belongs to the technical field of sulfur resource recovery. The catalytic combustion method comprises the following steps that firstly, H2S raw material gas and air with a certain proportion through a premixing system to realize gas mixing; then the mixed gas passes through a hexaaluminate composite oxide catalytic bed layer maintained in a specific temperature range, under the action of the catalyst, H2S is oxidized into SO2 according to the designed amount, NH3 is efficiently catalytically decomposed intoN2, and the hydrocarbon is catalytically oxidized into CO2; and the purification gas of the catalytic bed layer enters a subsequent process to generate a Claus reaction. According to the Claus processH2S acid gas catalytic combustion method, a catalytic combustion method is adopted, ignition and flame burning are not needed, the combustion temperature, the equipment investment and the operation cost can be effectively reduced, and the operation is simple and safe.

Description

technical field [0001] The present invention relates to a Claus process H 2 The invention discloses a catalytic combustion method for S acid gas, which belongs to the technical field of sulfur resource recovery. Background technique [0002] At present, the industry mainly adopts the Claus process to treat H 2 S acid gas treatment and sulfur resource recovery. The sulfur furnace is the core device of the Claus process. On the one hand, it must not only strictly ensure the H 2 S / SO 2 The molar ratio is equal to or close to 2 to ensure the smooth progress of the subsequent Claus reaction; on the other hand, it is also necessary to ensure that the impurity gas ammonia in the acid gas is completely oxidized and decomposed into N by combustion. 2 and H 2 O, and completely burn impurities such as hydrocarbons, mercaptans, and cyanide into SO 2 , CO 2 、H 2 O et al. Because these impurity gases (NH 3 and HC) can be extremely detrimental to the Claus process, especially amm...

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Problems solved by technology

Ammonia will react with various acidic components in the process gas stream to form ammonium salts, which will form various solid ammonium salt deposits at low temperature parts of the device, increasing the pressure drop of the system, and will block downstream equipment in severe cases

Moreover, ammonia can also cause an increase in the corresponding side reactions of the Claus reaction, reducing the conversion rate and recovery rate of sulfur

In the actual production process, there are also certain problems in the sulfur furnace, mainly: (1) to ensure that the NH 3 The temperature of the sulfur furnace must be maintained above 1200°C. Due to the high reaction temperature, the requirements for the material of the equipment are strict, and there are also great potential safety hazards; (2) In order to ensure the mixing degree of the gas, the combustion Ammonia burners mainly rely on imports, and the investment is high; (3) The combustion of ammonia needs to be carried out under oxygen-enriched conditions, and in order to ensure the combustion of H 2 S / SO 2 The molar ratio is equal to or close to 2, H 2 Combustion of S requires hypoxic combustion

Therefore, on the one hand, the air distribution volume of the furnace changes with the flow and composition of the two acid gases, which makes the air distribution adjustment of the sulfur furnace more complicated.

NH on the other hand 3 Combustion generates a large amount of NOx, causing NOx emissions to exceed the standard

At the same time, NOx can promote SO 2 Oxidation to SO 3 , and further react with water to generate sulfuric acid, which brings serious corrosion problems

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