Simulation Study On Removal Of Hydrogen Sulfide From Coke-oven Gas By Ionic Liquid

The efficient use of coke-oven gas has aroused lots attention with the rapid development of the coking industry and the strict implementation of national environmental protection policies recently.The crude gas coming out of the coke oven contains hydrogen sulfide impurities,which not only corrode pipes and equipment,but also poison the downstream catalyst.Therefore,the efficient removal of hydrogen sulfide from coke-oven gas is significant in the industrial process.Desulfurization method commonly used in the industry nowadays,the alkanolamine method,has problems such as high solvent loss,high energy consumption,and difficulty in treating the waste liquid of the desulfurization.Therefore,it is very important to find a new type of efficient green-friendly desulfurizer to improve the traditional desulfurization process.Ionic liquid,known as the new "green solvent",has the advantages of extremely low vapor pressure,good thermal stability,wide liquid temperature range and designable structure,which can selectively separate and absorb gases.To investigate the application prospects of ionic liquids in the removal of H2S gas from coke-oven gas,this paper designed a new process for removing hydrogen sulfide from coke-oven gas by ionic liquid based on Apsen Plus software followed by the simulation and optimizition.The methyldiethanolamine(MDEA)process desulfurization process was for comparison.This project used Apsen Plus software to establish the process of removing H2S from coke-oven gas,and the optimal operating parameters were simulated and optimized.With the optimal operating conditions and the desulfurization rate reaching 99.80%,the total heat energy was 19721 kW and the total electrical energy consumption was 2.8414 kW.In addition,the ionic liquid 1-butyl-3-methyl-imidazolium acetate([Bmim]Ac)was selected as the absorbent,and the new process of the removal of H2S from coke-oven gas by[Bmim]Ac was designed in Aspen Plus to simulate and optimize for the best operating parameters.With the optimal operating conditions and the desulfurization rate reaching 98.78%,the total heat energy was 7600.6 kW and the total electrical energy consumption was 26.91kW.After comparing the two processes,on the basis that the removal rate of both processes reached more than 98%,the specific energy consumption of MDEA process was 43.80 GJ/tH2S,and the specific energy consumption of[Bmim]Ac process was 17.30 GJ/tH2S.From the results,the[Bmim]Ac absorption process had lower energy consumption and savesd 61.02%.Therefore,ionic liquid has great industrial application prospects in the removal of H2S from coke-oven gas.