Simulation And Experimental Research Of CO₂Chemical Absorption System

Global warming caused by the greenhouse gas is becoming more and more dangerous to the survival of human beings. The researchers begin to focus on the control of CO2emission, which is the main greenhouse gas. The chemical absorption method is one of the most important and mature technologies in CO2emission control, though there are still some disadvantages in this technology. The thesis uses Aspen Plus to focus on three aspects:the simulation of the CO2chemical absorption system and the ammonia abatement system; the comparison of absorption and regeneration characteristics between ammonia and MEA; the simulation and optimization of novel CO2direct steam stripping process based on the experimental results.Through the simulation of CO2absorption system in300MW coal power plant and the ammonia abatement system, it can find the effect of lean solvent’s CO2loading, flow, temperature and the packing height in the CO2absorption process; the effect of rich solvent’s temperature, boilup ratio, pressure and cooler temperature in the regeneration process; the effect of solvent concentration, temperature, pressure in the ammonia abatement system.Compare the absorption and regeneration characters of the7wt%ammonia solvent and the30wt%MEA solvent. The results show the MEA solvent has a higher absorption rate,but lower absorption ability than ammonia.The average temperature profile of MEA in the absorption and regeneration column is higher than the ammonia solvent. Compare the reboiler heat,the cooler temperature and the pressure between the ammonia and MEA in the stripper. At last, calculate and compare the diffirence of regenerationenergy between the two solvents.It isstudied the impacts of the steam flow rate, the steam superheated temperature, the preheat temperature of the rich solvent, the column pressure and the packing type via experimental and modeling approaches in the CO2direct stream stripping. The results show that the stream flow rate and temperature of rich stream havenoticeableeffection on the CO2regeneration rate, while superheat temperature of the steam has little effection. The impact of column pressure to the CO2regeneration rate has some relationship with the steam flow rate. CY has the best CO2regeneration performance among MellaPak,Mellapak plus,SuperPak,CY,IMTP. Additionally, this system can reduce regeneration energy to3MJ/kg CO2or even lower in optimization conditions when compared with the traditional system.