有机胺催化热钾碱液吸收和解吸CO_2的研究

通过理论分析,导出了题述速率方程的近似解。该解考虑了液相中存在平行反应时,被吸收气体在各反应中的不同平衡浓度对传质推动力的影响。采用搅拌反应器,以二乙醇胺为有机胺,吸收和解吸温度分别为353K和373K,系统总压0.104MPa时得到的实验数据对该解作了验证。计算结果表明:在胺催化吸收的穿梭机理中,消耗的游离胺大部分在膜内再生。界面游离胺浓度下降所引起的传质推动力减小是影响胺催化能力的重要因素,但这下降要受界面CO_2平衡浓度的制约。加速游离胺再生能显著促进吸收。解吸中有机胺并非一定通过均相催化起作用,其机理和吸收时无明显区别。

Absorption and Desorption of CO_2 by Amine-Promoted Hot Potash Solution

The approximate solution for the rate equation of CO_2 absorption and desorption as stated in the title has been derived through theoretical analysis; the effect of different equilibrium concentrations of absorbed gas in parallel reactions on the mass transfer driving force having been taken into account. To verify the solution, an experiment was carried out in a stirred reactor with diethanolamine as the promotor at 353 K for absorption and 373 K for desorption under pressure of 0.104 MPa. It has been shown from the calculation that most of the free amine consumed in the shuttle mechanism of aminepromoted absorption is regenerated in the film. The depletion of free amine at the interface reduces the driving force, and hence decreases the absorption rate significantly; but this depletion is limited by the interface equilibrium concentration of CO_2. The absorption rate can be raised by accelerating the regeneration of free amine. The promotion by amine in desorption is not definitely put into effect via homogeneous catalysis. The mechanism of promotion in desorption is much the same as in absorption.