硫磺回收装置烟气二氧化硫浓度的影响因素分析  

Analysis on Factors Influencing Sulfur Dioxide Concentration in Flue Gas from Sulfur Recovery Unit

作　　者：胡久元 Hu Jiuyuan(SINOPEC Yangzi Petrochemical Co.,Ltd.,Nanjing Jiangsu 210048)

机构地区：[1]中国石化扬子石油化工有限公司,江苏南京210048

出　　处：《中外能源》2022年第2期92-96,共5页Sino-Global Energy

摘　　要：硫磺回收装置是大型炼厂的主要环保配套装置之一,随着国家环保排放指标的日益严格,对硫磺回收装置烟气二氧化硫排放限值进一步收紧,这对装置的改造及运行管理提出了更高的要求。大多数硫磺回收装置烟气主要由净化尾气、液硫池脱气废气组成,部分装置还加工S_Zorb再生烟气,烟气中二氧化硫排放浓度主要取决于净化尾气中的硫化氢含量。通过采取优化燃烧炉配风、确保流程有效隔离、选择性能较好的有机硫水解催化剂、提高脱硫溶剂MDEA的吸收效率等措施,可有效降低净化尾气中硫化氢含量。液硫脱气废气进入克劳斯炉处理,或者经过水洗后进入焚烧炉。通过改造增设烟气碱洗系统,对焚烧产生的二氧化硫进行碱液吸收,可进一步将烟气二氧化硫排放浓度降低至10mg/m^(3)(标准)以下,远低于国家及地方标准。煤制气酸性气因硫化氢浓度低,会导致克劳斯炉温度偏低,同时因含有有机硫,最终影响烟气达标排放,不建议直接进入硫磺回收装置处理。S_Zorb再生烟气如需进入硫磺回收装置处理,必须控制好氧含量(体积分数不大于5%)及二氧化硫含量,以免造成加氢反应器超温。Sulfur recovery unit is one of the main environmental protection units in large-scale refineries.With the increasingly strict national environmental protection emission standards,the sulfur dioxide emission limit for flue gas from sulfur recovery unit is further tightened,which puts forward higher requirements for the transformation and operation management of sulfur recovery unit.The flue gas from most of sulfur recovery units mainly consists of purified tail gas and degassed waste gas from liquid sulfur pool.Some of the units also process S_Zorb regenerator flue gas.The sulfur dioxide emission concentration in flue gas mainly depends on the hydrogen sulfide content of purified tail gas.The hydrogen sulfide content of purified tail gas can be effectively reduced by optimizing the air distribution in combustion furnace,ensuring the effective isolation of processes,selecting organic sulfur hydrolysis catalysts with better performance and improving the absorption ef-ficiency of desulfurization solvent MDEA.The degassed waste gas from liquid sulfur pool is treated in Claus furnace or sent to incinerator after washing.By installing flue gas caustic washing unit to absorb the sulfur dioxide generated in incineration,the sulfur dioxide emission concentration in flue gas can be further reduced to below 10 mg/Nm^(3),far lower than that stipulated in national and local emission standards.The low hydrogen sulfide concentration in acid gas of coal-to-gas may lead to low temperature in the Claus furnace,and the organic sulfur in acid gas may eventually affect the up-to-standard emission of flue gas,so it is not recommended to send the acid gas directly to sulfur recovery unit for treatment.If the S_Zorb regenerator flue gas needs to be treated in sulfur recovery unit,its oxygen content(volume fraction no higher than 5%)and sulfur dioxide content must be controlled to avoid the over-temperature of hydrogenation reactor.

关 键 词：硫磺回收 烟气 二氧化硫 净化尾气 硫化氢 碱液吸收 

分 类 号：TQ125.11[化学工程—无机化工] TE96[石油与天然气工程—石油机械设备]