规整填料内乙醇胺吸收CO2的计算流体力学模拟

为模拟规整填料单元内乙醇胺吸收烟气二氧化碳的过程,利用计算流体力学(CFD),考虑包含化学反应气液质量传递过程,建立伴有二级化学反应的气液两相流动模型.通过改变吸收过程的操作条件,如气液入口流量比、CO_2入口质量分数、乙醇胺入口摩尔分数、压强等,分析吸收塔规整填料单元内碳捕捉过程的影响因素.CFD模拟结果表明:CO_2吸收率随乙醇胺浓度与压强的增大而升高;随烟气CO_2浓度与气液流量比的增大而下降;对各影响因素影响定量排序,乙醇胺浓度对吸收效率影响最突出,其次依次是CO_2入口浓度、气液入口流量比、压强.模拟与试验结果相吻合,得出了相应的最优参数.

CFD simulation of carbon dioxide in flue gas with monoethanolamine in structured packing

The method of computational fluid dynamics (CFD) containing reactive mass transfer is adopted to simulate the process of carbon dioxide capture from flue gases with MEA in structured packing. The simulation of complex flows with second order reaction of CO₂ with MEA is built in representative elementary units (REU) of structured packed column. Various operating conditions including ratio of gas inlet flow to liquid inlet flow, CO₂ inlet mass fraction, MEA mole fraction and pressure on CO₂ capture process are examined. The absorption efficiency increases with the addition of MEA concentration and operating pressure, but decreases with CO₂ concentration and gas-liquid flow ratio. The influences of different factors on the absorption are ordered as MEA mole fraction, CO₂ mass fraction, ratio of gas inlet flow to liquid inlet flow and pressure. The CFD results of CO₂ absorption rate at different operating parameters are consistent with the reported ones, and the optimal parameters are got.