Abstract: the use of organic sulfur in temperature organic sulfur hydrolysis catalyst removal transformation gas at room temperature, does not need the mild hydrolysis desulfurization temperature, hydrolysis of H2S under variable and removing, simple process, low cost of desulfurization, good protective effect on decarbonization anddesulfurization up.
Keywords: temperature hydrolysis desulfurization
1 Introduction
At present, the water gas for more raw material for the synthesis of methanol and other chemical products enterprises, due to the higher concentration of CO,transform depth is low, high content of organic sulfur, organic sulfur removalgenerally encountered difficult problems, especially with higher concentration ofCO2 raw materials, conversion absorption desulfurizer used cycle greatly reduced,normal temperature the hydrolysis process of complex, organic sulfur removalprocess selection is a problem worthy of attention.
Kenli County chemical fertilizer plant is a methanol as the leading products, the main raw material for oil and gas, in order to expand the scale of production, make full use of oil field gas hydrogen group excess transforming gas, reduce production costs, improve the competitiveness of enterprises in the market, the original coal gas system incorporated into the methanol production system at present, the scale of production has reached 60000 tons / year. But more and organic sulfur removalproblem is more significant, directly affects the stable operation of production.
2 the desulfurization condition
Fig. 2.1 schematic process
Coal gas, desulfurization, sulfur tolerant of partial transformation to transform gas desulfurization and decarbonization (wet) (PC), fine desulfurization, low-pressure methanol synthesis
Oil gas, desulfurization, conversion, fine desulfurization agent, low pressure synthesis.
Water gas wet desulfurization by tannin extract and transform gas heat to transformfurnace, the gas by sulfur tolerant shift, by controlling the transformation rateregulating water vapor content, steam / gas about 0.2, transform the bed layer temperature 350-380 ℃, gas desulphurization catalyst 888 soda ash anddesulfurization, removal of carbon with propylene carbonate method. Anothersource for natural gas, first by the coarse iron desulfurization, then steamconversion and desulfurization, two kinds of raw materials in the compressorsection with 4 entrance, compressed into methanol synthesis.
2.2 before the rectification sulfide distribution see Table 1
Table 1 the rectification of sulfide distribution (unit: mg/m3)
The sampling site H2S COS CS2
After wet desulfurization 7 62.9 2.50
After the transformation of 10.1 58.5 1.15
Get off after 5 57.7-
Decarburization - 0.12-
Gas conversion 1.74 0.10-
Fine desulfurization before 0.10 0.23 0.11
Fine desulfurization after 0.08 - 0.22
From the above analysis results can be seen: the removal effect of H2S wet desulfurization is good, but the transformation of the catalyst for conversion oforganic sulfur is not ideal, according to shift catalyst operation, the transformfunction is good. If the transformation of catalyst on the conversion of organic sulfurmainly in the following two kinds of mechanism: 1:
Hydrolysis of COS+H2O (steam) =CO2+H2S
CS2+2H2O (steam) =CO2+2H2S
Hydrogenation of COS+H2=CO+H2S
CS2+4H2=CH4+2H2S
And by hydrolysis, and hydrolysis is an exothermic reaction, high temperature and the equilibrium conversion rate is low, and the system of gas steam is relatively low,the reaction temperature is higher.