对降低尾气处理装置SO2排放的认识与建议

Review and suggestions on reducing SO2 emission concentration of Claus tail gas treatment unit

关键词:  Claus装置  尾气处理  SCOT工艺  Cansolv工艺  SO₂排放浓度 

Key words:  Claus unit  tail gas treatment  SCOT technology  Cansolv technology  SO₂ emission concentration

摘要:

针对将硫磺回收装置排放尾气中SO₂质量浓度从960 mg/m³降至500 mg/m³以下的技术方案,提出通过降低贫液进入SCOT工艺选吸塔的温度及贫液中H₂S浓度,可有效地将总硫回收率提高至99.9%以上；若再辅以配方型溶剂的应用,则有望进一步改善选吸效果与总硫回收率。但现有工业数据表明,目前,属于氧化-吸收型的Cansolv总硫回收率低于常规SCOT工艺。因此,对采用Cansolv工艺处理Claus硫磺回收装置尾气的方案宜采取慎重态度。 

Abstract:

For the technical plan of reducing SO₂ concentration from 960 mg/m³ to below 500 mg/m³ in Claus unit tail gas, it was pointed out that decreasing lean solution temperature and H₂S concentration in selective absorber of SCOT unit, the total sulfur recovery rate can be effectively increased to more than 99.9%. If formulated solvents are used in addition, the efficiency of selective absorption and total sulfur recovery rate could be further improved. Currently industrial data showed that Cansolv method belongs to oxidation-absorption technology of tail gas treatment and the total sulfur recovery is lower than that of standard-type SCOT units. Therefore, the adoption of Cansolv technology for treating the tail gas of Claus unit should be carefully reviewed.