The present invention pertains to a process for producing captured carbon dioxide. Calcium carbonate may be reacted with sulfur dioxide to produce calcium sulfite and gaseous carbon dioxide. Calcium sulfite may be thermally decomposed to produce gaseous sulfur dioxide. The processes may be used in conjunction with combusting various fuels such as a carbonaceous fuel, or a sulfurous fuel, or a nitrogenous fuel, or a hydrogen fuel, or a combination thereof.

The present application pertains to methods for making metal oxides and/or citric acid. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth-bisulfite and aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

The present application pertains to methods for making metal oxides and/or citric acid. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation—carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation—carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth—bisulfite and aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

The present invention pertains to a process for producing captured carbon dioxide. Calcium carbonate may be reacted with sulfur dioxide to produce calcium sulfite and gaseous carbon dioxide. Calcium sulfite may be thermally decomposed to produce gaseous sulfur dioxide. The processes may be used in conjunction with combusting various fuels such as a carbonaceous fuel, or a sulfurous fuel, or a nitrogenous fuel, or a hydrogen fuel, or a combination thereof.

The present invention pertains to processes of, for example, preparing zinc oxide and other substances. In one embodiment an exemplary process pertains to reacting ammonium chloride with zinc oxide to form a zinc chloride, gaseous ammonia, and gaseous water vapor. The zinc chloride may be reacted with sulfuric acid to form a zinc sulfate and hydrochloric acid. The zinc sulfate may be decomposed to produce zinc oxide among other substances.

To treat organic sludge while keeping facility costs, cement production efficiency, and a reduction in clinker production amount to a minimum. An organic sludge treatment device includes: a fractionation device 7 that fractionates a preheated raw material R2 from a preheater cyclone 4C excluding a bottommost cyclone of a cement burning device 1; a mixing device 8 that mixes an organic sludge S with the fractionated preheated raw material, and that dries the organic sludge using sensible heat of the preheated raw material; and a supply device (mixture chute 12, double-flap damper 13, shut damper 14) that supplies a mixture M from the mixing device to a calciner furnace 5 of the cement burning device or to a duct disposed between a kiln inlet portion of a cement kiln 2 and the calciner furnace. The treatment device may be provided with an introduction device for introducing an exhaust gas G2 including dust, odor and water vapor from the mixing device to a gas outlet of a bottommost cyclone 4A of the cement burning device.

A method of treating cement kiln fuel includes introducing an additive to a fuel component to form a fuel mixture. The fuel component includes a sulfur-generating combustible fuel and the additive includes a micronized lime component. The method further includes combusting the fuel component within a cement kiln. The sulfur generated by the combustion of the combustible fuel forms calcium-containing sulfur compounds with lime provided by the micronized lime component. The calcium-containing sulfur compounds fall to a bed of clinker forming beneath the flame and some portion thereof may become resident in the clinker.

A process for producing fly ash in a fluidized bed boiler includes combusting a fuel in a fluidized bed combustor in the presence of limestone particles, recovering fly ash, and recovering bottom ash. The fuel contains hydrocarbons and sulfur. A majority of the sulfur from the fuel is recovered from the bottom ash. The fly ash may contain less than 5% by weight of sulfur oxides. This may be achieved by using limestone particles having certain properties and/or narrowing an inlet from the boiler into a cyclone.

A method of producing clinker includes placing a pre-clinker mixture comprising a source of CaO into a starting material feed port in a vertically-oriented reaction chamber of a vertical reactor. The method includes placing a gaseous combustion mixture into the combustion mixture inlet. The method includes combusting the gaseous combustion mixture within the vertical reactor to heat the pre-clinker mixture, release CO 2 therefrom, and form the clinker therefrom. The method also includes removing the clinker from the product exit port.

Processes and plants for producing cement clinker, in which an oxygen-containing gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen is conveyed from a first section of the cooler directly adjoining the top of the furnace into the rotary furnace and is optionally additionally conveyed to the calciner, and where the total gas streams fed in to the combustion processes consist to an extent of more than 50% by volume (preferably more than 85% by volume) of oxygen.