A method for producing a concentrated aqueous sodium hydroxide solution from a purge stream deriving from a sodium carbonate, or sesquicarbonate, or wegsheiderite crystallizer, or sodium bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or bicarbonate, and at least 1% of sodium chloride or sodium sulfate and a soluble impurity from an ore deposit comprising at least one of the following elements: As, Ba, B, Ca, Co, K, Li, Mo, P, Pb, Se, Sn, Sr, Te, Tl, Ti, V, and W, to be purified, the method comprising: causticizing at least 50 mol. % of the sodium carbonate into a caustic solution and into a calcium carbonate mud with lime and water; separating the mud from the caustic solution; concentrating the caustic solution by removing part of the water to obtain a concentrated caustic solution comprising at least 25% NaOH, and a crystallized solid comprising sodium carbonate and sodium chloride and/or sulfate; and separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized.

A method for producing a concentrated aqueous sodium hydroxide solution from a purge stream deriving from a sodium carbonate, or sesquicarbonate, or wegsheiderite crystallizer, or sodium bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or bicarbonate, and at least 1% of sodium chloride or sodium sulfate and a soluble impurity from an ore deposit comprising at least one of the following elements: As, Ba, B, Ca, Co, K, Li, Mo, P, Pb, Se, Sn, Sr, Te, Tl, Ti, V, and W, to be purified, the method comprising: causticizing at least 50 mol. % of the sodium carbonate into a caustic solution and into a calcium carbonate mud with lime and water; separating the mud from the caustic solution; concentrating the caustic solution by removing part of the water to obtain a concentrated caustic solution comprising at least 25% NaOH, and a crystallized solid comprising sodium carbonate and sodium chloride and/or sulfate; and separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized.

A catalyst system includes a complex having formula I which advantageously has a sterically protecting N-heterocyclic carbene (NHC) carbene-pyridine ligand to handle harsh reactions conditions than many prior art catalysts:

##STR00001##

wherein M is a transition metal; o is 0, 1, 2, 3, or 4; R.sub.1 is a C.sub.1-6 alkyl, a C.sub.6-18 aryl, or an optionally substituted C.sub.5-18 heteroaryl. In a refinement, R.sub.1 is methyl, ethyl, butyl, n-propyl, isopropyl, n-butyl, sec-butyl, or t-butyl; R.sub.2, R.sub.3, R.sub.3′ are independently an optionally substituted C.sub.1-6 alkyl, halo (e.g., Cl, F, Br, etc), NO.sub.2, an optionally substituted C.sub.6-18 aryl, or an optionally substituted C.sub.5-18 heteroaryl; R.sub.4, R.sub.4′ are independently an optionally substituted C.sub.1-6 alkyl, halo, NO.sub.2, an optionally substituted C.sub.6-18 aryl, or an optionally substituted C.sub.5-18 heteroaryl; and X.sup.− is a negatively charge counter ion and L.sub.1, L.sub.2 are each independently a neutral ligand.

A catalyst system includes a complex having formula I which advantageously has a sterically protecting N-heterocyclic carbene (NHC) carbene-pyridine ligand to handle harsh reactions conditions than many prior art catalysts:

##STR00001##

wherein M is a transition metal; o is 0, 1, 2, 3, or 4; R.sub.1 is a C.sub.1-6 alkyl, a C.sub.6-18 aryl, or an optionally substituted C.sub.5-18 heteroaryl. In a refinement, R.sub.1 is methyl, ethyl, butyl, n-propyl, isopropyl, n-butyl, sec-butyl, or t-butyl; R.sub.2, R.sub.3, R.sub.3′ are independently an optionally substituted C.sub.1-6 alkyl, halo (e.g., Cl, F, Br, etc), NO.sub.2, an optionally substituted C.sub.6-18 aryl, or an optionally substituted C.sub.5-18 heteroaryl; R.sub.4, R.sub.4′ are independently an optionally substituted C.sub.1-6 alkyl, halo, NO.sub.2, an optionally substituted C.sub.6-18 aryl, or an optionally substituted C.sub.5-18 heteroaryl; and X.sup.− is a negatively charge counter ion and L.sub.1, L.sub.2 are each independently a neutral ligand.

