Study On Viscous Oil-water-alcohol Coupling Reaction And Its Mechanism

Under the increasing demand of heavy oil development,researchers have developed a variety of viscosity reduction technologies and carried out field application.At present,steam huff and puff,steam flooding and in-situ hydro thermal cracking are usually used to improve the quality and viscosity of heavy oil.However,most of these researches stay on the preparation and application of catalytic viscosity reducer,lacking in-depth study on its viscosity reduction mechanism,and the catalytic hydro thermal cracking effect of heavy oil is poor.Therefore,based on the understanding that alcohol water reforming reaction provides abundant active hydrogen,it is of great theoretical value and practical significance to design a high-efficiency heavy oil catalytic viscosity reduction system by using the super molecular mechanism of in-situ active minerals and exogenous metal complexes to catalyze heavy oil high-efficiency hydrothermal cracking.The main contents of this paper are as follows:(1)Two typical heavy oil samples were used in the study.Firstly,the reaction time,reaction temperature,and the type and dosage of alcohols of the three components were investigated.The results show that isopropanol has obvious effect on viscosity reduction of heavy oil,and the optimal coupling reaction conditions are as follows: reaction time is 6h,reaction temperature is 180?,mass ratio is 10:3:2;(2)Typical heavy oil model compounds(?-Octene,phenol,thiophene,benzothiophene,nonylphenol,pyridine,quinoline)were reacted under the optimal reaction conditions.After GC-MS analysis,the structures of phenol and nonylphenol remained unchanged;The ring opening reaction of nitrogen-containing compound quinoline occurred,and the structure of pyridine remained unchanged;(3)After the coupling reaction of thiophene and benzothiophene with water and isopropanol,thiophene is hydrogenated in the water pyrolysis reaction,and chain breaking occurs in the coupling reaction to generate alkanes.The aromatic rings in benzothiophene are hydrogenated to produce partial or total hydrogenated products,followed by hydrodesulfurization of C-S bond and C-C bond breaking reaction,?-Chain breaking reaction of octane;(4)A series of transition metal catalysts supported on bentonite were synthesized and used in three component coupling reaction.When the reaction temperature is180?,the reaction time is 6h and the amount of catalyst Sec4 is 0.5%,the viscosity reduction rate of oil sample 1 can reach 65.78% and the pour point can be reduced by2.1?.The viscosity reduction rate of oil sample 2 can reach 61.02%,and the pour point drop range is 4.8?;The results of heavy oil component analysis show that: after synergistic catalytic coupling reaction,the content of light components such as aromatic hydrocarbon and saturated hydrocarbon increases,while the content of heavy components such as gum and asphaltene decreases;The results of TGA,DSC and GC-MS analysis showed that the content of light components increased significantly after the coupling reaction with catalyst.The experimental results show that the coordination effect of clay supported transition metal complexes in the three component coupling reaction is obvious.