Proposed are a photocatalyst, including titanium dioxide particles including titanium dioxide (TiO.sub.2), a carbon material located on all or part of the surface of the titanium dioxide particles and including at least one selected from the group consisting of graphene, reduced graphene oxide (rGO), and carbon nanotubes (CNTs), and bimetallic nanoparticles supported on the carbon material and including first metal nanoparticles and second metal nanoparticles, and a water treatment method using the same. In the photocatalyst and the water treatment method using the same, the photocatalyst including bimetallic nanoparticles and graphene oxide is prepared, thereby exhibiting high reduction efficiency and high selectivity to nitrogen gas even without the use of an external electron donor.

The invention relates to a cyclical method for producing a nitrogen fraction, the purity of which is greater than or equal to 95 mol %, and a hydrocarbon-enriched fraction from a filler containing nitrogen and a hydrocarbon, said method using a specific class of porous hybrid solids as an adsorbent in a pressure-swing adsorption (PSA) process. The invention also relates to equipment for implementing said method.

A fluid system includes an inlet conduit disposed in a fluid flow path between a fluid source and a fluid destination. The fluid conduit includes a fluid mixing portion. The fluid system includes a fluid separation module disposed in the flow path downstream of the constriction between the source and the destination. The fluid separation module includes a first fluid separator, The fluid system includes a second fluid separator disposed in the flow path upstream of the first fluid separator, The fluid system includes a feedback conduit that may provide fluid communication between an outlet of the fluid separation module and the fluid mixing portion.

A device for separating gases comprises the following components: a source for the gases and flow adjustment means; a membrane unit for the production of a permeate gas and a retentate gas, one of which is the product gas; purity determining means for the product gas; a first control unit for the device; a retentate control system and a product gas pressure measurement, whereby the source has a second control unit for the flow adjustment means as a function of a target value of the gases and the first control unit is connected to the second control unit and to the retentate control system, whereby the first control unit can determine the target value and can control the retentate control system.

An apparatus/system for generating a high-purity nitrogen gas using a fuel cell includes; a fuel cell that operates by taking in air or a gas containing nitrogen and oxygen, and a fuel gas; a dehumidification mechanism that reduces moisture or water vapor content in an exhaust gas that is extracted from the fuel cell and has a lower oxygen concentration than air; and a filtering mechanism which includes a filter using fibers having different degrees of permeation for nitrogen and oxygen and converts the exhaust gas having a reduced moisture or water vapor content into a gas having an increased nitrogen concentration. The filter recovery ratio is higher when an oxygen concentration of a gas to be filtered is lower. The dehumidification mechanism is a pump unit including a water seal pump to provide an adiabatic expansion chamber in which the exhaust gas extracted from the fuel cell expands adiabatically.

An apparatus/system for generating a high-purity nitrogen gas using a fuel cell includes; a fuel cell that operates by taking in air or a gas containing nitrogen and oxygen, and a fuel gas; a dehumidification mechanism that reduces moisture or water vapor content in an exhaust gas that is extracted from the fuel cell and has a lower oxygen concentration than air; and a filtering mechanism which includes a filter using fibers having different degrees of permeation for nitrogen and oxygen and converts the exhaust gas having a reduced moisture or water vapor content into a gas having an increased nitrogen concentration. The filter recovery ratio is higher when an oxygen concentration of a gas to be filtered is lower. The dehumidification mechanism is a pump unit including a water seal pump to provide an adiabatic expansion chamber in which the exhaust gas extracted from the fuel cell expands adiabatically.

The invention relates to an improved process for preparing metal-organic framework materials, metal-organic frameworks obtainable by such processes, methods using the same, and the use thereof. The process of the invention provides an improved process for preparing metal-organic frameworks in particular monocrystalline metal-organic frameworks having large crystal sizes. The invention also relates to metal organic frameworks comprising iron or titanium, and their uses.

The present invention provides a method including: a gas absorption step of bringing exhaust gas into contact with an aqueous solution containing alkaline carbonate, so that carbon dioxide gas in the exhaust gas is allowed to react therewith, thereby obtaining an aqueous solution containing alkaline bicarbonate; a gas recovery step of recovering a gas containing nitrogen gas and oxygen gas obtained as a result of the gas absorption step; a decomposition step of decomposing at least a part of the alkaline bicarbonate obtained in the gas absorption step into the alkaline carbonate and the carbon dioxide gas; a circulation step of circulating at least a part of the alkaline carbonate obtained in the decomposition step to the gas absorption step; and a carbon dioxide gas recovery step of bringing a gas containing the carbon dioxide gas obtained as a result of the decomposition step into contact with an aqueous solution, thereby recovering the carbon dioxide gas obtained in the decomposition step.

A method of fuel tank inerting includes separating process air into nitrogen-enriched air and oxygen-enriched air with an air separation membrane. A vacuum is applied to the air separation membrane to produce a pressure differential across the air separation membrane. The vacuum is manipulated to vary the pressure differential and vary purity of the nitrogen-enriched air.

In some examples, an air treatment system includes a filter, an ozone sensor, and a separator configured to separate air into a nitrogen-enriched gas and an oxygen-enriched gas. The filter is configured to remove ozone from an air stream and supply filtered air to the separator. The ozone sensor is configured to sense an ozone level of the filtered air issuing from the filter prior to encountering the separator. The air treatment system may include processing circuitry configured to monitor the ozone level sensed. The air treatment system may be part of an inerting system configured to supply the nitrogen-enriched gas to an ullage space of a fuel tank.