Abstract: A method for controlling hydrogen combustion in a hydrogen internal combustion engine system includes a combustion chamber linked to an intake port via an intake valve, the hydrogen internal combustion engine system comprising a piston slidably moving between a top dead center position and a bottom dead center position, characterized by the steps of: injecting water in liquid phase in the intake port when the piston is between 0 and 40 crank angle degrees before opening of the intake valve, injecting hydrogen after opening of the intake valve and when the piston is between 0 and 60 crank angle degrees after the top dead center position, stopping hydrogen injection when the piston is between 0 and 100 crank angle degrees before the bottom dead center position.

Abstract: The present disclosure relates to thin-walled carbon nanomaterial, such as thin-walled carbon nanotubes, and systems, methods and compositions for production thereof. The method for producing a thin walled carbon nanotube comprises heating a carbonate electrolyte to obtain a molten carbonate electrolyte; disposing the molten carbonate electrolyte between an anode and a cathode in a cell; applying an electrical current to the cathode and the anode in the cell; and, limiting a diameter of the carbon nanomaterial.

Abstract: Apparatus for seawater acidification including an ion exchange, cathode and anode electrode compartments and cation-permeable membranes that separate the electrode compartments from the ion exchange compartment. Means is provided for feeding seawater through the ion exchange compartment and for feeding a dissociable liquid media through the anode and cathode electrode compartments. A cathode is located in the cathode electrode compartment and an anode is located in the anode electrode compartment and a means for application of current to the cathode and anode is provided. A method for the acidification of seawater by subjecting the seawater to an ion exchange reaction to exchange H+ ions for Na+ ions. Carbon dioxide may be extracted from the acidified seawater. Optionally, the ion exchange reaction can be conducted under conditions which produce hydrogen as well as carbon dioxide. The carbon dioxide and hydrogen may be used to produce hydrocarbons.

Abstract: Provided herein are methods of removing carbon dioxide from an aqueous stream or gaseous stream by: contacting the gaseous stream comprising carbon dioxide, when present, with an aqueous solution comprising ions capable of forming an insoluble carbonate salt; contacting the aqueous solution comprising carbon dioxide with an electroactive mesh that induces its alkalinization thereby forcing the precipitation of a carbonate solid from the solution and thereby the removal of dissolved inorganic carbon by electrolysis; and removing the precipitated carbonate solids from the solution, or the surface of the mesh where they may deposit. Also provided herein are flow-through electrolytic reactors comprising an intake device in fluid connection with a rotating cylinder comprising an electroactive mesh, and a scraping device and/or liquid-spray based device for separating a solid from the mesh surface.

Abstract: A carbon dioxide electrolytic device includes: an electrolysis cell including a cathode, an anode, cathode and anode flow paths, and a separator; a carbon dioxide source to supply carbon dioxide to the cathode flow path; a solution source to supply an electrolytic solution containing water to the anode flow path; at least one sensor to acquire at least one data of a data indicating a discharge amount per unit time of a liquid containing water to be discharged from at least one flow path and a data indicating a concentration of at least one ion in the liquid; a refresh material source including a gas source to supply a gaseous substance to the at least one flow path; and a controller programmed to stop the supply of the carbon dioxide and the electrolytic solution, and start supply of a gaseous substance from the refresh material source, in accordance with the at least one data.

Abstract: A healthy gas generating system for generating healthy gas for inhalation by a user includes an electrolysis device, a gas mixing device, and a backfire barrier. The electrolysis device electrolyzes water to generate a gas with hydrogen. The gas mixing device includes a mixer and a vibrator for mixing the combination gas with an atomized gas to produce the healthy gas. The backfire barrier is configured on the output of the gas mixing device or the gas passage of receiving the combination gas to avoid the backflow of the gas.

Abstract: Sweep-based gas separation processes for reducing carbon dioxide emissions from gas-fired power plants. The invention involves at least two compression steps, a combustion step, a carbon dioxide capture step, a power generate step, and a sweep-based membrane separation step. One of the compression steps is used to produce a low-pressure, low-temperature compressed stream that is sent for treatment in the carbon dioxide capture step, thereby avoiding the need to expend large amounts of energy to cool an otherwise hot compressed stream from a typical compressor that produces a high-pressure stream, usually at 20-30 bar or more.

Abstract: The invention relates to an electrolyte, comprising at least one lithium salt, a solvent, and at least one compound according to general formula (1). The invention further relates to lithium-based energy stores comprising such an electrolyte.

Abstract: An electrolysis method of preventing the voltage of an electrolytic bath from rising over time without halting electrolysis and an electrolysis device for executing the method are provided such that: in operation of a two-compartment electrolytic bath, which has a membrane partitioning an anode compartment from a cathode compartment and in which a sulfide ion-containing white liquor for use in a pulp production process is fed into the anode compartment while direct current is supplied to the electrolytic bath to produce polysulfide in the anode compartment through electrolysis, and a sulfide ion-containing white liquor for use in a pulp production process that contains at least one of a scale cleaning agent and a scale inhibitor is fed to the anode compartment.

