WO2021129957A1 - Procédé de fabrication d'un dispositif photocatalytique, dispositif photocatalytique, composition photocatalytique et appareil de dépollution de gaz - Google Patents

Procédé de fabrication d'un dispositif photocatalytique, dispositif photocatalytique, composition photocatalytique et appareil de dépollution de gaz Download PDF

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Publication number
WO2021129957A1
WO2021129957A1 PCT/EP2020/070931 EP2020070931W WO2021129957A1 WO 2021129957 A1 WO2021129957 A1 WO 2021129957A1 EP 2020070931 W EP2020070931 W EP 2020070931W WO 2021129957 A1 WO2021129957 A1 WO 2021129957A1
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Prior art keywords
catalyst
catalytic
adsorbent
gas
carrier
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PCT/EP2020/070931
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English (en)
Inventor
Jérôme TARANTO
Original Assignee
Calistair Sas
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Application filed by Calistair Sas filed Critical Calistair Sas
Priority to PCT/EP2020/087920 priority Critical patent/WO2021130388A1/fr
Priority to US17/787,800 priority patent/US20230025309A1/en
Priority to KR1020227023480A priority patent/KR20220115593A/ko
Priority to EP20841727.9A priority patent/EP4081340A1/fr
Priority to JP2022539206A priority patent/JP2023508180A/ja
Priority to CN202080089800.9A priority patent/CN115279487A/zh
Priority to CA3157933A priority patent/CA3157933A1/fr
Publication of WO2021129957A1 publication Critical patent/WO2021129957A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/39—Photocatalytic properties
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L9/00—Disinfection, sterilisation or deodorisation of air
    • A61L9/16—Disinfection, sterilisation or deodorisation of air using physical phenomena
    • A61L9/18—Radiation
    • A61L9/20—Ultraviolet radiation
    • A61L9/205—Ultraviolet radiation using a photocatalyst or photosensitiser
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
    • B01J21/063—Titanium; Oxides or hydroxides thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/32—Manganese, technetium or rhenium
    • B01J23/34—Manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
    • B01J29/7003—A-type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/19—Catalysts containing parts with different compositions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
    • B01J37/0027—Powdering
    • B01J37/0045—Drying a slurry, e.g. spray drying
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0215—Coating
    • B01J37/0221—Coating of particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/04—Mixing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
    • F24F8/10—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering
    • F24F8/15—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering by chemical means
    • F24F8/167—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering by chemical means using catalytic reactions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/102—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/106—Silica or silicates
    • B01D2253/108—Zeolites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/30—Physical properties of adsorbents
    • B01D2253/302—Dimensions
    • B01D2253/306—Surface area, e.g. BET-specific surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20707—Titanium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/2073—Manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/80—Type of catalytic reaction
    • B01D2255/802—Photocatalytic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/92—Dimensions
    • B01D2255/9202—Linear dimensions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
    • B01D2257/702—Hydrocarbons
    • B01D2257/7022—Aliphatic hydrocarbons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
    • B01D2257/702—Hydrocarbons
    • B01D2257/7027—Aromatic hydrocarbons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
    • B01D2257/708—Volatile organic compounds V.O.C.'s
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/91—Bacteria; Microorganisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/06—Polluted air
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2259/00—Type of treatment
    • B01D2259/80—Employing electric, magnetic, electromagnetic or wave energy, or particle radiation
    • B01D2259/804—UV light
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8668—Removing organic compounds not provided for in B01D53/8603 - B01D53/8665
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/88—Handling or mounting catalysts
    • B01D53/885—Devices in general for catalytic purification of waste gases

Definitions

  • the invention relates to a method for manufacturing a catalytic device. According to another aspect the invention relates to a catalytic device obtainable via such a method. According to another aspect the invention relates to a catalytic composition. According to another as pect the invention relates to a gas depolluting apparatus, comprising such a catalytic device and/or catalytic composition.
  • Contaminants within gases can be of various types. They can be divided into particles, gaseous or volatile chemical contaminants and biological contaminants. Biological contaminants are microor ganisms such as bacteria, fungi including their spores or mites as well as viruses, phages and the like.
  • VOC Volatile Organic Compounds
  • VOC are usually defined as compounds that contain at least one carbon atom and one or more atoms of hydrogen, halogen, oxygen, sulfur, phosphorus and/or silicon and that have a vapor pressure of at least 0,01 kPa at a temperature of 20 °C or a certain volatility under certain circumstances.
  • Carbon oxides and inorganic carbonates or bicar bonates are usually not considered to be VOC.
  • VOC therefore represent a wide range of different substances which have in common that they easily evaporate or sublime. Exam ples of volatile or gaseous contaminants are formaldehyde, carbon monoxide, nitrogen ox ides, ozone or radioactive substances like radon.
  • HEPA filters filtering particulate contaminants as well as some biolog ical contaminants. Therefore they have the disadvantage that they need to be cleaned or replaced after a certain time.
  • microbiological contamination of the filters can lead to the production and secretion of possibly harmful or toxic substances from bacteria or the like, which are then carried with the gas flow.
  • these toxic substances can be endotoxins formed after lysis of some gram-negative bacteria cell walls or VOC from microorganism decomposition on filters.
  • Vulnerable microorganisms such as Staphylococ cus epidermidis, E.
  • coli or Brevundimonas diminuta can survive for 2 - 6 days on such a filter.
  • Robust biological contaminants such as Bacillus atrophaeus, MS-2 Coliphage, and Aspergillus brasilensis survive more than six days. Bacillus atrophaeus can remain viable for more than 210 days. Therefore the use of such filters can lead to an additional contam ination of the gas to be cleaned.
  • the biological contaminants can lead to a saturation of the filter which leads to an increased flow resistance.
  • the saturation of the filter by biological contaminants, which are filtered and afterwards additionally colonizing the filter surface can lead to a global decrease of the performance of a gas depolluting apparatus.
  • a high energy is used to form oxygen ions, e.g. by a high voltage or with specific lamps. These accumulate on the surface of particulate contaminants, such as dust, and promote the formation of larger clusters, which can then be filtered or descend to the floor.
  • ozone can be generated which on the one hand is disin fecting but on the other hand may cause allergies or be harmful for people nearby.
  • ozonation ozone is formed which is highly reactive and a strong oxidizing agent. It reacts both with microbiological and chemical contaminants.
  • a disadvantage is that not all of the generated ozone directly reacts with contaminants so that again ozone may be harm ful to people nearby.
  • Catalysts are used in many industrial fields.
  • a catalyst is a substance which is able to cata lyze reactions, namely to increase the rate of a chemical reaction without being consumed in the reaction.
  • One specific field is the use of catalysts for depolluting gases such as air, especially ambient air, or exhaust or process gases. They can be used in air conditioning systems or air purifying systems for cleaning ambient air in hospitals, quarantine stations or public places like restaurants or public authorities and the like.
  • Catalysts having a photocatalytic activity are known in the state of the art. They are often referred to as photocatalysts and are usually semiconductors.
  • a photocatalyst is UV activatable. When the UV activatable photocatalyst is irradiated with UV radiation, namely electromagnetic radiation with a wavelength of about 100 nm to about 400 nm, it is then activated and therefore able to catalyze reactions.
