Coconut Shell Activated Carbon Supported Quaternary Ammonium for Continuous Cycloaddition of CO2 and Biogas Upgrading in a Packed Bed

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• 作者：Yilu Zhang ; Yulian Zhang ; Lei Wang ; Hong Jiang ; Chunrong Xiong
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2015
• 出版时间：June 10, 2015
• 年：2015
• 卷：54
• 期：22
• 页码：5894-5900
• 全文大小：358K
• ISSN：1520-5045

文摘

Quaternary ammonium was successfully prepared on coconut shell activated carbon (CSAC) granules. The samples were characterized by FT-IR, N₂ adsorption鈥揹esorption, XPS, TG, and EA. The immobilized quaternary ammonium was thermally stable below 320 掳C. The amount of immobilized quaternary ammonium on the CSAC was 0.957 mmol/g. Continuous cycloaddition of CO₂ to epichlorohydrin (ECH) was carried out in a packed-bed reactor without using solvent or cocatalyst. When the reaction conditions were 130 掳C and 1.4 MPa, the conversion of ECH and the corresponding turnover frequency (TOF) were 43.5% and 64.6 h^鈥?, respectively. The selectivity to epichlorohydrin carbonate (ECHC) reached 鈭?00%. In biogas upgrading, grafting of quaternary ammonium was demonstrated to enhance CO₂ capture capacity of the CSAC. The saturated CO₂ capture capacities of the CSAC and the quaternary ammonium functionalized CSAC were 1.82 and 2.40 mmol/g at 20 掳C and 0.5 MPa, respectively. The adsorption selectivities of CO₂ over CH₄ were 鈭?7% and 85% for the CSAC and the supported quaternary ammonium, respectively. The adsorption heat was 20鈥?0 kJ/mol for the adsorbents. The supported quaternary ammonium also exhibited a relatively stable cyclability in a packed bed.