Abstract: Powder compositions comprising alkali metal bicarbonate particles and an additive. A process for preparing alkali metal bicarbonate particles by spray-drying of an aqueous solution or suspension comprising 1-10% by weight of alkali metal bicarbonate and a resin acid or a fatty acid as additive. A process for preparing alkali metal bicarbonate particles by co-grinding the alkali metal bicarbonate in the presence of a resin acid as additive. A process for preparing alkali metal bicarbonate particles by fluidized bed coating of the alkali metal bicarbonate in the presence of a resin acid, fatty acid or a wax as additive.

Abstract: Gas separation unit for separation of a gas component from a process gas stream, said separation unit comprising a stator and a rotor comprising a plurality of sectors, each sector containing a separation device arranged to separate the gas component from the process gas stream which is led into the separation device and each sector being fluidically connected with at least one valve. The valve is a rotary active valve which comprises a rotor open area which is located at the rotor and a stator open area which is located at the stator. The rotor open area and the stator open area can overlap and can be laterally separated from each other by rotation of the rotor relative to the stator. In this way, the valve can at least partially be opened and closed. The extent of overlap of the rotor open area and the stator open area defines the extent of opening and closing of the valve, respectively. The extent of overlap corresponds to the extent of partial opening of the valve.

Abstract: A method for preparing alkali metal bicarbonate particles by crystallization from an alkali metal carbonate and/or bicarbonate solution with an additive present in the solution, chosen from among sulfates, sulfonates, polysulfonates, amines, hydroysultaines, polycarboxylates, polysaccharides, polyethers and ether-phenols, alkali metal hexametaphosphate, phosphates, sulfosuccinates, amidosulfonates, amine sulfonates, preferably chosen from among polysaccharides, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably at most 200 ppm.

Abstract: Method for producing sodium bicarbonate particles by spray-drying of an aqueous solution comprising 1 to 10% by weight of sodium bicarbonate and an additive selected from the group consisting of: magnesium salt, sodium alkylbenzene sulfonate and soybean lecithin. Sodium bicarbonate particles obtainable by such process and comprising at least 20 mg of the additive per kg of sodium bicarbonate particles.

Abstract: A method for preparing alkali metal bicarbonate particles by crystallization from an alkali metal carbonate and/or bicarbonate solution with an additive present in the solution, chosen from among sulfates, sulfonates, polysulfonates, amines, hydroxysultaines, polycarboxylates, polysaccharides, polyethers and ether-phenols, alkali metal hexametaphosphate, phosphates, sulfosuccinates, amidosulfonates, amine sulfonates, preferably chosen from among polysaccharides, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably at most 200 ppm.

Abstract: Gas separation unit for separation of a gas component from a process gas stream, said separation unit comprising a stator and a rotor comprising a plurality of sectors, each sector containing a separation device arranged to separate the gas component from the process gas stream which is led into the separation device and each sector being fluidically connected with at least one valve. The valve is a rotary active valve which comprises a rotor open area which is located at the rotor and a stator open area which is located at the stator. The rotor open area and the stator open area can overlap and can be laterally separated from each other by rotation of the rotor relative to the stator. In this way, the valve can at least partially be opened and closed. The extent of overlap of the rotor open area and the stator open area defines the extent of opening and closing of the valve, respectively. The extent of overlap corresponds to the extent of partial opening of the valve.

Abstract: Process wherein a low CO2 content process gas generated by an ammonia-soda process unit or a refined sodium bicarbonate unit is enriched by using a Temperature Swing Adsorption CO2 concentration module into a CO2 enriched gas whose CO2 content is increased by at least +10% by volume on dry gas basis relative to the process gas, and which is subsequently recycled to the ammonia-soda process unit or optionally to the refined sodium bicarbonate unit, in order: to produce sodium carbonate, or sodium bicarbonate, or to carbonate at least part of effluent from the unit for producing sodium carbonate or bicarbonate.

Abstract: Process for producing sodium carbonate with ammonia and/or for producing refined sodium bicarbonate, wherein: a low CO2 content gas generated by a unit for producing sodium carbonate with ammonia and/or generated by a unit for producing refined sodium bicarbonate is enriched into a CO2-enriched gas by using a CO2 concentration module, such as an amine-type or ammonia or PSA or TSA or cryogenic distillation or membrane-type CO2 concentration module, and said CO2-enriched gas has an increased CO2 content of: +10% (at least) to +90% (at most), by volume on a dry gas basis relative to the CO2 concentration of the low content gas, and the CO2-enriched gas is subsequently recycled to the unit for producing sodium carbonate with ammonia and/or to the unit for producing refined sodium bicarbonate, to produce sodium carbonate, or sodium bicarbonate, or to carbonate at least one part of effluent from the unit for producing sodium carbonate and/or from the unit for producing sodium bicarbonate.

Abstract: A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the amines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the ether-phenols, alkali metal hexametaphosphate, the phosphates, the sulfosuccinates, the amidosulfonates, the aminosulfonates, preferably selected from the polycarboxylates having a mean molecular weight lower than 8000 g/mol, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

Abstract: Powder composition comprising alkali metal bicarbonate particles and an amino acid as additive. A process for preparing alkali metal bicarbonate particles by spray-drying of an aqueous solution comprising 1-10% by weight of alkali metal bicarbonate and an amino acid as additive. A process for preparing alkali metal bicarbonate particles by co-grinding the alkali metal bicarbonate in the presence of an amino acid as additive.