  • UV radiation namely electromagnetic radiation with a wavelength of about 100 nm to about 400 nm
  • On the surface of the catalyst for exam ple water is reacted to highly reactive OH-radicals, which are then reacting with contami nants.
  • molecular oxygen can be reacted to the so called ROS (reactive oxygen species), especially the superoxide anion.
  • ROS reactive oxygen species
  • UV radiation When using photocatalysts for gas depollution, usually a source of UV radiation needs to be present. These radiation sources usually consume a high amount of energy and only have an energy efficiency of 30 - 40 %. Thus, only 30-40 % of the energy is used to activate the photocatalyst.
  • each stage contains a specific compound, for example one stage contains titanium dioxide, one stage contains manganese monoxide and one stage contains a zeolite. These are provided one after another in a direction of flow of a gas to be depolluted.
  • catalytic compositions for gas depollution consist of an adsorbent which is loaded with precursors of manganese oxide, e.g. a manganese acetate, and partly with a precursor for titanium diox ide, e.g. butyl titanate. Afterwards the adsorbent with the precursors is calcined at temper atures of 300 °C or higher, thereby forming manganese oxide and titanium dioxide. Due to the high calcination temperature, predominantly or solely manganese dioxide is formed.
  • precursors of manganese oxide e.g. a manganese acetate
  • titanium diox ide e.g. butyl titanate
  • a catalytic composition consisting of a manga nese oxide, titanium dioxide and an adsorbent. These are bound to a solid support via a binder.
  • the binder partly covers the catalysts and therefore only a reduced amount can be reached by activating UV radiation and the molecules to be cracked.
  • a suspension of the components is impregnated into a porous body or a fabric. These however provide a high flow resistance to a gas to be depolluted. Therefore it is not possible to efficiently clean large amounts of gases per time unit.
  • the ratio second catalyst may not exceed an amount of 22% of the titanium dioxide in order not to deteriorate the activity of the titanium dioxide.
  • the invention achieves this objective with a method for manufacturing a catalytic device, with the steps: a) providing a first catalyst having photocatalytic activity, a second catalyst, different from the first catalyst, and an adsorbent, each in a powdered state, b) mingling the first catalyst, the second catalyst and the adsorbent to obtain a catalytic composition and suspending them in a suspension liquid to form a slurry, and c) repeatedly coating the slurry onto a solid grid-like carrier having a plurality of through holes, configured to allow a gas to flow through the carrier, and evaporating the suspension liquid.
  • a mixture of the first catalyst, the second catalyst and an adsorbent each in a powdered state can - if suspended in a suspension liquid, which for example is demineralized water or a solution of demineralized water and ethanol, and then repeatedly applied to a solid carrier, adheres well to the carrier and forms an effective catalytic device.
  • a suspension liquid which for example is demineralized water or a solution of demineralized water and ethanol
  • An advantage of the combination is that it has a high depolluting efficiency and at the same no microbial growth takes place on the catalytic device as is the case on simple filters. Furthermore it is possible to not only destroy contaminants but also byproducts of the de struction process which can be undesired or harmful as well. Preferably it is possible to depollute gases that contain only a few ppb up to a few hundred ppm of contaminants.
  • the first catalyst, the second catalyst and the adsorbent are provided as distinct powders. On the one hand this makes it easier to handle, since no precursors or the like are to be impregnated onto another substance. On the other hand in some embodiments this is chemically necessary, since for example calcination temperatures of the individual compo nents are different so that forming or treating two components at the same time can be impossible.
  • the mingling of the first catalyst, the second catalyst and the adsorbent is preferably per formed before suspending them in the suspension liquid.
  • a mixture of the com ponents is made, which is then introduced into the suspension liquid to form the slurry.
  • the suspension liquid is preferably a liquid or solution in which none of the components is soluble. This is preferably the case when the solubility of the first catalyst, the second cat alyst and the adsorbent each lies below 1 g/l of the suspension liquid, more preferably below 0.1 g/l.
  • the slurry is repeatedly applied to the grid-like carrier. This means that it is applied in more than one layer and applied at least twice, preferably at least five times, more preferably at least ten times. Preferably the slurry is not applied more than 100 times, more preferably not more than 50 times. That the slurry is applied repeatedly means preferably that in each repetition or passage at least 50 % of the surface, more preferably at least 75 % of the surface, most preferably at least 90 % of the surface, especially each time the complete surface is coated with slurry.
  • the slurry is coated onto the grid-like carrier it forms a layer on the surface of the carrier and/or the layer of coating below.
  • the coating becomes preferably not too dense so that many of the catalyst molecules are available for reactions and for activation with UV radiation.
  • the suspension liquid is evaporated, for example by heating or preferably under air flow especially without additional heating.
  • This obviously includes capillary bound suspension liquid, which is not evaporated during a nor mal evaporation process, e.g. at 100 °C - 150 °C.
  • the suspension liquid is not fully but partly evaporated, for example at least 75 % of the suspension liquid is evaporated, before a next layer is applied.
  • no suspension liquid or only a part of the suspension liquid not exceeding 25 % is evaporated before applying a new layer. The less suspension liquid is evaporated before applying a new layer, the less time consuming is the procedure. The best results are usually obtained after evaporating as much suspension liquid as possible before applying a new layer.
  • the carrier can for example be formed from a metal, such as aluminum or steel, a plastic material or a composite material. It can for example be formed as a grid, a plate or an expanded metal.
  • the carrier is shaped from a corrugated and/or folded sheet forming a plurality of through holes, preferably in a honeycomb manner. Ad vantages of a honeycomb panel compared to a plane material are a larger surface to be coated and a lower pressure drop. Also the irradiance within the cells is better.
  • the carrier is then often simply referred to as a honeycomb or honeycomb panel.
  • the through holes have a hexagonal cross section.
  • the through holes account for at least 80% of the volume of the carrier, more preferably for at least 85 %, most preferably for at least 90 %, especially of at least 95 % of the volume of the carrier.
  • the supporting structure of the carrier is provided thinly, for example in the form of thin metal, preferably aluminum, or another inert material.
  • Aluminum provides the advantage of being lightweight and sufficiently inert, so that the catalysts are not attacking the carrier itself in a critical manner.
  • the through holes preferably have a length, along which the gas can flow through the car rier, of at least 1 cm, more preferably at least 2 cm. Preferably the length does not exceed 20 cm, more preferably 10 cm.
  • the length of the holes which usually equals the thickness of the grid-like carrier, has great influence on the efficiency of the depollution. If the length is too short, the catalytically active surface provided is low and therefore the depollution is not efficient. If the length is too high, the UV radiation will not or not sufficiently reach the photocatalyst in the center of the holes, so that a part of the provided photocatalyst is not activated. Furthermore it is difficult to satisfactorily coat the center parts of long through holes.
  • the ratio between length and diameter of the holes can be important.
  • the ratio is preferably larger than 2, more preferably larger than 5, especially larger than 10 and preferably not larger than 50, more preferably not larger than 30, especially not larger than 20.
  • the diameter of an approxi mated circumscribed circle or a circle approximated via the least squares method may be used to determine the diameter for calculation of the ratio.
  • the diameter of the holes pref erably is at least 2 mm, more preferably at least 5 mm, especially at least 7 mm.
