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Mixed Alkanolamine‐Polyethylenimine Functionalized Silica for CO 2 capture
Author(s) -
Fan Yanfang,
Rezaei Fateme,
Yang Xiaomei
Publication year - 2019
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201800481
Subject(s) - adsorption , amine gas treating , polyethylenimine , mesoporous silica , chemistry , diethanolamine , alkanolamine , flue gas , desorption , mesoporous material , nuclear chemistry , selectivity , inorganic chemistry , organic chemistry , catalysis , aqueous solution , transfection , biochemistry , gene
High amine efficiency amine‐modified silica adsorbents with fast adsorption rates have been developed by adding amine species including hydroxyl groups into polyethyleneimine (PEI)‐loaded mesoporous silica for CO 2 capture. Two amine species of diethanolamine (DEA) and 3‐amino‐1,2‐propanediol (AP) including hydroxyl groups were introduced into PEI to reduce the CO 2 diffusion resistance and increase the active CO 2 adsorption sites. The DEA promoted adsorbents were found to exhibit much higher adsorption capacity than AP promoted adsorbents. Through tuning the ratio of PEI to DEA in amine mixture during adsorbent impregnation step, a threshold value of PEI/DEA weight ratio (∼50 : 50) was found, where the maximum CO 2 capacity of 2.93 mmol/g was achieved under dry CO 2 at 35 °C.The adsorption capacity for this newly synthesized adsorbent increased by 50 % in comparison to PEI‐silica materials. Their amine efficiency was 0.40 mol CO 2 /mol N, which was more than twice than that of PEI‐silica (0.17 mol CO 2 /mol N). Under simulated humid flue gas conditions, the DEA promoted adsorbents had a CO 2 breakthrough capacity q b of 1.57 mmol/g and a CO 2 capacity q 50 of 2.49 mmol/g. Such adsorbents possess good reversibility and the adsorption capacity is nearly stable after two adsorption‐desorption cycles. The synthesis methodology reported in this investigation proves to be an efficient strategy to develop highly efficient amine‐impregnated adsorbents.