Abstract: SINOPEC Henan Refining & Chemical Co.,Ltd. in order to improve the 200 kt/a alkylation unitalkylated oil yieldand solve the problem of high gasoline vapor pressure in the summer, mixing a certain amount of C₅ components from gas fractionator (C₅) to the alkylation unit, and the yield of alkylated oil was improved successfully, but during the blending of C₅, the relevant pipelines and equipments of the device were prone to clogging, resulting in the C₅ could not be blended successfully.In response to the situation, through the analysis of the clogging situation and causes, it was found that the N-methyldiethanolamines impurity carried by C₅ were the main cause of clogging of the pipelines and equipments. Then, the impurities in the C₅ were successfully removed by leading the C₅ to the water washing system of the alkylation unit, which made the mass concentration of nitrogen of the washing water in the water washing tank of the C₅ and the water samples in the total discharge of the neutralization pool be controlled stably at about 126.1mg/L and 47.4mg/L respectively, and the pH of the total discharge water sample of the neutralization pool was stabilized at the range of 6—7, which was in line with the requirements of the back-channel emission indexes. And after the water-washed C₅ was introduced into the alkylation reaction system, the differential pressure of the original easily clogged pipeline and equipment of the device was stable and controllable, and the key production parameters such as feedstock alkene ratio, reaction temperature, mass fraction of acid, acid consumption, and volume fraction of isobutane could be stably controlled at about 1.3, 3℃, 92%, 83.79kg/t, and 88.8% respectively. While ensuring the smooth operation of the plant, the high quality alkylated oil products with octane number of 94.6, Reid's saturated vapor pressure of 47.91 kPa, final distillation point of 191.1℃, density(20℃) of 695.5kg/m³ and copper flake corrosion grade of 1a were obtained, and the target of alkylated oil yield increase of 3.48 percentage points was achieved successfully, which provided strong guarantee and support for the improvement of the quality of gasoline in the refinery as well as the increase of the efficiency of the refinery.

Key words: alkylation catalyzed by sulfuric acid, alkylated oil, C₅ components from gas fractionator, water washing measures