Abstract: The invention relates to semipermeable organomineral membranes usable in reverse osmosis.This organomineral semipermeable membrane comprises a porous inorganic material support coated with a vinylidene fluoride polymer or copolymer-based organic layer incorporating functional groups giving the membrane a permeability to water or other solvents.The porous inorganic material support is preferably constituted by a macroporous substrate coated with a microporous layer, e.g. produced from a single or mixed metal oxide or hydroxide. The organic layer can be constituted by polyvinylidene fluoride grafted by an appropriate monomer, such as styrene incorporating functional groups giving it selective permeability, e.g. hydrophilic groups, such as sulphonic groups.

Abstract: A hydrotreatment method, for example, hydroviscoreduction or hydrodesulfurization in which the charge of hydrocarbons is reacted with hydrogen in contact with a catalyst finely dispersed in the liquid phase. To separate the product from the catalyst, the effluent freed from its accompanying free gas is passed along, and in contact with the upstream wall of a porous inorganic membrane. The oil that has not been filtered contains a concentrate of catalyst and is recycled to the hydrotreatment reactor. The filtered oil constitutes the product of the method.