Abstract: Methods and systems for on-site, continuous generation of peracid chemistry, namely peroxycarboxylic acids and peroxycarboxylic acid forming compositions, are disclosed. In particular, an adjustable biocide formulator or generator system is designed for on-site generation of peroxycarboxylic acids and peroxycarboxylic acid forming compositions from sugar esters. Methods of using the in situ generated peroxycarboxylic acids and peroxycarboxylic acid forming compositions are also disclosed.

Abstract: Various embodiments provide a leaching solution monitoring module comprising a first leaching solution distribution system interface, a flow meter in fluid communication with the first leaching solution distribution system interface, the flow meter in fluid communication a 3-way pressure regulator, and a second leaching solution distribution system interface in fluid communication with the 3-way pressure regulator.

Abstract: Methods and systems for on-site, continuous generation of peracid chemistry, namely peroxycarboxylic acids and peroxycarboxylic acid forming compositions, are disclosed. In particular, an adjustable biocide formulator or generator system is designed for on-site generation of peroxycarboxylic acids and peroxycarboxylic acid forming compositions from sugar esters. Methods of using the in situ generated peroxycarboxylic acids and peroxycarboxylic acid forming compositions are also disclosed.

Abstract: 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+[X—O]? where X is Cl, Br, or I.

Abstract: Systems and methods for generating reactive oxygen species formulations useful in various oxidation applications. Exemplary formulations include singlet oxygen or superoxide and can also contain hydroxyl radicals or hydroperoxy radicals, among others. Formulations can contain other reactive species, including other radicals. Exemplary formulations containing peracids are activated to generate singlet oxygen. Exemplary formulations include those containing a mixture of superoxide and hydrogen peroxide. Exemplary formulations include those in which one or more components of the formulation are generated electrochemically. Formulations of the invention containing reactive oxygen species can be further activated to generate reactive oxygen species using activation chosen from a Fenton or Fenton-like catalyst, ultrasound, ultraviolet radiation or thermal activation.

Abstract: A hydrogen producing cell of the present invention is provided with an electrolyte supply hole, an electrolyte discharge hole, a first hydrogen circulation hole and a second hydrogen circulation hole respectively penetrating a housing. In disposing the hydrogen producing cell, the electrolyte supply hole is arranged on a vertically upper side than the electrolyte discharge hole, the first hydrogen circulation hole is arranged on a vertically upper side than the electrolyte supply hole, and the second hydrogen circulation hole is arranged on a vertically upper side than the electrolyte discharge hole. By this configuration, it is possible to considerably reduce the length of a pipe and the number of manifolds concerning the electrolyte and hydrogen, and to link the hydrogen producing cells with one another simply and rationally.

Abstract: Methods and systems for on-site, continuous generation of peracid chemistry, namely peroxycarboxylic acids and peroxycarboxylic acid forming compositions, are disclosed. In particular, an adjustable biocide formulator or generator system is designed for on-site generation of peroxycarboxylic acids and peroxycarboxylic acid forming compositions from sugar esters. Methods of using the in situ generated peroxycarboxylic acids and peroxycarboxylic acid forming compositions are also disclosed.

Abstract: Disclosed is an electrolyzer including an electrode including a nanoporous oxide-coated conducting material. Also disclosed is a method of producing a gas through electrolysis by contacting an aqueous solution with an electrode connected to an electrical power source, wherein the electrode includes a nanoporous oxide-coated conducting material.

Abstract: A method for synthesis of nanostructured metal oxide powders. The method comprises converting the metallic material into a precipitate of metal hydroxide by an electrochemical reaction and calcinating the metal hydroxide to form the metal oxides. The method of the invention is also used for the development of cermet particulates and topological insulator particles.

Abstract: There are provided methods and systems for an electrochemical cell including an anode and a cathode where the anode is contacted with a metal ion that converts the metal ion from a lower oxidation state to a higher oxidation state. The metal ion in the higher oxidation state is reacted with hydrogen gas, an unsaturated hydrocarbon, and/or a saturated hydrocarbon to form products.

Abstract: A burning-free and non-cyanide method for recycling waste printed circuit board is provided, comprising the following steps: desoldering to separate lead and tin; crashing and electrostatic selecting to respectively extract stibium, aluminum, copper, nickel, silver, gold, platinum and palladium. The method can realize the maximization of recycling of valuable metal resources, can thoroughly separate the metal lead and tin for recycling, and meanwhile increase the recycling rate of the metal palladium.

Abstract: Methods for enhancing alkalinity and performance of ash-based detergents are disclosed. Nonhazardous ash-based detergent alkalinity is enhanced through increasing the ratio of sodium hydroxide to ash-based alkalinity. Methods according to the invention do not require the addition of chemical ingredients, do not generate additional waste streams and use the entirety of the ash-based detergent. The methods according to the invention provide alkalinity-enhanced detergent use solutions that are sufficiently concentrated for adequate cleaning capability while only requiring minimal amounts of the use solution to be dispensed for an in situ cleaning process.

