| Global climate change is becoming more and more serious, and it has become oneof the main factors threatening the sustainable development of human being. Emissionreduction of greenhouse gases especially for the CO2from coal-fired power plant isbecoming the international focus of concern. Organic amine chemical absorption forCO2capture from flue gas CO2is one of the most effective methods at home and abroad,and a number of demonstration projects have been built up. But the shortcoming ofalcohol amine solvent absorption according to the current absorption performance isinstability, low absorption rate, low absorption capacity, and low regeneration rate, thehigh regeneration temperature, and high corrosion rate. Besides, there is not forming amature research system for the kinetic study of composite solvent, which has becomethe bottleneck for the development of CO2chemical absorption.Using N2and CO2mixed gas as simulated flue gas, three kinds of organic aminesolution of ethanolamine (MEA), two ethanol (DEA), triethanolamine (TEA) by theuse of stirred tank test device of has been evaluated, and MEA was selected as the best.Furthermore, the activator piperazine (PZ), N-methyl piperazine (N-MPP) andaminoethyl piperazine (AEP) were screened, and the research showed that amino ethylpiperazine has the best comprehensive performance. The ratio monoethanolamineamine and amino ethyl piperazine was optimized through comprehensive comparisonof absorption capacity, absorption rate, reaction temperature, the amount ofregeneration and regeneration rate. The result showed that12%MEA+8%AEPaqueous solution as the best MEA-AEP diamine system formulation solvent. Then, thecorrosion inhibitor, antioxidant was studied, and the results showed that the500mg/LCI-03(inhibitor), the mass fraction of0.1%AOD-01(antioxidant) as the goodcomposite ratio.Based on the research of solvent, mass transfer kinetics of MEA+AEP dual aminesystem was studied by the application of disc column experiment. The factors(temperature, pressure, gas composition, concentration, solvent flow rate, absorptiontime), which affecting the performance of mass transfer for CO2absorption anddesorption process were studied in the experiment, and the double amine system absorption mass transfer kinetics parameters of CO2(diffusion coefficient, the Henry coefficient, density, viscosity) was measured accurately. The results were compared with the literature data, and could provide data support for the following establishment and verification of dynamic model.Based on the research of the pilot test (disc tower test), continuous simulation on MEA-AEP dual amine system with the capacity of lONm3/h flue gas was studied. Continuous absorption kinetics of mass transfer performance of CO2for complex solvent MEA-AEP and MEA were evaluated and examined by simulating actual production. The effects of the lean liquid load, rich liquid load, flue gas flow rate, concentration of the absorption liquid, gas-liquid ratio, CO2concentration in flue gas, the absorption temperature, the regeneration temperature, regeneration heat load and other parameters on the capture rate and regeneration performance of the solution of MEA-AEP were discussed by compared with the pure MEA solution, and screen the optimized parameters. When absorption temperature was40℃, concentration of solvent was3mol/L, liquid gas ratio was10L/m3, regeneration temperature was105℃, the regeneration effect of MEA-AEP compound solution can achieve the best condition, which CO2in the flue gas basic are almost removed with the capture rate≥90%, lean liquid load of αCO2<0.1L/LPilot test was conducted on the100t/d CO2capture and purification pilot plant equipment to expend the model experiment. Results of the trial indicated that compared with the conventional MEA solvent, the new MEA-AEP solvent could reduce the steam energy consumption by29%.Mass transfer kinetics of the absorbing CO2system by double amine was based the lab experiment, model experiment and pilot test. Based on the zwitter-ion reaction mechanism and the reaction model, the model of mass transfer kinetics of the CO2+B(liquid1)+C(liquid1)→products system is established:Then the model of mass transfer kinetics of the MEA-AEP solution absorbing CO2system is established:The model of MEA-AEP absorption rate is analyzed with parameters solving, then the overall rate constant is: The apparent rate constant is:The accuracy of MEA-AEP mass transfer kinetics model is verified by the lab experiment, simulation experiment and pilot test. Results of the trial indicated that the model fit the data of experiment very well. |
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