Abstract: Precipitation method was used to prepare hydroxylated iron oxide (α-FeOOH) adsorbent to test its adsorption capacity for H2S using a fixed bed gas chromatography platform in this work. It was found that its sulfur capacity reached 63.8 mg/g, and the effects of O2 and H2O atmospheres on sulfur capacity were tested. It was found that there were optimal concentrations for O2 and H2O under the selected conditions, being 0.3vol% and 3vol%, respectively. The physicochemical properties of adsorbents and the occurrence forms of sulfur-containing components were characterized by XRD, XPS, TG, and CO2-TPD. It was found that the main sulfur-containing species were elemental sulfur and sulfate (SO42-) after α-FeOOH adsorbed H2S. The role of O2 in the reaction was analyzed by pre-adsorbing oxygen test. The adsorbed oxygen promoted the formation of sulfur elemental, while the presence of gaseous O2 increased the proportion of SO42-. In situ diffuse reflectance infrared spectroscopy showed the intermediate products adsorbed by H2S. H2S combined with the lattice oxygen or hydroxyl groups on α-FeOOH surface to generate HS-, and then HS- was further oxidized by Fe3+ with electron transfer to generate elemental sulfur, or HS- was oxidized by O2 to generate SO42-. This work provides a theoretical basis for the optimization of adsorbent preparation and the application of blast furnace gas purification technology.

Key words: blast furnace gas, hydroxyl iron oxide, hydrogen sulfide, adsorption-oxidation, sulfur capacity

摘要： 采用沉淀法制备了羟基氧化铁(α-FeOOH)吸附剂，利用固定床-气相色谱联用平台测试了其对H2S的吸附容量，发现其硫容达到了63.8 mg/g，测试了O2和H2O对硫容的影响，发现二者均存在最佳浓度，在选定条件下O2和H2O最佳浓度分别为0.3vol%和3vol%。采用XRD, XPS, TG和CO2-TPD等表征了吸附剂的理化性质及含硫组分的赋存形态，发现α-FeOOH吸附H2S后硫物种主要为硫单质和硫酸盐(SO42-)。通过预吸附氧气的方式分析了O2在反应中的作用，吸附态的氧促进硫单质形成，气态的O2存在会增加SO42-的比例。通过原位漫反射红外光谱测试了H2S吸附的中间产物，H2S在α-FeOOH表面吸附与晶格氧或羟基结合生成HS-，HS-被Fe3+氧化发生电子转移生成硫单质或者被O2氧化生成SO42-。本工作为吸附剂优化制备及高炉煤气净化技术应用提供了理论依据。

关键词: 高炉煤气, 羟基氧化铁, 硫化氢, 吸附氧化, 硫容