连续重整装置预处理系统的腐蚀与防护

中国石油化工股份有限公司齐鲁分公司胜利炼油厂600kt/a连续重整装置预处理系统为全馏分加氢的工艺流程。为了增加对原料的适应能力,增上了脱氯反应器(原料氯含量的设计值为7μg/g)。预处理系统的原料主要由第一、二常减压蒸馏装置的常顶石脑油、部分乙烯抽提油及外购石脑油组成,石脑油经加氢反应后,由脱氯反应器脱除反应生成的HCl,在蒸发脱水塔脱水、脱硫化氢,在预分馏塔切除C6以下的组分(即拔头油),为重整催化剂提供合格的原料。装置开工运转7个月后预处理系统首次出现铵盐堵塞现象,12个月后设备开始出现腐蚀泄漏情况。针对装置的腐蚀状况,采取了水洗及增加副线等措施,同时提出了根本解决顸处理系统腐蚀问题的建议。

Corrosion in Pre-treatment System of Continuous Catalytic Reformer and Protection

The pre-treatment system of 600,000 tpy CCR unit in Shengli Refinery of Qilu Petrochemical Company is a full-range distillate hydrotreating process. In order to cope with the variation of the feedstocks, a new dechlorination unit was installed (the design chlorine is 7 ppm). The feedstock of the pre-treatment system is mainly the naphtha from the overhead of No. 1 and No. 2 atmospheric distillation units, raffinate oil of ethylene cracker and imported naphtha.After the pre-treatment, the hydrotreated naphtha then goes to the dechlorination unit to remove chlorine in the form of HC1, to vaporizer to remove water and ammonium sulfide and to pre-fractionation tower to separate C6 minus components so as to provide on-specification feed for the CCR.The pre-treatment system experienced plugging by ammonia salt 7 months after the unit came on stream and corrosion leakage 12 month after the start-up of the unit. The necessary measures are suggested to deal with the corrosion problems in addition to the water washing already implemented.