  • the diameter of the holes does not exceed 50 mm, more preferably 20 mm, especially 10 mm.
  • the through holes preferably run straight and are not curved or angled along their length.
  • the ratio between the diameter of the through holes and the thickness of the bars or sheets of the carrier separating neighboring through holes is preferably larger than 10, more pref erably larger than 20, especially larger than 40.
  • the slurry is binder-free. This means that no additional inorganic or organic binder is added, to enhance the adherence of the first catalyst, the second cata lyst and the adsorbent on the carrier.
  • Binders for example are cellulose and its derivatives, certain proteins or polymers and inorganic binders such as silica or alumina. Residual amounts of the suspension liquid, for example capillary bound, are not considered a binder. Also water, for example deriving from atmospheric humidity, is not considered a binder.
  • a slurry is still considered binder-free, as long as it does not exceed an amount of binder of 2 % in relation to the total mass of the adsorbent, the first catalyst and the second catalyst. Especially there is no matrix of binder molecules formed around the cata lysts and the adsorbent on the carrier after evaporating the suspension liquid.
  • the slurry can be applied to the carrier by various methods, including dipping.
  • the slurry is applied via spray coating.
  • Spray coating resulted in a very durable and consisting coating, especially without the need for providing a separate binder to the slurry.
  • the coating preferably resists an air pressure of up to 4 bars, especially without using a binder.
  • the slurry is preferably applied with a spray gun.
  • a manual spray gun is used, which especially is a low-medium pressure spray gun, for example with a maximum pressure P max of 8 bar. It preferably has a gravitational suction cup.
  • the spray coating is preferably performed vertically.
  • the inlet pressure is 3.5 bar and the liquid flow is 2.5 - 3.0 liters per minute.
  • the distance between the carrier and the spray gun preferably lies between 10 and 30 cm, preferably at about 15 cm. With the above mentioned exemplary parameters, good coating properties were achieved. Specifically the coating adhered satisfactorily to the carrier, which preferably is an aluminum honeycomb
  • the coating preferably has a total thickness of at least 50 pm, preferably at least 75 pm, especially at least 100 pm.
  • a coating of such thickness especially provides a satisfactory amount of catalyst for gas depollution.
  • the thickness does not exceed 500 pm, more preferably does not exceed 350 pm, and especially does not exceed 250 pm.
  • a pre ferred range lies between 100 pm and 250 pm. If the coating is too thick, it is possible that lower layers are not sufficiently irradiated and/or not sufficiently reached by contaminants to be depolluted. It can therefore lead to a waste of catalytic molecules.
  • the first catalyst can for example consist of tungsten oxide and/or zinc oxide. It is preferred but not necessarily the case that only one type of first catalyst is used. It is also possible to use more than one catalyst having photocatalytic activity.
  • the first catalyst is titanium dioxide PO2.
  • Titanium dioxide is very well known for its photocatalytic properties. It is a semiconductor and can be activated by irradiation with UV radiation of a wavelength from 100 nm to 400 nm.
  • the UV radiation used for activating the first catalyst, especially titanium dioxide has a wavelength of 365 nm or less, more preferable in the UV-C range between 100 nm and 280 nm, most preferably of 254 nm.
  • the use of UV radiation in the UV-C range has the advantage of additionally using the direct disinfecting properties of the UV-C radiation. UV-C radiation therefore acts directly biocidal due to its high energy and indirectly biocidal as well as on non-biological contaminants by activating the first catalyst.
  • the titanium dioxide can be al ready photo-activated.
  • any kind of UV radiation emitting sources or light sources can be used, for example artificial lamps emitting UV radiation or light emit ting diodes or fluorescent tubes emitting UV radiation or UV radiation formed by cold plasma-type electrodes.
  • Titanium dioxide has the advantage of being cost-efficient and having the ability to at least partly regenerate itself. It is highly active against different contaminants, including chemical and biological contaminants.
  • titanium dioxide in the crystalline form of anatase has the highest catalytic activity. Therefore it is one embodiment of the invention that the titanium dioxide completely is of the anatase type.
  • the first catalyst is titanium dioxide T1O2 in the form of a mixture of anatase and rutile with an anatase/rutile ratio between 60/40 and 99/1.
  • the ratio is at least 60/40, more preferably at least 70/30 and especially at least 80/20.
  • the ratio is preferably not exceeding 99/1 , more preferably not exceeding 95/5, and especially not exceeding 90/10.
  • the ratio is between 77/23 and 83/17, especially 80/20.
  • the first catalyst, especially titanium dioxide is doped, especially with silver ions or platinum ions. Doping of the first catalyst increases the biocidal effect on biological contaminants and on the destruction of possibly harmful byproducts of the destroyed contaminants. The presence of the doping ions increases the number of possible oxidation and reduction reactions.
  • the second catalyst is a low-temperature catalyst.
  • a low temperature catalyst preferably is a catalyst being already catalytically active at temperature lower than 100 °C, more preferably at temperatures lower than 50 °C, most preferably already at room temperature of 20 °C. This does however not imply, that it must be inactive at higher temperatures.
  • the catalytic activity is increased with increasing temperature at least over a certain temperature interval, preferably 20°C to 100 °C or 50° C to 100 °C.
  • Low-temperature catalysts are for example metal oxides like nickel oxide or cerium oxide.
  • the second catalyst is manganese monoxide MnO, which is an efficient low- temperature catalyst. Explorations of the applicants have shown that manganese monoxide is significantly more efficient than the well-known manganese dioxide MnC>2, whose catalytic activity is insufficient. Therefore preferably the manganese monoxide used in this embodiment is not or substantially not contaminated with manganese dioxide.
  • the amount of manganese dioxide is lower than 5 %, more preferably lower than 1 %, most preferably lower than 0.1 % of the total mass of the manganese monoxide used as second catalyst. Optimally, no manganese dioxide is present as an impurity of the manganese monoxide second catalyst.
  • Manganese monoxide allows the generation of highly reactive radical species when in contact with oxygen, for example from the air.
  • the temperature is higher than 35 °C, especially between 35 °C and 55 °C, more preferably between 45 and 50 °C.
  • the relative humidity of the gas to be depolluted, especially air is between 30 - 80 %, more preferably 50 %. Under these circumstances a very efficient generation of the radical species is possible.
  • the radical species are able to react also with very small contaminants in the nano or micro scale, such as aldehydes like formaldehyde, which are usually hard to crack. This is, inter alia, because such small molecules are hard to be trapped.
  • Hydrophilic catalysts are usually quickly saturated with water or other polar small molecules so that hardly any sites are available for small contaminants to be trapped and then oxidized.
  • Manganese monoxide offers the specific advantage that it is only poorly reacting with water and trapping water molecules on its surface so that more sites are avail able for contaminants.
  • the cavities within the manganese monoxide are pref erably smaller than those of the titanium dioxide so that larger molecules are trapped less and, again, more sites remain available for small contaminants.
  • the radical species also react with biological contaminants.
  • a disadvantage of manganese monoxide is that it is unstable compared to manganese di oxide. Therefore, when synthesizing manganese monoxide, special care needs to be taken on the reaction parameters, when the formation of manganese dioxide is to be avoided, as preferred.
