Preparation Of Supported Nanoscale Zero Valence Iron And Its Feasibility In Viscosity Reduction Of Heavy Oil

With conventional oil reserves gradually reduced and the rapid development of industrialization andeconomic increasing demands for oil, light oil resources have been difficult to meet the needs of thedevelopment of the world. The geological reserves of heavy crude oil is about three times as large asconventional crude oil all around the world, because heavy oil has high viscosity, high density and poorflowability, so the key technology for production heavy oil is viscosity reduction. Heavy oil resource canbe in-situ upgraded by aquathermolysis.In this paper, a series of modified SiO2supported nanoscale zero valence iron and its bimetallic alloycatalysts with the phase transfer function were prepared, we utilize these catalysts for Shengli oil fieldheavy oil viscosity reduction. The main research contents and results are as follows:1. Preparation and characterization of catalytic viscosity reducerModified SiO2supported nanoscale zero valence iron and its bimetallic alloy catalysts with the phasetransfer function were prepared by in situ reduction from FeCl3, NiCl2and CuCl2in aqueous solution, andtheir formation mechanism is discussed. Characterized the prepared catalysts using TEM, IR, XRD, BETand the results showed that the supported nanoscale zero valence iron and it’s bimetallic alloy (Fe/SiO2,Fe/Ni/SiO2, Fe/Cu/SiO2) were spherical, they had good dispersibility and almost no agglomerated. TheXRD showed as-prepared catalysys had microcrystalline structure. Compared with the unloaded sample,supported catalysts had smaller size with mean diameter2~5nm and the specific surface area and total porevolume were also significantly increased. Besides, supported catalysts can be transfered from water to oil.2. Evaluation of viscosity reducing effect of Shengli Oilfield heavy oilViscosity reducing effect of supported catalyst was better than unloaded sample in catalyticvisbreaking experiment of Shengli oilfield heavy oil. In general, heavy oil viscosity decreases with theincrease of the amount of catalyst, the viscosity remained basically unchanged when they reach a certainconcentration. When0.10%Fe/SiO2-2was added into the reaction system at150℃for24h, the viscosityof the heavy oil sampie is greatly reduced from184Pa·s to42Pa·s and the viscosity reduction rate reached77%. When the reaction conditions were the same, the effect of different catalysts on the viscosity reduction of heavy oil from large to small is Fe/SiO2-2> Fe/Cu/SiO2-2> Fe/Ni/SiO2-2> Fe/SiO2-3>Fe/Cu/SiO2-3> Fe/Ni/SiO2-3> Fe/Ni> Fe/Cu> Fe.3. We have discussed the effect of reaction temperature (120℃,150℃,180℃) and reaction time(12~72h) on heavy oil viscosity reduction, the results showed that the higher the temperature, the better theeffect of the heavy oil viscosity reduction. Supported catalysts had better effect of viscosity reduction ofheavy oil compared with the unloaded sample and the effect rate of viscosity reduction of heavy oil wasbetter when the reaction temperature rised to180℃. Viscosity reduction of heavy oil increased withreaction time increasing when the reaction temperature is the same. When they reached a certain reactiontime, viscosity remained stable. The optimal reaction time of Fe/SiO2-2, Fe/Ni/SiO2-2and Fe/Cu/SiO2-2was24h,48h and12h, the viscosity reduction rate reached69%,77%and72%, respectively.