Hydrogenation of bitumen in supercritical water flow and the effect of zinc addition

The composition of liquid and volatile products and residue of bitumen conversion in supercritical water (SCW) flow at 400°C and 30 MPa with and without addition of zinc savings to bitumen is investigated. The yield of liquid products upon bitumen SCW conversion reaches 47.3%. The data on oxygen and hydrogen balance in the initial bitumen, products, and conversion residue indicate the chemical participation of H2O molecules in the conversion. The yield of liquid products is increased up to 62.3% if zinc is added to the initial bitumen with a simultaneous increase of the H/C atomic ratio in the products. Hydrogenation is due to hydrogen evolution during zinc oxidation by supercritical water. Under these conditions, ZnO nanoparticles with a size of 50–100 nm are formed. The data of transmission electronic microscopy and X-ray diffraction analysis of oxidized zinc demonstrate the presence of about 0.5 wt % of ZnS and about 1.2 wt % of metal zinc clusters (up to 10-nm size) in the samples. According to the sulfur atoms’ balance accounting products and conversion residue, 12.6 wt % of bitumen sulfur participates in the formation of zinc sulfide.