CAJ | 학술논문

延迟焦化工艺是目前渣油深度加工的主要手段，但在加工过程中会产生大量硫化氢气体并溶解于焦化酸性水中。在湿硫化氢环境中，硫化氢会电离，并与单质铁发生原电池反应，从而对设备造成严重腐蚀，常采用添加缓蚀剂的方法来减缓其对装置的腐蚀。目前评价缓蚀剂性能的指标是检测焦化酸性水中的铁离子含量，通常规定焦化酸性水中铁含量应小于3.0 mg/L。通过FeS的溶度积，计算了不同pH值、不同H2S含量的水溶液中 Fe2+的含量。结果显示：即使不添加缓蚀剂，焦化酸性水中 Fe2+的理论最大浓度也不会高于现行标准中所规定的3.0 mg/L。比较可靠的缓蚀评价方法是将腐蚀挂片或腐蚀探针悬挂于管道设备内部，其监测数据能够比较真实体现腐蚀状况。
연지초화공예시목전사유심도가공적주요수단，단재가공과정중회산생대량류화경기체병용해우초화산성수중。재습류화경배경중，류화경회전리，병여단질철발생원전지반응，종이대설비조성엄중부식，상채용첨가완식제적방법래감완기대장치적부식。목전평개완식제성능적지표시검측초화산성수중적철리자함량，통상규정초화산성수중철함량응소우3.0 mg/L。통과FeS적용도적，계산료불동pH치、불동H2S함량적수용액중 Fe2+적함량。결과현시：즉사불첨가완식제，초화산성수중 Fe2+적이론최대농도야불회고우현행표준중소규정적3.0 mg/L。비교가고적완식평개방법시장부식괘편혹부식탐침현괘우관도설비내부，기감측수거능구비교진실체현부식상황。
Delayed coking process is the primary means for deep processing of residue. However, large amounts of hydrogen sulfide gas produced in this process will dissolved in coking wastewater. H2S ionizes in a humid environment to form a galvanic cell with elemental iron, which can cause serious corrosion of equipments. Corrosion inhibitor is often used to slow down the corrosion of the unit. Currently, the content of Fe2+ in coking wastewater is the major evaluation index of inhibitor. Usually, the content of Fe2+ should be less than 3.0 mg/L. In this paper, content of Fe2+ dissolved in wastewater under different conditions was calculated by the solubility product of FeS. The results show that the content of Fe2+in wastewater even without inhibitor is less than 3.0 mg/L which was provided in existing regulations. More reliable methods to evaluate the corrosion are the corrosion coupon or corrosion probe suspended in the pipeline or equipment and its monitoring data can embody the real corrosion condition.