  • One important reaction parameter is the temperature. When using a calcination temperature higher than 300 °C, a substantial amount or solely manganese dioxide is formed.
  • titanium dioxide from precursors usually requires temperatures of more than 300 °C, for example 300° C - 600 °C, a simultaneous calcination of manganese monoxide precursors and titanium dioxide precursors to form manganese monoxide on the one hand and titanium dioxide on the other hand, is impossible.
  • a calcination temperature of higher than 600 °C during the formation of the titanium dioxide may lead to an excessive formation of rutile, which is undesired.
  • a certain amount of rutile as described above, enhances the efficiency of the catalyst.
  • the first catalyst is titanium dioxide and the second catalyst is manganese monoxide, preferably no simultaneous calcination takes place.
  • the synthesis of the first catalyst, the second catalyst and/or the adsorbent is part of the manufacturing method of the catalytic device. Preferred embodiments of the synthesis will be explained in detail below. If at least the synthesis of titanium dioxide as first catalyst and manganese monoxide as second catalyst is part of the manufacturing method, no simultaneous calcination of their precursors prefer ably takes place. They are preferably synthesized apart from each other.
  • One advantage of using a low-temperature catalyst, especially manganese monoxide, is that the necessarily accruing waste heat of the UV radiation source can be used to warm the low-temperature catalyst thereby increasing its catalytic efficiency.
  • a synergy can be achieved when combining a photocatalyst and a low-temperature catalyst in one stage and preferably arrange them spatially close to the UV radiation source in order to use the waste heat efficiently.
  • a temperature of up to 40 °C, up to 50 °C or up to 90 °C can be achieved on the surface of the catalytic device.
  • the adsorbent is preferably a compound having a large specific surface area, preferably of at least 300 m 2 /g, more preferably of at least 500 m 2 /g, most preferably of at least 1000 m 2 /g, especially more than 2000 m 2 /g.
  • the adsorbent can for example be activated carbon or activated coke.
  • the adsorbent is a zeolite.
  • Zeolites are microporous aluminosili cate minerals which can be naturally occurring or artificial. Zeolites can be synthetic.
  • a hydrophilic zeolite is used, as explorations of the applicant show that biological contaminants tend to be better adsorbed by a hydrophilic than a hydrophobic zeolite.
  • a zeolite of type A or ZSM-5 is used.
  • the zeolite is preferably a synthetic zeolite, especially a synthetic zeolite of type A or ZSM-5. Synthetic zeolite has the advantage of being pure and having a homogenous structure due to the fact that is synthesized.
  • the first catalyst is titanium dioxide
  • the second catalyst is manganese monoxide
  • the adsorbent is a zeolite.
  • the zeolite is preferably a synthetic hydrophilic zeolite of type A. These configurations are preferred for all applicable embodiments described herein.
  • Hydrophilic zeolite of type A has a high affinity to chemical and biological contaminants and no natural equivalent. It has an affinity to the cellular membranes of microorganisms. These adsorb to the surface of the zeolite for electrostatic reasons. Additionally, the hydrophilic zeolite of type A has a direct antimicrobial effect, which makes its use even more synergis tic. Hydrophilic zeolite of type A has a crystal structure formed from an anionic aluminosili cate structure, neutralized by alkaline or alkaline earth metal cations.
  • the zeolite especially the zeolite of type A comprises a sodalite crystal structure.
  • the structure of the zeolite links multiple elementary sodalite cages.
  • a sodalite cage con sists of multiple polyhedrons with eight hexagonal faces and six square-shaped faces.
  • the sodalite cages forming the zeolite are interconnected via the square-shaped faces.
  • the specific structure of the sodalite cages gives the zeolite an open 3D structure, whereby especially 47 % of the total volume is formed by interstices. Therefore the zeolite provides a large surface for adsorption of biological and chemical contaminants within a small vol ume. Additionally the open 3D structure allows for a high water absorption and retention capacity. Since water can be used to form highly reactive radical species like the hydroxyl radical on the surface of the catalysts, this can be advantageous.
  • the water retention capacity may, depending on the circumstances, ensure that no water film is formed on the catalysts, thereby degrading their efficiency.
  • a very high amount of adsorbent, especially zeolite may provide for a water excess, thereby degrading the efficiency of the catalysts.
  • the amount of adsorbent therefore does not ex ceed 80 %, especially does not exceed 70 % of the total mass of first catalyst, second catalyst and adsorbent.
  • the amount of adsorbent preferably is not lower than 40 % especially not lower than 30 % of the total mass of first catalyst, second catalyst and adsorbent.
  • the applicants have explored that the combination of two different catalysts and an adsor bent is synergistically effective for depolluting a gas.
  • the contaminants are adsorbed onto the adsorbent. By way of the mass transfer phenomenon, they migrate to the catalyst par ticles.
  • the generation of reactive species on the surface of the catalysts then leads to de struction of the contaminants, preferably to complete mineralization of the contaminant.
  • byproducts during the destruction of the contaminants are preferably destroyed further so that no possibly harmful byproducts are released into the depolluted gas or are released but destroyed within one of the next depolluting cycles.
  • the adsorbent can thereby also form a reservoir for pollutants to be destroyed, for example during a peak load of the gas with contaminants.
  • an amount of contaminants that would exceed the catalytic capacity of the catalysts per time unit can therefore preferably be held back by the adsorbent and then be guided to the catalysts with a time delay. This makes it possible to also treat peak loads that would, without adsorbent, exceed the capacity of the catalysts per se.
  • the amount of the adsorbent is preferably higher than the amount of each catalyst and/or the cumulated amount of the catalysts, with respect of the total mass of the first catalyst, the second catalyst and the adsorbent.
  • the adsorbent is holding back contaminants which are then transferred to the catalysts via mass transfer. On the other side, by this phenomenon, the adsorbent is constantly regen erated and its adsorbing capacity restored. This demonstrates a real synergy of providing these compounds within one mixture. In order to optimally achieve this effect, the mingling of the catalysts and the adsorbent is preferably performed intensively, especially to provide a mixture as homogenous as possible.
  • the amount of the first catalyst is preferably at least 10 %, more preferably at least 20% and does preferably not exceed 30 %, especially does not exceed 40 % of the total mass of the first catalyst, the second catalyst and the adsorbent.
  • the amount of the second cat alyst is preferably at least 5 %, more preferably at least 10 %, especially at least 15 % and does preferably not exceed 20 %, especially does not exceed 30 % of the total mass of the first catalyst, the second catalyst and the adsorbent.
  • the components are provided in the following ranges, in weight percent with regard to their total mass: Between 27% and 30% of the first catalyst, between 11 % and 17% of the second catalyst and between 55% and 59% of the adsorbent.
  • a specific and preferred embodiment contains an amount of 29 % of the first catalyst, 12 % of the second catalyst and 59 % of the adsorbent.
  • this ratio shows a good efficiency as well as satisfying water retention capacities and contaminant retention capacities. With these amounts an especially sustainable and long lasting composition is provided that also pro vides very good depolluting attributes. Additionally, the amount of UV radiation needed to activate the titanium dioxide in this amount provides for a sufficient and useful amount of waste heat to increase the catalytic activity of the second catalyst in this amount, when the second catalyst is a low-temperature catalyst.
