Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/06—Tubular membrane modules
  • B01D63/062—Tubular membrane modules with membranes on a surface of a support tube
  • B01D63/065—Tubular membrane modules with membranes on a surface of a support tube on the outer surface thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/06—Tubular membrane modules
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D65/00—Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
  • B01D65/003—Membrane bonding or sealing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/10—Supported membranes; Membrane supports
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/10—Supported membranes; Membrane supports
  • B01D69/108—Inorganic support material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/12—Composite membranes; Ultra-thin membranes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/12—Composite membranes; Ultra-thin membranes
  • B01D69/1213—Laminated layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/12—Composite membranes; Ultra-thin membranes
  • B01D69/1216—Three or more layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/02—Inorganic material
  • B01D71/022—Metals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/02—Inorganic material
  • B01D71/022—Metals
  • B01D71/0223—Group 8, 9 or 10 metals
  • B01D71/02231—Palladium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/02—Inorganic material
  • B01D71/022—Metals
  • B01D71/0227—Metals comprising an intermediate layer for avoiding intermetallic diffusion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/02—Inorganic material
  • B01D71/024—Oxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/02—Inorganic material
  • B01D71/024—Oxides
  • B01D71/025—Aluminium oxide
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/50—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
  • C01B3/501—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by diffusion
  • C01B3/503—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by diffusion characterised by the membrane
  • C01B3/505—Membranes containing palladium
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
  • F16L55/04—Devices damping pulsations or vibrations in fluids
  • F16L55/045—Devices damping pulsations or vibrations in fluids specially adapted to prevent or minimise the effects of water hammer
  • F16L55/05—Buffers therefor
  • F16L55/052—Pneumatic reservoirs
  • F16L55/053—Pneumatic reservoirs the gas in the reservoir being separated from the fluid in the pipe
  • F16L55/054—Pneumatic reservoirs the gas in the reservoir being separated from the fluid in the pipe the reservoir being placed in or around the pipe from which it is separated by a sleeve-shaped membrane
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
  • F16L55/24—Preventing accumulation of dirt or other matter in the pipes, e.g. by traps, by strainers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2313/00—Details relating to membrane modules or apparatus
  • B01D2313/02—Specific tightening or locking mechanisms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2313/00—Details relating to membrane modules or apparatus
  • B01D2313/13—Specific connectors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2323/00—Details relating to membrane preparation
  • B01D2323/58—Fusion; Welding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/02—Details relating to pores or porosity of the membranes
  • B01D2325/0283—Pore size

Definitions

• the present invention relates to a membrane assembly for permeative
• the invention further relates to a method for producing such a membrane arrangement.
• Membrane arrangements of this type are generally used for the selective separation of a gas from gas mixtures, in particular for the separation of hydrogen
• Hydrogen-containing gas mixtures eg from steam-reformed natural gas
• a thin layer such as a layer on a support or as intrinsically stable film
• a gas mixture having a certain partial pressure of the gas to be separated such as at a certain H2 partial pressure, on one side of the membrane
• Atoms / molecules of the gas to be separated endeavors to pass through the membrane to the other side until the same partial pressure of the gas to be separated exists on both sides.
• the membrane surface may be a specific gas flow of the gas to be separated, in particular a specific H2 gas flow, as a so-called
• thin membranes in the range of several ⁇ (microns) have a very low dimensional stability and rigidity, they are often as a layer on a porous, gas-permeable, tubular or planar carrier substrate, which ensures gas supply to and / or gas removal from the membrane and a flat surface provides for applying the membrane is formed.
• Metallic materials for the carrier substrate are distinguished from ceramic materials by low production costs and are relatively easy to connect to a at least superficially gas-tight and metallic coupling part, such as by welding or soldering. So can via the coupling part the Integration of the membrane assembly in a module (with several membrane arrangements of this type) or more generally in a plant within which the gas separation
• a ceramic, gas-permeable, porous, first intermediate layer is frequently provided which prevents the diffusion effects and, in many cases, also gradually
• transition from the porous carrier substrate via the cohesive connection (eg weld seam) to the dense, metallic surface of the coupling part presents a high challenge in the application of the above-mentioned layers.
• this transition region a gas-tight separation of the two gas spaces, at least as far as the ensure that other gases are contained in the gas mixture in addition to the gas to be separated.
• this transitional area represents the mechanical weak point and there are always spalling of the layers.
