A method for optimizing reduction and content of total titratable alkali of green liquor of a recovery boiler. The method comprises producing green liquor in a dissolving tank by conveying smelt and weak white liquor into the dissolving tank and measuring at least the contents of sodium sulphate, sodium hydroxide, sodium sulphide, and sodium carbonate of the green liquor. The method comprises controlling at least a process parameter of a recovery boiler to maximize the reduction of the recovery boiler and controlling the flow of the weak white liquor into the dissolving tank to optimize the content of total titratable alkali of the green liquor. In addition, a system for producing green liquor with optimized reduction and content of total titratable alkali. The system comprises a first sensor arrangement, a first and a second regulator, and a processing unit arrangement configured to perform the method.

A method for optimizing reduction and content of total titratable alkali of green liquor of a recovery boiler. The method comprises producing green liquor in a dissolving tank by conveying smelt and weak white liquor into the dissolving tank and measuring at least the contents of sodium sulphate, sodium hydroxide, sodium sulphide, and sodium carbonate of the green liquor. The method comprises controlling at least a process parameter of a recovery boiler to maximize the reduction of the recovery boiler and controlling the flow of the weak white liquor into the dissolving tank to optimize the content of total titratable alkali of the green liquor. In addition, a system for producing green liquor with optimized reduction and content of total titratable alkali. The system comprises a first sensor arrangement, a first and a second regulator, and a processing unit arrangement configured to perform the method.

Systems and methods for preventing biocorrosion of fuel handling components located in a sump in a fuel dispensing environment. One method includes exposing a hygroscopic material to moisture-laden air in the sump such that the hygroscopic material deliquesces into a liquid solution and exposing a buffer material to ethanol-blended fuel vapors in the sump. The method also includes collecting the liquid solution in a reservoir and monitoring the level of the liquid solution in the reservoir using a liquid level sensor. Further, the method includes notifying service personnel of the level of the liquid solution in the reservoir.

Systems and methods for preventing biocorrosion of fuel handling components located in a sump in a fuel dispensing environment. One method includes exposing a hygroscopic material to moisture-laden air in the sump such that the hygroscopic material deliquesces into a liquid solution and exposing a buffer material to ethanol-blended fuel vapors in the sump. The method also includes collecting the liquid solution in a reservoir and monitoring the level of the liquid solution in the reservoir using a liquid level sensor. Further, the method includes notifying service personnel of the level of the liquid solution in the reservoir.

Hydrogen sulfide is scrubbed from a gas stream to prepare dissolved alkali metal sulfide or hydrosulfide, which is used to prepare feed electrolyte solution for electrochemical processing to generate alkali metal hydroxide in catholyte and polysulfide in anolyte, which may be recovered from an electrochemical reactor and which may be subjected to further processing to precipitate elemental sulfur. Aqueous scrubbing solution may include alkali metal carbonate capture agent to capture hydrogen sulfide in alkali metal bicarbonate The gas stream may include carbon dioxide in addition to hydrogen sulfide, and a ratio of dissolved alkali metal carbonate to bicarbonate may be increased prior to electrochemical processing.

Hydrogen sulfide is scrubbed from a gas stream to prepare dissolved alkali metal sulfide or hydrosulfide, which is used to prepare feed electrolyte solution for electrochemical processing to generate alkali metal hydroxide in catholyte and polysulfide in anolyte, which may be recovered from an electrochemical reactor and which may be subjected to further processing to precipitate elemental sulfur. Aqueous scrubbing solution may include alkali metal carbonate capture agent to capture hydrogen sulfide in alkali metal bicarbonate The gas stream may include carbon dioxide in addition to hydrogen sulfide, and a ratio of dissolved alkali metal carbonate to bicarbonate may be increased prior to electrochemical processing.

Methods for preparing and compositions including untreated and surface-treated alkaline earth metal carbonate particulates are described. For example, a method for processing alkaline earth metal carbonate may include introducing alkaline earth metal carbonate into a stirred media mill, and dry grinding the alkaline earth metal carbonate in the stirred media mill to produce an untreated alkaline earth metal carbonate particulate having certain characteristics. In some examples, the method may include introducing carboxylic acid and/or carboxylic acid salt into the stirred media mill, and dry grinding the alkaline earth metal carbonate and the carboxylic acid and/or carboxylic acid salt in an integrated dry grinding and surface-treating process in the stirred media mill to produce a surface-treated alkaline earth metal carbonate particulate. In some examples, heating may be added during the dry grinding process.

The present invention relates to a negative electrode active material for a lithium secondary battery, which comprises graphite having an alkali carbonate layer formed on a surface thereof, wherein the graphite has an I.sub.D/I.sub.G ratio of 0.05 to 0.3 in Raman spectroscopy, and a method of preparing the same, wherein, since the negative electrode active material for a lithium secondary battery of the present invention includes the graphite having an alkali carbonate layer formed on the surface thereof, the alkali carbonate layer contributes to the formation of a stable solid electrolyte interface (SEI) to reduce a side reaction with an electrolyte solution including propylene carbonate. Thus, since low-temperature performance and initial efficiency of the lithium secondary battery may be improved, the negative electrode active material for a lithium secondary battery of the present invention is suitable for the preparation of the lithium secondary battery.

The present invention relates to a negative electrode active material for a lithium secondary battery, which comprises graphite having an alkali carbonate layer formed on a surface thereof, wherein the graphite has an I.sub.D/I.sub.G ratio of 0.05 to 0.3 in Raman spectroscopy, and a method of preparing the same, wherein, since the negative electrode active material for a lithium secondary battery of the present invention includes the graphite having an alkali carbonate layer formed on the surface thereof, the alkali carbonate layer contributes to the formation of a stable solid electrolyte interface (SEI) to reduce a side reaction with an electrolyte solution including propylene carbonate. Thus, since low-temperature performance and initial efficiency of the lithium secondary battery may be improved, the negative electrode active material for a lithium secondary battery of the present invention is suitable for the preparation of the lithium secondary battery.

The present invention relates to a process for reducing in a gas stream the concentration of carbon dioxide and for reducing in an aqueous stream the concentration of sodium chloride, which process comprises contacting a feed gas comprising greater than or equal to 0.1% by volume carbon dioxide with an aqueous feed comprising: (a) sodium chloride; and (b) calcium oxide and/or calcium hydroxide at a total concentration of greater than or equal to 0.5% by weight,
wherein the pH of the aqueous feed is greater than or equal to 10.0. A product aqueous stream obtained from the process of the invention is also described.