CIESC Journal ›› 2015, Vol. 66 ›› Issue (2): 612-617.DOI: 10.11949/j.issn.0438-1157.20141071

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Effect of Ce, Zr on cyclic performance of CaO-based CO2 sorbents

ZHANG Lei1,2, ZHANG Li1,2, YAN Yunfei1,2, YANG Zhongqing1,2, GUO Mingnü1   

  1. 1 Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China;
    2 School of Power Engineering, Chongqing University, Chongqing 400044, China
  • Received:2014-07-16 Revised:2014-09-28 Online:2015-02-05 Published:2015-02-05
  • Supported by:

    supported by the Fundamental Research Funds for the Central Universities (CDJZR12140034), the Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education of PRC, the Fund for Visiting Scholars (LLEUTS-201301).

掺杂Ce、Zr对CO2钙基吸附剂循环特性的影响

张雷1,2, 张力1,2, 闫云飞1,2, 杨仲卿1,2, 郭名女1   

  1. 1 低品位能源利用技术及系统教育部重点实验室(重庆大学), 重庆 400044;
    2 重庆大学动力工程学院, 重庆 400044
  • 通讯作者: 张力
  • 基金资助:

    中央高校基本科研业务费专项资金(CDJZR12140034);低品位能源利用技术及系统教育部重点实验室访问学者基金项目(LLEUTS-201301)。

Abstract:

CaO-based sorbents with Ce and Zr as dopants were prepared by the method of wet mixing and subsequent calcination. The cyclic CO2 sorption/desorption performance of 24 sorbents was tested with thermogravimetric analyzer (TGA). CeO2 could increase CO2 sorption rate in the diffusion-controlled regime because the large quantity of oxygen vacancies in CeO2 could facilitate CO2 diffusion through the produced CaCO3 layer and then react with the uncreated CaO. Dispersion of CeO2 on CaO could also inhibit agglomeration of CaO crystal and its sintering at high temperature. Stability of CaO in sorption/desorption cycle increased with increasing amount of CeO2 in the sorbents. With a high Tammann temperature, the newly produced CaZrO3 from zirconia and calcium oxide could serve as a supporting framework and effectively restrain sintering.

Key words: oxygen vacancy, CaO-based sorbent, adsorption, CO2 capture, conversion, stability

摘要:

利用湿法混合-煅烧法将元素Ce、Zr掺杂到CO2钙基吸附剂中,利用热重分析仪(TGA)研究了24种改性钙基吸附剂吸附CO2的循环特性。研究发现:CeO2散布在CaO晶粒之间可抑制晶粒融合,对吸附剂烧结有一定的阻碍作用;CeO2可明显提高吸附剂在扩散控制阶段对CO2的吸附速率,原因在于CeO2中丰富的氧空位可促进CO2以离子迁移的方式穿过表面产物层到达内部与CaO反应;吸附剂中CeO2含量越高,稳定性越强;ZrO2与CaO高温化合成具有高塔曼温度的CaZrO3,均匀分散在CaO晶粒间,构成稳固的支撑骨架,有效抑制了吸附剂烧结。

关键词: 氧空位, 钙基吸附剂, 吸附, 二氧化碳捕集, 转化率, 稳定性

CLC Number: