Influence of nanonickl catalyst on viscosity reduction of Shengli extraheavy oil by aquathermolysis

Key words:  heavy oil  aquathermolysis  nanonickel  viscosity reduction

Abstract:

Nanonickel catalyst was synthesized by microemulsion method, characterized by transmission electron microscopy (TEM), and then used in the extraheavy oil aquathermolysis at 200 ℃. The physicochemical properties of heavy oil both before and after reaction were analyzed by using gas chromatography (GC), elemental analysis (EL), molecular weight analysis (VPO), fourier transform infrared (FTIR). The results show that the viscosity reduction ratio of extraheavy oil reaches 90.36％, the contents of resin and asphaltene decrease, and the average moleculars of heavy oil and asphaltene reduce after the catalytic aquathermolysis. The HC ratio in heavy oil, resin and asphaltene increases. The contents of sulfur and nitrogen decrease, but oxygen content increases in the heavy oil after treatment. A lot of polymerize reactions occurred in the course of aquathermolysis, and the nanonickel catalyst not only slowed down the polymerize reactions but also speeded up the aquathermolysis. The pyrolysis of asphaltene plays a very important role in synergism reactions between high temperature water and nanonickel catalyst during the catalytic aquathermolysis, and produces more substances such as alcohol, carboxylate and fatty acid which results in the viscosity reduction of heavy oil.