天然气净化厂SO2达标排放技术适应性分析研究

目的解决国内中小规模天然气净化厂硫磺回收装置烟气中SO₂达标排放及装置在低负荷或低H₂S含量的条件下开工、停工除硫及加氢催化剂预硫化期间高浓度SO₂短时超标排放的问题。 方法统计研究了国内28座天然气净化厂硫磺回收、尾气处理工艺和硫磺产量,分析了现阶段还原吸收、氧化吸收、碱液洗涤及液相氧化还原4种处理工艺在天然气行业的应用情况,介绍了天然气研究院开发的Claus尾气中SO₂催化吸附技术的相关情况。 结果对天然气净化厂SO₂减排技术提出以下建议:①充分重视气田潜硫量变化引起的装置低负荷稳定运行等问题；②现有装置增设尾气处理装置时,避免对原硫磺回收装置工艺进行改变,选择环保、无二次污染物产生且能与工厂智能化建设衔接的工艺技术；③SO₂减排需从源头解决问题,着眼于硫磺回收单元的精细化操作和管理、催化剂正确使用及性能跟踪分析,进而提高硫回收率,减少后端处理的负荷。 结论采用上述研究结果,一方面可保障硫磺回收装置长周期稳定运行,另一方面可在现有排放的基础上进一步减少SO₂排放。 

Analysis and research on adaptability of sulfur dioxide up-to-standard emission technology in natural gas purification plant

ObjectiveSolve the up-to-standard emission problems of SO₂ in flue gas of sulfur recovery unit of domestic small and medium-sized natural gas purification plant, and the short-term excessive emission of high concentration SO₂ during start-up and shutdown of sulfur removal unit under the condition of low load or low H₂S content and pre-vulcanization of hydrogenation catalyst. Methods The sulfur recovery, tail gas treatment process and sulfur output of 28 natural gas purification plants in China were statistically studied, and the application of four treatment processes at the present stage in the natural gas industry was analyzed, this paper introduced the relevant situation of SO₂ catalytic adsorption technology in Claus tail gas developed by Research Institute of Natural Gas Technology. ResultsSome suggestions on SO₂ emission reduction technology of natural gas purification plant were put forward:(1) Pay full attention to the problems of low load and stable operation of the unit caused by the change of potential sulfur in the gas field. (2) When adding tail gas treatment unit to the existing unit, avoid changing the process of the original sulfur recovery unit, and select the process technology that is environmental friendly, free of secondary pollutants and can be connected with the intelligent construction of the plant. (3) SO₂ emission reduction should solve problems from the source, focusing on the fine operation and management of sulfur recovery unit, the correct use of catalyst and performance tracking analysis, so as to improve the sulfur recovery rate and reduce the load of back-end treatment. ConclusionsUsing above research results, on the one hand, it can ensure the long-term and stable operation of sulfur recovery unit, on the other hand, it can further reduce sulfur dioxide emission on the basis of existing emission.