摘要
低温催化水解羰基硫(COS)是推动煤气洁净转化利用的关键技术之一。现代合成气经高温净化后COS含量低,但工业气源(如高炉和焦炉煤气)中COS含量较高(75~400 mg·m^(-3))。因此,研究COS水解技术对工业煤气净化及未来合成气高效制备意义重大。前期研究发现,γ-Al_(2)O_(3)负载稀土金属在低浓度COS条件下表现出较强的催化水解活性,但其在低温和高浓度COS气氛下的催化水解行为尚不明确。本研究探讨了不同稀土金属氧化物(La_(2)O_(3)、Sm_(2)O_(3)和CeO_(2))对γ-Al_(2)O_(3)催化水解行为的提升作用;并基于气体组成影响规律及多种结构表征,剖析了优选稀土金属与γ-Al_(2)O_(3)间的相互作用。结果表明:在70℃、1000 mg·m^(-3) COS、3%(体积分数)H_(2)O及0.5%(体积分数)O_(2)条件下,负载Sm_(2)O_(3)(质量分数为5%)的改性催化剂(Sm_(2)O_(3)/γ-Al_(2)O_(3))表现出最佳性能,反应8 h后H_(2)S选择性为86.3%,且COS转化率保持在90%以上,高于未改性γ-Al_(2)O_(3)(65.3%)。此外,Sm掺杂提高了抗H_(2)S中毒能力,归因于Sm改性增加了γ-Al_(2)O_(3)表面的碱性位点。CO_(2)的存在显著削弱了Sm_(2)O_(3)/γ-Al_(2)O_(3)对COS转化率的提升作用(降低39.6%),这是由于CO_(2)的竞争吸附导致催化剂失活,且该过程可逆。另外,在H_(2)S和CO_(2)共存条件下,CO_(2)优先吸附在催化剂表面,占据碱性位点使催化剂快速失活。
Low temperature catalytic hydrolysis of carbonyl sulfide(COS)is a key technology for promoting the clean conversion and utilization of gas.Modern syngas has low COS content after high temperature purification,but industrial gas sources(such as blast furnace and coke oven)have high COS content(75—400 mg·m^(-3)).Therefore,the study of COS hydrolysis technology is of great significance for industrial gas purification and efficient preparation of syngas in the future.Previous studies have shown thatγ-Al_(2)O_(3) loaded with rare earth metals exhibits strong catalytic hydrolysis activity under low COS concentrations,but its behavior under low temperature and high COS concentrations remains unclear.This study investigates the enhancement effects of different rare earth metal oxides(La_(2)O_(3),Sm_(2)O_(3) and CeO_(2))on the catalytic hydrolysis behavior ofγ-Al_(2)O_(3).Based on the influence of gas composition and various structural characterizations,the interactions between the selected rare earth metals andγ-Al_(2)O_(3) are analyzed.The results indicate that,under conditions of 70℃,1000 mg·m^(-3) COS,3%H_(2)O and 0.5%O_(2),the modified catalyst(Sm_(2)O_(3)/γ-Al_(2)O_(3))with Sm_(2)O_(3)(the mass fraction is 5%)loading shows the best performance.After 8 h of reaction,the selectivity of H_(2)S is 86.3%,and the COS conversion rate remains above 90%,which is higher than that of unmodifiedγ-Al_(2)O_(3)(65.3%).Additionally,Sm doping enhances the resistance to H_(2)S poisoning,attributed to the increased basic sites on the surface ofγ-Al_(2)O_(3).The presence of CO_(2) significantly weakens the effect of Sm_(2)O_(3)/γ-Al_(2)O_(3) on COS conversion(reduced by 39.6%),which is due to the competitive adsorption of CO_(2) leading to catalyst deactivation,and this process is reversible.In addition,under the coexistence of H_(2)S and CO_(2),CO_(2) preferentially adsorbs on the catalyst surface,occupies basic sites and rapidly deactivates the catalyst.
作者
杨敏
段新伟
吴俊宏
米杰
王建成
武蒙蒙
YANG Min;DUAN Xinwei;WU Junhong;MI Jie;WANG Jiancheng;WU Mengmeng(State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;Key Laboratory of Coal Science and Technology,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;College of Environmental Science and Engineering,Taiyuan University of Technology,Jinzhong 030600,Shanxi,China)
出处
《化工学报》
北大核心
2025年第8期4061-4070,共10页
CIESC Journal
基金
国家自然科学基金面上项目(22278294)
山西省自然科学基金面上项目(20210302123191)
中央引导地方科技发展资金项目(YDZJSX2025C006)。
作者简介
第一作者:杨敏(1999-),女,硕士研究生,yangmin990603@163.com;通信作者:武蒙蒙(1985-),男,博士,副教授,wumengmeng@tyut.edu.cn。
