Methods and compositions for carbon dioxide (CO.sub.2) sequestration in a wellbore. A method includes locating a lost circulation zone in the wellbore during drilling. Methods may further include flushing drilling mud from the wellbore to prepare the lost circulation zone for lost circulation mitigation and injecting a cleaning solution into the wellbore. Then, injecting a composition for CO.sub.2 sequestration into the wellbore, where the composition may include a brine solution, an alkali and/or an alkaline compound, and a catalyst. The method may further include injecting a volume of CO.sub.2 into the wellbore, mineralizing the alkali and/or the alkaline compound and the volume of CO.sub.2 to produce an alkali and/or alkaline carbonate compound, injecting drilling mud into the wellbore and resuming drilling operations.

Provided herein are methods and compositions for carbonation of recycled concrete aggregates (RCA) to produce carbonated RCA. In addition, uses of the carbonated RCA, such as in building materials, and building materials containing RCA, are included. Carbonation of RCA may be used alone or may be used in combination with other carbonation processes associated with concrete manufacture, such as carbonation of wet concrete mixes and/or carbonation of concrete wash water.

Provided herein are methods and compositions for carbonation of recycled concrete aggregates (RCA) to produce carbonated RCA. In addition, uses of the carbonated RCA, such as in building materials, and building materials containing RCA, are included. Carbonation of RCA may be used alone or may be used in combination with other carbonation processes associated with concrete manufacture, such as carbonation of wet concrete mixes and/or carbonation of concrete wash water.

The present invention relates to a method of capturing carbon dioxide comprising: a) providing a particulate material, wherein the particulate material comprises calcium carbonate and/or titanium dioxide, b) providing a silane, c) providing a surface activator, d) mixing the particulate material and the surface activator to form a surface activated particulate material, e) mixing the silane and the surface activated particulate material to form a mixture, f) mixing water and the mixture to form a composition, g) drying the composition to produce a carrier, and h) treating the carrier with carbon dioxide.

The present invention relates to a method of capturing carbon dioxide comprising: a) providing a particulate material, wherein the particulate material comprises calcium carbonate and/or titanium dioxide, b) providing a silane, c) providing a surface activator, d) mixing the particulate material and the surface activator to form a surface activated particulate material, e) mixing the silane and the surface activated particulate material to form a mixture, f) mixing water and the mixture to form a composition, g) drying the composition to produce a carrier, and h) treating the carrier with carbon dioxide.

The invention relates to a relates to an acid activated mixture comprising: an acid activated magnesium-iron solid solution silicate filler; cementitious material; and carbon dioxide (CO2); wherein the magnesium-iron solid solution silicate filler has at most 7% free water, and wherein the magnesium-iron solid solution silicate filler is between 4% and 55% by weight of cementitious material. The invention further relates to a method for producing an acid activated cement slurry comprising the steps: making a slurry comprising a non-acid activated or acid activated magnesium-iron solid solution silicate filler, water, and cementitious material; adding carbon dioxide (CO2) to the slurry; and optionally adding an acid to the slurry; wherein the magnesium-iron solid solution silicate filler is between 4% and 55% by weight of cementitious material. The invention also relates to a process for making an acid activated structure, an acid activated cement slurry obtainable by the method, use of the acid-activated cement slurry for making an acid activated structure, aspect, and an acid activated structure obtainable by the process.

Disclosed herein is a composition comprising a) of about 80 wt % to about 99 wt % of a cementitious material; b) of about 0.05 wt % to about 3 wt % of a water-soluble organic compound and/or salts thereof, and c) of about 1 wt % to about 20 wt % of carbon dioxide. Additionally, articles comprising the disclosed herein composition are also disclosed. Also disclosed are methods of making the compositions and the articles.

An aqueous dispersion of graphene oxide is prepared in an additive process by subjecting graphitic carbon, such as biochar, in water or an aqueous solution to a high-shear environment in the presence of a dispersing agent to exfoliate graphene oxide. An intercalating agent may be added to facilitate exfoliation, and optionally neutralized. The graphitic carbon may be pre-processed by wet milling prior to exfoliation. The aqueous dispersion of graphene oxide may be used as a concrete admixture in a concrete composition.

An aqueous dispersion of graphene oxide is prepared in an additive process by subjecting graphitic carbon, such as biochar, in water or an aqueous solution to a high-shear environment in the presence of a dispersing agent to exfoliate graphene oxide. An intercalating agent may be added to facilitate exfoliation, and optionally neutralized. The graphitic carbon may be pre-processed by wet milling prior to exfoliation. The aqueous dispersion of graphene oxide may be used as a concrete admixture in a concrete composition.

Methods and compositions for carbon dioxide (CO.sub.2) sequestration in a wellbore. A method includes locating a lost circulation zone in the wellbore during drilling. Methods may further include flushing drilling mud from the wellbore to prepare the lost circulation zone for lost circulation mitigation and injecting a cleaning solution into the wellbore. Then, injecting a composition for CO.sub.2 sequestration into the wellbore, where the composition may include a brine solution, an alkali and/or an alkaline compound, and a catalyst. The method may further include injecting a volume of CO.sub.2 into the wellbore, mineralizing the alkali and/or the alkaline compound and the volume of CO.sub.2 to produce an alkali and/or alkaline carbonate compound, injecting drilling mud into the wellbore and resuming drilling operations.