Research On Reasons For Corrosion Of Sulfur Recovery Unit And The Protective Measures

The emission requirements of waste water and gas are much stricter as there is increasing demand for environmental protection, working depth and quality of crude oil in the refining companies of C hina. For most oil refining factories, sulfur recovery unit is used to recycle H2 S in waste water and gas to make sulfur. Since its medium is very complicated and will react under high temperature, some parts of sulfur recovery unit are inclined to get corroded, especially the acidic water tank, regenerating unit of amine, sulfur condenser, and liquid sulfur storage tank, etc. This thesis is mainly to study the corrosion and anticorrosion mechanism aiming to the four devices in Daqing Petrified Refinery Factory.In this thesis, I stimulate the corrosion environment, conduct corrosion resistance test by the means of weight- loss method, polarization curve, and impedance spectroscopy, and observe the corrosion condition with SEM, EDS analysis of chemical elements and XRD analysis of corrosion products, finally finding out the corrosion and anticorrosion mechanism1.Main material of acidic water tank is Q235 B. Test environment is acidic water under room temperature in Daqing Petrified Refinery Factory;2.In regenerating unit of amine, main material of amine liquid re- generator is Q245 R and that of rich liquor pipeline is 20#. The test environment of amine liquid regenerator is R-NH2—H2—CO2—H2O corrosion system and that of rich liquor pipeline is simulated thermal stability of salt system;3.Main material of sulfur condenser is 10#. Test medium is sulfur of 45%, and test temperature is 60℃;4.Main material of liquid sulfur storage tank is Q235 B. Test environment is saturated H2 S solution. Test temperature is 70℃.