Methods and systems for making calcium oxide (CaO), carbon dioxide (CO.sub.2) and/or calcium hydroxide (Ca(OH).sub.2) from aragonite, for example, oolitic aragonite, are provided. The method can include applying solar energy, for example, by focusing one or more mirrors in one or more heliostats, to heat a reactant mixture in a vessel. The reactant mixture includes oolitic aragonite and can be heated to a temperature from 500° C. to 950° C. The system can include a vessel and a means for applying solar energy to heat a supply of oolitic aragonite disposed inside the vessel. Methods of converting the CO.sub.2 to ethanol, ethylene, graphene, and/or methane are also provided.

Methods and systems for making calcium oxide (CaO), carbon dioxide (CO.sub.2) and/or calcium hydroxide (Ca(OH).sub.2) from aragonite, for example, oolitic aragonite, are provided. The method can include applying solar energy, for example, by focusing one or more mirrors in one or more heliostats, to heat a reactant mixture in a vessel. The reactant mixture includes oolitic aragonite and can be heated to a temperature from 500° C. to 950° C. The system can include a vessel and a means for applying solar energy to heat a supply of oolitic aragonite disposed inside the vessel. Methods of converting the CO.sub.2 to ethanol, ethylene, graphene, and/or methane are also provided.

The present invention provides for a composition comprising a heterostructure capable of electrochemical CO reduction to a carbon-carbon product, comprising an inorganic material and a porous molecule. In some embodiments, the heterostructure comprises the following structure: ##STR00001##

The present invention provides for a composition comprising a heterostructure capable of electrochemical CO reduction to a carbon-carbon product, comprising an inorganic material and a porous molecule. In some embodiments, the heterostructure comprises the following structure: ##STR00001##

The present invention provides for a composition comprising a heterostructure capable of electrochemical CO reduction to a carbon-carbon product, comprising an inorganic material and a porous molecule. In some embodiments, the heterostructure comprises the following structure: ##STR00001##

An apparatus is provided for producing methanol from organic material, characterized in that the apparatus includes

an anaerobic digestion arrangement for receiving the organic material and for anaerobically-digesting the organic material in oxygen-depleted conditions to generate methane gas; and
a chemical reaction arrangement for reacting the methane gas with water vapour and carbon dioxide in a stoichiometric condition (Eq. 4) between methane steam reforming and methane dry reforming to generate methanol.

The apparatus is operable to support a stoichiometric reaction as follows:

CO.sub.2+3CH.sub.4+2H.sub.2O=4CH.sub.3OH  Eq. 4

The chemical reaction arrangement is operable to provide the stoichiometric condition (Eq. 4)

at a first stage for steam reforming at a pressure in a range of 10 Bar to 30 Bar, and at a temperature in a range of 750° C. to 950° C.; and
at a second stage of methanol synthesis at a pressure in a range of 50 Bar to 100 Bar, and at a temperature in a range of 200° C. to 250° C.

Optionally, a catalyst arrangement is employed for at least the second stage.

An apparatus is provided for producing methanol from organic material, characterized in that the apparatus includes

an anaerobic digestion arrangement for receiving the organic material and for anaerobically-digesting the organic material in oxygen-depleted conditions to generate methane gas; and
a chemical reaction arrangement for reacting the methane gas with water vapour and carbon dioxide in a stoichiometric condition (Eq. 4) between methane steam reforming and methane dry reforming to generate methanol.

The apparatus is operable to support a stoichiometric reaction as follows:

CO.sub.2+3CH.sub.4+2H.sub.2O=4CH.sub.3OH  Eq. 4

The chemical reaction arrangement is operable to provide the stoichiometric condition (Eq. 4)

at a first stage for steam reforming at a pressure in a range of 10 Bar to 30 Bar, and at a temperature in a range of 750° C. to 950° C.; and
at a second stage of methanol synthesis at a pressure in a range of 50 Bar to 100 Bar, and at a temperature in a range of 200° C. to 250° C.

Optionally, a catalyst arrangement is employed for at least the second stage.

Disclosed herein are carbon doped tin disulphide (C—SnS.sub.2) and other SnS.sub.2 composites as visible light photocatalyst for CO.sub.2 reduction to solar fuels. The in situ carbon doped SnS.sub.2 photocatalyst provide higher efficiency than the undoped pure SnS.sub.2. Also disclosed herein are methods for preparing the catalysts.

Disclosed herein are carbon doped tin disulphide (C—SnS.sub.2) and other SnS.sub.2 composites as visible light photocatalyst for CO.sub.2 reduction to solar fuels. The in situ carbon doped SnS.sub.2 photocatalyst provide higher efficiency than the undoped pure SnS.sub.2. Also disclosed herein are methods for preparing the catalysts.

Disclosed herein are carbon doped tin disulphide (C—SnS.sub.2) and other SnS.sub.2 composites as visible light photocatalyst for CO.sub.2 reduction to solar fuels. The in situ carbon doped SnS.sub.2 photocatalyst provide higher efficiency than the undoped pure SnS.sub.2. Also disclosed herein are methods for preparing the catalysts.