• the intermediate layer provided between the carrier substrate and the membrane extends beyond the connection region between the carrier substrate and the coupling part, but extends in the direction of the coupling part in front of the membrane.
• Membrane arrangement in which a dense layer in the transition region on a porous, ceramic support substrate and a gas-tight, ceramic
• the object of the present invention is a membrane assembly of the type specified above and a method for producing such a
• Transition region between the carrier substrate and the coupling part remains flat over a long dauem away with the respective substrate.
• a membrane assembly for the permeative separation of a gas from gas mixtures eg H 2 from H 2 containing
• the membrane assembly in this case has a porous, gas-permeable, metallic carrier substrate, a formed on the carrier substrate, selectively for the separated gas-permeable membrane (gas separation membrane), and an at least superficially made of a gas-tight, metallic material coupling part, wherein the carrier substrate along an edge portion of the same cohesively is connected to the coupling part.
• the gas-permeable surface of the carrier substrate is separated from the gas-tight surface of the coupling part by a boundary line.
• Coupling part extends at least to a distance of 2 mm to the boundary line, and in the same direction on the gas-tight surface of the
• Coupling part at most over a distance of 2 mm beyond the boundary line extends.
• the structure of the claimed membrane assembly is associated with several advantages, which will be described below with reference to the operation of the individual components be explained.
• the membrane is a thin, selectively for certain types of gas (especially for H 2 ) permeable layer of a material referred.
• the membrane (or its material) is selected according to the gas to be separated off (eg H 2 ).
• the other gases contained in the respective gas mixture may also have to be included in the design and material selection of the components of the membrane arrangement, for example if a component must be gas-tight for all of these gases of the gas mixture.
• the membrane may in principle be formed as an intrinsically stable foil as well as (at least) one layer on a carrier substrate. With regard to the highest possible performance parameter is in the membrane assembly according to the invention a flat trained
• Carrier substrate used for the membrane to provide the membrane as a thin layer The carrier substrate must be porous and permeable to gas in order, depending on which side of the membrane, the carrier substrate is used (in tubular design preferably inside the membrane) to ensure the gas supply to or gas removal from the membrane.
• the carrier substrate and thus also for the membrane applied thereon, there are two common basic forms, namely a planar and a tubular basic shape, wherein the focus is more and more on the tubular or tubular basic shape.
• both metallic and ceramic materials are used, wherein the presently claimed, metallic carrier substrate with respect to ceramic
• porous carrier substrates are obtained with a typical for powder metallurgy macrostructure.
• This microstructure is characterized in that the individual grains of the metal powder are recognizable, these individual grains are interconnected depending on the degree of sintering by more or less pronounced Sinterotrolse (recognizable, for example, via an electron micrograph of a micrograph).
• porous, gas-permeable, metallic carrier substrates in particular such carrier substrates produced by powder metallurgy, have a relatively large size Pore size (sometimes up to 50 ⁇ ), which significantly complicates the sealing with a typically only a few microns thick membrane (thickness in gas separation membranes in particular in the range of 5-15 ⁇ ).
• Suitable materials for the carrier substrate are in particular iron (Fe) based (ie at least 50 wt.%, In particular at least 70 wt.% Fe-containing), a high chromium content
• Carrier substrate and the (for the H 2 separation regularly also metallic) membrane which would lead over time to a degradation or destruction of the membrane.
• at least one ceramic, gas-permeable, porous is formed between the carrier substrate and the membrane
• Interlayer eg from 8YSZ, ie from a 8 mol% yttria (Y 2 0 3 ) fully stabilized zirconia
• 8YSZ 8 mol% yttria
• Y 2 0 3 8 mol% yttria
• Intermediate layer is that over them, possibly also in stages (in particular on the application of several intermediate layers, i.e., a "graded layer structure"), the pore size to a few ⁇ , in particular one for the final
• Coating through the membrane suitable average pore size in the range of 0.03-0.50 ⁇ , can be reduced.
• the layer structure (carrier substrate with intermediate layer (s) and membrane) is for the gas-tight supply and removal of the process gases with appropriate
• connection lines of the system eg reactor to connect.
• a coupling part which is at least superficially made of a gas-tight, metallic material is provided immediately adjacent to the carrier substrate.
• the carrier substrate is integrally connected to the coupling part along an edge section thereof (such as, for example, via a welding, soldering or adhesive connection). This connection can be through suitable positive and / or non-positive connections of the coupling part are reinforced with the carrier substrate.