  • this invention relates to an embodiment in which the amount of the first catalyst is lower than 27 % and higher than 30 %, the amount of the second catalyst is lower than 11 % and higher than 17 % and the amount of the adsorbent is lower than 55% and higher than 59%, each in weight percent and with regard to their total mass. All further preferred configurations and embodiments described herein apply to this specific embodiment.
  • the synthesis of the first catalyst, the second catalyst and/or the adsorbent is part of the manufacturing method of the catalytic device.
  • the syntheses each are performed apart from another.
  • the first catalyst is titanium dioxide
  • it is preferably synthesized by using a sol-gel process and precursors like titanium tetrachloride or butyl titanate, followed by a calcination at temperatures of 300 - 600 °C.
  • sol-gel process for synthesizing the titanium dioxide first catalyst in a powdered form is now described in detail:
  • the precursor titanium tetrachloride is mixed with absolute ethanol in a ratio between 0.5:10 and 3:10, preferably with a ratio of 1:10, for4h at room temperature.
  • the formed sol is then placed in an ultrasonic bath for a time of 20 to 40 minutes, preferably 30 minutes. Consec utively the sol is dried at a temperature of 100 °C and 130 °C, preferably 120 °C for a time between 1h and 24h, preferably 7h in order to obtain a powder.
  • This powder is then pro gressively calcined at a temperature between 530 and 570 °C, preferably at 550 °C, for 2h to 3h, preferably 2h. Thereby the temperature is increased in steps of 10 - 12 °C/minute.
  • the obtained powdered titanium oxide is then cleansed with deionized water and consecu tively dried at a temperature between 90 and 110 °C, preferably 100 °C.
  • the second catalyst is, as preferred, manganese monoxide, it is preferably synthesized from precursors like manganese acetate, manganese nitrate and/or manganese sulfate fol lowed by a calcination at temperatures below 300 °C.
  • a precursor, preferably manganese acetate, is mixed with a solution of potassium perman ganate in a ratio in mol/l of 1 ,8/1 ,2 for at least 24 h at room temperature between 21 and 25 °C. Afterwards it is filtered and rinsed with deionized water. The obtained powder is calcined for several hours, preferably 72h, with an increase in temperature of 6°C/min until a tem perature between 280 and 300 °C is reached. The result is rinsed with deionized water and consecutively dried at 100°C until the powdered manganese monoxide is obtained which can then be used. In order to obtain a well useable powder, the liquid is preferably fully evaporated.
  • the low temperature below 300 °C is used to avoid the formation of the more stable but undesired manganese dioxide.
  • the adsorbent is a synthetic hydrophilic zeolite of type A, it is preferably synthesized as follows:
  • Step 1 Providing a sodium hydroxide solution by mixing of sodium hydroxide, for example pellets of sodium hydroxide, in distilled water with a ratio of 110:1 to obtain a homogenous sodium hydroxide solution.
  • Step 2 Dividing the sodium hydroxide solution into two equal parts, thereby obtaining a first volume and a second volume of sodium hydroxide solution.
  • Step 3 Crystalline odium aluminate is, volume per volume and within 10 to 20 min, mixed to the first volume up to 17 % to obtain a solution A.
  • Step 4 Crystalline sodium silicate Na 2 Si0 3 is, volume per volume, solved in distilled water up to 57 % to obtain a solution B.
  • Step 5 Solution B, is mixed with the second volume, with a ratio of 3.8/1000, to obtain a mixture C, preferably a clear mixture C.
  • Step 6 The clear mixture C is added to solution A to obtain a mixture D.
  • Step 7 Mixture D is heated until the water is fully evaporated.
  • Step 8 Mixture D is cooled by lowering the temperature until a solid E appears.
  • Step 9 The solid E is filtered and rinsed with distilled water until a pH-value between 8.5 and 9.5 of the rinsing water is obtained.
  • Step 10 Drying the solid E for a period of 8h to 15h, preferably 12h, at a temperature be tween 100 and 120 °C, preferably 110 °C, to obtain the synthetic hydrophilic zeolite of type A.
  • Step 11 Grinding the synthetic hydrophilic zeolite of type A into a powder.
  • the temperature is between 75 and 130 °C, preferably 100 °C for 3h to 4h. It is the target to fully evaporate the water from mixture D.
  • step 8 mixture D is cooled by lowering the temperature to a value lower than in step 7 but above room temperature. This cooling allows to avoid the forming crystals of solid E to stick to the bottom of the container in which mixture D is initially located.
  • the temperature is lowered to 30 °C, considering that room temperature is between 20 and 25 °C, so that it is easy to remove solid E without it sticking to the bottom.
  • the pH-value of the rinsing water in step 9 is measured with a pH meter or any other measuring device known by the person skilled in the art that allow a determi nation of the pH-value. By measuring the pH value of the rinsing water indirectly the surface pH-value of solid E, which will form the synthetic hydrophilic zeolite of type A is measured.
  • the surface of the zeolite is slightly alkaline, since this enhances the formation of van der Waals forces with the titanium dioxide and the manganese monoxide, which have a slightly acidic surface. This facilitates to generate a homogenous catalytic composition.
  • step 10 the drying duration and temperature of solid E allow a gradual removal of the water molecules on the surface of the zeolite. Removing the water too rapidly would lead to the risk of crack formation in the surface of the zeolite. This cracks would weaken the im portant 3D structure. This is why a drying time between 8 and 15 h with a temperature of 100 - 120 °C is chosen, to progressively remove the water molecules without risking to weaken the structure of the zeolite.
  • step 11 the synthetic hydrophilic zeolite of type A can be grinded using any grinding device.
  • the adsorbent especially the zeolite, is grinded to achieve a particle size between 0.5 and 2.5 pm. This particle size increases the affinity for certain microorganisms
  • a preferred method for mingling the first catalyst, the second catalyst and the adsorbent is to introduce the first catalyst, the second catalyst and the adsorbent, each in a powdered state and either already pre-mingled or separate, into a liquid to form a slurry.
  • This slurry is then preferably vigorously mixed and the liquid is evaporated to form a dry powdered mix ture of the first catalyst, the second catalyst and the adsorbent. This mixture can then be used per se or to form the slurry that is coated onto the carrier.
  • a liquid preferably consisting of 20 % alcohol and 80 % deionized water
  • between 5 and 10 % of titanium dioxide, between 2 and 6 % of manganese monoxide and between 10 and 20 % of the zeolite, each in regard to the total mass of the liquid are mixed. Consecutively the mixture is heated to evaporate the liquid in order to obtain a powdered catalytic composition which can then be used. It is preferably heated to a temperature of 75 °C - 130° C for a period between 24 h and 120 h, preferably 72h.
  • the invention also specifically relates to a slurry, formed from the first catalyst, the second catalyst, the adsorbent and deionized water.
  • the invention relates to a catalytic device, obtainable via a manufacturing method as described herein.
  • the invention relates to a catalytic composition, containing, in weight percent with regard to its total mass and each in a powdered state, between 27% and 30% of a first catalyst having photocatalytic activity, between 11 % and 17% of a second catalyst and between 55% and 59% of an adsorbent.
  • the catalytic composition can also be called a non-thermal or athermal catalyst, since no high heating is necessary to activate the catalyst. Since the first catalyst, the second catalyst and the adsorbent are each provided in the powdered state, the catalytic composition can also be called a powdery non-thermal or athermal catalyst. In one embodiment, the first catalyst having photocatalytic activity is yet photo-activated.
