Development Of Carbon Capture Phase Change Absorbent And Impurity Removal Technology In Coal-fired Flue Gas

China's coal dominated energy system has introduced sever air pollution and CO2 release.The frequency of extreme weather has increased,as well as the heave smog phenomena.On the basis of limiting coal consumption and promoting renewable energy,the implement of low CO2 emission is the strategic choice of the sustainable development.Exaust fuel gas consists of PM2.5,SO2 and CO2,and each component influnces others during the emission reduction process.Therefore,three techniques of dust elimination,desulphurization and decarbonization are applied to remove PM2.5,SO2 and CO2 respectively.This thesis studies the process enhancement of dust elimination,desulphurization and carbon capture in three chapters,in order to reduce the energy consumption and combustion pollution.The innovative PTFE membrane is capable to remove 99.9%fine particle(PM2.5)produced by coal combustion.However,the filteration process consumes considerable energy.The first chapter focuses on reduce the filtration cake resistance in order to reduce the energy cost.According to the the capillary condensation,liquid bridge force was introduced to the fine particular system by controlling the ambient humidity.The loose cake structure,which facilitas the filtration process,was achieved by tuning the liquid bridges.The experimental results have shown that PTFE membrane filter removed nearly 99.99%particles in highly humid environment.Moreover,the hydrophobicity of PTFE membrane surface,the increasement of humidity does not affect the filtration resistance.The ambient humidity has increased from 32.5%to 100%,which leads to cake voidage increasment from 69.8%to 92%.The ultra loose cake structure has significantly enhanced the dust removal capacity from 489g/(m2·kPa)in the dry condition to 2401g/(m2·kPa),indicating the filtration resisense has reduced by 90%per dust load.The third chapter focuses on carbon capture.Based on the salting-out and cosolvent effect,monoamine+1-propanol/dioxane/1-butanol+water phase change absorbent was designed.The polyamine+1-butanol/dioxane+water phase change absorbent was developed for the further investigation,especially DETA+dioxane+water phase change absorbent.For the phase change absorbent composed of DETA+dioxane+water,the volume ratio of the upper and lower liquid phases and the amount of CO2 cycling capacity were measured.When the DETA+dioxane+water ratio is 3:5:2,the lower liquid phase volume reach the smallest,the rich liquid CO2 loading and the cyclic capacity reach the largest,and the rich liquid CO2 loading and CO2 cyclic capacity are 6.11 mol/kg and 2.30 mol/kg,respectively.The CO2 cyclic capacity increased by 83.53%compared to 30%DETA.To summarize,PM2.5 capture,desulphurization and decarbonization were studied by utilizing innovative methods.PM2.5 removal was enhaced by using liquid bridge,while SO2 and CO2 removel were developed by using innovative phase change absorbent.All these experiments combined with modeling work shed lights on the future low CO2 emission technology.