Abstract: A ceramic support having a multiplicity of parallel passageways therethrough, the passageways being coated with an ultrafiltration membrane, the support having a specific surface area to volume ratio and defined permeability characteristics.

Abstract: An apparatus useful for the separation of the components of fluid mixtures by means of pressure and a permselective membrane, applicable to reverse osmosis, ultrafiltration, electrofiltration, and gaseous separation processes, comprises a shell, containing a porous body with multiple passages therethrough, with a selectively permeable membrane supported by at least a portion of the surfaces of the passages and a coating of either a semipermeable or a non-permeable material on all other surfaces except for areas left uncoated for egress of fluids from the porous body, means for passing a fluid mixture into contact with the surfaces of the body under pressure, and a conduit in fluid-tight relation to the membrane for removing fluids passing through the membrane from the porous body. Such an apparatus can be operated at high pressure because of the compressive stress exerted on the porous body when the shell is pressurized, and permits for advantageous ratios of membrane surface area to body volume.