摘要
目前对高炉煤气脱硫进行源头控制,有利于推进钢铁行业全流程超低排放改造。高炉煤气脱硫的难点是羰基硫(COS)的脱除,针对高炉煤气温度波动频繁、压力大、组分复杂等排放特征,采用氧化铝催化剂催化水解COS,考察了温度、氯离子、粉尘和氧气对羰基硫水解转化率的影响,并分析了各因素对COS水解的影响程度以及影响机理。结果表明,温度对COS催化水解的效率影响最为显著,温度由50℃升高到150℃时,水解效率由49%增加到90%,较高温度有利于COS水解反应的发生;Cl^(-)使催化剂比表面积降低20.1%,孔容积降低40.0%,Cl^(-)使催化剂失活包括2方面,一是减少了水解催化剂表面碱性中心,二是堵塞催化剂孔道、覆盖部分活性位点,Cl^(-)的失活作用最显著;高炉煤气中纳米级粉尘会堵塞催化剂孔道,使催化剂比表面积降低43.5%,孔容积降低60.0%,随着粉尘的累积,水解效率明显下降;O_(2)体积分数为0.5%时,随着反应时间的延长,水解效率由85%降至82%,没有明显下降,但当O_(2)体积分数提高到1%时,水解效率由85%降至66%,O_(2)体积分数升高后硫沉积的抑制作用明显。水解催化剂的抗氯、抗粉尘、抗氧是需重点关注的因素,工业上可采取在水解前预脱除多组分,以减少高炉煤气杂质对COS水解效率的影响。
It is of great significance to implement the source control of FGD for the whole process of ultra-low emission transformation in the iron and steel industry,at present.The difficulty of desulfurization of blast furnace gas is the removal of carbonyl sulfur(COS).Aiming at the emission characteristics of blast furnace gas with frequent temperature fluctuations,high pressure and complex components,alumi⁃na catalyst was used to catalyze and hydrolyze COS,and the effects of temperature,chloride ion,dust and oxygen on the conversion rate of carbonyl sulfur were investigated.The influence degree and mechanism of various factors on COS hydrolysis were analyzed.The results indicate that the temperature has the most significant effect on the efficiency of COS hydrolysis.When the temperature is increased from 50℃to 150℃,the hydrolysis efficiency increases from 49%to 90%.The higher temperature is conducive to the occurrence of COS hy⁃drolysis reaction.Chloride ion reduces the specific surface area of the catalyst by 20.1%,and the pore volume by 40.0%.The catalyst de⁃activation caused by chloride ion comes from two aspects,including the reduction of alkaline center on the surface of hydrolysis catalyst,the blockage of catalyst channels and the covering of some active sites.Chloride ion has the most significant inactivation effect.The nano dust in blast furnace gas has a blocking effect on the catalyst pore,reduces the specific surface area of the catalyst by 43.5%and the pore vol⁃ume by 60.0%.The hydrolysis efficiency decreases significantly with the accumulation of dust.When the oxygen concentration is 0.5%,the hydrolysis efficiency decreases from 85%to 82%with the extension of reaction time and there is no significant decline.Still,when the oxy⁃gen concentration increases to 1%,the hydrolysis efficiency decreases from 85%to 66%,the inhibition effect of sulfur deposition is obvious when the oxygen concentration increases.Anti-chlorine,dust resistance and oxygen resistance are the key factors of hydrolysis catalyst.Pre-removal of multiple components in industry can be adopted before hydrolysis to reduce the impact of blast furnace gas impurities on COS hydrolysis efficiency.
作者
王斌
林玉婷
李玉然
王健
朱廷钰
WANG Bin;LIN Yuting;LI Yuran;WANG Jian;ZHU Tingyu(Key Laboratory of Green Process and Engineering,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;Innovation Academy for Green Manufacture,Chinese Academy of Sciences,Beijing 100190,China)
出处
《洁净煤技术》
CAS
北大核心
2021年第5期233-238,共6页
Clean Coal Technology
基金
国家重点研发计划资助项目(2018YFC0213406)。
关键词
高炉煤气脱硫
羰基硫水解
氧化铝催化剂
硫化氢脱除
催化剂抗性
blast furnace gas desulfurization
hydrolysis of carbonyl sulfide
alumina catalyst
hydrogen sulfide removal
catalyst resistance
