The physical solubilities and diffusivities of N2O and CO2 in aqueous ammonia solutions on the additions of AMP, glycerol and ethylene glycol

Abstract

Carbon dioxide (CO2) is a major greenhouse gas, the emissions of which should be reduced. There are various technologies for the effective separation of CO2. Of these, chemical absorption methods are generally accepted as the most effective. The monoethanolamine (MEA) process is an effective way to remove CO2, but is an expensive option for the separation of CO2 from massive gas-discharging plants. Therefore, ammonia solution, which is less expensive and more effective than MEA, was used for the removal of CO2. In this study, the physical solubility of N2O in (ammonia+water), (ammonia+2-amino-2-methyl-1-propanol+water), (ammonia+glycerol+water) and (ammonia+ ethylene glycol+water) was measured at 293, 303, 313, 323 K. Additive concentrations of 1, 3, and 5 wt% AMP, glycerol and ethylene glycol were added for each 9 wt% ammonia solution. A solubility apparatus was used to investigate the solubility of N2O in ammonia solutions. The diffusivity was measured with a wetted wall column absorber. The “N2O analogy” is used to estimate the solubility and diffusivity of CO2 in the aqueous ammonia solutions. OriginPro 7.5 was used to correlate the solubility and diffusivity of N2O in ammonia solutions. The parameters of the correlation were determined from the measured solubility and diffusivity.