Bentonite-Metal Composite Catalyzed Heavy Oil-Water-Alcohol Three Component Reaction And Its Mechanism Research

China is rich in heavy oil resources,but the high viscosity and high pour point of crude oil cause difficulties to its recovery.Therefore,finding effective mining technologies has become a top priority.At present,there are many crude oil recovery technologies,among which steam huff and puff technology are the most widely used,and the effect of crude oil emulsification and viscosity reduction is better.However,the water content of the oil produced by these technologies is relatively high.In particular,the water content of steam huff and puff technology is generally about 30%,and it is difficult to take off water.The viscosity of crude oil remains high when the temperature drops.At present,the catalytic aquathermolysis technology of heavy oil has become a hot spot in the research and development of heavy oil exploitation technology.It can radically reduce the viscosity of heavy oil through chemical reaction and has a broad application prospect.This paper mainly uses the catalytic aquathermolysis technology to reduce the viscosity of crude oil.The two ligands are complexed with transition metals respectively,and then loaded in clay by ion exchange to reduce the viscosity of heavy oil by catalytic aquathermolysis.In addition,selecting model compounds to explore the reaction mechanism of catalytic aquathermolysis.First,the physical and chemical properties of the heavy oil were investigated,and the catalytic aquathermolysis conditions were screened.The experimental results showed that:(1)Selected heavy oil samples,the L8401 oil sample is more suitable for catalytic aquathermolysis;(2)confirmed the reaction time of the oil sample is 4h,the reaction temperature is 250 ? and the amount of water added is 3:10 by mass ratio of water/oil.The mineral type is sodium bentonite and the dosage is 0.5% of the mass of heavy oil,and the hydrogen donor is ethanol and dosage is 10% of the mass of heavy oil.A series of chromium oleate loaded sodium bentonite was synthesized as a catalyst.When the dosage was 0.5%,the viscosity reduction rate of L8401 heavy oil reached 76%,and the pour point dropped by 14.0 ?.Under the same reaction conditions,the transition metal complex of catechol salt and oleate was supported on bentonite to catalyze the viscosity reduction of heavy oil.Under optimized reaction conditions,catechol chromium-supported sodium bentonite was used as a catalyst.When the catalyst was added at 0.5%,the viscosity reduction rate of L8401 heavy oil can reach 70%,and the pour point dropped by 15.0 ?.The analysis results of heavy oil components showed that after the catalytic aquathermolysis reaction,the content of light components such as aromatic hydrocarbons and saturated hydrocarbons in heavy oil increased,while the content of heavy components such as colloid and asphaltenes decreased.TGA,DSC and GC-MS analysis results show that the content of light components in heavy oil is significantly increased after the catalytic aquathermolysis reaction.The characterization results of the model compound show that the compound undergoes reactions such as alkyl chain scission,heteroatom removal,and ring opening under the reaction conditions.After the hydrothermal cracking reaction of heavy oil,the structure of the compound in the water phase changes significantly.The reaction conditions for the catalytic aquathermolysis of heavy oil were optimized.When the viscosity reduction rate of heavy oil reaches 80%,the reaction temperature can be reduced to 180 ?,the reaction time is 4 h,the water-oil mass ratio is 3:10,n-propanol is used as hydrogen donor,alcohol/oil mass ratio is 1:5,the catalyst oil mass ratio is 1:200,and the reaction conditions are significantly reduced.