Simulation of Carbon Dioxide Capture from Small Power Plant Flue Gas by Adsorption

• Main Authors: Yen-hsiang Wang, 王彥翔
• Other Authors: Cheng-tung Chou
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/62604317969711581689

碩士 === 國立中央大學 === 化學工程與材料工程學系 === 102 === In this simulation study, there are two adsorption process, one-bed four-step temperature swing adsorption (TSA) and one-bed three-step pressure swing adsorption (PSA) which are utilized to separate CO2 and N2 from small size power plant flue gas(15.03% CO2, 84.97% N2) with solid polyaniline sorbent. The adsorption capacity of sorbent was measured by the Micro-Balance Thermo D-200 to obtain adsorption equilibrium data of CO2, CO2 is the only adsorbate. Then Langmuir-Freundlich isotherm model is used to establish the equilibrium isotherms by regression. After the isotherm regression, the verification of breakthrough curves are implemented to determine mass transfer coefficient, . After the process operation variables discussion, the optimal conditions are obtained to concentrate CO2 above 90% purity for storage to reduce the emission of green-house-gases. The method of lines is utilized, combined with upwind differences, cubic spline approximation and LSODE of ODEPACK software to solve the problem. The concentration, temperature, and adsorption quantity in the bed are integrated with respect to time by LSODE of ODEPACK software. The simulation is stopped when the system reaches a cyclic steady state. After the variables discussion, the best process is one-bed three-step PSA process with nitrogen purge and the best operating condition is feed pressure 4.0 atm, co-current depressurization pressure 1.0 atm, vacuum pressure 0.1 atm, bed length 550 cm and step time at 400, 30 and 450 s. The results of the best operating condition are 91.77% purity and 91.08% recovery of CO2 with an energy consumption of 1.04 GJ/tonCO2 at adiabatic compression and expansion conditions.