Abstract: Powder compositions comprising alkali metal bicarbonate particles and an additive. A process for preparing alkali metal bicarbonate particles by spray-drying of an aqueous solution or suspension comprising 1-10% by weight of alkali metal bicarbonate and a resin acid or a fatty acid as additive. A process for preparing alkali metal bicarbonate particles by co-grinding the alkali metal bicarbonate in the presence of a resin acid as additive. A process for preparing alkali metal bicarbonate particles by fluidized bed coating of the alkali metal bicarbonate in the presence of a resin acid, fatty acid or a wax as additive.

Abstract: A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the mines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the etherphenols, alkali metal hexametaphosphate, the phosphates such as the organophosphates or the phosphonates, the sulfosuccinates, the amido-sulfonates, the aminosulfonates, preferably selected from: the phosphates, the organophosphates or the phosphonates, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

Abstract: A process for preparing sodium bicarbonate particles, comprising the steps of: (a) adding at least one alkali metal carbonate to an aqueous solution in order to form an aqueous composition; wherein the alkali metal carbonate comprises sodium carbonate and wherein the aqueous composition comprises at least one polycarboxylic acid and/or the salts thereof, in an amount of at least 200 ppm based on the weight of the aqueous composition; and (b) precipitating solid particles comprising sodium bicarbonate crystals and separating said sodium bicarbonate particles from the aqueous composition, in order to obtain sodium bicarbonate particles and an aqueous mother liquor.

Abstract: A treatment method for stabilizing at least a portion of at least one heavy metal contained in a sodic fly ash to reduce leachability, wherein the sodic fly ash is provided by a process whereby a sodium-based sorbent is injected in a combustion flue gas to remove pollutants therefrom. The treatment method comprises contacting the sodic fly ash with at least one water-soluble source of silicate and at least one additive comprising calcium and/or magnesium. The material obtained from the contacting step is preferably dried. The additive may be selected from the group consisting of lime kiln dust, fine limestone, quicklime, hydrated lime, dolomitic lime, dolomite, selectively calcined dolomite, hydrated dolomite, magnesium hydroxide, magnesium carbonate, magnesium oxide, and any mixture thereof. A particularly preferred additive comprises lime kiln dust and/or dolomitic lime. The heavy metal to be stabilized in the sodic fly ash may comprise selenium and/or arsenic.

Abstract: A method for preparing alkali metal bicarbonate particles by crystallization from an alkali metal carbonate and/or bicarbonate solution with an additive present in the solution, chosen from among sulfates, sulfonates, polysulfonates, amines, hydroysultaines, polycarboxylates, polysaccharides, polyethers and ether-phenols, alkali metal hexametaphosphate, phosphates, sulfosuccinates, amidosulfonates, amine sulfonates, preferably chosen from among polysaccharides, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably at most 200 ppm.

Abstract: A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the amines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the ether-phenols, alkali metal hexametaphosphate, the phosphates, the sulfosuccinates, the amidosulfonates, the aminosulfonates, preferably selected from the polycarboxylates having a mean molecular weight lower than 8000 g/mol, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

Abstract: A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the mines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the etherphenols, alkali metal hexametaphosphate, the phosphates such as the organophosphates or the phosphonates, the sulfosuccinates, the amido-sulfonates, the aminosulfonates, preferably selected from: the phosphates, the organophosphates or the phosphonates, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

Abstract: Method for producing sodium bicarbonate particles by spray-drying of an aqueous solution comprising 1 to 10% by weight of sodium bicarbonate and an additive selected from the group consisting of: magnesium salt, sodium alkylbenzene sulfonate and soybean lecithin. Sodium bicarbonate particles obtainable by such process and comprising at least 20 mg of the additive per kg of sodium bicarbonate particles.

Abstract: A treatment method for reducing the leachability of selenium contained in a sodic fly ash which is provided by a combustion process when a sodium-based sorbent comes in contact with a flue gas generated by combustion to remove at least a portion of pollutants contained in the flue gas. The method comprises: (a) contacting the sodic fly ash with at least one additive in the presence of water; and (b) drying the material (preferably a paste) from step (a) to form a dried matter. The additive may comprise at least one strontium-containing compound, at least one barium-containing compound, dolomite, a dolomite derivative such as calcined or hydrated dolomite, at least one silicate-containing compound, or any combinations of two or more thereof. A particularly suitable additive may comprise strontium chloride, strontium hydroxide, pulverized dolomitic lime, sodium silicate, or any combinations of two or more thereof.

Abstract: A process for preparing sodium bicarbonate particles, comprising the steps of: (a) adding at least one alkali metal carbonate to an aqueous solution in order to form an aqueous composition; wherein the alkali metal carbonate comprises sodium carbonate and wherein the aqueous composition comprises at least one polycarboxylic acid and/or the salts thereof, in an amount of at least 200 ppm based on the weight of the aqueous composition; and (b) precipitating solid particles comprising sodium bicarbonate crystals and separating said sodium bicarbonate particles from the aqueous composition, in order to obtain sodium bicarbonate particles and an aqueous mother liquor.