庆阳石化分公司脱铁前后原油铁含量分布的研究

Study on iron distribution in crude oil after iron removal treatment

以中国石油天然气股份有限公司庆阳石化分公司加工的原油为研究对象,经过适当的预处理后,对原油中铁的含量、存在形态以及分布进行了研究。结果表明,庆阳石化分公司加工的原油总铁质量分数为14～18μg/g;原油中铁的存在形态以油溶性铁为主,占86%～90%,水溶性铁含量较少,占10%～14%;油溶性铁中石油酸铁约占45%,卟啉铁约占30%,非卟啉铁约占25%。在温度120℃、注水量5%/级、脱铁剂CPAS质量分数50～70μg/g、弱电场强度500～800V/cm、弱电场时间3～6min、沉降时间21min的实验条件下,使用中性原油脱铁剂CPAS对庆阳石化分公司西罐区原油进行二级脱铁处理。脱铁后油样中铁的质量分数为2.0～3.5μg/g,铁的脱除率可达80%～85%。中性原油脱铁剂CPAS能够较好地脱除原油中的金属铁,并能避免弱酸性助剂带来的腐蚀等生产安全问题,具有较好的推广应用前景。

The content, forms and distribution of irons in the crude oil processed by PetroChina Qingyang Petrochemical Co. were studied after pretreatment. The results show that the ion content in crude oil is 14 - 18 ppm, the iron is mainly oil-soluble iron accounting to 86% -90% , the water-soluble iron is low, which is 10% - 14% , the petroleum acid iron and porphyrin iron in oil-soluble iron are about 45% and 30% respec- tively, and the non - porphyrin iron is about 25 %. After 2-stage iron removal treatment of crude oil in the West Tank Farm of Qingyang Petrochemical Co. with neutral iron removal agent CPA-S under the conditions of 120 ℃ temperature, 5% injection water/per stage, 50 -70 ppm iron removal agent CPA-S, 500-800 V/cm electric field, 3 -6 minutes weak electric field time and 21 minutes settlement time, the iron in the crude oil after treatment is 2.0 - 3.5 ppm, and iron removal rate is 80% - 85%. The neutral crude oil iron removal agent CPA - S can effectively remove irons from crude oil without corrosion to the unit which is caused by weak acidic agent. The iron removal agent CPA-S is safe in operation and has a good application prospect.