Abstract: The invention relates to a method for optimizing the conductivity provided by the displacement of H+ protons and/or OH? ions in a conductive membrane made of a material permitting the insertion of steam into said membrane, wherein said method comprises the step of inserting under pressure gaseous flow containing the steam into said membrane in order to force said steam into said membrane under a certain partial pressure so as to obtained the desired conductivity at a given temperature, said partial pressure being higher than or equal to 1 bar, a drop in the operational temperature being compensated by an increase in said partial pressure in order to obtain the same desired conductivity. The invention can be used in particularly interesting applications in the fields of high-temperature water electrolysis for producing hydrogen, of the manufacture of fuel cells using hydrogen fuel, and of hydrogen separation and purification.

Abstract: A homogeneous bulky porous ceramic material is provided, the average pore diameter D50 of which is less than 4 &mgr;m and the closed porosity of which is less than 2 &mgr;m, and having a bubble point that matches the pore diameter measured on the material. A hollow fiber based on the material and a module employing such fibers together with a paste constituting a precursor for the material and including a pore-forming agent are also provided.

Abstract: The invention is directed to a method for preparing a membrane comprising a homogeneous porous carrier, on which a layer of a molecular sieve is deposited, comprising the following steps (i) preparing an inert solution and a precursor solution of the molecular sieve; (ii) impregnating the porosity of the carrier with the inert solution and/or the precursor solution; (iii) bringing the region of the ceramic carrier intended to receive the layer of a molecular sieve into contact with the precursor solution, and bringing the region of the carrier not intended to receive the layer of a molecular sieve into contact with the inert solution; and (iv) forming a molecular sieve in situ. The invention applies e.g., to filtration or gas or liquid fluid separation, reverse osmosis or catalysis.

Abstract: A multi-channel porous ceramic fiber is provided, preferably having a particular geometry, together with a filtration and/or reaction module comprising such fibers and a precursor paste for the fiber comprising a compression binder as the extrusion binder.

Abstract: A macroporous support is disclosed, the permeability of the support varying in the direction of flow of a fluid to be treated, mean porosity increasing in the direction of flow. A method for preparing it and its use for cross-flow filtration are also disclosed.

Abstract: A method for sintering tube pre-forms in an furnace for obtaining ceramic tubes which are extremely straight is provided, in which, during sintering, the tube preforms are placed inside supporting tubes in ceramic material, the support tubes 1 containing the tube preforms being arranged parallel to each other forming stacks 7 of layers 3 supported by support plates 4 in a refractory material, the inside surface of the support tubes being out-of-true by less than 0.1 mm over a length of 90 mm.

Abstract: A fluid treatment module, particularly for treating ultra-pure fluids by separation or catalytic treatment having at least one treatment membrane in a porous sintered material comprises a rigid tube casing, a rigid compression plate at one or each end thereof having a coating compatible with the fluid(s) to be treated and at least one compensating plate able to slide on the coating, the dimensions and thickness of the compensating plate being set to ensure the module remains sealed over a complete temperature range at which the module is designed to operate.

Abstract: The present invention relates to a module for filtering, separating, purifying gases or liquids, or for catalytic conversion, comprising:- a substantially cylindrical housing (13),- at least one rigid element (4) of which at least one end (5) is substantially cylindrical and whose axis is parallel to that of the housing (13),- at least one elastically deformable metal part in the form of a ring (6), fixed firstly to the housing (13) and connected secondly to said end (5) of said element (4), characterized in that the joint between said ring (6) and said end (5) of said element (4) is a hoop fitting.

Abstract: The present invention relates to a module for filtering, separating, purifying gases or liquids, or for catalytic conversion, including:a substantially cylindrical housing (13),at least one rigid element (4) of which at least one end (5) is substantially cylindrical and whose axis is parallel to that of the housing (13),at least one elastically deformable metal part in the form of a ring (6), fixed firstly to the housing (13) and connected secondly to the end (5) of the element (4), characterized in that the joint between the ring (6) and the end (5) of the element (4) is a hoop fitting.

Abstract: Membrane apparatus for performing filtration, separation or a catalytic reaction, the apparatus including a macroporous block provided with parallel longitudinal through channels, the surface of each channel being covered with a respective membrane having finer pores than those of the block. According to the invention, the pores in both ends of said block are filled with a dense material (3) formed by a monometallic or polymetallic organic-inorganic polycondensate which has been subjected to heat treatment, this type of condensate being known under the name of ORMOSIL (organically modified silicate) or ORMOCER (organically modified ceramic).