  • the first cat alyst is titanium dioxide T1O2
  • the second catalyst is manganese monoxide MnO
  • the adsorbent is a zeolite.
  • the zeolite preferably is a synthetic hydrophilic zeolite of type A.
  • this invention relates to an embodiment of the catalytic composition, in which the amount of the first catalyst is lower than 27 % and higher than 30 %, the amount of the second catalyst is lower than 11 % and higher than 17 % and the amount of the adsorbent is lower than 55% and higher than 59%, each in weight percent and with regard to their total mass. All further preferred configurations and embodiments described herein apply to this specific embodiment.
  • the invention relates to the use of a catalytic composition as described herein and/or a catalyst device as described herein for depolluting a gas, espe cially air.
  • the gas preferably contains humidity.
  • the invention relates to a gas depolluting apparatus, comprising a catalytic device as described herein and/or a catalytic composition as described herein coated onto a carrier, wherein the catalytic device and/or the catalytic composition is at least partially provided within a designated flow path of the gas to be depolluted.
  • the gas depolluting apparatus comprises a flow path, which is for example determinate by a pipe or a tube or a housing of the gas depolluting apparatus, especially an inner wall of the housing.
  • the gas to be depolluted enters the gas depolluting apparatus through an entry opening, flows through the apparatus along the flow path and exits the apparatus through an exit opening.
  • the entry opening is provided near a bottom of the apparatus and the exit opening is provided near a top of the apparatus or vice-versa.
  • An entry filter may be assigned to the entry opening or may be provided behind the entry opening in the direction of flow and before the catalytic device and/or the catalytic compo sition in the direction of flow.
  • the catalytic composition and the catalytic device is very ef fective in depolluting, namely cracking gaseous chemical contaminants and biological con taminants. Particulate contaminants on the other hand can only partially be cracked. There fore the use of a particulate filter as entry filter is helpful.
  • the entry filter is designed to filter particulate contaminants that are larger than biological contaminants such as bacteria, viruses and the like. This is reasonable for two reasons. When the entry filter lets biological contaminants pass through, they do not colo nize the filter surface, which would be disadvantageous and possibly dangerous. On the other hand, since the catalytic composition and the catalytic device are very efficient in destroying biological contaminants, it is useful to enable the biological contaminants within the gas to reach them so that they can be destroyed instead of being trapped within the entry filter.
  • An exit filter may additionally or alternatively be assigned to the exit opening or may be provided before the exit opening in the direction of flow and behind the catalytic device and/or the catalytic composition in the direction of flow.
  • the exit filter serves to trap contam inants that were not destroyed by the catalytic treatment.
  • Using an exit filter instead of an entry filter has the advantage that all biological contaminants are guided to the catalytic device and/or the catalytic composition. Those contaminants surviving the treatment can then be trapped by the exit filter.
  • the exit filter preferably is a HEPA filter.
  • the gas depolluting apparatus preferably contains one or more treatment stages. Each treatment stage is defined by one or more catalytic device and/or catalytic composition be ing provided at least partially within the flow path. In the simplest embodiment, the gas depolluting apparatus contains precisely one treatment stage, which is defined by precisely one catalytic device or catalytic composition coated onto a carrier.
  • the catalytic devices, catalytic compositions or treatment stages extend over the complete cross section of the flow path, so that no gas can bypass it but must flow through or along it. It is possible to form one treatment stage of more than one catalytic device and/or catalytic composition. In this case, they are provided side by side in the direction of flow but not one behind the other in the direction of flow. When catalytic devices and/or catalytic compositions are provided one behind another, they form separate treatment stages.
  • the gas depolluting apparatus comprises more than one treat ment stage, which may be formed from precisely one catalytic device and/or catalytic com position or from more than one catalytic device and/or catalytic composition being provided side by side per stage.
  • the gas depolluting apparatus preferably comprises at least one suction unit, or a suction unit is assigned to the apparatus.
  • the suction unit is sucking the gas to be depolluted and provides the gas flow through the gas depolluting apparatus.
  • the suction unit can for ex ample be a fan or blower or one or more fans or blowers.
  • Embodiments of the gas depol luting apparatus can be used and/or are designed for depolluting small volumes per time unit and therefore providing a low gas flow, such as 10 liters per hour or more.
  • the gas depolluting apparatus is designed to provide a gas flow through the apparatus of at least 500 m 3 /h, more preferably at least 1000 m 3 /h, further pref erably at least 1400 m 3 /h, especially at least 2000 m 3 /h.
  • the gas flow is the product of the flow velocity and the flow cross-section. When the flow velocity is kept constant, the gas flow is a function of the flow cross-section and thereby correlating to the catalytic surface. Therefore, especially as long as certain maximum gas velocities are observed, the gas flow can be upscaled simply by increasing the flow cross-section.
  • the gas flow velocity is preferably not exceeding 10 m/s, more preferably not exceeding 7 m/s, es pecially not exceeding 5 m/s.
  • the gas flow velocity is preferably maintained constant during the depolluting process, preferably via the suction unit. The velocity is especially seen as being constant as long as it only varies around a mean value at ⁇ 20 % in use.
  • At least one UV radiation source is also provided.
  • the at least one UV radiation source is configured to irradiate one or more of the treatment stages with UV radiation in order to activate their photocatalysts. It can for example be provided within the side walls of the housing or components limiting the flow path to the sides.
  • the UV radiation source preferably is a UV emitting lamp, such as LED or a fluorescent tube, especially an array of UV emitting lamps.
  • the at least one source of UV radiation is arranged in the des ignated flow path and configured to irradiate the catalytic composition and/or the catalytic device in order to activate the first catalyst.
  • the gas to be depolluted can flow along or through the UV radiation source, which preferably is formed as an array of UV emitting lamps, arranged in a way that gas can flow through the array and thereby along the individual lamps.
  • the UV radiation source which preferably is formed as an array of UV emitting lamps, arranged in a way that gas can flow through the array and thereby along the individual lamps.
  • one source of UV radiation is arranged in the designated flow path and one catalytic device or catalytic composition is arranged upstream and one cata lytic device or catalytic composition is arranged downstream of the source of UV radiation.
  • This design can be called a sandwich design, since the UV radiation source is sandwiched between the catalytic devices and/or the catalytic compositions.
  • the UV radiation source preferably formed as an array of UV emitting lamps, can be sandwiched between two treatment stages, which can each be formed from a single catalytic composition or catalytic device and/or a plurality of catalytic compositions and/or catalytic devices.
  • This sandwich design offers the advantage, that both, the UV radiation generated by the UV radiation source and the waste heat from the radiation source inevitably occurring can be used efficiently.
  • the waste heat is used to increase the activity of the second catalyst, provided it is a low- temperature catalyst as preferred. Furthermore the UV radiation can be used efficiently, since on both sides of the UV radiation source a photocatalyst is present.
  • precisely one catalytic device, catalytic composition or treatment stage is provided upstream and/or precisely one catalytic device, catalytic composition or treatment stage is provided upstream of the UV radiation source.
  • Preferably no further catalysts are provided in the gas depolluting apparatus.
