Study On Absorption Of Carbon Dioxide Using Sterically Hindered Amine AMP (2-Amino-2-Methyl-1-Propyl Alcohol)

As the global attention of the greenhouse effect and the extensiveapplication of CO₂in many fields, how to get a more efficient and economy methodof capturing CO₂from the flue gas has been receiving a great deal of interest.Sterically hindered amine AMP （2-amino-2-methyl-1-propanol） has beenproposed as a new and promising solvent owing to the high absorbing capacity andthe low corrosion. Compared with other conventional solvents, we choose AMP asthe main absorption agent and establish absorption-resolution circulation system onthis study. To research the absorbability of the mixed solvent, AMP and a smallamount of activator have been mixed as the absorbent. The suitable activator wassifted from piperazine（PZ） and its homologues. The influence of absorptiontemperature、the content of AMP and the gas and liquid flow rate has been studied.In this paper, the pure component solution of AMP、MEA（monoethanolamine） and MDEA（N-methyldiethanolamine） have been considered toprove the superiority of the space steric hindrance effect of AMP. The experimentalresults show that the absorption affection of AMP is better than that of MEA andMDEA in the outlet concentration of CO₂、removal efficiency、absorption rate andthe CO₂capacity. AMP has both the high absorption rate of primary amine andsecondary amine and the high CO₂capacity of tertiary amine.Reaction simulated the industry cycle absorption process with a AMPaqueous solution respectively blend with PZ （piperazine） and its homologues AEP （N-ammonia ethyl piperazine）、HEPZ （hydroxyethyl piperazine） and NMPRZ （1-methylpiperazine） as activator for reaction. Compared their activation performance to theAMP, we can find that AEP shows the better activation performance. At the sametime we can find that the absorption affection which piperazine and its homologuesas activator was mainly related to the functional groups, rather than the amineconcentration relationship.The influence of absorption temperature、the content of AMP、gas andliquid flow rate has been studied respectively about a blended aqueous with AMP and a bit AEP. The result shows that the optimal concentration ratio for AMP: AEPwas6:4. The lower the absorption temperature is, the better the absorption effect.But the low temperature may influence the activation energy of the reaction,reducing the reaction rate constant. The higher parsing temperature is, the betterthe absorption effect. Increased the gas flow rate, for tail gas CO₂concentration andremoval efficiency are disadvantageous, but for the absorption rate is getting higherand higher. Increased fluid flow rate, the outlet CO₂concentration is reduced, but theremoval efficiency and absorption rate were increased.Taken AMP+AEP system as an example, the function relationship ofabsorption rate with time and solution composition was established under the cycliccapture.Comparing the influence of gas and liquid flow rate in a mixed solvent AMP+AMP to the absorption rate, it can be found that the total transfer coefficient ismainly influenced by the vapor flow rate. The absorption process was controlled bythe gas phase mass transfer resistance. The main resistance was gas mass transferresistance. Increasing gas flow rate can effectively accelerate absorption process.At the end of the paper the ternary system of AMP, AEP, MEA has beenstudied. The absorption effect of the tribasic organic solvent was better than thebinary system AMP+AEP under the same conditions. And in the case of holding molpercentage content constant of the primary absorber AMP, the higher the content ofthe MEA, the better the absorption effect of the solvent.