The invention is directed to kits, compositions, tools and methods comprising a cyclic industrial process to form biocement. In particular, the invention is directed to materials and methods for decomposing calcium carbonate into calcium oxide and carbon dioxide at an elevated temperature, reacting calcium oxide with ammonium chloride to form calcium chloride, water, and ammonia gas; and reacting ammonia gas and carbon dioxide at high pressure to form urea and water, which are then utilized to form biocement. This cyclic process can be achieved by combining industrial processes with the resulting product as biocement. The process may involve retention of calcium carbonate currently utilized in the manufacture of Portland Cement.

The present application pertains to processes producing oxides using a weak acid intermediate. In one embodiment a material comprising calcium carbonate is reacted with a solution comprising aqueous carboxylic acid to form a gas comprising carbon dioxide and a solution comprising aqueous calcium carboxylate. The solution comprising aqueous calcium carboxylate is reacted with sodium sulfate to form a solution comprising aqueous sodium carboxylate and a solid comprising calcium sulfate. The solution comprising aqueous sodium carboxylate is reacted with sulfur dioxide to form sodium sulfite and an aqueous carboxylic acid. The sodium sulfite is separated from said aqueous carboxylic acid and reacted to form a solid comprising calcium sulfite which is decomposed to form calcium oxide and sulfur dioxide.

The present application pertains to processes producing oxides using a weak acid intermediate. In one embodiment a material comprising calcium carbonate is reacted with a solution comprising aqueous carboxylic acid to form a gas comprising carbon dioxide and a solution comprising aqueous calcium carboxylate. The solution comprising aqueous calcium carboxylate is reacted with sodium sulfate to form a solution comprising aqueous sodium carboxylate and a solid comprising calcium sulfate. The solution comprising aqueous sodium carboxylate is reacted with sulfur dioxide to form sodium sulfite and an aqueous carboxylic acid. The sodium sulfite is separated from said aqueous carboxylic acid and reacted to form a solid comprising calcium sulfite which is decomposed to form calcium oxide and sulfur dioxide.

Some protocols herein implement a first separation between first and second hybrid biochar production runs as a selective and conditional response to a sensor-based event whereby the first hybrid biochar production run is protected from a risk pertaining to the second hybrid biochar production run. Some variants implement synergies featuring biochar pyrolysis in close proximity to calcination or that otherwise facilitate durable green cement. Some variants implement a production line that can switch between a first operating protocol calibrated to yield more power and a second operating protocol calibrated to reduce a biochar-blend-type inventory shortage. And in some variants steam from one or more heaters powers a first turbine and a first condenser downstream is positioned adjacent an oxygen-depleted vessel so that some of the thermal energy recaptured during condensation is applied to produce biochar.

Some protocols herein implement a first separation between first and second hybrid biochar production runs as a selective and conditional response to a sensor-based event whereby the first hybrid biochar production run is protected from a risk pertaining to the second hybrid biochar production run. Some variants implement synergies featuring biochar pyrolysis in close proximity to calcination or that otherwise facilitate durable green cement. Some variants implement a production line that can switch between a first operating protocol calibrated to yield more power and a second operating protocol calibrated to reduce a biochar-blend-type inventory shortage. And in some variants steam from one or more heaters powers a first turbine and a first condenser downstream is positioned adjacent an oxygen-depleted vessel so that some of the thermal energy recaptured during condensation is applied to produce biochar.

The disclosure features methods that include obtaining a first plurality of particles that include calcium carbonate, where the particles have a distribution of sizes between 8 mm and 12 mm, and heating the first plurality of particles to a temperature of between 900 C. and 1200 C. for a time period of at least 1 hour to generate a second plurality of particles that include calcium oxide.

The disclosure features methods that include obtaining a first plurality of particles that include calcium carbonate, where the particles have a distribution of sizes between 8 mm and 12 mm, and heating the first plurality of particles to a temperature of between 900 C. and 1200 C. for a time period of at least 1 hour to generate a second plurality of particles that include calcium oxide.

The disclosure features methods that include obtaining a first calcium hydroxide solution that includes a first concentration of calcium ions and a second calcium hydroxide solution that includes a second concentration of calcium ions, adding a phosphoric acid solution to the first calcium hydroxide solution to generate a combined solution featuring an aqueous suspension of calcium dihydrogen phosphate particles, and adding the second calcium hydroxide solution to the combined solution to form a product solution that includes an aqueous suspension of particles of a calcium phosphate composition.

The disclosure features compositions that include a material featuring three calcium phosphate phases that form one or more integral units of a solid, where a first one of the three phases includes one or more regions formed of hydroxyapatite, a second one of the three phases includes one or more regions formed of -tricalcium phosphate, a third one of the three phases includes one or more regions formed of amorphous calcium phosphate, and where at least some of the regions corresponding to the first, second, and third phases contact one another in the one or more integral units of the solid.

A method for calcination includes providing a heated coarse solid particle stream with a carbon dioxide rich sorbent to a reactor having a rotatable container.