Reductive regeneration of sulfated CuO/Al2O3 catalyst-sorbent in ammonia
Reductive regeneration of sulfated CuO/Al2O3 catalyst-sorbent in ammonia
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DOI：
10.1016/s0926-3373(03)00166-8
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发表时间：
2003-10
影响因子：
22.1
通讯作者：
Guoyong Xie;Zhenyu Liu;Zhenping Zhu;Qingya Liu;Jianrong Ma
中科院分区：
文献类型：
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作者：
Guoyong Xie;Zhenyu Liu;Zhenping Zhu;Qingya Liu;Jianrong Ma
适用于同时去除烟道气中 SO2 和 NOx 的硫酸化 CuO/Al2O3 催化剂吸附剂的还原再生在 5vol.% NH3/Ar 中进行。研究了再生温度对再生催化剂-吸附剂脱SO2活性的影响。采用元素分析、X射线光电子能谱(XPS)、X射线衍射(XRD)和物理吸收对再生前后催化剂-吸附剂的化学形貌和物理结构进行了表征。结果表明，硫酸化催化剂吸附剂中的主要铜物种硫酸铜在350-450℃下可以有效再生。 Al2O3 与烟气中的 SO2 反应生成的硫酸铝在该条件下不可还原，导致再生催化剂吸附剂的 SO2 去除活性较新鲜催化剂吸附剂降低。 400°C 再生后的主要铜物质是 Cu3N。硫化铜的不存在表明在 NH3 中避免了 H2 中发生的过度还原。当还原温度为400℃或更高时，再生催化剂吸附剂的BET表面积和孔径分布与新鲜催化剂吸附剂几乎相同。氨除作为还原剂外，还在反应器出口处与再生过程中生成的SO2反应生成硫酸羟胺。
Reductive regeneration of a sulfated CuO/Al2O3catalyst-sorbent suitable for simultaneous SO2and NOxremoval from flue gases was carried out in 5vol.% NH3/Ar. Effect of regeneration temperature on SO2removal activity of the regenerated catalyst-sorbent was investigated. Chemical morphology and physical structure of the catalyst-sorbent before and after the regeneration were characterized using elemental analysis, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and physical absorption. The results show that copper sulfate, the main copper species in the sulfated catalyst-sorbent, can be effectively regenerated at 350–450°C. Aluminum sulfate, resulted from the reaction between Al2O3and SO2in flue gas, is unreductable under the conditions, which leads to reduced SO2removal activity of the regenerated catalyst-sorbent compared to the fresh catalyst-sorbent. The main copper species after the regeneration at 400°C is Cu3N. The nonexistance of copper sulfide suggests that over-reduction occurring in H2is avoided in NH3. BET surface area and pore size distribution of the regenerated catalyst-sorbent are almost the same as that of the fresh one when the reduction temperature is 400°C or higher. Besides as a reductant, ammonia also reacts with SO2formed in the regeneration to form hydroxyamine sulfate at the outlet of the reactor.