On Macro Parameters of CO2 Capture by Ammonia Method

An novel technology of CO₂ capture from coal-fired flue gas is Ammonia chemical adsorption method. Experimental system of CO₂ adsorption by ammonia water is established on the base of a bubble column reactor in this paper. Effects of key parameters on CO₂ adsorption process, such as ammonia water concentrations, PH values of solutions, C/N molar ratios, amounts of water brought by gas, are studied through the system. From the analysis of experimental results, it indicates that, utilization rate of high concentration ammonia water is low, and escape rate is high, but CO₂ removal efficiency is high. On the other hand, utilization rate of low concentration ammonia water is high, and escape rate is low, but CO₂ removal efficiency is low. In CO₂ capture process, the PH of solution decreases dramatically. When the reaction solution invalids, PH values of different solutions are close to 8.7. When the absorbent PH is lower than 8.7, it has no capacity to absorb CO₂. The mass ratio of carbon capture capacity by ammonia method is much higher than that by MEA, and the mass ratio of carbon capture capacity by low concentration ammonia water is higher.