石油学会 年会（研究発表会）

Supercritical fluids have unique physicochemical properties such as gas-like viscosity, liquid-like density, zero surface tension, and reactivity, which can be controlled by adjusting temperatures and pressures. These factors make supercritical fluids particularly suitable to upgrade unconventional crude and heavy fractions. In this talk, the use of supercritical water and supercritical methanol in the upgrading of unconventional crude oil and heavy fraction is presented. The beneficial reactions associated with supercritical fluids such as cracking, hydrolysis, and esterification resulted in reducing the acidity of high acid crudes and in increasing the light fractions. The role of supercritical fluids in the biomass liquefaction is also discussed.