Study On Performance Of Amino Modified Mesoporous Materials For CO₂ Adsorption

In recent years,the emissions of greenhouse gas is too high.Greenhouse effect caused by greenhouse gas emissions has seriously affected the ecological stability of nature.For its large amount of CO₂ emission,the CO₂ capture and utilization in coal-fired power plant tail gas has become focal point of greenhouse gas emission reduction research at present.In existing CO₂ capture methods for plant,the adsorption method with a large number of advantage has widespread application prospects in industry,such as the simple and cheap process,the easily filled and replaced way,and the less damage to the equipment,This paper focused on the synthesis of a kind of cheap,environment-friendly,high CO₂ adsorption adsorbent in the exhaust gas of power plant,.On the basis of reducing the amount of CO₂ emissions,the recovery cost can be reduced.Using ordered mesoporous alumina（referred to as OMA）and SBA-15 as adsorbent carrier,2-amino-2-methyl-1-alcohol（referred to as AMP）and polyethyleneimine（referred to as PEI）as modifier,amino modification of the two carriers was carried out in this thesis.The physical properties such as the morphology,structure of the original adsorbent and the modified adsorbent were characterized by nitrogen isothermal adsorption desorption instrument,X-ray diffraction,transmission electron microscope and other instruments.The influence of modification time,bed temperature,gas flow rate and modified concentration on the adsorption properties were discussed by the simulated flue gas adsorption equipment.The OMA synthesized by precipitation method with cheap inorganic aluminum source has high surface area,uniform pore size distribution and worm hole channel motifs.After amino modification,the structure of absorbent has no chang.The adsorption capacity of OMA modified by amino group was proved to be significantly improved.Under the operating conditions with the temperature of 80℃,the gas flow rate of50ml/min,AMP of the load concentration of 70%,the saturated adsorption capacity of modified OMA was 96.92 mg/g_AMP-OMA.Meanwhile,the saturated adsorption capacity of modified OMA was 90.64 mg/g_PEI-OMA.at the temperature of 60℃,the gas flow rate of50ml/min,PEI of the load concentration of 60%.Silicon based mesoporous material SBA-15 has super high specific surface area,regular pore structure,homogeneous pore size,and regular six square channel.The results showed that the amino modified AMP-SBA-15 and PEI-SBA-15 compared with before modification,the structure properties of materials were basically unchanged.The adsorption ability of amino modified AMP-SBA-15 and PEI-SBA-15 was the best respectively at the temperature of 60℃,the load concentration of 70%,the gas flow rate of 50ml/min,and the temperature of 50℃,the load concentration of 70%,the gas flow rate of 50ml/min.The best adsorption capacity were 151.51 mg/g_AMP-SBA-15 and173.14mg/gPEI-SBA-15.Repreparation of the modified adsorbent in suitable conditions after 8 times,the adsorption abilitywas stable.The good regeneration performance shows that the modified adsorbent could be used to meet the industrialized requirements.