• the coupling part is preferably a metal component which is metallic in the solid material and which is connected in a material-bonded manner to the carrier substrate. In this case, the carrier substrate and the
• Coupling part to originally two separate components is to be taken with materially connected components explicitly on an arrangement in which the carrier substrate and the coupling part are integrally formed and thus of two imaginary components that are in material contact, are constructed.
• the originally porous carrier substrate can be made gas-tight in an aftertreatment step in the areas required as a coupling part. This can be done, for example, by means of pressing or by superficial superficial melting in the required areas, for example by means of a laser beam, as a result of which the coupling part is rendered gas-tight at least on the surface.
• the gastight, metallic region of the coupling part is preferably located on the same side as the membrane on the adjacent carrier substrate, in the case of a tubular basic shape, in particular on the outside.
• the different embodiments of the coupling part and of the carrier substrate have in common that on the carrier substrate provided for the gas separation gas-permeable surface of the carrier substrate is present, while at least the surface of the coupling part is gas-tight.
• a boundary line (joint) is defined, wherein surfaces with gas-tight welds or solder joints are assigned to the gas-tight surface.
• the coupling part may have other functions, such as the Zusarrmien Adjust or division of several connecting lines meet.
• correspondingly functionalized sections can be formed on the coupling part and / or connected to it.
• the coupling part is also tubular, at least in the region adjoining the carrier substrate, and the cohesive connection extends around the entire circumference of the adjoining components.
• the first intermediate layer (and optionally further intermediate layers) and the membrane extend substantially over the entire, provided for the gas separation gas-permeable surface of the carrier substrate.
• this corresponds to the cylindrical outer surface (or possibly the cylindrical inner surface) of the carrier substrate, it being possible for at least one axial edge region (eg for attaching a connection component or a sealing end) to be recessed.
• the sealing takes place (apart from the
• the challenge addressed by the present invention is the gas-tight embodiment of the gas-tight construction, at least with regard to the further gases contained in the gas mixture in addition to the gas to be separated off (hereinafter: "further gases”)
• the first intermediate layer extends substantially over the entire gas-permeable surface of the carrier substrate, but not beyond, i. the first intermediate layer extends (apart from a production-related small gap) to the boundary line in the direction of the coupling part, but not significantly beyond. Quantified, this means that the first intermediate layer moves in the direction of the
• Coupling member on the gas-permeable surface of the porous support substrate at least to a distance of 2 mm, in particular up to a distance of 1 mm, more preferably up to a distance of 0.5 mm, extending to the boundary line, while in the same direction at most over a distance of 2 mm, preferably at most over a distance of 1 mm, more preferably at most over a distance of 0.5 mm, extending over the boundary line away.
• the first intermediate layer covers the entire gas-permeable surface of the supporting substrate, except for an area with a maximum distance of 2 mm from the boundary line, and extends except for a maximum distance of 2 mm from the area Borderline removed - not on the gas-tight surface of the assembly.
• the first intermediate layer is in direct contact with the carrier substrate. Direct contact of the first intermediate layer with the gas-tight surface, which is problematic due to inadequate adhesion, is largely or completely avoided.
• sealing in the transition region in particular serves the membrane itself or alternatively also for the other or all gases of the gas mixture gas-tight, adjacent to the membrane or overlapping trained layer, which are pulled out beyond the coupling part, and then directly abut on the coupling part and gas-tight (for the other or all gases of the gas mixture) complete.
• the first intermediate layer expediently has a smaller average pore size than the carrier substrate. This reduces the mean pore size towards the membrane and provides a smoother surface for membrane application.
• the porosity of the first intermediate layer is preferably at least 20%, wherein the determination of the porosity due to the small layer thickness and due to the most angular shape of the individual ceramic particles is associated with a relatively large measurement error.
• Intermediate layer is in the range of from 0.20 ⁇ up to and including 2.00 ⁇ , in particular in the range of from 0.31 ⁇ up to and including 1, 2 ⁇ , more preferably in the range of from 0.31 ⁇ up to and including 0.8 ⁇ if the membrane is applied directly to the first intermediate layer and no further intermediate layers are provided for a staggered reduction of the porosity in the direction of the membrane.
• the average pore size is particularly preferably smaller than 0.5 .mu.m inclusive.
