Embodiments of the present invention relates to integrated catalyst systems and associated processes that directly converts carbon dioxide or carbohydrate to CO, methane, or other valuable chemicals at room temperature and atmospheric pressure, requiring no extra energy. The integrated catalyst systems are comprised of nitrogenous heterocyclic compounds and at least two metal elements, wherein one metal element needs to be active than the other one. The integrated catalyst systems can be applied to reduce carbon dioxide and carbohydrate at room temperature with considerable conversion efficiency. The reduction process involves the steps of: a) nitrogenous heterocyclic compounds performance as solvent/major catalyst, dual component as reducing agent / co-catalyst; b) introducing the above integrated catalysts into the reactor full of CO.sub.2 or carbohydrate, and keeping stirring the reacting system for 1 to 4 hours, without any illumination or heating; c) CO, methane, or other reduction product is achieved with a conversion efficiency of about 100%; d) the reduction products are gases, which can be directly separated from the system without any additional separation process or involving additional chemicals.

One variation of a method includes: ingesting an air sample captured during an air capture period at a target location for collection of a first mixture including carbon dioxide and a first concentration of impurities; conveying the first mixture through a liquefaction unit to generate a second mixture including carbon dioxide and a second concentration of impurities less than the first concentration of impurities; in a methanation reactor, mixing the second mixture with hydrogen to generate a first hydrocarbon mixture comprising a third concentration of impurities comprising nitrogen, carbon dioxide, and hydrogen; conveying the first hydrocarbon mixture through a separation unit configured to remove impurities from the first hydrocarbon mixture to generate a second hydrocarbon a fourth concentration of impurities less than the third concentration of impurities; and depositing the second hydrocarbon mixture in a diamond reactor containing a set of diamond seeds to generate a first set of diamonds.

A method for synthesizing a hydrocarbon by reducing carbon dioxide in water, said method comprising supplying oxygen to water containing carbon dioxide to generate oxygen nanobubbles, irradiating the water containing the oxygen nanobubbles with ultraviolet light in the presence of a photocatalyst to generate active oxygen, and reducing carbon dioxide in the presence of the active oxygen.

A method for synthesizing a hydrocarbon by reducing carbon dioxide in water, said method comprising supplying oxygen to water containing carbon dioxide to generate oxygen nanobubbles, irradiating the water containing the oxygen nanobubbles with ultraviolet light in the presence of a photocatalyst to generate active oxygen, and reducing carbon dioxide in the presence of the active oxygen.

The invention relates to use of a catalyst comprising particles of nickel dispersed in a porous silica matrix for catalyzing a methanation reaction. There is also described a method for methanation of a feedstock at least comprising gases carbon monoxide and hydrogen, said method comprising contacting the feedstock with the catalyst.

The invention relates to use of a catalyst comprising particles of nickel dispersed in a porous silica matrix for catalyzing a methanation reaction. There is also described a method for methanation of a feedstock at least comprising gases carbon monoxide and hydrogen, said method comprising contacting the feedstock with the catalyst.

Integrated systems are provided for the production of higher hydrocarbon compositions, for example liquid hydrocarbon compositions, from methane using an oxidative coupling of methane system to convert methane to ethylene, followed by conversion of ethylene to selectable higher hydrocarbon products. Integrated systems and processes are provided that process methane through to these higher hydrocarbon products.

A device for converting carbon dioxide in flue gas into natural gas using dump energy. The device includes a transformer and rectifier device, an electrolytic cell, a turbine, a carbon dioxide heater, a primary fixed bed reactor, a secondary fixed bed reactor, a natural gas condenser, and a process water line. An outlet of the transformer and rectifier device is connected to a power interface of the electrolytic cell, a gas-liquid outlet of a cathode of the electrolytic cell is connected to a gas-liquid inlet of a hydrogen separator, and a liquid outlet of the hydrogen separator is connected to a liquid reflux port of the cathode of the electrolytic cell.

In a broad form the present disclosure relates to a stabilized catalyst support comprising in oxide form; aluminum, zirconium, and one or more lanthanoid elements taken from the lanthanoid group of the periodic system characterized in that at least a part of the aluminum is present as transition alumina such as χ, κ, γ, δ, η, ρ and θ-alumina, characterized in the concentration of zirconium being at least 1.5 wt %, 5 wt % or 10 wt %, the concentration of lanthanoid being at least 0.5 wt %, 1.0 wt %, 2 wt % or 4 wt % and the combined concentration of zirconium and lanthanoid being at least 4 wt %, 7 wt % or 10 wt %, with the associated benefit of a support comprising transition alumina being a high surface area due to the small crystallites typical for transition alumina, and the benefit of the combined presence of oxides of zirconium and lanthanoid in the stated amounts being that at these levels these oxides stabilize the structure of the transition alumina.

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.