A method for subsurface sequestration of carbon in a subterranean zone includes forming a fluid-filled volume in the subterranean zone by injecting an aqueous into the subterranean zone and injecting a mixture comprising silicate nanoparticles suspended in an acidic solution having a pH of less than 4. Carbon in the form of carbon dioxide is injected into the fluid-filled volume such that a least a portion of the carbon is sequestered by precipitation of carbonate minerals. At least a portion of the carbonate minerals are formed from reaction of metal cations with bicarbonate formed from the carbon dioxide, and least a portion of the metal cations are a product of decomposition of the silicate nanoparticles in the acidic solution.

The present invention relates to a rapid-setting hydraulic binder composition and, more specifically, to a hydraulic binder composition, which contains tricalcium aluminate (C3A) and dodecacalcium heptaaluminate (C12A7), and thus is rapidly set, has an easily adjustable setting time, and is bio-friendly.

A hydrocarbon feed stream is exposed to heat in an absence of oxygen to the convert the hydrocarbon feed stream into a solids stream and a gas stream. The gas stream is separated into an exhaust gas stream and hydrogen. The carbon is separated from the solids stream as a carbon stream. Electrolysis is performed on a water stream to produce an oxygen stream and hydrogen. The oxygen and a portion of the carbon are combined to generate power and a carbon dioxide stream. At least a portion of the carbon stream, cement, and water are mixed to form a concrete mixture. The concrete mixture can be used to produce ready-mix concrete and precast concrete. Carbon dioxide used for curing the concrete can be sourced from the carbon dioxide stream produced by power generation.

A hydrocarbon feed stream is exposed to heat in an absence of oxygen to the convert the hydrocarbon feed stream into a solids stream and a gas stream. The gas stream is separated into an exhaust gas stream and hydrogen. The carbon is separated from the solids stream as a carbon stream. Electrolysis is performed on a water stream to produce an oxygen stream and hydrogen. The oxygen and a portion of the carbon are combined to generate power and a carbon dioxide stream. At least a portion of the carbon stream, cement, and water are mixed to form a concrete mixture. The concrete mixture can be used to produce ready-mix concrete and precast concrete. Carbon dioxide used for curing the concrete can be sourced from the carbon dioxide stream produced by power generation.

A method for processing material that contains cement rock may involve comminuting the material in a first comminuting device, feeding the material to a reactor in which the material is mixed with an aqueous liquid and CO.sub.2 and in which a mixing movement of the material is generated, and removing the material from the reactor and subdividing the material into at least two fractions by way of a classifying device. The temperature and the pressure in the reactor are maintained such that the pressure exceeds atmospheric pressure and such that the temperature is greater than 100? C. The method may further involve removing a withdrawal stream of the aqueous liquid from the reactor and separating and discharging suspended particles of the material from the withdrawal stream.

A method for processing material that contains cement rock may involve comminuting the material in a first comminuting device, feeding the material to a reactor in which the material is mixed with an aqueous liquid and CO.sub.2 and in which a mixing movement of the material is generated, and removing the material from the reactor and subdividing the material into at least two fractions by way of a classifying device. The temperature and the pressure in the reactor are maintained such that the pressure exceeds atmospheric pressure and such that the temperature is greater than 100? C. The method may further involve removing a withdrawal stream of the aqueous liquid from the reactor and separating and discharging suspended particles of the material from the withdrawal stream.

A method of making a cement composite can include contacting an aqueous solution comprising calcium ions with a carbon dioxide source producing a carbonated aqueous solution. Fine particles can be submerged in the carbonated aqueous solution to produce microaggregate particles comprising the fine particles coated with calcium carbonate. The microaggregate particles can be combined with cement particles to produce the cement composite. The cement composite can be used in cementing applications for hydrocarbon wells including for casing liners and well plugs.

A method of making a cement composite can include contacting an aqueous solution comprising calcium ions with a carbon dioxide source producing a carbonated aqueous solution. Fine particles can be submerged in the carbonated aqueous solution to produce microaggregate particles comprising the fine particles coated with calcium carbonate. The microaggregate particles can be combined with cement particles to produce the cement composite. The cement composite can be used in cementing applications for hydrocarbon wells including for casing liners and well plugs.

A method for subsurface sequestration of carbon in a subterranean zone includes forming a fluid-filled volume in the subterranean zone by injecting an aqueous into the subterranean zone and injecting a mixture comprising silicate nanoparticles suspended in an acidic solution having a pH of less than 4. Carbon in the form of carbon dioxide is injected into the fluid-filled volume such that a least a portion of the carbon is sequestered by precipitation of carbonate minerals. At least a portion of the carbonate minerals are formed from reaction of metal cations with bicarbonate formed from the carbon dioxide, and least a portion of the metal cations are a product of decomposition of the silicate nanoparticles in the acidic solution.

A method for subsurface sequestration of carbon in a subterranean zone includes forming a fluid-filled volume in the subterranean zone by injecting an aqueous into the subterranean zone and injecting a mixture comprising silicate nanoparticles suspended in an acidic solution having a pH of less than 4. Carbon in the form of carbon dioxide is injected into the fluid-filled volume such that a least a portion of the carbon is sequestered by precipitation of carbonate minerals. At least a portion of the carbonate minerals are formed from reaction of metal cations with bicarbonate formed from the carbon dioxide, and least a portion of the metal cations are a product of decomposition of the silicate nanoparticles in the acidic solution.