关键词: CO₂捕集, Na₂CO₃基吸附剂颗粒, 挤压-滚圆, 负载量, 机械性能

Abstract:

Na₂CO₃-based CO₂ sorbent pellets were prepared via extrusion-spheronization method, and whose CO₂ capture performance was tested using a self-designed CO₂ sorption system. The microstructure, CO₂ capture performance and mechanical properties of Na₂CO₃-based sorbent pellets with different supports and loadings were investigated. The results showed that Na₂CO₃-based sorbent pellets with different supports exhibited relatively large discrepancy on CO₂ capture performance. The alumina-supported sorbent pellet (Na₂CO₃/Al₂O₃) possessed the highest CO₂ capture capacity of 1.14mmol/g. However, the calcium aluminate cement-supported sorbent pellets (Na₂CO₃/CA) exhibited the good mechanical properties and inferior CO₂ capture performance. Comprehensively considering the CO₂ capture performance and mechanical properties, Na₂CO₃/Al₂O₃ is the most suitable CO₂ sorbent. Moreover, the effect of loading amount of Na₂CO₃ on performance of Na₂CO₃/Al₂O₃ sorbent pellets was further studied. It was found that the microstructure, CO₂ capture performance and mechanical properties of Na₂CO₃/Al₂O₃ sorbent pellets were closely related to loading amount of NaCO₃. Although the pellets loaded with 60% of NaCO₃ exhibited the superior mechanical properties and CO₂ capture performance, their poor sphericity impeded the practical application. The Na₂CO₃/Al₂O₃ sorbent pellets loaded with 40% of NaCO₃ exhibited good CO₂ capture performance, mechanical properties and sphericity, whose CO₂ capture capacity is 1.36mmol/g. Therefore, the Na₂CO₃-based sorbent pellets prepared via extrusion-spheronization were suitable to be applied for CO₂ removal in power plant flue gas due to their good fluidization characteristics, CO₂ capture performance and mechanical properties.

Key words: CO₂ capture, Na₂CO₃-based sorbent pellets, extrusion-spheronization, loading amount, mechanical properties