Abstract: This invention relates to a method of manufacturing a product based on a simple or mixed metal oxide, or silicon oxide, from a charge of one or more precursors comprising one or more organic precursors. These oxides can be, for example, oxides of Ti, Al, Mg, Th, Si, Ba, Bc or Zr etc. The method comprises bringing the charge of organo-metallic precursors into contact with a reaction medium that comprises supercritical C02, at a temperature of from 31 to 100° C. and a supercritical pressure of from 3×107 to 5×107 Pa, in order to form from the precursor, a product based on a simple or mixed metal oxide, or silicon oxide, from the reaction medium by reducing the pressure of the supercritical C02 to a pressure lower than the supercritical pressure.

Abstract: The invention relates to a method of tangential filtration of a viscous fluid or liquid in which a supercritical substance is dissolved in a supercritical state in this viscous fluid or liquid so as to lower the viscosity. The invention also relates to the installation for the implementation of the method. The invention is applicable particularly to the filtration of heat sensitive organic liquids and used motor oils.