Liu Yongzhuo, Gao Minggang, Zhang Xintao, Hu Xiude, Guo Qingjie
Key Laboratory of Clean Chemical Engineering of Colleges and Universities of Shandong Province, Qingdao University of Science and Technology Qingdao 266042 People's Republic of China
State Key Laboratory of Coal Clean Utilization and Ecological Chemical Engineering, Ningxia University Yinchuan 750021 People's Republic of China.
RSC Adv. 2018 Jun 27;8(41):23372-23381. doi: 10.1039/c8ra03425g. eCollection 2018 Jun 21.
CaSO is considered to be a potential oxygen carrier for chemical-looping combustion (CLC) due to its cheapness and high oxygen transport capacity. To improve the physicochemical stability of the CaSO oxygen carrier, CaSO composite oxygen carriers supported with clay, cement, and ash separately were prepared. It was found that the attrition resistance of the CaSO oxygen carrier composed of clay and cement improved due to the bond action of clay and cement. The reactivity of the composite oxygen carrier with coal was investigated in a thermogravimetric analyser (TGA) and fluidised bed. Sulphurous gas products were analysed by mass spectrometry (TG-MS) and gas chromatography (GC). Based on the catalysis of the active components in clay, cement and ash, the reaction rate of CaSO with coal was improved by the active materials. However, the side reaction generating the sulphurous gas was severe in both the reduction and oxidation stages, especially when using steam as the gasifying agent. To enhance the regeneration, the CaSO/clay composite oxygen carrier was upgraded by adding CaO. It was demonstrated that SO release can be restrained in both the reduction and oxidation stages when the mass ratio of CaO to the CaSO/clay composite oxygen carrier was higher than 1. At this point, the corresponding oxygen transport capacity was about 14.1 wt%.
由于其廉价且氧传输能力高，硫酸钙被认为是化学链燃烧（CLC）的潜在氧载体。为提高硫酸钙氧载体的物理化学稳定性，分别制备了以粘土、水泥和灰分负载的硫酸钙复合氧载体。研究发现，由于粘土和水泥的粘结作用，由粘土和水泥组成的硫酸钙氧载体的耐磨性得到提高。在热重分析仪（TGA）和流化床中研究了复合氧载体与煤的反应活性。通过质谱（TG-MS）和气相色谱（GC）分析含硫气体产物。基于粘土、水泥和灰分中活性成分的催化作用，活性材料提高了硫酸钙与煤的反应速率。然而，在还原和氧化阶段，生成含硫气体的副反应都很严重，尤其是使用蒸汽作为气化剂时。为提高再生性能，通过添加CaO对硫酸钙/粘土复合氧载体进行升级。结果表明，当CaO与硫酸钙/粘土复合氧载体的质量比高于1时，还原和氧化阶段的SO释放均可得到抑制。此时，相应的氧传输能力约为14.1 wt%。
