CAJ | 학술논문

钙基吸收剂循环煅烧/碳酸化反应吸收 CO2是经济高效的 CO2减排方法之一.为提高吸收剂的 CO2循环捕集效率,文中利用粉煤灰对钙基吸收剂进行改性处理并考察其循环碳酸化性能.具体考察不同溶液条件下采用水合化法,以及对粉煤灰进行研磨、煅烧或碱浸等预处理手段优化制备改性吸收剂的碳酸化性能,并从成分和微观结构方面揭示吸收剂碳酸化特性提高的原因.结果表明,粉煤灰改性钙基吸收剂能提高吸收剂的碳酸化性能.其中,在 50%乙酸溶液中水合条件下制备的改性吸收剂的碳酸化性能较好,经历 8次循环反应碳酸化转化率较未改性CaO提高了84%;粉煤灰经研磨、煅烧或碱浸等预处理后制备的改性吸收剂的碳酸化性能得到进一步提高.粉煤灰改性钙基吸收剂在循环反应过程中生成CaSiO3和Ca12Al14O33,是改性吸收剂碳酸化性能得以提高并随循环次数增加衰减缓慢的主要原因.
개기흡수제순배단소/탄산화반응흡수 CO2시경제고효적 CO2감배방법지일.위제고흡수제적 CO2순배포집효솔,문중이용분매회대개기흡수제진행개성처리병고찰기순배탄산화성능.구체고찰불동용액조건하채용수합화법,이급대분매회진행연마、단소혹감침등예처리수단우화제비개성흡수제적탄산화성능,병종성분화미관결구방면게시흡수제탄산화특성제고적원인.결과표명,분매회개성개기흡수제능제고흡수제적탄산화성능.기중,재 50%을산용액중수합조건하제비적개성흡수제적탄산화성능교호,경력 8차순배반응탄산화전화솔교미개성CaO제고료84%;분매회경연마、단소혹감침등예처리후제비적개성흡수제적탄산화성능득도진일보제고.분매회개성개기흡수제재순배반응과정중생성CaSiO3화Ca12Al14O33,시개성흡수제탄산화성능득이제고병수순배차수증가쇠감완만적주요원인.
Calcium looping cycle is one of the most promising technologies for CO2 capture, which is based on the reversible carbonation reaction of CaO. The calcium based sorbents were attempted to be modified with fly ash to enhance its CO2 capture capacity. The modification conditions were optimized by changing the hydration solution and pretreating the fly ash with grinding, calcination or alkali treatment. The carbonation property of the modified sorbents was investigated. The composition of and microstructure of the preferable modified sorbents were also analyzed to reveal the mechanism of CO2 capture capacity enhancement. Results show that higher CO2 capture performance is achieved for the sorbent modified by coal fly ash in hydration compared with the pure CaO. The sorbents modified with coal fly ash in hydration with 50% acetic acid solution (CaO/FA Hyd(50%CA)) presented better CO2 capture performance compared with other modified sorbents. Carbonation conversion of CaO/FA Hyd(50%CA) is 84% higher than that of CaO after 8 cycles. Besides, sorbents modified by pretreatment of fly ash with grinding, calcination or alkaline leaching presented higher CO2 capture capacity than those without fly ash treatment. The composition analysis of these sorbents showed that CaSiO3 and Ca12Al14O33 was generated during the initial calcination and multiple cycles, which can restrain the sintering of sorbents leading to the improvement in surface area and pore volume of sorbents and thus the activity of sorbents.