Study On Corrosion Mechanism Of High Pressure Hydrocracking Desulfurization Regeneration Tower And Pipeline

In recent years,due to the increasing prevalence of high sulfur crude oil,hydrogen sulfide corrosion generated during hydrogenation and erosion corrosion under operating conditions have become common problems in the industry,easily causing various production safety issues and frequent unplanned shutdowns.MEDA desulfurization method is one of the common desulfurization methods in petrochemical production,using its characteristics to adsorb and resolve the material,and MEDA can be recycled to achieve the purpose of improving economic benefits.In addition to the chemical corrosion caused by sulfur,the changes in the flow field caused by the high speed fluid flowing in the tower and pipeline can aggravate the corrosion and also cause physical cutting on the wall.Under the comprehensive influence of many causes the tower or pipeline thinning or even leakage phenomenon,known as erosion corrosion problem.This article explores the corrosion mechanism of the high-pressure hydrocracking desulfurization regeneration tower and its auxiliary pipelines,and conducts corresponding anti-corrosion prevention and control discussions.Firstly,the model of solvent regenerating device was established by means of numerical simulation.By comparing the actual working conditions,the benchmark model built with the actual data was basically consistent with the actual device,and the errors were all within the allowable range.By comparing the results of the model calculation with the actual production,the material quantities calculated by the model were basically consistent with the actual production,and the accuracy of the model met the requirements.Through CFD software,the whole numerical simulation of regeneration tower and pipeline is carried out.The simulation results show that the corrosion of the regenerator tower is mainly located at the elbow of the reboiler return tower,near the liquid distributor of the feed and return ports,and where the top of the tower is connected with the outlet.The corrosion of regenerated tower and pipeline mainly includes flow accelerated corrosion and erosion corrosion,among which the flow accelerated corrosion of regenerated tower is more important,and the flow accelerated corrosion and erosion of elbow are mainly affected by flow accelerated corrosion.After that,the feasibility of reducing erosion and corrosion was explored by changing the parameters and operating conditions.In this paper,the main causes of corrosion at different parts of the high-pressure hydrocracking desulfurization regeneration tower and pipelines have been analyzed qualitatively and quantitatively.The corrosion rate calculated by the model is consistent with the actual operating conditions.Accordingly,corrosion prevention suggestions have been proposed through improving material materials,optimizing process conditions,and optimizing the structure of the regeneration tower and auxiliary pipelines.