Provided herein are zero carbon dioxide (CO.sub.2) emission processes and systems to carry out the processes, comprising a) calcining limestone in a cement plant in an electric kiln to form a mixture comprising calcium oxide and a first gaseous stream comprising clean carbon dioxide, wherein the clean carbon dioxide comprises no gaseous or non-gaseous components from combustion of fuel; b) treating the mixture comprising calcium oxide with a N-containing salt solution under one or more dissolution conditions to produce a first aqueous solution comprising calcium salt; and c) contacting the first aqueous solution with the first gaseous stream comprising clean carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising vaterite, aragonite, calcite, or combinations thereof.

Provided herein are zero carbon dioxide (CO.sub.2) emission processes and systems to carry out the processes, comprising a) calcining limestone in a cement plant in an electric kiln to form a mixture comprising calcium oxide and a first gaseous stream comprising clean carbon dioxide, wherein the clean carbon dioxide comprises no gaseous or non-gaseous components from combustion of fuel; b) treating the mixture comprising calcium oxide with a N-containing salt solution under one or more dissolution conditions to produce a first aqueous solution comprising calcium salt; and c) contacting the first aqueous solution with the first gaseous stream comprising clean carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising vaterite, aragonite, calcite, or combinations thereof.

Provided herein are zero carbon dioxide (CO.sub.2) emission processes and systems to carry out the processes, comprising a) calcining limestone in a cement plant in an electric kiln to form a mixture comprising calcium oxide and a first gaseous stream comprising clean carbon dioxide, wherein the clean carbon dioxide comprises no gaseous or non-gaseous components from combustion of fuel; b) treating the mixture comprising calcium oxide with a N-containing salt solution under one or more dissolution conditions to produce a first aqueous solution comprising calcium salt; and c) contacting the first aqueous solution with the first gaseous stream comprising clean carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising vaterite, aragonite, calcite, or combinations thereof.

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 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 invention discloses the systems of producing calcium and magnesium carbonate from the Ca/Mg containing solution leached by a CO.sub.2-based hydrometallurgical process which includes: a precipitation reactor that the Ca/Mg containing leached solution is continuously added and fully mixed with the alkaline reagent at specific mole ratio into the precipitation reactor and the reactor also comprises a CO.sub.2 bubbling module where CO.sub.2 is captured and recirculated from the thermal decomposition process as needed; a solid-liquid separation unit that the treated slurry is treated by the solid-liquid separation unit to produce precipitated calcium and magnesium carbonate products where the recirculating water is recycled back into the precipitation reactor; a thermal decomposition unit that the calcium and magnesium carbonate products is calcined by the thermal decomposition unit to produce an alkaline reagent and the alkaline reagent is recycled back into the precipitation reactor for the next batch of reaction.

The present disclosure provides systems for carbon capture in combination with production of one or more industrially useful materials. The disclosure also provides methods for carrying out carbon capture in combination with an industrial process. In particular, carbon capture can include carrying out calcination in a reactor, separation of carbon dioxide rich flue gases from industrially useful products, and capture of at least a portion of the carbon dioxide for sequestration of other use, such as enhanced oil recovery.

A process comprising the following steps: a) calcination of a metal carbonate by combustion of a fuel in the presence of a mixture of oxygen, water vapour and carbon dioxide, to generate a metal oxide, water vapour, carbon dioxide and heat; b) using the heat generated to drive an oxygen generation reaction; and c) use of the oxygen generated in step b) in calcination step a). The use of the process on carbon dioxide sequestration and/or in oxygen generation.

A process comprising the following steps: a) calcination of a metal carbonate by combustion of a fuel in the presence of a mixture of oxygen, water vapour and carbon dioxide, to generate a metal oxide, water vapour, carbon dioxide and heat; b) using the heat generated to drive an oxygen generation reaction; and c) use of the oxygen generated in step b) in calcination step a). The use of the process on carbon dioxide sequestration and/or in oxygen generation.

The procedures for obtaining calcium oxide from eggshells with applications in food processes, refers to the plurality of procedures for obtaining Calcium Oxide (XAM), from eggshells, is based on a circular economy, in which waste eggshells are collected from different food establishments and agglomerated in the production center. The application of high temperatures (>900° C.) to the crushed eggshells, provides the transformation of calcium carbonate (CaCO3) into calcium oxide (CaO) with a pH that exceeds 12. The use of XAM as a raw material with the aforementioned characteristics, constitutes the ideal component to alkalinize different preparations in the production of different foods and particularly in the nixtamalization procedures for the production of corn dough prior to the production of tortillas, tamales, and other varieties of food.