Methods and systems for forming vaterite from calcined limestone using electric kiln

A zero carbon dioxide (CO2) emission system, comprising:

• (i) a calcining system in a cement plant configured for calcining limestone 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 fossil fuel;
• (ii) a treatment reactor operably connected to the calcining system configured for receiving the mixture comprising calcium oxide and configured for dissolving the mixture comprising calcium oxide in a N-containing salt solution under one or more dissolution conditions to produce a first aqueous solution comprising calcium salt, and a second gaseous stream comprising ammonia;
• (iii) a cooling reactor operably connected to the calcining system and the treatment reactor and configured for receiving the first gaseous stream comprising clean carbon dioxide and the second gaseous stream comprising ammonia, and configured for subjecting the first and the second gaseous streams to a cooling process under one or more cooling conditions to condense a second aqueous solution comprising ammonium bicarbonate, ammonium carbonate, ammonia, or combinations thereof;
• and
• (iv) a contacting reactor operably connected to the treatment reactor and the cooling reactor and configured for receiving the first aqueous solution comprising calcium salt and the second aqueous solution comprising ammonium bicarbonate, ammonium carbonate, ammonia, or combinations thereof, and configured for treating the first aqueous solution with the second aqueous solution under one or more precipitation conditions to form a precipitation material comprising vaterite, aragonite, calcite, or combinations thereof.