| In China's primary energy consumption structure, the proportion of coal is close to 70%, which is the main source of energy in the future for a long period in China. However, the traditional coal utilization (combustion, coke, oil etc.) has many problems, such aslow utiliztion ratio, pollutant emissions and other issues.To achieve coal utilization efficient, clean, coal gasification technology are widely concerned. Hydrogen, as an energy carrier, is widely believed to have an important impact on the future of the world's energy economy. The use of hydrogen can effectively reduce greenhouse gas emissions, enhance energy supply and economic competitiveness. Traditional industrial hydrogen is made from raw materials such as oil, natural gas, and water. Combined with the energy structure characteristics of China, developing coal as the feedstock for hydrogen production match the requirements of China's development. And the integrated coal gasification hydrogen production system combined with the technology of coal gasification hydrogen production and heat recovery steam power generation technology, with the characteristics of clean, efficient utilization, is an effective way of coal hydrogen. CO2 emissions caused the greenhouse effect are paid more and more people's attention, researchers from all over the world have put forward many CO2 capture schemes, like post combustion capture, oxygen enriched combustion capture set and combustion of trapping three schemes.Combining with literature information, according to the different hydrogen and CC^capture method, namely traditional water gas conversion reaction with MDEA solution absorbing CO2 process (production technology); Cao adsorption of CO2 enhanced gas conversion process for hydrogen production (production technology) and Fe oxy-carrier circulating water vapor hydrogenation process of CO production process reduction established three gas of hydrogen-electric coupled cogeneration of CO2 capture sequestration process. Three processes were simulated by Plus Aspen, a large-scale process simulation software.The results show that the traditional water gas shift reaction of the resultant gas dehydration and CO2 content of 41.4%%, by MDEA solution absorption and drying, hydrogen content in the product was 94.8%; the H2 content in the co-production process from product gas was 99.1% and caught in CO2 gas, CO2 concentration of 99.4%; production process for the third of product gas in hydrogen concentration up to 99.99%, close to 100%, the trapping CO2 gas concentration was 98.70%. From the point of view of energy analysis available, integrated gasification hydrogen electric coupled cogeneration process for CO2 and process three respectively in terms of efficiency of hydrogen higher process 8.51% and 15.01; in terms of overall electrical efficiency were higher than 5.27% and 2.93%; in the net electrical efficiency respectively 5.17% and 4.45%, making in total system efficiency, cogeneration technology second higher 13.68% process and production process for three out of a process of 19.46%. Cogeneration technology three only in the overall electrical efficiency and net electrical efficiency were slightly lower than the production technology of 2.34% and 0.72%, but in hydrogen efficiency and total efficiency of the system, the advantages of the three cogeneration technology was, respectively, higher than the craft to 6.5% and 5.78%. From the perspective of carbon capture rate, carbon capture technology production rate was 99.95%, slightly lower than the three co production of 99.99% carbon capture rate. On integrated gasification hydrogen electricity cogeneration process three parameter optimization analysis, it is concluded that with the O/C increases from 0.5 to 0.7, the increase of the content of H2, and CO2, CO and H2O concentration decreased; when the O/C from 0.7 to 0.9, decreasing the H2 content of syngas, and increase the concentration of CO2 and H2O; when the O/C is equal to 0.8, the efficiency of hydrogen, net electrical efficiency and total efficiency reached the maximum. With the increase of S/C, H2, H2O and CO2 content showed increasing trend, and reduce the CO concentration; cold gas efficiency and hydrogen yield are not sensitive to the change of S/C; with the increase of S/C, hydrogen efficiency remains almost unchanged, while net electrical efficiency is slightly lower, but the efficiency of the whole system was to decrease.Through of exergy loss analysis can be drawn, in the process of the largest exergy destruction units in the processareFe-based cycle procss and gasifier, the exergy destruction of the two units add up to accounting for 65.37% of exergy loss of the whole system. Fe based cycle process includes the thermal transfer process and gas-solid reactions, resulting in a destruction of exergy. Solid fuel gasification furnace into synthetic gas will inevitably cause energy loss. Due to heat transfer, phase change and other reasons, the exergy of CASU, condenser, cooling unit and synthesis gas waste heat boiler energy loss arealso higher than other units. |
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