Demetallization Of Heavy Oil Under Supercritical Fluids

Characteristics of heavy oil with high viscosity,high specific gravity and high content of heteroatoms make its' transportation and process very difficult,and particularly high mental content of Ni and V is detrimental to FCC.The effect of structure of heavy components of heavy oil and phase structure of reaction system on heavy oil demetallization has been studied by introduced supercritical fluids(SCFs).First the acceleration of pyrolysis dominated by sequential condensation of oil fraction in SCFs has been confirmed by compared the pyrolysis of heavy oil in N2 and SCW environments.Then characteristics of enrichment of metals in the heaviest asphaltenes and the higher condensation activity of asphaltenes in Tsingtao VR have been found though thermal cracking Tsingtao VR and Tahe AR in typical SCW environment.At the meantime the analysis of reactants and products with XRD,EA,HNMR etc.has been doen,which explained that Tsingtao VR got more liquid product than Tahe AR's at same rate of demetallization.Then owing to different phase structure in SCF and SCBenzene,respectively pseudo single-phase and homogeneous phase,which is more beneficial for dealkylation and consdensation,the difference of demetallization has been observed.The dispersion of metal Ni and V compound enriched in asphaltenes on account of eminent solubility in SCBenzene just obtained 50%demetallization rate even at 30%coking.Finally,based on the above research,the demetallization performance of different absorbents has been examined in benzene system.Compared with MCM-41 molecular sieve with larger surface area,modified Kaoline has more advantages in adsorption demetallizaion.