A lost circulation material (LCM) is provided having an alkaline nanosilica dispersion and an ester activator. The alkaline nanosilica dispersion and the ester activator may form a gelled solid after interaction over a contact period. Methods of lost circulation control using the LCM are also provided.

Methods of conducting ureolysis-induced calcium carbonate precipitation with a heat-treated cell preparation, methods for preparing the heat-treated cell preparation, and related materials. The methods of conducting ureolysis-induced calcium carbonate precipitation include precipitating calcium carbonate at a location by introducing urea, calcium, and a heat-treated cell preparation comprising active urease enzyme to the location. The urease enzyme hydrolyzes the urea to ammonium carbonate, and the calcium reacts with the carbonate to form a calcium carbonate precipitate at the location. The methods of preparing the heat-treated cell preparation include heating a urease-producing cell preparation at a temperature and for a time sufficient to inactivate at least a portion of the cells in the urease-producing cell preparation while maintaining at least some urease activity of urease made by the cells in the urease-producing cell preparation

Methods of producing solid CO.sub.2 sequestering carbonate materials are provided. Aspects of the methods include introducing a divalent cation source into a flowing aqueous liquid (e.g., a bicarbonate rich product containing liquid) under conditions sufficient such that a non-slurry solid phase CO.sub.2 sequestering carbonate material is produced. Also provided are systems configured for carrying out the methods.

To produce a calcium carbonate in a controlled form while carbon dioxide gas is efficiently used. A method for producing a calcium carbonate comprises a carbon dioxide gas absorption step of allowing an aqueous sodium hydroxide solution at a concentration of 5 to 21% to absorb carbon dioxide gas to give an aqueous sodium carbonate solution at a concentration of 4 to 24%; a hydration step of reacting calcium oxide with an aqueous sodium hydroxide solution at a concentration of 0 to less than 6% to give a lime milk that is a suspension of calcium hydroxide having a BET specific surface area of 5 to 40 m.sup.2/g; and a carbonation step of adding the aqueous sodium carbonate solution to the lime milk and performing reaction.

To produce a calcium carbonate in a controlled form while carbon dioxide gas is efficiently used. A method for producing a calcium carbonate comprises a carbon dioxide gas absorption step of allowing an aqueous sodium hydroxide solution at a concentration of 5 to 21% to absorb carbon dioxide gas to give an aqueous sodium carbonate solution at a concentration of 4 to 24%; a hydration step of reacting calcium oxide with an aqueous sodium hydroxide solution at a concentration of 0 to less than 6% to give a lime milk that is a suspension of calcium hydroxide having a BET specific surface area of 5 to 40 m.sup.2/g; and a carbonation step of adding the aqueous sodium carbonate solution to the lime milk and performing reaction.

This invention describes a method and apparatus for the capture, storage and release of carbon dioxide for use in the horticulture industry, the method including reduction of a transition metal oxide to form a transition metal and carbon dioxide; carburization or partial carburization of the transition metal to form metal carbide; carbonation of an alkaline metal oxide or alkaline earth metal oxide to form an alkaline metal carbonate or alkaline earth metal carbonate; contacting the metal carbide with air to produce a transition metal oxide and carbon dioxide; and calcining the alkaline metal carbonate or alkaline earth metal carbonate to form carbon dioxide and alkaline metal oxide or alkaline earth metal oxide. Also described is a sorbent material for use in the method and apparatus of the invention.

This invention describes a method and apparatus for the capture, storage and release of carbon dioxide for use in the horticulture industry, the method including reduction of a transition metal oxide to form a transition metal and carbon dioxide; carburization or partial carburization of the transition metal to form metal carbide; carbonation of an alkaline metal oxide or alkaline earth metal oxide to form an alkaline metal carbonate or alkaline earth metal carbonate; contacting the metal carbide with air to produce a transition metal oxide and carbon dioxide; and calcining the alkaline metal carbonate or alkaline earth metal carbonate to form carbon dioxide and alkaline metal oxide or alkaline earth metal oxide. Also described is a sorbent material for use in the method and apparatus of the invention.

Disclosed herein are systems and methods for processing waste egg shells into (i) a first product including calcified egg shell particles having diameters of 3 μ or less, and (ii) a second product including calcified egg shell particles having diameters in a range from about 3 μ to about 7 μ. The first product may be used as a CaCO.sub.3 substitute for paint compositions and plastics compositions. The second product may be used as a CaCO.sub.3 blasting media substitute for use with abrasive blasting equipment.

Disclosed herein are systems and methods for processing waste egg shells into (i) a first product including calcified egg shell particles having diameters of 3 μ or less, and (ii) a second product including calcified egg shell particles having diameters in a range from about 3 μ to about 7 μ. The first product may be used as a CaCO.sub.3 substitute for paint compositions and plastics compositions. The second product may be used as a CaCO.sub.3 blasting media substitute for use with abrasive blasting equipment.

Disclosed herein are systems and methods for processing waste egg shells into (i) a first product including calcified egg shell particles having diameters of 3 μ or less, and (ii) a second product including calcified egg shell particles having diameters in a range from about 3 μ to about 7 μ. The first product may be used as a CaCO.sub.3 substitute for paint compositions and plastics compositions. The second product may be used as a CaCO.sub.3 blasting media substitute for use with abrasive blasting equipment.