Methods of enhancing productivity of a subterranean wellbore may include introducing a carbonated mixture comprising water and carbonate anions to a target zone of the subterranean wellbore; introducing basaltic particles to the target zone of the subterranean wellbore; contacting the basaltic particles with the carbonated mixture; dissolving at least a part of the basaltic particles with the carbonated mixture to release divalent cations including calcium cations, magnesium cations and ferrous cations; reacting, in the target zone of the subterranean wellbore, the divalent cations with the carbonate anions in the carbonated mixture to produce carbonate minerals; providing stimulus to the basaltic particles and the carbonated mixture to promote the dissolving and the reacting; depositing at least a part of the carbonate minerals to fractures of the target zone; and monitoring the reacting of the divalent cations with the carbonated anions and depositing.

The present invention describes an integrated process for carbon dioxide capture, sequestration and utilisation, which comprises: a) providing an aqueous slurry comprising an aqueous solution and a particulate solid comprising an activated magnesium silicate mineral; b) in a dissolution stage, contacting a CO.sub.2-containing gas stream with the aqueous slurry to dissolve magnesium from the mineral to provide a magnesium ion enriched aqueous solution and a magnesium depleted solid residue; c) recovering at least a portion of the magnesium depleted solid residue; d) in a separate acid treatment stage, reacting the recovered portion of the magnesium depleted solid residue with a solution comprising a mineral acid or acid salt to further dissolve magnesium and other metals and to provide an acid-treated solid residue; e) recovering the acid-treated solid residue; and f) in a separate precipitation stage, precipitating magnesium carbonate from the magnesium ion enriched aqueous solution.

The present invention describes an integrated process for carbon dioxide capture, sequestration and utilisation, which comprises: a) providing an aqueous slurry comprising an aqueous solution and a particulate solid comprising an activated magnesium silicate mineral; b) in a dissolution stage, contacting a CO.sub.2-containing gas stream with the aqueous slurry to dissolve magnesium from the mineral to provide a magnesium ion enriched aqueous solution and a magnesium depleted solid residue; c) recovering at least a portion of the magnesium depleted solid residue; d) in a separate acid treatment stage, reacting the recovered portion of the magnesium depleted solid residue with a solution comprising a mineral acid or acid salt to further dissolve magnesium and other metals and to provide an acid-treated solid residue; e) recovering the acid-treated solid residue; and f) in a separate precipitation stage, precipitating magnesium carbonate from the magnesium ion enriched aqueous solution.

Disclosed herein is a method for making hydrogen with carbon sequestration. The method may comprise using a biomass hydroconverter product to fuel a steam reformer that converts a hydrocarbon fuel stream into a gas mixture that contains at least hydrogen and carbon dioxide. The gas stream is separated to form a hydrogen-enriched gas stream and at least one hydrogen-depleted stream. The hydrogen-depleted stream may be stored or further processed to sequester the carbon contained therein. Additionally, or alternatively, the solid residue from the biomass hydroconverter also may be stored for further sequester carbon generated by the method.

A method/system for sequestering carbon dioxide from cement and lime production facilities wherein carbon dioxide from flue gases originating from cement or lime production facilities is recovered and transported to a building materials production facility where it is sequestered.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

An improved system for separating gas from a process stream by providing a stripping unit at the overhead stream of a fractionation column to selectively and effectively remove the gas using a stripping fluid without providing a dedicated light-ends separations unit. The stripper unit may be connected to the reflux drum at the overhead stream. The system for separating gas further achieves greater thermodynamic efficiency by means of a split column design using mechanical vapor recompression with the reboiler and condenser integrated in a falling-film evaporator- or thermosiphon-type vapo-condenser.

An improved system for separating gas from a process stream by providing a stripping unit at the overhead stream of a fractionation column to selectively and effectively remove the gas using a stripping fluid without providing a dedicated light-ends separations unit. The stripper unit may be connected to the reflux drum at the overhead stream. The system for separating gas further achieves greater thermodynamic efficiency by means of a split column design using mechanical vapor recompression with the reboiler and condenser integrated in a falling-film evaporator- or thermosiphon-type vapo-condenser.

Disclosed is a system and method for cooperatively treating water and gas to reduce pollutants and carbon emission. The system includes a flue gas pre-treatment unit, a wastewater pre-treatment unit, a gas-water cooperative cleaning unit, a remaining water treatment unit, and a circulating cooling evaporation unit.