A method of manufacture of Portland cement clinker is described in a dry process that captures the carbon dioxide emitted from the calcination of carbonate minerals, principally limestone. The process uses an indirectly heated, counter-flow reactor to pre-heat and calcine the cement meal to produce a separate calcined meal and carbon dioxide gas stream, with external heat being provided by the combustion of a secondary fuel stream with pre-heated air. This calcined meal is injected into the conventional rotary kiln, where the hot flue gas from combustion of the primary fuel with pre-heated air is used to fuse, react and sinter the powders to form granules of cement clinker. The clinker and carbon dioxide streams are cooled by the air pre-heaters.

The invention relates to a plant for generating negative emissions of CO.sub.2. The plant 100 comprises a gasifier 110, a lime kiln 130, a separator 150, and a CO.sub.2 permanent storage 170. The gasifier is suitable for receiving as input a fuel 111 and for producing as output a high-temperature syngas flow 114. The lime kiln is suitable for receiving as input carbonate mineral 131 and the high-temperature syngas flow, the lime kiln being further suitable for producing an oxide 134 and for releasing as output a flow of syngas 133 enriched with CO.sub.2. The separator is suitable for receiving as input a gas flow containing CO.sub.2 and for treating it so as to separately provide at least CO.sub.2 151. The CO.sub.2 permanent storage is suitable for enclosing along time the CO.sub.2. The invention also relates to a method for generating negative emissions of CO.sub.2.

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.

A process for synthesis of a waste-derived CO.sub.2-activated clinker, which comprises firing nodules at temperatures between 1000-1100? C. for a time sufficient to obtain CO.sub.2-reactive clinker phases within the nodules, cooling the clinker nodules, and reducing to powder to obtain a clinker powder; wherein the nodules are agglomerates of a stoichiometric mix of uniformly-sized powders of municipal solid waste (MSW) incineration residues; wherein the stoichiometric mix respects the primary compositional requisite of containing Ca, Al, and Si in their oxide forms within the ranges of 35-45 wt. % CaO, 2-8 wt. % AI.sub.2O.sub.3, and 12-20 wt. % SiO.sub.2; wherein the final stoichiometric mix has a total-sulfur content of 1 to 10 wt. %, total-carbon content of 2 to 20 wt. %, and a total-chlorine content of 2 to 15 wt. %.

Provided herein are methods comprising a) calcining limestone in a cement plant to form carbon dioxide and calcium compound selected from calcium oxide, calcium hydroxide, or combination thereof; b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with the carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

Provided herein are methods comprising a) calcining limestone in a cement plant to form carbon dioxide and calcium compound selected from calcium oxide, calcium hydroxide, or combination thereof; b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with the carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

The present invention relates to a rotary kiln for burning carbonate-containing material, in particular limestone or dolomite, including a rotary tube with an inlet end for the feeding of the material to be burned and an outlet end for the discharging of the burned material, the rotary tube having an inlet zone at its inlet end and an outlet zone at its outlet end wherein a preheating zone and a combustion zone are arranged between the inlet zone and outlet zone, the rotary kiln being characterized according to the invention in that in the inlet zone of the rotary tube at least one projection is provided, the at least one projection having at least one sliding surface inclined to the longitudinal axis of the rotary tube for conveying the material to be burned from the inlet zone into the preheating zone. The present invention further relates to a method for burning carbonate-containing material, in particular limestone or dolomite.

The present invention relates to a rotary kiln for burning carbonate-containing material, in particular limestone or dolomite, including a rotary tube with an inlet end for the feeding of the material to be burned and an outlet end for the discharging of the burned material, the rotary tube having an inlet zone at its inlet end and an outlet zone at its outlet end wherein a preheating zone and a combustion zone are arranged between the inlet zone and outlet zone, the rotary kiln being characterized according to the invention in that in the inlet zone of the rotary tube at least one projection is provided, the at least one projection having at least one sliding surface inclined to the longitudinal axis of the rotary tube for conveying the material to be burned from the inlet zone into the preheating zone. The present invention further relates to a method for burning carbonate-containing material, in particular limestone or dolomite.

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.

Clean version of the Abstract A production method of ready injection material aims at developing natural hydraulic lime at nano-size by using a single raw material. The production method includes: selecting marl, comprising at least 70% CaCO.sub.3, as the raw material, grinding the marl to have particle size lower than 400 lam, calcining the marl at a temperature between 1000-1200 C., re-grinding the marl after the calcination process, reducing a d.sub.90 particle size of calcined marl to between 200-700 nm after the grinding process, applying a dry mixing process to the material having a reduced particle size, adding water to the material after dry mixing and applying mechanical mixing process during duration between 3-6 minutes at a revolution between 800-1000 rpm, adding super-fluidizing chemical additive to the obtained material, and mixing the material for duration between 3-6 minutes by using ultrasonic homogenizer and mechanic mixing.