Abstract: An organic-inorganic polycondensate characterized by the fact that it satisfies the following formula:C.sub.v H.sub.w O.sub.x Si.sub.y Me.sub.zwhere:v=4 to 48w=5 to 52x=5 to 48y=2 to 16z=1the ratio v/(y+z) being less than 7;C.sub.v H.sub.w being a carbon-containing chain carried by silicon; andMe being a metal or a mixture of metals chosen from groups IVA, VA, VIA, IIIB, and IVB of the periodic table of elements.

Abstract: A membrane for a filter device or a device for gas or liquid separation, the membrane being constituted by a porous structure made of at least one material selected from sintered ceramic, sintered metals, microporous carbon, microporous glass, and polymers, said structure including at least one microporous layer, wherein the entire outside surface and inside surface of the pores of said structure is covered by a thin and continuous film of a polyphosphazene, the thickness of said film lying in the range 0.01% to 10% of the mean diameter of the pores of said microporous layer.

Abstract: A membrane device comprising a macroporous block of sintered material with the pores at each end of the block being filled with a porous sintered material, wherein the porous sintered material comprises at least two types of grain: grains of a first type called "frame" grains having a diameter lying in the range about 1% to about 20% of the diameter of the pores in said block; and grains of a second type called "finishing"grains having a diameter lying in the range about 0.2% to about 20% of the diameter of the frame grains, with the finishing grains being received in the pores defined between the frame grains.

Abstract: A membrane for a filtration, gas or liquid separation or pervaporation apparatus comprising at least one porous layer of an inorganic material selected from sintered ceramic, sintered metal, sintered glass or carbon and a separating layer of organic material, the membrane being characterized in that said organic material is a polyphosphazene, in that the average diameter of the pores in said porous layer of inorganic material is between about 5 nm and 1 .mu.m, and in that said separating layer is continuous and only penetrates into said porous layer to a depth of less than five times the diameter of said pores in said porous inorganic layer, said layers being strongly bonded to each other.

Abstract: A method of assembling a rigid element in a module, the rigid element having a membrane for separation, filtration, or catalytic transformation purposes. The outside shape of the element is substantially cylindrical or prismatic. The element is made from a support of sintered substance, the ends thereof are sealed, and an active layer is deposited thereon. The module is intended to contain at least one rigid element within a shell which is substantially cylindrical about an axis parallel to said rigid element and closed by two end plates having openings to which the ends of the elements are fixed, together with intervening seals. Each of the ends is provided with an extra thickness which is bonded to the support. The extra thickness mass is machined in such a manner as to obtain a shoulder whose outside surface has a predetermined circularly-symmetrical shape about an axis close to that of the element.

Abstract: The fiter membrane comprises a porous structure made of a material selected from sintered ceramics, sintered metals, microporous carbon, and microporous glass, and is characterized by the fact that its entire external surface, including the inside surface of the pores in the structure, is covered with a thin and continuous film of carbon or of an oxide. In a sintered aluminum membrane, the surfaces of pores are coated with a dense and continuous thin layer of zirconia which prevents the surfaces from being degraded in service. In the figure, curve 3 shows how the throughput of a membrane without a zirconia layer falls off over time, while curve 4 shows little change in the same membrane having such a layer.

Abstract: A module (1) for rigid cylinder membrane elements (2) for separation, filtration, or catalytic transformation, the elements (2) being received in a vessel which is generally cylindrical and parallel thereto, and closed by a first end plate (4) and a second end plate (5) to which the ends of the elements (2) are fixed by means of seals (6,7). The end plates are interconnected by at least one spacer constituted by at least three juxtaposed oblong parts (10, 20, 30) made of materials selected for reducing the expansion differences that would otherwise occur on a change in the temperature of the vessel and its membrane elements.

Abstract: The filter membrane comprises a porous structure made of a material selected from sintered ceramics, sintered metals, microporous carbon, and microporous glass, and is characterized by the fact that its entire external surface, including the inside surface of the pores in the structure, is covered with a thin and continuous film of carbon or of an oxide. In a sintered aluminum membrane, the surfaces of pores are coated with a dense and continuous thin layer of zirconia which prevents the surfaces from being degraded in service. In the figure, curve 3 shows how the throughput of a membrane without a zirconia layer falls off over time, while curve 4 shows little change in the same membrane having such a layer.

Abstract: A method of treatment of polluted emulsions or micro-emulsions (10) of oil in water, said method making use of tangential filtering through at least one membrane (1) constituted by a porous microfiltration structure which is constituted by titanium oxide, at least on the surface thereof. The method can be used to regenerate emulsions or micro-emulsions of oil in water.