摘要
将CaO添加到经不同酸改性后的CaSO_4氧载体中来制备CaSO_4-CaO复合氧载体。采用XRD、H_2-TPR、CO小型卧式管式炉开展恒温反应和循环实验,对氧载体进行表征和评价。主要研究了酸的种类对CO_2生成、气体硫化物的释放及复合氧载体循环反应性能的影响。结果表明:酸化的复合氧载体的氢气还原活性均明显优于未经改性过的CaSO_4,相比无酸化处理的CaSO_4氧载体,酸化后的CaSO_4-CaO复合氧载体,特别是HCl酸化,主要是提高了CaSO_4竞争还原副反应的选择性,导致主要气体硫化物SO_2释放显著增加,而COS释放略有降低。以CaCO_3煅烧得到的CaO与经HNO_3改性的CaSO_4进行机械混合制得的复合氧载体具有较好的反应活性,但是经过6次循环反应后,还原反应活性下降;循环反应中,气体硫化物主要来自于CaSO_4在还原阶段释放出的SO_2。
CaSO4-CaO combined oxygen carrier was prepared by mixing mechanically.The CaSO4 was modified with different types of acid.The characterizations and evaluation of modified CaSO4-CaO oxygen carrier were studied using XRD,H2-TPR,and a small tube furnace reactor.The effect of acid types on CaSO4 reductive reactivity,CO2 generation,SO2 and COS releases were studied.It was founded that the reactivity of acid-modified CaSO4-CaO oxygen carrier was obviously higher than that without preparation;the use of acid mainly increased the selectivity of side competitive reactions of CaSO4 reductions,which resulted in the emission of SO2 increased remarkably,and the release of COS dropped somewhat.CaSO4-CaO combined oxygen carrier,which CaO was from the CaCO3 calcination and CaSO4 was modified with HNO3,had good reactivity.So its cycle performance was studied.However,the reactivity decreased after 6th reduction-oxidation cycle.During the cycle test,SO2 was the main gas sulfides which was released during reduction phase.
作者
钟思梅
郑敏
邢艳彬
蒲思旭
ZHONG Simei;ZHENG Min;XING Yanbin;PU Sixu
出处
《化工进展》
EI
CAS
CSCD
北大核心
2018年第4期1426-1432,共7页
Chemical Industry and Engineering Progress
基金
国家自然科学基金项目(51306084
51374004)
