Study On Effect Of Metalloporphyrin On Hydrogenation Upgrading Of Heavy Oil

Various metallic elements were discovered in inferior heavy oil,including nickel and vanadium which are the most harmful among them.Nickel and vanadium can affect the processing and upgrading of heavy oil,such as the poisoning of catalyt during catalytic process,and promoting the coking during thermal processing.However nickel and vanadium sulfide show some catalytic activity for hydrogenation.Therefore,this paper studied the possibility of that petroporphyrins can be transformed to metal sulfide for promoting hydrogenating reaction in heavy oils,which has great significance for improving the effect of heavy oils upgrading and reducing the harm of metals.In this paper,the influence of metalloporphyrins on naphthalene hydrogenation in different reaction conditions and the hydrodemetalization products of metalloporphyrins were firstly studied.Secondly,petroporphyrins were enriched and purified from Canadian oil sand atmospheric residue(OSAR),and characterized by Fourier transform-ion cyclotron resonance mass spectrometry(FT-ICR MS).And then the structure characteristics of petroporphyrins were studied by density functional theory(DFT).Based on these results,this paper further investigated the influence of petroporphyrins on naphthalene hydrogenation in different reaction conditions.Finally the influence of metalloporphyrins and petroporphyrins on the effect of OSAR upgrading was studied in this paper.The main conclusions gained are as follows:The metalloporphyrins could markedly improve the hydro-conversion of naphthalene,with the existence of sulfur.At the early stage of reaction,the promotion effect of vanadium porphyrin on hydro-conversion of naphthalene was stronger than nickel porphyrin;With the increasing of reaction time,nickel porphyrin was stronger than vanadium porphyrin.Higer reaction pressure and temperature could enhance the effect of metalloporphyrin on hydro-conversion of naphthalene.When the reaction pressure and temperature rised above 15 MPa and 400?,that effect will increase slightly with the higer pressure and temperature.The hydrodemetalization products of metalloporphyrins were metal sulfide in the reaction.3 kinds of vanadium petroporphyrins were characterized by FT-ICR MS: N4 VO,N4VOS and N4VO2,with carbon number ranging form 24 to 61 and DBE ranging from 16 to 27.The dipole moment and stabilities of petroporphyrins in OSAR can be respectively ordered as following(from high to low): N4VO2 > N4 VOS > N4 VO > N4 Ni and N4 Ni > N4 VOS > N4 VO > N4VO2.The petroporphyrins which were same as metaloporphyrins,could also enhance the hydro-conversion of naphthalene.The viscosity,average molecular weight,number of aromatic and total rings of OSAR upgrading oil reduced by adding metalloporphyrins and petroporphyrins,especially nickel porphyrin.That indicates nickel and vanadium porphyrins could be activated and transformed to metal sulfide,and then promote the hydrogenation reactions in heavy oils,and finally enhance the upgrading effect of heavy oils.