A method of making sodium carbonate and/or sodium bicarbonate is disclosed in which carbon dioxide gas is reacted with an aqueous solution sodium hydroxide solution in the presence of a compound of the formula (I): Na.sup.+[XO].sup. where X is Cl, Br, or I.

A method for treating a purge stream derived from a sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or sodium bicarbonate and at least 1% by weight of sodium chloride and/or sodium sulfate, the method comprising: causticizing at least 50 mol. % of the sodium from sodium carbonate and/or sodium bicarbonate into a caustic solution and into a calcium carbonate mud with lime and water, separating the calcium carbonate 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, separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized, recycling part of the concentrated caustic solution to the sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer.

A method for treating a purge stream derived from a sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or sodium bicarbonate and at least 1% by weight of sodium chloride and/or sodium sulfate, the method comprising: causticizing at least 50 mol. % of the sodium from sodium carbonate and/or sodium bicarbonate into a caustic solution and into a calcium carbonate mud with lime and water, separating the calcium carbonate 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, separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized, recycling part of the concentrated caustic solution to the sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer.

Proposed is a carbon dioxide and sulfur oxide capture and carbon resource conversion system for an integrated gasification combined cycle, the system being capable of capturing and converting carbon dioxide in an exhaust gas into a carbon resource by using a basic alkali mixture solution, thereby being capable of reducing carbon dioxide and also capable of manufacturing sodium carbonate or sodium bicarbonate. In addition, sodium carbonate or sodium bicarbonate manufactured from the captured carbon dioxide is used as a desulfurizing agent capturing sulfur oxides in an exhaust gas discharged from an integrated gasification combined cycle power generation plant, and carbon dioxide and sulfur oxides are simultaneously captured, so that additional flue gas desulfurization equipment is not required to be mounted. Accordingly, the installation space of the desulfurization equipment for removing pollutants contained in gas introduced into carbon dioxide capture equipment may be minimized, and the process cost may be reduced.

Proposed is a carbon dioxide and sulfur oxide capture and carbon resource conversion system for an integrated gasification combined cycle, the system being capable of capturing and converting carbon dioxide in an exhaust gas into a carbon resource by using a basic alkali mixture solution, thereby being capable of reducing carbon dioxide and also capable of manufacturing sodium carbonate or sodium bicarbonate. In addition, sodium carbonate or sodium bicarbonate manufactured from the captured carbon dioxide is used as a desulfurizing agent capturing sulfur oxides in an exhaust gas discharged from an integrated gasification combined cycle power generation plant, and carbon dioxide and sulfur oxides are simultaneously captured, so that additional flue gas desulfurization equipment is not required to be mounted. Accordingly, the installation space of the desulfurization equipment for removing pollutants contained in gas introduced into carbon dioxide capture equipment may be minimized, and the process cost may be reduced.

A method for producing a concentrated aqueous sodium hydroxide solution from a purge stream deriving from a sodium carbonate, or sesqui-carbonate, 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 sesqui-carbonate, 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 process, apparatus, and cyclopropenimine (CPI) material for generating metal carbonates are disclosed. Generating the metal carbonates comprises reacting carbon dioxide (CO.sub.2) with CPI. Generating the metal carbonates also comprises forming a reaction mixture comprising water, metal cations, and a product of the reacting.

A process, apparatus, and cyclopropenimine (CPI) material for generating metal carbonates are disclosed. Generating the metal carbonates comprises reacting carbon dioxide (CO.sub.2) with CPI. Generating the metal carbonates also comprises forming a reaction mixture comprising water, metal cations, and a product of the reacting.

A CO.sub.2 collection system is configured to collect CO.sub.2 by bringing CO.sub.2-containing gas into contact with a reaction liquid containing NaOH and stored in a reaction tank to produce a target product. The target product to be extracted from the reaction liquid is adjusted according to a maximum temperature of the reaction liquid after production of NaHCO.sub.3 in the reaction liquid, an extraction temperature that is a temperature of the reaction liquid when the target product is extracted from the reaction tank, and an initial concentration of the NaOH in the reaction liquid.