• the first intermediate layer has an average particle size in the range from 0.7 to 3.5 ⁇ m, in particular in the range from 0.76 to 2.5 ⁇ m, more preferably in the range from 0.8 to 1.8 ⁇ m.
• the particle size distribution of the first intermediate layer is in the range of 0.01 to 100.00 ⁇ .
• the other ranges for the mean pore and particle sizes and the corresponding size distributions and in particular the narrower ranges are selected on the one hand to achieve good adhesion of the first intermediate layer on the substrate, on the other hand for producing a good transition to a possible second intermediate layer.
• the layer thickness of the first intermediate layer is in accordance with a development in the range between 5 - 120 ⁇ , in particular in the range between 10 - 100 ⁇ , more preferably in the range between 20 - 80 ⁇ .
• the layer thickness data for the first intermediate layer relate to the region of the carrier substrate with a substantially constant layer thickness profile, while in the Transition region to the coupling part out due to unevenness and layer thickness variations may occur. It should be noted that the material of the first intermediate layer may partially seep into the carrier substrate. In a preferred embodiment, at least one further ceramic, gas-permeable, porous, second intermediate layer is arranged between the first intermediate layer and the membrane, which has a smaller mean pore size and preferably a smaller average particle size than the first intermediate layer.
• this second intermediate layer extends in the direction of
• the invention is based on the finding that in the transition region
• the second layer further constitutes an additional diffusion barrier between the carrier substrate and the membrane and, in particular, includes a possible small production-related gap region on the gas-permeable surface of the carrier substrate in the transition region in the vicinity of the boundary line.
• a second intermediate layer having a reduced pore size and preferably a reduced particle size starting from the carrier substrate achieves a gradual reduction in the average pore size all the way to the membrane and a sufficiently smooth
• the second or optionally further intermediate layers as described below is unproblematic in this respect.
• Particularly advantageous for the second intermediate layer has a middle
• the second intermediate layer has an average particle size in the range from 0.01 to 1.00 ⁇ m, in particular in the range from 0.01 to 0.75 ⁇ m, more preferably in the range from 0.03 to 0.50 ⁇ m. In particular, lies the
• the layer thickness of the second intermediate layer is according to a development in the range between 5 - 75 ⁇ , in particular in the range between 5 - 50 ⁇ , more preferably in the range between 10 - 25 ⁇ .
• the layer thickness of the second or further intermediate layers may vary in order to avoid discontinuity, e.g. in the
• Transition region for example, to compensate at the edge of the first intermediate layer or in the region of a cohesive connection and provide a more uniform surface for subsequent layers or the membrane.
• the second or a further intermediate layer can become increasingly thinner towards the edge region and leak out or, in the region of a weld seam, e.g. be thicker. This improves the adhesion of the layer structure and reduces the risk of cracking.
• a reference for the layer thickness is therefore a position in the range of the first
• an additional layer may be provided in the transition region, wherein this additional layer does not extend over the entire gas-permeable surface of the
• Carrier substrate but only extends over the transition region. This additional layer also serves to compensate for any discontinuity in the transition region.
• the second intermediate layer can adjoin the membrane directly.
• one or more further, ceramic, gas-permeable, porous intermediate layer (s) may be provided between the second intermediate layer and the membrane, in which case preferably the mean pore size of this further intermediate layer (s) starting from the second intermediate layer to the Membrane even further decreases.
• the average pore size of the second or further intermediate layer deviates from the first or the immediately underlying intermediate layer by at least 0.10 ⁇ , in particular by at least 0.15 ⁇ , preferably even by at least 0.20 ⁇ , from the average pore size of the first intermediate layer or the immediately underlying intermediate layer. Due to the different porosity and the associated particle size good Hafrungseigenschaften favored possible stresses avoided, and it is ensured that in the manufacturing process when applying the subsequent layer, this does not penetrate too deeply into the previous layer or infiltrated.
• the different layers are in an electron micrograph of a cross-section micrograph on the basis of the regularly forming between them interfaces, which are particularly pronounced in the case of layers sintered layers, and the different pore size distinguishable from each other.
• the pore size or pore length of a single pore is determined as follows: the area of the respective pore in the micrograph is measured and, subsequently, its equivalent diameter, which would result for a circular shape of the same area size, is determined. Accordingly, the particle size is determined.
• a suitable grayscale value is selected as the threshold value.
