CO₂ Absorption And Desorption Performance Of BZA-DEEA/DMEA/1DMA2P/AMP Binary Blended Amines

The widely use of fossil fuel results in the increasingly improved CO₂ emission year by year and a series of environmental issues,which create and develop the CO₂Capture and Storage?CCS?technology.At present,CO₂ chemical absorption with aqueous amine is the most mature process of CCS.MEA,as absorbent in industry,is reacted with waste gas containing CO₂.Gas-liquid equilibrium is reached under filling waste gas,and then CO₂ stripping and solvent regeneration are achieved by elevating temperature.Although,there are some commercial cases for aqueous amine solution CO₂ absorption,issues still exist,such as volatility of solvent,high regeneration energy,formation precipitate and blockage pipe et al.Therefore,it is positive for reducing energy and Greenhouse effect to update and reform aqueous amine CO₂ absorption.The research of new and alternative amine is hot topics due to its diversity,economic feasibility and industrial implemental and so on.Multi-phase system is obtained more attention for its high mass transfer,low regeneration energy and synergistic effect.The CO₂ absorption-desorption performance of BZA based blended amines was studied.Three sections were mentioned following:Section one:The availability of substituting MEA with BZA was highly discussed in this section.The difference between BZA and MEA on overall CO₂ mass transfer constant K_G,enthalpy of protonation,corrosion performance and heat of absorption was discussed.Meanwhile,Absorption performance and regeneration efficiency of BZA and conventional amines?MEA,DEA,AMP and MDEA?were compared.It was found that the mass absorption performance of BZA was like that of MEA and the regeneration capacity of BZA was comparable to MDEA.Namely,BZA possessed the potentials and availability to substitute MEA.Section two:The CO₂ absorption paraments of blended solutions mixed BZA with three tertiary amines?DEEA,DMEA and 1DMA2P?were explored in this experiment.Absorption rate,equilibrium solubility,cyclic capacity and regeneration consumption of BZA-tertiary blended amine solutions were measured by detecting CO₂concentration change with gas-phase technology.It was found that,compared to 6M MEA,3M BZA-3M tertiary amine blended system showed significant increase on regeneration performance and heat utilization.BZA-DEEA and BZA-1DMA2P showed almost same absorption rate with 6M MEA.BZA-1DMA2P possessed highest cyclic capacity,lowest sensible heat and lowest heat duty.Heat duty of BZA-1DMA2P is 44.7%of that of MEA.It was innovative to propose desorption parament DP for rapidly evaluating the heat duty of similar amine.The order of tested system was BZA-1DMA2P?1.351[?mol CO₂?²/?min?L?]?>BZA-DEEA?0.400[?mol CO₂?²/?min?L?]?>BZA-DMEA?0.340[?mol CO₂?²/?min?L?]?>MEA?0.081[?mol CO₂?²/?min?L?]?.High DP means low heat duty and regeneration energy.Section three:The precipitate condition of BZA and AMP binary-amines is chiefly studied for its CO₂ absorption process.It was found that ivory-white precipitate appeared in BZA-AMP-H2O solution at high CO2 loading but not in BZA-AMP-ethanol solution,considering different solvent and flow rate.Equilibrium solubility of BZA+AMP-ethanol solution is lower than that of BZA-AMP-H₂O solution due to the high volatility of ethanol solvent.The influence of total intake flow rate on the equilibrium solubility of BZA-AMP-ethanol solution is not significant.