废弃蛋壳源高性能钙基吸收剂的制备及其碳捕集性能

基于食品工业废弃蛋壳，本文利用不同有机酸反应制取乙酸钙、柠檬酸钙及葡萄糖酸钙共三种蛋壳源有机钙。在高温固定床反应器及热重分析仪上研究了不同前体所制成钙基吸收剂的碳循环捕集性能及碳酸化特性。进一步通过XRD分析了不同钙基吸收剂的物相组成，通过N₂吸附仪及SEM分析了循环前后钙基吸收剂结构特性及微观形貌的变化。结果表明，在三种蛋壳源有机钙中，葡萄糖酸钙所制成的钙基吸收剂具有较高的反应活性和相对最佳的碳捕集性能，首次碳酸化转化率高达85.33%，其钙基吸收剂相比其他吸收剂晶粒更小，20~100nm孔径范围内的孔隙较为发达，具有相对较强的抗烧结能力。经过20次循环实验发现，随着循环次数的增加，几种钙基吸收剂小颗粒均团聚烧结成大颗粒，造成孔隙结构缺失，孔隙率降低，影响其后续碳捕集性能。

Preparation of the calcium based adsorbent derived from egg shell waste and its CO2 capture performance in the calcium looping

Based on the eggshell waste discarded in the food industry, three kinds of organic calcium adsorbents, including calcium acetate, calcium citrate and calcium gluconate, were prepared using the corresponding organic acids. Their cyclic CO₂ capture performance and carbonation characteristics were studied on a tailored dual temperature tubular reactor and thermogravimetric analyzer, respectively. Furthermore, variation of the crystalline phases, structural characteristic and microscopic morphology of the prepared CaO adsorbents over the cyclic CO₂ capture process were analyzed. The results indicated that the CaO adsorbent derived from calcium gluconate owned highest reactivity and the most pronounced CO₂ capture performance with the first carbonation conversion reaching as high as 85.33%, but it also had smaller crystalline grains of CaO than other absorbents with more developed pores within 20—100nm. After the twenty CO₂ capture cycles, the neighboring CaO particles involved were found to melt and agglomerate into larger particles, which resulted in loss of the pore structure and reduced porosity, and thereby its carbon capture performance decayed.