高氯原料对柴油加氢装置的影响与对策

Impact of high-chlorine feed on the operation of diesel hydrotreating unit and countermeasures

中国石油化工股份有限公司沧州分公司1.6 Mt/a汽柴油加氢装置于2013年6月因高氯原料的加入,导致高压换热器E-101A/B铵盐结晶,造成换热器换热效率下降,系统压力降增加,循环氢量下降,循环氢压缩机喘振,装置能耗增加,装置正常运行受到影响.通过对铵盐结晶的原因和危害进行深入分析,提出加强原料氯离子的监测、控制重整氢中氯质量分数小于2 μg/g、常压塔顶温度不低于120℃、反应产物去热高分温度为210～220℃、提高反应器入口温度、提高氢油比至550～ 600、增加注水点、控制总注水量、提高注水温度等相应的改进措施.经过改进后,换热器E-101A/B换热效率提高,系统及换热器压力降降低,保证了装置的正常运行,改进效果明显.

When the diesel hydrotreating unit in SINOPEC Cangzhou Petrochemical Company with a capacity of 1.6 million tons per year began to be fed with high-chlorine feedstocks in June 2013,the HP heat exchanger E101A/B suffered from ammonium salt crystallization,resulting in a decline of heat exchanger efficiency,increase of system pressure drop,reduction of recycle hydrogen,recycle hydrogen compressor surge and increase of unit energy consumption,which affected the normal operation of the unit.Through the analysis of the causes of ammonium salt crystallization and associated hazards,effective measures were recommended such as strengthening the monitoring of chlorine ions in feedstock,controlling the chlorine ions in reformer hydrogen to less than 2 ppm,the overhead temperature of atmosopheric tower at no lower than 120 ℃ and the temperature of reactor product to hot high-pressure separator within 210 ～ 220 ℃,elevating reactor inlet temperature,elevating hydrogen to oil ratio to 550 ～ 600,increasing the water injection points,controlling total water injection amount and raising water injection temperature,etc.After implementation of these measures,the heat exchanger efficiency of the heat exchanger E101A/B was improved,the pressure drop of the system and heat exchanger was lowered,the normal operation of the unit is ensured and the improvement result is obvious.