The subject process relates generally to producing an aqueous solution through a simple but highly effective chemical reaction. The aqueous solution is composed of a blended solution with water and an added solubilizer for the chemical reaction. The results produce an ionic solid and an alkaline liquid solution which are useful commercial products, and various applications including but not limited to use as a CO.sub.2 capture solvent.

The subject process relates generally to producing an aqueous solution through a simple but highly effective chemical reaction. The aqueous solution is composed of a blended solution with water and an added solubilizer for the chemical reaction. The results produce an ionic solid and an alkaline liquid solution which are useful commercial products, and various applications including but not limited to use as a CO.sub.2 capture solvent.

The present invention addresses to a method of removing scale from the DHSV of the oil production string aiming at maintaining the production of the wells and thus avoiding the loss of production. First, a neutralizing solution is placed in the service line, before pumping the scale removing solution through the string to act on the DHSV. Next, the acid is pumped into the production string to react with the calcium carbonate scale. After the time for the dissolution of the scale inside the DHSV, the well is opened for production by the service line. The spent acid is mixed with the neutralizing solution inside the service line, reducing its corrosiveness in relation to the service line, contributing to its preservation.

The present invention addresses to a method of removing scale from the DHSV of the oil production string aiming at maintaining the production of the wells and thus avoiding the loss of production. First, a neutralizing solution is placed in the service line, before pumping the scale removing solution through the string to act on the DHSV. Next, the acid is pumped into the production string to react with the calcium carbonate scale. After the time for the dissolution of the scale inside the DHSV, the well is opened for production by the service line. The spent acid is mixed with the neutralizing solution inside the service line, reducing its corrosiveness in relation to the service line, contributing to its preservation.

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 process for recovering alkali from power boiler ash is provided. The power boiler ash is first contacted with Na.sub.2CO.sub.3 to produce a mixture containing settling and non-settling solid particles. A fraction of the settling particles is then separated from the mixture to produce a first clarified alkaline solution. The first clarified alkaline solution contains species such as NaOH and KOH depending upon the power boiler ash characteristics. The non-settling solid particles may optionally be further separated from the first clarified alkaline solution to obtain a second clarified alkaline solution. This process is also applicable for the extraction of alkali from other oxide/hydroxide containing materials.

A treatment method for reducing carbon dioxide emission of combustion exhaust gas includes: a caustic soda synthesis step; a treatment step of reducing carbon dioxide emission of combustion exhaust gas; and a recycling step. In the caustic soda synthesis step, a natural sodium carbonate aqueous solution (Na.sub.2CO.sub.3) prepared by dissolving natural sodium carbonate ore powder composed of Na.sub.2CO.sub.3 and NaHCO.sub.3 in a caustic soda aqueous solution is used to generate a caustic soda aqueous solution and calcium carbonate precipitate by a causticization reaction with slaked lime, and solid-liquid separation is performed to obtain a synthetic caustic soda aqueous solution. In the treatment step, the synthetic caustic soda aqueous solution and purified combustion exhaust gas are brought into gas-liquid countercurrent contact so that carbon dioxide in the exhaust gas is absorbed by the synthetic caustic soda aqueous solution and immobilized as sodium carbonate.

A treatment method for reducing carbon dioxide emission of combustion exhaust gas includes: a caustic soda synthesis step; a treatment step of reducing carbon dioxide emission of combustion exhaust gas; and a recycling step. In the caustic soda synthesis step, a natural sodium carbonate aqueous solution (Na.sub.2CO.sub.3) prepared by dissolving natural sodium carbonate ore powder composed of Na.sub.2CO.sub.3 and NaHCO.sub.3 in a caustic soda aqueous solution is used to generate a caustic soda aqueous solution and calcium carbonate precipitate by a causticization reaction with slaked lime, and solid-liquid separation is performed to obtain a synthetic caustic soda aqueous solution. In the treatment step, the synthetic caustic soda aqueous solution and purified combustion exhaust gas are brought into gas-liquid countercurrent contact so that carbon dioxide in the exhaust gas is absorbed by the synthetic caustic soda aqueous solution and immobilized as sodium carbonate.

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.