• the pore size of all the pores of a representative region of the relevant layer previously selected in the micrograph is measured and subsequently becomes whose mean value is formed. Accordingly, the determination of the mean
• Particle size For the individual particles to be measured in each case, its geometric outline is decisive and not the grain boundaries of optionally a plurality of grains connected to a particle, each having a different, crystallographic orientation. Only the pores or particles that are completely within the selected range are included in the evaluation.
• the porosity of a layer can be determined in the micrograph (SEM-BSE image) by determining the area fraction of the pores within a selected area relative to the total area of that selected area, including the areas of the pores only partially within the selected area be involved.
• the Imagic ImageAccess program version: 11 Release 12.1 was used with the analysis module "particle analysis".
• the first intermediate layer and, if appropriate, further, provided intermediate layers are / are in each case a sintered ceramic layer (s).
• a ceramic, sintered layer is characterized by a typical microstructure, in which the individual ceramic grains are recognizable, these being interconnected by more or less pronounced sintering necks, depending on the degree of sintering (in the present, ceramic, sintered layers, the sintering necks can only be very weak).
• the typical microstructure is e.g. over a
• the individual, ceramic layers are each a wet-chemical
• the materials of the at least one intermediate layer are selected from the group of the following materials:
• YSZ yttria-stabilized zirconium oxide
• 8YSZ zirconium oxide
• Y 2 O 3 8 mol% yttrium oxide
• the ceramic intermediate layers are therefore in a preferred embodiment of the same material (or material).
• Coefficient of expansion achieved and allows a cost-effective production are YSZ, in particular 8YSZ.
• the individual layers may differ in their milieu structure, for example in the average pore size, the average particle size and the porosity.
• fully stabilized zirconium oxide eg addition of typically 8 mol% yttrium oxide with Y 2 O 3 as stabilizer
• a partially stabilized zirconium oxide eg addition of typically 3 mol% yttrium oxide with Y 2 O 3 as stabilizer.
• Further stabilizers of zirconium oxide furthermore include cerium oxide (CeO 2 ), scandium oxide (SCO 3) or ytterbium oxide (YbO 3 ).
• the carrier substrate and the coupling part are each tubular or tubular. Its cross-section is preferably circular with a constant diameter along the axial direction. Alternatively, however, it is also possible to provide an otherwise closed cross section, such as an oval cross section, as well as a cross section widening along the axial direction.
• a cohesive connection can, for example, by an integral design of the
• Coupling and the carrier substrate be formed by a solder joint, by an adhesive bond or by a welded joint.
• the cohesive connection is formed by a welded connection, which in the case of a tubular basic shape is preferably around the entire Extending circumference of the respective tubular edge portion.
• the cohesive connection is designed as a solder joint, which extends analogous to the welded joint in a tubular basic shape preferably around the entire circumference of the respective tubular edge portion.
• the solder joint is also inexpensive and reliable, it has the advantage over a welded joint that the parts to be joined are not melted and thus no distortion or no shrinkage occurs.
• An adhesive bond is also very inexpensive and has opposite to the aforementioned cohesive
• connection forms also have the advantage that they can be carried out at room temperature or at comparatively low temperatures.
• the materials used for the membrane are basically pure metals which have a certain permeability to hydrogen but which are a barrier to other atoms / molecules.
• noble metals in particular palladium, palladium-containing alloys (in particular more than 50% by weight of palladium), e.g. Palladium-vanadium, palladium-gold,
• Palladium-containing composite membranes such as with the layer sequence palladium, vanadium, palladium, used.
• the membrane is accordingly formed of palladium or a palladium-based, metallic material (eg alloy, composite, etc.).
• the Pd content of such membranes is in particular at least 50% by weight, preferably at least 80% by weight.
• the at least one intermediate layer is formed from yttrium oxide (Y 2 Os) stabilized zirconium oxide (ZrO 2 ), in particular from 8YSZ.
• the carrier substrate and the coupling part are each formed from iron-based materials.
• Membrane arrangement for the permeative separation of a gas from gas mixtures, especially for the separation of H 2 from H 2 -containing gas mixtures comprising a porous, gas-permeable, metallic carrier substrate and an at least superficially made of a gas-tight, metallic coupling part, wherein the carrier substrate along an edge portion the same cohesively connected to the coupling part.
