A series of three chemical reactions, including a combination of endothermic and exothermic reactions, is used to generate, store, and supply on-demand heat from renewable energy sources for use in a variety of processes. Products from one reaction are used in the next reaction, and the series of three reactions is carried out once or more than once, optionally as a closed loop process.

A series of three chemical reactions, including a combination of endothermic and exothermic reactions, is used to generate, store, and supply on-demand heat from renewable energy sources for use in a variety of processes. Products from one reaction are used in the next reaction, and the series of three reactions is carried out once or more than once, optionally as a closed loop process.

Disclosed is a Sabatier reactor apparatus including a carbon sorbent bed having an inlet for introducing a reactant stream to the carbon sorbent bed and an outlet for exiting a treated reactant stream from the carbon sorbent bed; and a Sabatier reactor having an inlet for introducing the treated reactant stream to the Sabatier reactor and an outlet for removing a product stream from the Sabatier reactor. Also disclosed is a method of preparing a reactant stream for a Sabatier reactor.

Disclosed is a Sabatier reactor apparatus including a carbon sorbent bed having an inlet for introducing a reactant stream to the carbon sorbent bed and an outlet for exiting a treated reactant stream from the carbon sorbent bed; and a Sabatier reactor having an inlet for introducing the treated reactant stream to the Sabatier reactor and an outlet for removing a product stream from the Sabatier reactor. Also disclosed is a method of preparing a reactant stream for a Sabatier reactor.

One variation of a diamond composition includes carbon: including a first amount of carbon-13 isotopes and a second amount of carbon-12 isotopes; and sourced from a hydrocarbon mixture including hydrocarbons and formed via methanation of a carbon dioxide mixture. The carbon dioxide mixture: sourced from a sample of air including carbon dioxide and impurities; conveyed through a separation unit configured to remove impurities; including carbon dioxide and impurities; conveyed through a distillation column configured to regulate amounts of carbon-13 isotopes and carbon-12 isotopes; and exhibiting a target ratio of carbon-13 isotopes to carbon-12 isotopes at an outlet of the distillation column. The diamond composition: formed via chemical vapor deposition; and exhibiting an isotopic signature defining a final ratio of the first amount of carbon-13 isotopes to the second amount of carbon-12 isotopes within a first target range corresponding to the target ratio exhibited by the carbon dioxide mixture.

One variation of a diamond composition includes carbon: including a first amount of carbon-13 isotopes and a second amount of carbon-12 isotopes; and sourced from a hydrocarbon mixture including hydrocarbons and formed via methanation of a carbon dioxide mixture. The carbon dioxide mixture: sourced from a sample of air including carbon dioxide and impurities; conveyed through a separation unit configured to remove impurities; including carbon dioxide and impurities; conveyed through a distillation column configured to regulate amounts of carbon-13 isotopes and carbon-12 isotopes; and exhibiting a target ratio of carbon-13 isotopes to carbon-12 isotopes at an outlet of the distillation column. The diamond composition: formed via chemical vapor deposition; and exhibiting an isotopic signature defining a final ratio of the first amount of carbon-13 isotopes to the second amount of carbon-12 isotopes within a first target range corresponding to the target ratio exhibited by the carbon dioxide mixture.

A CO.sub.2 separation/recover method in cement production exhaust gas has a step of harmful component removal that removes an acidic component and a harmful component from exhaust gas discharged from a cement production facility; and a step of CO.sub.2 separation and recover that separates and recovers CO.sub.2 by bringing the exhaust gas from which the acidic component and the harmful component are removed into contact with a CO.sub.2 absorption material, so that the acidic component and the harmful component are removed before separating and recovering CO.sub.2, resulting in deterioration of the absorbing ability of the CO.sub.2 absorption material being suppressed; and the cement production exhaust gas can be appropriately disposed.

A CO.sub.2 separation/recover method in cement production exhaust gas has a step of harmful component removal that removes an acidic component and a harmful component from exhaust gas discharged from a cement production facility; and a step of CO.sub.2 separation and recover that separates and recovers CO.sub.2 by bringing the exhaust gas from which the acidic component and the harmful component are removed into contact with a CO.sub.2 absorption material, so that the acidic component and the harmful component are removed before separating and recovering CO.sub.2, resulting in deterioration of the absorbing ability of the CO.sub.2 absorption material being suppressed; and the cement production exhaust gas can be appropriately disposed.

PROBLEM TO BE SOLVED:

In an apparatus for synthesizing methane from carbon dioxide and hydrogen, a device which is capable to remove the reaction heat and lower the reaction temperature as the reaction progresses in order to increase the conversion ratio to methane has been desired.

SOLUTION:

In the present invention, powders of magnesium hydroxide and magnesium carbonate, which are chemical heat storage agents, are used as part of the fluidizing medium of the multi-stage fluidized bed in the temperature range where the methanation reaction proceeds. The heat generated during the methanation reaction can be absorbed and stored in the powder. At this time, carbon dioxide generated from magnesium carbonate can be used as a raw material gas for the methanation reaction. Furthermore, after discharging the magnesium oxide generated by endotherm, the powder can be regenerated with an external regenerating facility and then the storage heat can be released and recovered. The regenerated powder can be fed to the uppermost stage of the multi-stage fluidized bed at a temperature lower than the internal temperature of the reactor to lower inside temperature. This made it possible to lower the reaction temperature of ascending reaction gas in the reactor along with the reaction progress, and to increase the conversion ratio to the produced methane by this lowered temperature.

PROBLEM TO BE SOLVED:

In an apparatus for synthesizing methane from carbon dioxide and hydrogen, a device which is capable to remove the reaction heat and lower the reaction temperature as the reaction progresses in order to increase the conversion ratio to methane has been desired.

SOLUTION:

In the present invention, powders of magnesium hydroxide and magnesium carbonate, which are chemical heat storage agents, are used as part of the fluidizing medium of the multi-stage fluidized bed in the temperature range where the methanation reaction proceeds. The heat generated during the methanation reaction can be absorbed and stored in the powder. At this time, carbon dioxide generated from magnesium carbonate can be used as a raw material gas for the methanation reaction. Furthermore, after discharging the magnesium oxide generated by endotherm, the powder can be regenerated with an external regenerating facility and then the storage heat can be released and recovered. The regenerated powder can be fed to the uppermost stage of the multi-stage fluidized bed at a temperature lower than the internal temperature of the reactor to lower inside temperature. This made it possible to lower the reaction temperature of ascending reaction gas in the reactor along with the reaction progress, and to increase the conversion ratio to the produced methane by this lowered temperature.