Solubility of CO2 in aqueous solutions of DAMP+MDEA, DAMP+MEA, DAH+MDEA and DAH+MEA

The main goal of this research is to investigate absorption rate and capacity of carbon dioxide in aqueous mixtures of DAMP(1,5-Diamino-2-methylpentane)+MDEA(Methyl-diethanolamine), DAMP+MEA(Monoethanolamine), DAH(1,6-Diaminohexane)+MDEA and DAH+MEA in an isothermal stirred batch reactor. The experiments are designed in temperature ranging from 30 to 50 °C, at low pressure and various molar ratios. The results show that although there is an interaction between diamine and conventional amines at low diamine concentration, after a minimum absorption point, increasing DAMP and DAH concentration in conventional amines increases absorption capacity of solutions in all temperatures. Then, a rate equation is developed to predict absorption rate of aqueous solution of DAMP based on Zwitterion mechanism. The kinetic constant and order of reaction are determined considering the absolute difference between measured and predicted rate as the objective function. The results show that the reaction is first order with respect to amine concentration and third order in overall.