Methanol enhanced catalytic viscosity-reduction of heavy oil by transition metal-Mannich base complex under low temperature

A series of transition metal-Mannich base complex was synthesized and screened for catalytic aquathermolysis of heavy oil and the results showed that the Ni(II)-Mannich base complex is the most effective one. The structure of catalyst was characterized by Fourier transform infrared (FTIR), ultraviolet and visible spectrophotometer (UV), and the group compositions C/H/N elemental analysis (EL), and thermogravimetric analysis (TGA) of the heavy oil were also conducted. The viscosity of the heavy oil can be decreased by 82.6% using 1.0 wt % catalyst with 15 wt % methanol in a reaction under 180°С for 24 h, and the composition analysis shows that 9.0% asphaltene is converted to resin and saturated HC. The group composition and the element content of the heavy oil before and after the aquathermolysis reaction were tested and analyzed.