Methods and systems for recovery of CO₂gas in cement-manufacturing facilities, and processes for manufacturing cement

摘要

An object of the present invention is to separate CO2 gas generated in a cement-manufacturing facility in a high concentration and recover the CO2 gas. The present invention includes: feeding a cement material before calcination and a heat medium which has a particle diameter larger than that of the cement material and has been heated to the calcination temperature or higher in a medium-heating furnace (14), to a mixing calciner (12); and recovering the CO2 gas generated by the calcination of the cement material. The heat medium circulates between the medium-heating furnace and the mixing calciner. Another aspect of the present invention includes: feeding a cement material before calcination to a regenerative calciner (112) which has been heated to the calcination temperature or higher and has stored heat therein; and recovering the CO2 gas generated by the calcination of the cement material.

主权项

1. A method for recovering CO2 gas generated in a cement-manufacturing facility, the method comprising:
feeding a non-calcined cement material, which has been extracted from a first preheater, to a mixing calciner; heating a heat medium, having a particle diameter larger than that of the cement material, to a calcination temperature or higher in a medium-heating furnace; feeding the heat medium to the mixing calciner; calcining the non-calcined cement material with the heat medium in the mixing calciner; separating a cement material which has been calcined from the heat medium; feeding the cement material which has been calcined to a cement kiln; returning the heat medium to the medium heating furnace and circulating the heat medium between the medium-heating furnace and the mixing calciner; and recovering CO2 gas generated by the calcining of the non-calcined cement material in the mixing calciner, wherein the cement-manufacturing facility preheats the non-calcined cement material in the first preheater, then feeds the preheated cement material to the mixing calciner and then to the cement kiln having an atmosphere in an inner part held at high temperature, and then burns the fed cement material, wherein the heat medium is a cement clinker obtained by burning the cement material in the cement kiln, quicklime of the formula CaO, silica stone of the formula SiO2, aluminum of the formula Al2O3, a heat-resistant alloy, or a mixture thereof.