• the method has the following steps: a. Applying a ceramic first intermediate layer directly on the
• the porous support substrate extends at least to a distance of 2 mm to the boundary line, and the first intermediate layer in the direction of the coupling part on the gas-tight surface of the
• At least one ceramic, porous gas-permeable second intermediate layer which has a smaller average pore size and preferably a smaller average particle size than the first intermediate layer, is applied to the first intermediate layer prior to application of the membrane.
• the intermediate layer containing an organic binder and ceramic particles is applied by means of a wet-chemical process and then sintered, and the subsequent layer (if appropriate in a corresponding manner) is applied only subsequently.
• Preference is given to the suspension of the second intermediate layer selected a lower viscosity than that of the first intermediate layer.
• the suspension used for the first intermediate layer has a high viscosity, whereby penetration (infiltration) of the material of the first
• the suspension of the second intermediate layer has a low viscosity, so that the sintered layer adheres well to a dense surface or to unsteady transitions.
• Fig. 1 a schematic cross-sectional view of an inventive
• Fig. 2 a schematic cross-sectional view of an inventive
• Fig. 2a an enlarged, marked with x section of the
• FIG. 3 shows a schematic cross-sectional view of a device according to the invention
• FIG. 4 shows a schematic cross-sectional view of a device according to the invention
• FIG. 6 Particle size distribution of the first intermediate layer according to FIG. 6
• Fig. 7 pore size distribution of the second intermediate layer according to a
• Embodiment of the invention. 1-4 are different, differing in construction embodiments of a membrane assembly for the permeative separation of a gas to be separated (eg H 2 ) from a gas mixture (eg steam-reformed natural gas containing CH 4 , H 2 0, C0 2 , CO, H 2 , etc.), with only the gas mixture (eg steam-reformed natural gas containing CH 4 , H 2 0, C0 2 , CO, H 2 , etc.), with only the
• Transition region is shown by the carrier substrate to the coupling part.
• a tubular, porous, gas-permeable, metallic support substrate 2 e.g., ITM
• a tubular coupling member 4 formed in solid metal (e.g., steel).
• the gas-permeable surface of the carrier substrate 2a is separated from the gas-tight surface of the coupling part 2b by a boundary line 5.
• a ceramic, gas-permeable, porous, first intermediate layer 6 e.g., sintered 8YSZ
• This first intermediate layer has a smaller average pore size than the carrier substrate 2.
• a second ceramic, gas-permeable, porous intermediate layer 7 for example made of sintered 8YSZ.
• This second intermediate layer 7 has a smaller mean pore size than the first one
• Intermediate layer on; it extends beyond the first intermediate layer 6 and runs directly on the coupling part 4. Due to their reduced compared to the first intermediate layer 6 average pore length, it can be a sufficiently smooth surface for the subsequent selectively permeable to the gas to be separated
• the second intermediate layer is in
• Transition region formed slightly thicker to compensate for the discontinuity at the edge of the first intermediate layer and a more uniform surface for the
• an additional layer 7 ' may be provided in the transition area, which serves the same purpose, an adjustment of any discontinuities.
• the membrane 8 immediately adjacent to the second intermediate layer extends in the direction of the coupling part (a) over the two
• the first intermediate layer 6 extends on the gas-permeable surface of the carrier substrate as far as the limit line 5, but not beyond. Due to the manufacturing process, only a very small area around the boundary line 5 is not covered by the first intermediate layer 6 on the gas-permeable surface of the carrier substance. According to the invention, the maximum distance d on the gas-permeable surface of the carrier substrate, which is not through the first
• Intermediate layer 6 is covered, smaller than 2 mm. All embodiments also have in common that the first intermediate layer 6 extends in the direction of the coupling part a on the gas-tight surface at most over a distance d 'of 2 mm beyond the boundary line 5 addition.
• the connection to the coupling part 4 is made by the second intermediate layer 7, which has a lower porosity, thereby better
• the integral connection is formed by a welded joint 3 ", the welding process causing a circumferential depression due to the porosity Similar to the second embodiment, direct contact of the first intermediate layer 6 with the smooth surface of the weld is avoided ,
• the coupling part 4 is formed of a porous, gas-permeable base material, in particular of the same material as the carrier substrate 2 (for example 1TM) and has only on the outside thereof
• Surface area 4a can be, for example, by applying a coating or a sealant or by superficial melting of the porous
• the carrier substrate and the coupling part are integrally formed.
