化工学报 ›› 2020, Vol. 71 ›› Issue (8): 3699-3709.DOI: 10.11949/0438-1157.20191466

• 能源和环境工程 • 上一篇    下一篇

基于CO2循环的低碳高效白云石煅烧新工艺

蒋滨繁1,2(),夏德宏1,2(),安苛苛1,张培昆1,敖雯青3   

  1. 1.北京科技大学能源与环境工程学院,北京 100083
    2.冶金工业节能减排北京市重点实验室,北京 100083
    3.北京科技大学材料工程学院,北京 100083
  • 收稿日期:2019-12-03 修回日期:2020-05-14 出版日期:2020-08-05 发布日期:2020-08-05
  • 通讯作者: 夏德宏
  • 作者简介:蒋滨繁(1994—),女,博士研究生,jiang@xs.ustb.edu.cn
  • 基金资助:
    国家重点研发计划项目(2018YFB0605900)

Efficient low-carbon dolomite calcination process based on CO2 looping and recovering

Binfan JIANG1,2(),Dehong XIA1,2(),Keke AN1,Peikun ZHANG1,Wenqing AO3   

  1. 1.School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
    2.Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, Beijing 100083, China
    3.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2019-12-03 Revised:2020-05-14 Online:2020-08-05 Published:2020-08-05
  • Contact: Dehong XIA

摘要:

白云石是一种广泛应用的冶金、建材和化工原料。针对白云石煅烧过程中CO2排放严重等问题,构建了基于CO2循环载热与资源化回收的白云石低碳煅烧竖窑新工艺。通过白云石(CaCO3·MgCO3)煅烧过程的Gibbs自由能变计算,发现提高煅烧温度(50~100 K)可有效克服CO2对反应的抑制作用;通过纯CO2环境中CaCO3分解过程的热重实验分析,验证了CO2循环煅烧白云石煅烧的可行性;通过化学反应动力学计算,解析了全CO2组分环境下CO2压力对CaCO3·MgCO3高温分解过程的影响,并发现提高CO2压力可促进气固传热,从而提升分解速率和改善矿料分解均匀性;对CO2循环煅烧工艺系统能-质平衡计算表明:该工艺理论能耗仅为140 kg/(t 煅白),且煅烧过程的CO2排放降低70%以上,环境效益显著。

关键词: 二氧化碳, 循环, 白云石, 煅烧, 热解, 反应动力学

Abstract:

Dolomite (CaCO3·MgCO3) is a widely-used raw material in metallurgy, building materials and chemical industry. Aiming at the problem of serious CO2 emission during dolomite calcination, a new process of low-carbon calcined shaft kiln based on CO2 cycle heat carrying and resource recovery was constructed. According to thermochemistry, Gibbs free energy change of CaCO3·MgCO3 decomposition in pure CO2 environment is analyzed which shows that increase of temperature (50—100 K) is an efficient way to overcome the reaction depression by high CO2 concentration. Thermogravimetric analysis of CaCO3 decomposition in pure CO2 atmosphere is conducted, which confirms the feasibility of dolomite calcining in high CO2 concentration. The effect of CO2 pressure (PCO2) on CaCO3·MgCO3 decomposition is investigated. The heat transfer between gas and solid can be enhanced attributed to the high PCO2, which therefore improve the dolomite calcination efficiency. Afterwards, thermal analysis of the dolomite calcination system with CO2 loop is conducted, which turns out that the theoretical energy consumption is 140 kg/(t MgO), and more than 70% CO2 emission would be reduced from the calcination process.

Key words: carbon dioxide, looping, dolomite, calcination, pyrolysis, reaction kinetics

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