Study On Dehydrogenation And Desulfurization Process Of Recycled Hydrogen Sources From Oil Refinery

This thesis comes from the hydrogen system optimization project of M Refinery.At present,M Refinery uses natural gas as a raw material to produce hydrogen,which results in higher cost of hydrogen production.A large amounts of hydrogen sources in the M Refinery are discharged into the fuel gas system or flare system without recycling,It causes the waste of resources of hydrogen,light hydrocarbons and other components in refinery gas,as well as environmental pollution.This thesis analyzes the hydrogen pinch of the hydrogen system of the M Refinery to obtain some recyclable hydrogen source streams.These streams are recovered by selecting a suitable process route and designing a set of dehydrocarbon and desulfurization equipment.Using the graphical method to analyze the hydrogen system of the M refinery and finding that the recoverable hydrogen source which is below the hydrogen pinch 88.59%is 17430 Nm³/h.Relying on the existing conditions of the refinery and comprehensively considering the economics of the plan,the process route of"Oil absorption method to recover light hydrocarbons+amine desulfurization"was determined.Using Aspen HYSYS to simulate the process,and satisfying the prerequisites for the hydraulic calculation of the tower equipment,the operating conditions of the diesel absorption tower are:the absorption temperature of 40?,the catalytic diesel mass flow of 67000 kg/h,and the diesel absorption tower of 9 theoretical plates;The operating conditions of the desulfurization tower are:the operating temperature of 40?,the operating pressure of 2.25 MPa,the MDEA solvent mass flow rate of 3500 kg/h,and the desulfurization tower of 6 theoretical plates.The purified hydrogen source stream is used as the raw material of the pressure swing adsorption device,totaling 12350 Nm³/h.A total of 10.79 t/h of C₃+light hydrocarbons can be recovered through this process route.Through economic evaluation,the process has the characteristics of good economic benefits and short investment recovery period.It can be used as a reference for the refinery hydrogen source optimization,desulfurization andlight hydrocarbon removal,it also has certain practical application value.