Method and installation for calcining cement raw meal in a calciner whereby fuel and a calciner oxidant having an oxygen content of at least 30% vol are introduced into the calciner so as to generate either an oxidant-lean zone or a fuel-lean zone in the calciner located between the lowermost fuel inlet level and the lowermost oxidant inlet level of the calciner, between 50% and 100% by weight of the raw meal being supplied to the calciner upstream of and/or within the oxidant-lean, respectively the fuel-lean zone.

An arrangement for burning lime mud into lime in a lime kiln. The lime mud flows counter-currently to flue gases from a feed end to a firing end and the fuel used is flue gas that is produced by gasifying a fuel in the presence of combustion air in a gasifier. The combustion air for gasification is preheated with heat generated in lime mud combustion. The arrangement is provided with a conduit between the lime kiln and the gasifier for leading air from the lime kiln into the gasifier as combustion air. At least a portion of the combustion air for gasification is preheated with heat generated in the lime mud combustion so that air is led into cooling of lime obtained in the combustion and further into the kiln, from or through the firing end of which air is taken into the gasification.

An arrangement for burning lime mud into lime in a lime kiln. The lime mud flows counter-currently to flue gases from a feed end to a firing end and the fuel used is flue gas that is produced by gasifying a fuel in the presence of combustion air in a gasifier. The combustion air for gasification is preheated with heat generated in lime mud combustion. The arrangement is provided with a conduit between the lime kiln and the gasifier for leading air from the lime kiln into the gasifier as combustion air. At least a portion of the combustion air for gasification is preheated with heat generated in the lime mud combustion so that air is led into cooling of lime obtained in the combustion and further into the kiln, from or through the firing end of which air is taken into the gasification.

The present disclosure relates to a process for the decarbonation of limestone, dolomite or other carbonated materials. The process may include heating particles of carbonated materials in a reactor of a first circuit to obtain decarbonated particles. Particles of carbonated materials are conveyed by a first entraining gas in the first circuit for preheating. The gas includes the carbon dioxide, the gas composition being substantially free of nitrogen. The carbonated particles are separated from a first entraining gas flow. The decarbonated particles are transferred to a cooling section of a second circuit having a second entraining gas in which the conveyed decarbonated particles release a portion of their thermal energy. The decarbonated particles are separated from a second entraining gas flow. The second entraining gas is substantially free of carbon dioxide.

Method and installation for calcining cement raw meal in a calciner whereby fuel and a calciner oxidant having an oxygen content of at least 30% vol are introduced into the calciner so as to generate either an oxidant-lean zone or a fuel-lean zone in the calciner located between the lowermost fuel inlet level and the lowermost oxidant inlet level of the calciner, between 50% and 100% by weight of the raw meal being supplied to the calciner upstream of and/or within the oxidant-lean, respectively the fuel-lean zone.

Method and installation for calcining cement raw meal in a calciner whereby fuel and a calciner oxidant having an oxygen content of at least 30% vol are introduced into the calciner so as to generate either an oxidant-lean zone or a fuel-lean zone in the calciner located between the lowermost fuel inlet level and the lowermost oxidant inlet level of the calciner, between 50% and 100% by weight of the raw meal being supplied to the calciner upstream of and/or within the oxidant-lean, respectively the fuel-lean zone.

The present disclosure provides systems and methods that combine direct capture of one or more moieties from a gaseous mixture with one or both of calcium oxide production and power production. The systems and methods can utilize combinations of a capture unit, a regeneration unit, a calcination unit, a slaking unit, a heat exchange unit, a separation unit, and a power production unit. The present disclosure provides the ability to remove carbon dioxide and other moieties from air or other gaseous mixtures in a truly carbon negative manner by utilizing electricity from a power production unit that is operated in a carbon neutral or carbon negative manner and simultaneously provide useful products, such as calcium oxide and calcium hydroxide.

The present invention provides compositions and methods relative to controlling hydration onset of an alkaline earth metal oxide such as calcium oxide, comprising heating an inorganic alkaline earth metal oxide to sub-calcination temperatures in the presence of organic material comprising a carbohydrate, an amino-carboxylic acid, a hydroxycarboxylic acid, or a mixture thereof. Preferred treated particles comprise at least 40% and more preferably at least 80% by dry weight calcium oxide which is heated in the presence of ascorbic acid and a starch. Treated particles of the present invention manifest an unexpected, surprising hydration induction postponement behavior as demonstrated through calorimetric testing.

The present invention relates to a process for conducting endothermic gas phase or gas-solid reactions, wherein the endothermic reaction is conducted in a production phase in a first reactor zone, the production zone, which is at least partly filled with solid particles, where the solid particles are in the form of a fixed bed, of a moving bed and in sections/or in the form of a fluidized bed, and the product-containing gas stream is drawn off from the production zone in the region of the highest temperature level plus/minus 200 K and the product-containing gas stream is guided through a second reactor zone, the heat recycling zone, which at least partly comprises a fixed bed, where the heat from the product-containing gas stream is stored in the fixed bed, and, in the subsequent purge step, a purge gas is guided through the production zone and the heat recycling zone in the same flow direction, and, in a heating zone disposed between the production zone and the heat recycling zone, the heat required for the endothermic reaction is introduced into the product-containing gas stream and into the purge stream or into the purge stream, and then, in a regeneration phase, a gas is passed through the two reactor zones in the reverse flow direction and the production zone is heated up; the present invention further relates to a structured reactor comprising three zones, a production zone containing solid particles, a heating zone and a heat recycling zone containing a fixed bed, wherein the solid particles and the fixed bed consist of different materials.

A method/system for sequestering carbon dioxide from cement and lime production facilities wherein carbon dioxide from flue gases originating from cement or lime production facilities is recovered and transported to a building materials production facility where it is sequestered.