摘要
酸性水罐区是炼油厂最大的污水罐区,排放气中含有高浓度H2S,NH3,有机硫化物、油气、水蒸气和空气,直接排放导致空气恶臭污染严重且浪费油气资源。采用来水脱气罐、罐顶气连通管网、减少罐内气相空间体积、将排水高峰安排在夜间等措施,可减排气体50%以上。采用罐内气相空间惰性气保护,可防止硫化亚铁自燃引发火灾事故。罐区排放气采用"低温粗柴油吸收-碱液吸收"工艺,粗柴油来自催化裂化分馏塔或常压塔,富吸收油进加氢装置处理;采用氢氧化钠或氨水吸收H2S时,废吸收液进酸性水罐处理;采用醇胺吸收液时,富吸收液进再生系统。该工艺的H2S、有机硫化物回收率接近100%;NH3回收率60%～90%;油气回收率可达95%以上;净化气体中的油气质量浓度小于25 g/m3;H2S,NH3、甲硫醇、甲硫醚、二甲二硫排放量小于GB 14554—93《恶臭污染物排放标准》。
Sour water tank farm is the largest waste water tank farm in refinery. The vent gas of which consists of H2S, ammonia, organic sulfides, oil vapor, steam and air. Direct emission of odor gas will pollute the air and waste oil vapor. The emission can be reduced more than 50% by degassing waste water, connecting vent gas pipelines together, reducing gas volume in the tank, arranging the drain time at night, etc. The fire by auto-ignition of FeS can be prevented by introducing inert gases to the tank. The vent gas of the tank farm is treated by ＂low-temperature diesel oil absorption-alkali absorption＂; The diesel oil comes from FCC fractionator and the rich absorption oil flows to hydrotreating unit. When the hydrogen sulfide is absorbed by sodium hydroxide or ammonia, the spent absorption liquid is treated in sour water tank. When hydrogen sul- fide is absorbed by alcohol amine, the rich absorption liquid enters regeneration system. The removal rate of hydrogen sulfide and organic sulfides of the process is close to 100% and the recovery rate of NH3 is 60%- 90%, the recovery rate of oil vapor is higher than 95%, and the oil vapor concentration in the purified gas is less than 25 g/era3, and the emission concentrations （kg/h） of H2S, NH3, methyl mercaptan, dimethyl sulfide and dimethyl disulfide are all below （GB 14544-93 ） ＂Emission Standards for Odor Pollutants＂.
出处
《炼油技术与工程》
CAS
2012年第3期58-62,共5页
Petroleum Refinery Engineering
关键词
酸性水
罐区
恶臭
油气回收
sour water, tank tarm, odor gas, oil vapor recovery
