Comparison of ammonia and monoethanolamine solvents to reduce CO2 greenhouse gas emissions

This paper presents experimental results on the evaluation of two reagents, ammonia (NH3) and monoethanolamine (MEA) solvents, for scrubbing carbon dioxide (CO2) greenhouse gas emissions. The scrubbing of CO2 by NH3 solvent is a novel study developed by the authors, and the MEA process is a traditional process for gas purification of removing CO2. The performance of these two solvents are compared in terms of CO2 removal efficiency and absorption capacity. Test results show that both the CO2 removal efficiency and absorption capacity of NH3 solvent are better than those of MEA solvent under the operating conditions conducted in this study. The maximum CO2 removal efficiency by NH3 solvent can achieve 99% and the CO2 absorption capacity can approach 1.20 kg CO2/kg NH3. On the other hand, the maximum CO2 removal efficiency and absorption capacity by MEA solvent are 94% and 0.40 kg CO2/kg MEA, respectively, under the same operating conditions tested by NH3 solvent. Besides, the temperature increases due to exothermal reactions in the NH3 scrubbing process are lower than those in the MEA scrubbing process. This indicates that the energy requirement for the regeneration of NH3 reagent should be less than that for the regeneration of MEA reagent.