  • the UV radiation source is provided as an array of more than one UV emitting lamp, preferably of two to six, especially four UV emitting lamps.
  • the lamps are provided in a unit frame which also provides at least one, preferably two bearings or receptacles for each at least one catalytic device, preferably on both sides of the unit frame.
  • catalytic devices can be introduced into or applied onto the receptacles or bearings of the unit frame, to form a compact depolluting unit, in which the array is pref erably sandwiched by at least two catalytic devices.
  • the receptacles can be supporting surfaces, onto which the catalytic devices are positioned and especially affixed.
  • the recep tacles can also be slots, into which catalytic devices, formed as slide-in-modules, can be slid in.
  • the depolluting unit is the gas depolluting appa ratus.
  • the gas depolluting apparatus can be used in a manifold of areas. It can for example be used to depollute air in hospitals, preferably in operation theatres or on quarantine stations. Furthermore a small version of the apparatus can for example be used on tables in restau rants or offices for in situ depollution of air being exchanged between persons sitting oppo site each other at the table.
  • the apparatus has shown great efficiency in reducing the amount of a certain coronavirus in the air. It is therefore also a possible and preferred use of the catalytic device, the catalytic composition and/or the gas depolluting apparatus to be used in the treatment of air possibly or definitely containing the coronavirus SARS-CoV-2 for re ducing or removing the virus in/from the air.
  • Experimental protocol and results :
  • Legionella pneumophila in a concentration between 10 4 and 10 6 CFU/m 3
  • T2-bacteriophages in a concentration between 10 3 and 10 4 plaque-forming units (PFU)/m 3
  • the experiments were performed in an isolator of class A with 0.8 m 3 in which an apparatus having the sandwich design as described above was arranged.
  • the carrier was made of aluminum in the honeycomb shape.
  • the UV radiation source was a UV-C emitting lamp of 18W.
  • An aerosol generator is used to provide the air flow within the isolator. Each time the air comprises only one of the mentioned contaminants. The contaminated air is then treated with the apparatus.
  • a bio collector is used to collect samples from the air before and after the treatment, to provide a comparison.
  • the samples are used to prepare a culture in a medium corresponding to the contaminant used.
  • a BYCE medium obtained from Biomerieux is used, containing agar and L-cysteine.
  • Bacillus subtilis an LB Luria Bertani medium is used.
  • T2-bacteriophages a medium comprising E. Coli BAM was used and the number of lysis plagues deriving from active virus was examined.
  • H-CoV-229E human coronavirus strain 229E
  • the efficiency for removing staphylococcus epidermidis was > 99.88% and for removing aspergillus brasiliensis (ATCC 16404) >99.75 % at 1400 m 3 /h.
  • the efficiency for removing staphylococcus epidermidis was > 99.91% and for removing aspergillus brasiliensis (ATCC 16404) >99.82 % at 1000 m 3 /h.
  • the efficiency for removing staphylococcus epidermidis was 92.94% and for removing aspergillus brasiliensis (ATCC 16 404) 93.59 % at 1400 m 3 /h.
  • the efficiency for removing staphylococcus epidermidis was 96.32% and for removing aspergillus brasiliensis (ATCC 16404) approx. 90.00 % at 1000 m 3 /h.
  • the efficiency for removing acetaldehyde was 31.5% ⁇ 20% (A), 39.4 % ⁇ 11.1 % (B), 45.5% ⁇ 11.0% (C) and 56,2 % ⁇ 8,2 % (D).
  • the efficiency for removing acetone was 98.1% ⁇ 1.7 % (A), 94.5% ⁇ 0.5% (B), 90.5 ⁇ 1.3% (C) and 100% ⁇ 2.3% (D).
  • the efficiency for removing acidic acid was 99.7 ⁇ 0.1% (A), 99.3 ⁇ 0.2% (B), 99.5% ⁇ 0.10% (C) and 99.4% ⁇ 0.1% (D).
  • the efficiency for removing heptane was 98.0 ⁇ 0.2 (A) and toluene 98.4% ⁇ 0.1% (A).
  • Figure 1 shows a perspective view onto an embodiment of carrier for a catalytic de vice
  • figure 2 shows a perspective section of the carrier of figure 1 in a coated state, thereby forming an embodiment of a catalytic device
  • figure 3 shows an exploded view of a partially assembled depolluting unit of an em bodiment of the gas depolluting apparatus
  • figure 4 shows a perspective view of the assembled depolluting unit from figure 3.
  • FIG 1 a perspective view onto a solid grid-like carrier 2 is shown.
  • the dotted lines indicate, that only a section of the complete carrier is depicted.
  • the carrier 2 is designed as a honeycomb panel, which preferably is formed from sheets being cor rugated to form combs 4.
  • the sheets are preferably made of an inert material such as aluminum.
  • Each comb 4 forms a through hole 6, which allows a gas to flow through the carrier 2.
  • the carrier 2 has a longitudinal axis L, along which the length of the combs 4 ex tends.
  • the combs 4 each have a hexagonal cross section, which preferably remains constant along their length.
  • the through holes 6 also have a hexag onal cross section.
  • FIG 2 a section of a carrier 2 as shown in figure 1 is shown in a coated state, thereby forming a catalytic device 8.
  • One comb 4 is depicted with two hinted side- walls of adjacent combs 4.
  • the surface of the carrier 2 is almost, preferably completely coated with the first catalyst, the second catalyst and the ad sorbent.
  • the coating 10 is depicted only on the edges of the combs 4 for clarity reasons. Notwithstanding this, the coating 10 is also applied to the inner sur faces 12 of the combs 4 as well as to the outer surfaces 14 of the combs 4, which - aside from the side ends of the carrier 2 - form inner surfaces 12 of adjacent combs 4.
  • the surfaces are coated with multiple layers to form a resulting layer having a thickness of preferably 100 pm to 250 pm.
  • Figure 3 shows a partially assembled embodiment of a depolluting unit 16 of an em bodiment of the gas depolluting apparatus.
  • the depolluting unit 16 is the gas depolluting apparatus.
  • the gas depolluting apparatus comprises a housing, which defines a desig nated flow path for the gas to be depolluted. The depolluting unit 16 is then arranged within this designated flow path.
  • the depolluting unit 16 comprises two catalytic devices 8, of which only one is de picted in figure 3, with carriers 2 that are coated with the first catalyst, the second catalyst and the adsorbent.
  • the carriers 2 are each formed from honeycomb panels, which are encased by a carrier housing 18 on their side ends. When the carriers 2 are encased in a carrier housing 18, it is possible but not necessarily the case, that only those combs 4 and/or surfaces of the combs of the carrier 2 are coated, which are exposed to the environment and not covered by the carrier housing 18.
  • the depolluting unit 16 further comprises a UV radiation source 20, designed as an array of four UV radiation emitting lamps 22. Preferably these are lamps emitting UV- C radiation.
  • the lamps 22 are arranged within a unit frame 24.
  • the unit frame 24 preferably comprises sockets 26 for removably mounting the UV emitting lamps 22.
  • the unit frame 24 furthermore comprises at least one power supply for the UV emitting lamps 22.
  • the unit frame 24 also comprises two receptacles 28 to accommodate the catalytic devices 8.
