2018年12月发布的GB 17820-2018 《天然气》将一类气总硫含量限值由60 mg/m3降到20 mg/m3,结合我国国情分析可知:1)当前我国SO2排放控制卓有成效,北京、上海等国际大都市大气中SO2年均浓度都已降至20 μg/m3以下,远优于日本东京(57 μg/m3,2013年);2)我国自主开发的物理化学混合溶剂脱有机硫效率可达90%,但对硫醇含量较高的原料气，尚无法在一次脱硫过程中将硫醇含量降至16 mg/m3以下;3)我国目前尚未掌握“1+1”组合式脱水脱硫醇工艺的技术关键,且使用此类硫减排举措将大幅度增加能耗和碳排量,对天然气工业协调稳定发展带来的负面影响不可低估;4)目前全球除德国外,没有其它采用总硫含量限值20 mg/m3的国家,且对我国国情而言,即使实现了此指标,每年SO2减排量仅 3 580 t,不足当前SO2年均减排量的0.4 %;5)汽、柴油国Ⅴ标准总硫含量限值与GB 17820-2018 《天然气》规定的商品天然气总硫含量限值之间并无内在联系,且完全没有必要要求不同工业的、以完全不同工艺生产的两种不同产品达到同样的总硫限值;6)大力发展天然气工业本身就是有效改善环境质量的重要举措。综上可得:该总硫含量限值规定既无必要,还可能产生诸多负面影响。

The limit value of total sulfur content of gas class one has been lowered from 60 mg/m3to 20 mg/m3byGB/T 17820-2018 Natural Gas, which was released in December 2018.Combined with the analysis of China's national conditions, it can be seen that: 1) at present, China's SO2emission control has witnessed effective result, and the annual average concentration of SO2in the atmosphere of Beijing, Shanghai and other international metropolises has been reduced to less than 20 μg/m3,which is far better than that of Tokyo (57 μg/m3, 2013) in Japan;2)the organic sulfur removal efficiency of the physical and chemical mixed solvent developed by China can reach 90%,but as for feed gas with high mercaptan content, the mercaptan cannot be reduced to less than 16 mg/m3in a single desulfurization process;3)at present, China has not mastered the technical key of "1 + 1" combined dehydration and mercaptan removal process.Moreover, the negative impact on the coordinated and stable development of the natural gas industry caused by the use of such sulfur emission reduction measures at the cost of significantly increasing energy consumption and carbon emission cannot be underestimated;4)currently, except Germany, there is no country in the world adopting the limit value of total sulfur content at 20 mg/m3,and for China's national conditions, even if this indicator is achieved,the annual SO2emission reduction is only 3580t, which is less than 0.4% of the current annual SO2emission reduction;5) there is no internal relationship between limit value of total sulfur content of gasoline and diesel specified by the China V standard and that of commercial gas specified in GB17820-2018, and it is unnecessary to require those two different products, produced by different industries with completely different processes, to have the same total sulfur limit value;6)vigorously developing the natural gas industry itself is an important way to effectively improve the environment.To sum up, this restriction is unnecessary and may bring about many negative effects.