The present application provides a lime kiln apparatus recycling CO.sub.2 which includes a kiln body (100) and a heat-accumulating furnace set (20). The kiln body (100) defines no burner therein, and the heat-accumulating furnace set (20) provides hot CO.sub.2 (70) heated to a set temperature to the kiln body (100) for calcining mineral material, thereby finished lime is obtained. CO.sub.2 generated during the lime production is all recycled. After being dedusted, a part of the recycled CO.sub.2 is transported to the heat-accumulating furnace set (20) for heating, and is sent back to the kiln for calcining the mineral material after being heated to a temperature within a range of 800 C.-1200 C., and the other part of the recycled CO.sub.2 is recycled for use.

An apparatus for production of burnt lime or dolomite has: a shaft furnace having a preheating zone, a reaction zone, a separation zone and a cooling zone; a first feed apparatus for CO.sub.2 at the boundary of the separation zone to the reaction zone; a first removal apparatus at the boundary of the cooling zone to the separation zone; a second removal apparatus for CO.sub.2 at the start of the preheating zone; and at least one heating apparatus, wherein the heating apparatus has a regenerator system.

The regenerator system has at least two regenerators, a preheater, a feed for fuel and a feed for fresh air; the second removal apparatus opens into the at least one heating apparatus; and the first feed apparatus is formed by the at least one heating apparatus for the shaft furnace.

An apparatus for production of burnt lime or dolomite has: a shaft furnace having a preheating zone, a reaction zone, a separation zone and a cooling zone; a first feed apparatus for CO.sub.2 at the boundary of the separation zone to the reaction zone; a first removal apparatus at the boundary of the cooling zone to the separation zone; a second removal apparatus for CO.sub.2 at the start of the preheating zone; and at least one heating apparatus, wherein the heating apparatus has a regenerator system.

The regenerator system has at least two regenerators, a preheater, a feed for fuel and a feed for fresh air; the second removal apparatus opens into the at least one heating apparatus; and the first feed apparatus is formed by the at least one heating apparatus for the shaft furnace.

An apparatus for production of burnt lime or dolomite has: a shaft furnace having a preheating zone, a reaction zone, a separation zone and a cooling zone; a first feed apparatus for CO.sub.2 at the boundary of the separation zone to the reaction zone; a first removal apparatus at the boundary of the cooling zone to the separation zone; a second removal apparatus for CO.sub.2 at the start of the preheating zone; and at least one heating apparatus.

The shaft furnace also has a third removal apparatus for CO.sub.2 above the reaction zone; the third removal apparatus opens into the second removal apparatus outside the shaft furnace and upstream of the at least one heating apparatus; the second removal apparatus opens into the at least one heating apparatus; and the first feed apparatus is formed by the at least one heating apparatus for the shaft furnace.

An apparatus for production of burnt lime or dolomite has: a shaft furnace having a preheating zone, a reaction zone, a separation zone and a cooling zone; a first feed apparatus for CO.sub.2 at the boundary of the separation zone to the reaction zone; a first removal apparatus at the boundary of the cooling zone to the separation zone; a second removal apparatus for CO.sub.2 at the start of the preheating zone; and at least one heating apparatus.

The shaft furnace also has a third removal apparatus for CO.sub.2 above the reaction zone; the third removal apparatus opens into the second removal apparatus outside the shaft furnace and upstream of the at least one heating apparatus; the second removal apparatus opens into the at least one heating apparatus; and the first feed apparatus is formed by the at least one heating apparatus for the shaft furnace.

A furnace may include at least two vertical shafts, each of which may have at an upper end thereof an inlet for material to be burnt and at a lower end thereof a burnt material outlet. The inlet and the outlet may be connected by a transfer channel. In each case, at least one main burner may be positioned above the transfer channel, and a cooling gas inlet may be positioned below the transfer channel. At least one additional burner may be positioned below the transfer channel in each of the shafts. Such a furnace can be operated such that the material to be burnt in the currently fired shaft is at least partially calcined in a main burning zone above the transfer channel, and then thermally aftertreated in an additional burning zone positioned between the transfer channel and the additional burner.

The disclosure generally provides a modification of a calcination process of lime bearing sludge in such a way that the flue gas generated by the calcination process contains primarily carbon dioxide and water vapor along with only minor amounts of other gaseous species. Such a flue gas can be treated by standard industrial gas scrubbing and purification processes to remove residual particulate solids, to condense and remove the water vapor as liquid water, and further treatment to produce essentially pure carbon dioxide. The resulting product may be used for purposes that do not involve a net emission of carbon dioxide to the atmosphere, thereby reducing environmental harm. Such purified carbon dioxide may be used in industry for enhanced oil recovery (EOR) processes, synthetic fuels production, carbonated beverage production, pharmaceutical production, or other beneficial uses.

The disclosure generally provides a modification of a calcination process of lime bearing sludge in such a way that the flue gas generated by the calcination process contains primarily carbon dioxide and water vapor along with only minor amounts of other gaseous species. Such a flue gas can be treated by standard industrial gas scrubbing and purification processes to remove residual particulate solids, to condense and remove the water vapor as liquid water, and further treatment to produce essentially pure carbon dioxide. The resulting product may be used for purposes that do not involve a net emission of carbon dioxide to the atmosphere, thereby reducing environmental harm. Such purified carbon dioxide may be used in industry for enhanced oil recovery (EOR) processes, synthetic fuels production, carbonated beverage production, pharmaceutical production, or other beneficial uses.

A method for producing lime or dolime, which includes a calcination step for the calcination of calcareous or dolomitic material which is brought into contact with the first fumes which are obtained by combustion of fuel with an oxidizing gas, a cooling of calcined lime or dolime with discharge and collection thereof and a release of a gaseous effluent containing CO.sub.2. Subsequent processing steps result in the formation of a CaO-based sorbent material with separation between the CaO-based sorbent material and a CO.sub.2-concentrated gas stream which is collected. The recycling of said separated CaO-based sorbent material is recycled into a CO.sub.2 depletion step resulting in the extraction of a valorizable fraction of the CaCO.sub.3CaO based charge with a compensatory introduction of fresh CaCO.sub.3 in the calcination step.

A method for producing lime or dolime, which includes a calcination step for the calcination of calcareous or dolomitic material which is brought into contact with the first fumes which are obtained by combustion of fuel with an oxidizing gas, a cooling of calcined lime or dolime with discharge and collection thereof and a release of a gaseous effluent containing CO.sub.2. Subsequent processing steps result in the formation of a CaO-based sorbent material with separation between the CaO-based sorbent material and a CO.sub.2-concentrated gas stream which is collected. The recycling of said separated CaO-based sorbent material is recycled into a CO.sub.2 depletion step resulting in the extraction of a valorizable fraction of the CaCO.sub.3CaO based charge with a compensatory introduction of fresh CaCO.sub.3 in the calcination step.