制氢装置中温变换流程改造

Revamping of medium temperature shift process for hydrogen generation plant

中国石油化工股份有限公司洛阳分公司制氢装置采用轻烃水蒸气制氢技术。装置自2009年开工以来,中变气进空气冷却器入口温度及除盐水换热后进除氧器的上水温度均超出设计值,存在PSA联锁停车风险及水气系统管线氧腐蚀等问题。对中温变换流程进行如下改造:在第一分水罐后面增设1台蒸汽发生器,并拆除除盐水预热器限流孔板。装置改造后,解决了中温变换后路热量过多的问题,利用中温变换余热可产出0.5 MPa蒸汽外送管网,产生经济效益约604.8×104RMB$/a;空冷风机由停工前的4台全开,改为目前的2开2备,可节约电费约19×104RMB$/a;利用自产的0.5 MPa蒸汽代替1.0 MPa蒸汽,满足生产要求,装置能耗可降低4 186.8 MJ/t;除氧器上水温度得到有效控制后,自产除氧水除氧效果改善明显,有利于制氢装置的长周期安全生产。

The process of light hydrocarbon steam reforming for hydrogen production has been applied for the hydrogen generation plant of SINOPEC Luoyang Company. Ever since the start-up of the plant in 2009, the inlet temperature of shift gas to the air cooler and the temperature of desalted water to the de-aerator after heat exchange have exceeded the design specifications. The risk of interlock shutdown of PSA unit and oxidation corrosion of water and steam systems existed. The medium temperature shift process was revamped as follows ： a steam generator was added downstream of the knock-out drum, and the orifice plate of desalted water preheater was drawn out. After the revamp, the problem of excessive heat after heat exchange has been solved. The waste heat from heat exchange could be used to generate 0.5 MPa steam for export. The annual economic benefit is 6. 048 million Yuan （RMB）. Of the 4 air coolers, 2 air coolers are operating and 2 standby instead of 4 operating before the revamping. The annual saving from electricity is 190,000 Yuan （RMB）. The utilization of 0.5 MPa steam to replace 1.0 MPa steam has reduced the steam consumption by 4 186.8 MJ/t. The inlet temperature of deaerator is brought under control, and deaeration result by the deaeration water is obviously improved, which is favorable for the long-term operation of the hydrogen generation plant.