  • the receptacles 28 are formed by the supporting surfaces 30, to which the carriers 2 and the carrier housings 18 are designed correspondingly. They are either simply positioned to lie on the supporting surfaces 30 or attached to the unit frame 24 via clamps or the like.
  • the receptacles 28 are designed as slots corresponding to the catalytic devices 8 being designed as slide- in-modules.
  • the gas to be depolluted flows through the carriers 2 and the UV radiation source 20 along the direction of flow F. Obviously, the direction of flow F, depending on the de sign of the gas depolluting apparatus, can also run in the opposite direction. The di rection of flow F especially runs along the longitudinal axis L.
  • the depolluting unit 16 being designed as depicted is, that the cat alytic devices 8 and correspondingly the catalysts within the coating 10 of the carri ers 2 are spatially very close to the UV radiation source 20. Therefore, the UV radia tion can be used well for activating the photocatalyst, especially because on both sides of the UV radiation source 20 a catalytic device 8 is present.
  • the waste heat of the lamps 22 can be used to enhance the catalytic activity of the sec ond catalyst, which preferably is a low-temperature catalyst.
  • Figure 4 shows the depolluting unit 16 in an assembled state with two catalytic de vices 8, attached to the unit frame 24, each abutting the support surfaces 30 of the receptacles 28. It can be seen, that the dimensions of the catalytic devices 8 are cor responding to those of the unit frame 24.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
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  • Crystallography & Structural Chemistry (AREA)
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  • Catalysts (AREA)

Abstract

L'invention concerne un procédé de fabrication d'un dispositif catalytique, comprenant les étapes consistant à : a) fournir un premier catalyseur ayant une activité photocatalytique, un second catalyseur, différent du premier catalyseur, et un adsorbant, chacun dans un état pulvérulent, b) mélanger le premier catalyseur, le second catalyseur et l'adsorbant pour former une composition catalytique et mettre en suspension ceux-ci dans un liquide de suspension pour former une bouillie, et c) déposer de manière répétée la suspension épaisse sur un support de type grille solide ayant une pluralité de trous traversants, conçus pour permettre à un gaz de s'écouler à travers le support, et évaporer le liquide de suspension.
PCT/EP2020/070931 2019-12-27 2020-07-24 Procédé de fabrication d'un dispositif photocatalytique, dispositif photocatalytique, composition photocatalytique et appareil de dépollution de gaz WO2021129957A1 (fr)

Priority Applications (7)

Application Number Priority Date Filing Date Title
PCT/EP2020/087920 WO2021130388A1 (fr) 2019-12-27 2020-12-28 Procédé de fabrication d'un dispositif photocatalytique, dispositif photocatalytique, composition photocatalytique et appareil de dépollution de gaz
US17/787,800 US20230025309A1 (en) 2019-12-27 2020-12-28 Method for manufacturing a photocatalytic device, photocatalytic device, photocatalytic composition and gas depolluting apparatus
KR1020227023480A KR20220115593A (ko) 2019-12-27 2020-12-28 광촉매 장치를 제조하기 위한 방법, 광촉매 장치, 광촉매 조성물 및 기체 오염 제거 장치
EP20841727.9A EP4081340A1 (fr) 2019-12-27 2020-12-28 Procédé de fabrication d'un dispositif photocatalytique, dispositif photocatalytique, composition photocatalytique et appareil de dépollution de gaz
JP2022539206A JP2023508180A (ja) 2019-12-27 2020-12-28 光触媒デバイスを製造する方法、光触媒デバイス、光触媒組成物およびガス除染装置
CN202080089800.9A CN115279487A (zh) 2019-12-27 2020-12-28 用于制造光催化装置的方法、光催化装置、光催化组合物和气体去污染设备
CA3157933A CA3157933A1 (fr) 2019-12-27 2020-12-28 Procede de fabrication d'un dispositif photocatalytique, dispositif photocatalytique, composition photocatalytique et appareil de depollution de gaz

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1915667A FR3105742B1 (fr) 2019-12-27 2019-12-27 Catalyseur athermique pulvérulent
FRFR1915667 2019-12-27

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WO2021129957A1 true WO2021129957A1 (fr) 2021-07-01

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JP2000279761A (ja) * 1999-03-30 2000-10-10 Mitsubishi Paper Mills Ltd 空気浄化方法
JP2001087614A (ja) * 1999-09-22 2001-04-03 Mitsubishi Paper Mills Ltd 空気清浄化フィルター
US6607702B1 (en) * 1999-05-27 2003-08-19 Lg Electronics Inc. Photocatalyst filter, method for fabricating the same and air cleaner thereof
US20070237943A1 (en) * 2004-04-26 2007-10-11 Yasuaki Wakizaka Coating Material and Use Thereof
US20090202397A1 (en) * 2005-07-22 2009-08-13 Sharper Image Corporation System and method for delivering and conditioning air to reduce volatile organic compounds and ozone
FR2942965A1 (fr) * 2009-03-16 2010-09-17 Biowind Nouveau dispositif pour le traitement de l'air
KR20140023692A (ko) * 2012-08-17 2014-02-27 (주)우리나노필 화생방보호복용 원단을 제조하는 방법
CN105597528A (zh) 2015-11-03 2016-05-25 中山大学 一种废气净化装置及工艺
CN106582265A (zh) 2016-11-16 2017-04-26 中山大学 一种光催化氧化的空气净化装置和方法
CN106732572A (zh) * 2016-11-16 2017-05-31 中山大学 一种气态污染物的净化材料及其制备方法和应用
CN110465320A (zh) * 2019-08-28 2019-11-19 国合通用(青岛)测试评价有限公司 一种复合型二氧化钛光催化活性涂层及其制备方法

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000279761A (ja) * 1999-03-30 2000-10-10 Mitsubishi Paper Mills Ltd 空気浄化方法
US6607702B1 (en) * 1999-05-27 2003-08-19 Lg Electronics Inc. Photocatalyst filter, method for fabricating the same and air cleaner thereof
JP2001087614A (ja) * 1999-09-22 2001-04-03 Mitsubishi Paper Mills Ltd 空気清浄化フィルター
US20070237943A1 (en) * 2004-04-26 2007-10-11 Yasuaki Wakizaka Coating Material and Use Thereof
US20090202397A1 (en) * 2005-07-22 2009-08-13 Sharper Image Corporation System and method for delivering and conditioning air to reduce volatile organic compounds and ozone
FR2942965A1 (fr) * 2009-03-16 2010-09-17 Biowind Nouveau dispositif pour le traitement de l'air
KR20140023692A (ko) * 2012-08-17 2014-02-27 (주)우리나노필 화생방보호복용 원단을 제조하는 방법
CN105597528A (zh) 2015-11-03 2016-05-25 中山大学 一种废气净化装置及工艺
CN106582265A (zh) 2016-11-16 2017-04-26 中山大学 一种光催化氧化的空气净化装置和方法
CN106732572A (zh) * 2016-11-16 2017-05-31 中山大学 一种气态污染物的净化材料及其制备方法和应用
CN110465320A (zh) * 2019-08-28 2019-11-19 国合通用(青岛)测试评价有限公司 一种复合型二氧化钛光催化活性涂层及其制备方法

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FR3105742A1 (fr) 2021-07-02

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