The present invention relates to a method for the production of sodium bicarbonate, particularly for producing sodium bicarbonate on an industrial scale, the method comprising the steps of: a. treating a carbonaceous feedstock to form a product stream comprising up to 10 v/v % carbon dioxide; b. capturing at least a portion of the carbon dioxide from the product stream to form a carbon dioxide stream; c. feeding the carbon dioxide stream to a reaction vessel; d. feeding an aqueous sodium carbonate solution to the reaction vessel; e. contacting at least a portion of the carbon dioxide stream with at least a portion of the aqueous sodium carbonate solution to form a slurry comprising solid sodium bicarbonate; and f. separating the solid component of the slurry from the liquid component of the slurry to provide solid sodium bicarbonate and an aqueous liquor.

The present invention relates to a method for the production of sodium bicarbonate, particularly for producing sodium bicarbonate on an industrial scale, the method comprising the steps of: a. treating a carbonaceous feedstock to form a product stream comprising up to 10 v/v % carbon dioxide; b. capturing at least a portion of the carbon dioxide from the product stream to form a carbon dioxide stream; c. feeding the carbon dioxide stream to a reaction vessel; d. feeding an aqueous sodium carbonate solution to the reaction vessel; e. contacting at least a portion of the carbon dioxide stream with at least a portion of the aqueous sodium carbonate solution to form a slurry comprising solid sodium bicarbonate; and f. separating the solid component of the slurry from the liquid component of the slurry to provide solid sodium bicarbonate and an aqueous liquor.

The present invention relates to a process for preparing a formulation comprising an alkali metal salt selected from the group consisting of alkali metal bicarbonate salts, alkali metal carbonate salts, alkali metal sesquicarbonate salts and combinations thereof, wherein said process comprises the step of extruding a paste-like composition comprising a functionalizing agent and the metal salt. The invention furthermore relates to a formulation obtainable from said process and to the use of this formulation in various applications such as in plastic foaming or in food and feed leavening compositions.

The present invention relates to a process for preparing a formulation comprising an alkali metal salt selected from the group consisting of alkali metal bicarbonate salts, alkali metal carbonate salts, alkali metal sesquicarbonate salts and combinations thereof, wherein said process comprises the step of extruding a paste-like composition comprising a functionalizing agent and the metal salt. The invention furthermore relates to a formulation obtainable from said process and to the use of this formulation in various applications such as in plastic foaming or in food and feed leavening compositions.

The present invention relates to a method for the production of sodium bicarbonate, particularly for producing sodium bicarbonate on an industrial scale, the method comprising the steps of: a. treating a carbonaceous feedstock to form a product stream comprising up to 10 v/v % carbon dioxide; b. capturing at least a portion of the carbon dioxide from the product stream to form a carbon dioxide stream; c. feeding the carbon dioxide stream to a reaction vessel; d. feeding an aqueous sodium carbonate solution to the reaction vessel; e. contacting at least a portion of the carbon dioxide stream with at least a portion of the aqueous sodium carbonate solution to form a slurry comprising solid sodium bicarbonate; and f. separating the solid component of the slurry from the liquid component of the slurry to provide solid sodium bicarbonate and an aqueous liquor.

The present invention relates to a method for the production of sodium bicarbonate, particularly for producing sodium bicarbonate on an industrial scale, the method comprising the steps of: a. treating a carbonaceous feedstock to form a product stream comprising up to 10 v/v % carbon dioxide; b. capturing at least a portion of the carbon dioxide from the product stream to form a carbon dioxide stream; c. feeding the carbon dioxide stream to a reaction vessel; d. feeding an aqueous sodium carbonate solution to the reaction vessel; e. contacting at least a portion of the carbon dioxide stream with at least a portion of the aqueous sodium carbonate solution to form a slurry comprising solid sodium bicarbonate; and f. separating the solid component of the slurry from the liquid component of the slurry to provide solid sodium bicarbonate and an aqueous liquor.