TiAl基羰基硫水解催化剂的中毒机制与抗氧性能研究  

Poisoning mechanism and antioxidant performance of TiAl-based carbonyl sulfur hydrolysis catalyst

作　　者：黄俊 刘羿良 吴鹏 沈凯 张亚平 HUANG Jun;LIU Yiliang;WU Peng;SHEN Kai;ZHANG Yaping(China Guodian Corporation,Zhenjiang 212006,Jiangsu,China;School of Energy and Environment,Southeast University,Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,Nanjing 210096,Jiangsu,China)

机构地区：[1]国家能源集团谏壁发电厂,江苏镇江212006 [2]东南大学能源与环境学院,能源热转换及其过程测控教育部重点实验室,江苏南京210096

出　　处：《化工学报》2022年第10期4461-4471,共11页CIESC Journal

基　　金：江苏省重点研发计划项目(BE2022832)。

摘　　要：高炉煤气脱硫是实现钢铁行业多工序全流程超低排放的关键。高炉煤气中主要有机硫组分是羰基硫(COS),常用γ-Al_(2)O_(3)基催化剂水解脱除,但是其抗氧性能有待提高。采用共沉淀法制备了Ti_(0.5)Al和K_(0.2)Ti_(0.5)Al催化剂,考察了催化剂在含氧气氛下的COS水解催化性能,并分析了氧体积分数对COS转化率和H_(2)S产率的影响规律。活性测试结果表明,Ti_(0.5)Al催化剂的初始COS转化率接近90%,随着反应时间增长效率逐渐降低至60%以下;K_(0.2)Ti_(0.5)Al催化剂在0.5%(体积分数)O_(2)的气氛下持续反应22 h后,其COS转化率仍可保持在93.44%。表征结果显示,催化剂失活后比表面积大幅减小,表面碱性显著减弱。此外,活性中心Al原子硫酸化是导致催化剂失活的主要原因,而硫酸盐的沉积为次要原因。原位红外结果表明,K的引入可显著减弱O_(2)在催化剂表面的吸附,并且阻断中间过渡物种的氧化,这是K提高催化剂抗氧性能的关键。Desulfurization of blast furnace gas is the key to achieving ultra-low emissions in the steel industry with multiple processes and the entire process.In this paper,Ti_(0.5)Al and K_(0.2)Ti_(0.5)Al catalysts were prepared by co precipitation method,and the catalytic performance of COS hydrolysis under oxygen-containing atmosphere was investigated.Besides,the effect law of oxygen volume fraction on COS conversion and H_(2)S selectivity was analyzed.A series of characterization methods were used to systematically investigate the physicochemical properties of the catalysts before and after deactivation,and the effect of O_(2) on the mechanism of COS hydrolysis reaction was investigated by in situ DRIFTS simulation.The activity test results showed that the initial COS conversion of Ti_(0.5)Al catalyst was close to 90%while the efficiency gradually decreased to below 60%as the reaction time increased.As a comparison,the COS conversion of the K_(0.2)Ti_(0.5)Al catalyst could still be maintained at 93.44%after 22 h of continuous reaction under 0.5%(vol)O_(2) atmosphere.The characterization results showed that the specific surface area is greatly reduced after deactivation,and the surface basicity is significantly weakened.In addition,sulfation of the active center Al atoms was the main cause of catalyst deactivation,while sulfate deposition was a secondary cause.The in situ DRIFTS results showed that the introduction of K significantly attenuated the adsorption of O_(2) on the catalyst surface and blocked the oxidation of intermediate transition species,which were the key for K to improve the antioxidant performance of the catalyst.

关 键 词：高炉煤气 羰基硫 催化水解 氧中毒 原位红外 

分 类 号：X511[环境科学与工程—环境工程]