硫磺回收装置环境保护若干问题探析

Discussion on several issues of environmental protection of sulfur recovery unit

硫磺回收装置酸性气不放火炬是安全生产与保护环境的双重体现。开工阶段通过优化非加氢型酸性水汽提装置和加氢型酸性水汽提装置的开工顺序,再生单元采用"冷胺循环"富集H_2S,最大程度提高酸性气负荷,可以实现硫磺回收装置开工不放火炬。停工阶段采用"热氮吹硫"工艺可将排放烟气SO_2质量浓度降至100 mg/m^3以下,满足GB 31570—2015《石油炼制工业污染物排放标准》特别排放限值的要求。液体硫磺(液硫)脱气关系到硫磺产品质量、安全与职业卫生和环境保护问题。将液硫脱气的废气直接引入尾气焚烧炉会导致排放烟气SO_2质量浓度增加100~200 mg/m^3,应将废气引入酸性气燃烧炉或加氢反应器(前)处理。建议加大对液硫储罐和液硫装车设施逸散废气的治理力度,减少其对环境和人体健康的影响。

It is a double embodiment of safety production and environmental protection that sour gas of sulfur recovery unit does not release flare.By optimizing the start-up sequence of sour water from non-hydroprocessing unit stripping unit and sour water from hydroprocessing unit stripping unit at the start-up stage,the regeneration unit adopts“cold amine cycle”to enrich H 2S and maximize the sour gas load,so as to realize the start-up of sulfur recovery unit without flare.In the shutdown stage,“hot nitrogen and sulfur blowing”process can reduce the SO 2 concentration of flue gas emission to below 100 mg/m 3,which meets the requirements of GB 31570—2015 special emission limit.Liquid sulfur degassing is an important measure to control the quality of sulfur products,as well as safety,environmental protection and occupational health.The direct introduction of the waste gas from liquid sulfur degassing into the tail gas incinerator will increase the mass concentration of SO 2 in the discharged flue gas by about 100~200 mg/m 3.The waste gas shall be introduced into the sour gas combustion furnace or hydrogenation reactor(pre)for treatment.It is suggested that more efforts should be made to control the waste gas from liquid sulfur storage tanks and loading facilities to reduce the impact on the environment and human health.