The Study Of The Corrosion And Protection Of The FCCU Main Fractionator's Overhead And Top-Circulation System

This paper is mainly focused on the study work of the corrosion and protection which are caused by the corrosive problems of the 300milion ton/year the FCCU main fractionator's overhead and top-circulation system in refinery of LAN Zhou petrochemical company.The paper combines the corrosive current conditions of the FCCU main fractionator's overhead and top-circulation system,and finds out the reasions of the corrosion in the fractionator overhead's condensing system and top-circulation system by the analysis of the corrosive material(sulphuer,chlorine,nitrogen)in the device feeding(residue and wax oil),the content of the corrosive medium in the fractionator overhead's condensate,as well as the failure of the pipeline in the top-circulation system.In the end,this paper judge that the fractionator overhead 's condensing system mainly occurs corrosion of HCl-H2S-NH3-HCN-H2O and the top-circulation system mainly occurs corrosion HCl-H2S-NH3-H2O.On the basis of the analysis of the above corrosive reasons,and the combination of the working condition of the devive field,we need to make pointed references to develop the study of the corrosion and protection.Through the choices of the material,injection of corrosion inhibitor and installate the corrosion monitoring probes etc.As well as raising the combination of anticorrosion measure which gives priority of the'Process Anti-Corrosion',we can control the corrosion of the 300milion ton/year the FCCU main fractionator's overhead and top-circulation system effectively.The practice manifests that after the corrosion and protection measures,which this paper studies and develops,applies in the FCCU,it releases the corrosion of the device of the fractionator overhead and top-circulation system and realize the on-time monitor to it,moreover,it ensures the device to operate for a long time,safely,steadily,full-loadly and excellently.This kind of the corrotion and protection measure has the technical advance in the domestic oil refining industry's corrosive control,thus it can widely use in the same kind devices.