• a carrier substrate in the form of a porous tube made of ITM with an outer diameter of 5-10 mm, a length of 100-300 mm, a porosity of about 40% and an average pore size of ⁇ 50 ⁇ is at an axial end of the same with a in the Solid material made of steel,
• the resulting component is annealed under a hydrogen atmosphere at a temperature of 1200 ° C. Subsequently, the surface in the area of the welded joint is sandblasted to obtain a more uniform surface. Next, the coupling part is covered with the weld.
• an 8YSZ powder in particular a powder having a d80 value of about 2 ⁇ m (and having a d 50 value of about 1 ⁇ m), a suspension suitable for a wet-chemical coating method,
• the first intermediate layer is formed by dip-coating, i. by immersing the rohrfbrmigen component in the suspension, to the beginning of
• FIGS. 5 and 6 A typical pore size distribution and particle size distribution of a first intermediate layer produced in this way is shown in FIGS. 5 and 6.
• the pore size distribution is in the range of 0.08 to 12.87 ⁇ (with an average pore size of 0.55 ⁇ ), as shown in FIG. 5 can be seen (with a few pores are not shown with a larger diameter), and the
• Particle size distribution is in the range of 0.08 - 61.37 ⁇ (with an average particle size of 1.27 ⁇ ), as shown in FIG. 6 can be seen (with a few particles are no longer shown with a larger diameter).
• a suspension of 8YSZ powder for the second intermediate layer is prepared, with the statements made above on the first intermediate layer applying mutatis mutandis, except that an overall finer 8YSZ powder is used and a slightly lower viscosity of the suspension is set than in the first intermediate layer.
• a ceramic powder a mixture of two 8YSZ powders of different particle size, in particular a powder having a d80 value of about 2 ⁇ (and with a d50 value of about 1 ⁇ ) and a very fine powder having a particle size ( crystallite size) of about 25 nm (nanometers).
• the second intermediate layer is also applied by dip coating. The second
• Intermediate layer completely covers the first intermediate layer and runs out directly on the coupling part. Any discontinuities in the transition area at the edge of the first intermediate layer are compensated by applying (brushing) of additional material. Subsequently, the obtained component is sintered under a hydrogen atmosphere at a temperature of 1,200 ° C, whereby the organic components are burned out, takes place sintering of the ceramic layer and the porous, sintered, ceramic second intermediate layer is obtained.
• the micrograph of the second intermediate layer shows in cross-section a homogeneous course, even if the material of the second intermediate layer in several
• FIGS. 7 and 8 A typical pore size distribution and particle size distribution of a second intermediate layer produced in this way is shown in FIGS. 7 and 8.
• the pore size distribution is in the range of 0.03 to 5.72 ⁇ (with an average pore size of 0.13 ⁇ ), as can be seen from FIG. 7 (with a few pores having a larger diameter are no longer shown), and the
• Particle size distribution is in the range of 0.03 to 18.87 ⁇ (with an average particle size of 0.24 ⁇ ), as with reference to FIG. 8 can be seen (with a few particles with a larger diameter are no longer shown).
• a Pd membrane is applied via a sputtering process. It completely covers the second intermediate layer as well as the underlying first intermediate layer. Finally, a further Pd layer is applied to the Pd sputter layer via a galvanic process in order to seal the latter and to achieve the required gas tightness.
• the cohesive connection is not mandatory to realize as a welded joint.
• it can also be executed as a solder joint or adhesive bond.
• the cohesive connection is not mandatory to realize as a welded joint.
• it can also be executed as a solder joint or adhesive bond.
• Coupling member and the support substrate also be formed integrally or monolithically and the cohesive connection forms the transition between the
• gas-permeable carrier substrate and the at least superficially gas-tight
• Coupling part For example, in the fourth embodiment (FIG. 4), a monolithic design of the carrier substrate and of the coupling part would also be possible. Furthermore, the structure described is suitable not only for the H2 separation, but also for the separation of other gases (eg C0 2 , 0 2 , etc.). Furthermore, alternative membranes can be used, such as microporous, ceramic membranes (A1 2 0 3 , Zr0 2 , Si0 2 , Ti0 2 , zeolites, etc.) or dense, proton-conducting ceramics (SrCe0 3-5 , BaCe0 3 -5, etc. ).

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• 2016
  • 2016-06-22 AT ATGM152/2016U patent/AT15435U1/de not_active IP Right Cessation
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  • 2017-06-14 CA CA3029060A patent/CA3029060A1/en not_active Abandoned
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