酸性水汽提装置恶臭气体治理问题及对策

Problems and countermeasures of malodorous gases treatment in sour water stripping unit

分析了酸性水汽提装置恶臭气体治理过程中出现的脱臭罐压降过大及酸性水原料罐抽空等问题的原因,并提出了相应的解决措施。结果表明,脱臭罐压降过大是由于恶臭气体携带的汽、油类、固体颗粒等物质在吸附剂间的空隙积聚,造成床层空隙率下降所致;酸性水原料罐抽空是由于该罐与水封罐间的气相连接管道存在"U形弯",气体所携带的水分在"U形弯"管道中形成"液阻"所致。建议增设1台脱臭罐,当床层压降超过1.8 kPa时,将该罐切除,进行氮气、蒸汽吹扫等再生处理;水原料罐与水封罐之间的联通管线应尽可能短并畅通。针对恶臭气体治理,还可采取尽量将恶臭气体自酸性水脱气罐中密闭排出,将富含H2S和NH3的循环液返至酸性水原料罐出口,增加酸性水原料罐中油层厚度等措施。

The reasons for excessive pressure drop of deodorization tank and evacuation of sour water feed tank in the malodorous gases treatment of sour water stripping unit were analyzed,and the corresponding countermeasures were proposed.The results showed that the excessive pressure drop of deodorization tank was due to the bed voidage decrease caused by the accumulation of gas,oil and solid particles which were carried in by the malodorous gas in the adsorbent gap.The evacuation of sour water feed tank was attributed to the pocket shaped section design of gas connection pipeline between this tank and water sealing tank,where the water carried by the gas accumulated and formed ＂ U bend＂.Adding a spare tank was advised for deodorization tank,so that the in-use tank could be switche over from production line and purged with nitrogen and steam for regeneration treatment when its bed pressure drop exceeded 1.8 kPa.The connection pipeline between the water feed tank and the water sealing tank should be as short and smooth as possible.Countermeasures could be taken for the malodorous gas treatment：blowing down the malodorous gas from the sour water degassing drum to a in closed system,recycling the liquid rich in H2S and NH3 back to the outlet of sour water feed tank,increasing the oil layer thickness in sour water feed tank,etc.