Abstract: An improved electrolytic cell, its method and system is disclosed. The electrolytic cell (12) is configured, at least in one design, to recycle the catholyte to increase chlorine capture and concentration in the output solution. The cell (12) includes at least an anode chamber (39) and a cathode chamber (35). And in one design, a chamber or reservoir (31) for that serves as a source of anions and cations for the anode and cathode chambers. The outlet (38) of the cathode chamber is preferably connected in fluid communication with the inlet (44) of a degassing chamber (14) and the outlet (46) of the degassing chamber is preferably connected in fluid communication with the inlet (40) of the anode chamber.

Abstract: Apparatus for separating CO2 from an electrolyte solution are provided. Example apparatus can include: a vessel defining an interior volume and configured to house an electrolyte solution; an input conduit in fluid communication with the interior volume; an output conduit in fluid communication with the interior volume; an exhaust conduit in fluid communication with the interior volume; and an anode located within the interior volume. Other example apparatus can include: an elongated vessel having two regions; an input conduit extending outwardly from the one region; an output conduit extending outwardly from the other region; an exhaust conduit in fluid communication with the one region; and an anode located within the one region. Methods for separating CO2 from an electrolyte solution are provided. Example methods can include: providing a CO2 rich electrolyte solution to a vessel containing an anode; and distributing hydrogen from the anode to acidify the electrolyte solution.

Abstract: Methods and systems for electrochemical conversion of carbon dioxide to organic products including formate and formic acid are provided. A method may include, but is not limited to, steps (A) to (C). Step (A) may introduce an acidic anolyte to a first compartment of an electrochemical cell. The first compartment may include an anode. Step (B) may introduce a bicarbonate-based catholyte saturated with carbon dioxide to a second compartment of the electrochemical cell. The second compartment may include a high surface area cathode including indium and having a void volume of between about 30% to 98%. At least a portion of the bicarbonate-based catholyte is recycled. Step (C) may apply an electrical potential between the anode and the cathode sufficient to reduce the carbon dioxide to at least one of a single-carbon based product or a multi-carbon based product.

Abstract: The present disclosure is a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte comprising carbon dioxide. The method may include another step of contacting the second region with an anolyte comprising a recycled reactant and at least one of an alkane, haloalkane, alkene, haloalkene, aromatic compound, haloaromatic compound, heteroaromatic compound or halo-heteroaromatic compound. Further, the method may include a step of applying an electrical potential between the anode and the cathode sufficient to produce a first product recoverable from the first region and a second product recoverable from the second region.

Abstract: Methods and systems for electrochemical conversion of carbon dioxide to organic products including formate and formic acid are provided. A method may include, but is not limited to, steps (A) to (C). Step (A) may introduce an acidic anolyte to a first compartment of an electrochemical cell. The first compartment may include an anode. Step (B) may introduce a bicarbonate-based catholyte saturated with carbon dioxide to a second compartment of the electrochemical cell. The second compartment may include a high surface area cathode including indium and having a void volume of between about 30% to 98%. At least a portion of the bicarbonate-based catholyte is recycled. Step (C) may apply an electrical potential between the anode and the cathode sufficient to reduce the carbon dioxide to at least one of a single-carbon based product or a multi-carbon based product.

Abstract: The present disclosure is a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte including carbon dioxide and contacting the second region with an anolyte including a recycled reactant. The method may further include applying an electrical potential between the anode and the cathode sufficient to produce carbon monoxide recoverable from the first region and a halogen recoverable from the second region.

Abstract: An electrochemical system and method are disclosed for On Site Generation (OSG) of oxidants, such as free available chlorine, mixed oxidants and persulfate. Operation at high current density, using at least a diamond anode, provides for higher current efficiency, extended lifetime operation, and improved cost efficiency. High current density operation, in either a single pass or recycle mode, provides for rapid generation of oxidants, with high current efficiency, which potentially allows for more compact systems. Beneficially, operation in reverse polarity for a short cleaning cycle manages scaling, provides for improved efficiency and electrode lifetime and allows for use of impure feedstocks without requiring water softeners. Systems have application for generation of chlorine or other oxidants, including mixed oxidants providing high disinfection rate per unit of oxidant, e.g. for water treatment to remove microorganisms or for degradation of organics in industrial waste water.

Abstract: The present disclosure is a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte comprising carbon dioxide. The method may include another step of contacting the second region with an anolyte comprising a recycled reactant. The method may include a step of applying an electrical potential between the anode and the cathode sufficient to produce a first product recoverable from the first region and a second product recoverable from the second region. The second product may be removed from the second region and introduced to a secondary reactor. The method may include forming the recycled reactant in the secondary reactor.

Abstract: Methods and systems for electrochemically generating an oxidation product and a reduction product may include one or more operations including, but not limited to: receiving a feed of at least one organic compound into an anolyte region of an electrochemical cell including an anode; at least partially oxidizing the at least one organic compound at the anode to generate at least carbon dioxide; receiving a feed including carbon dioxide into a catholyte region of the electrochemical cell including a cathode; and at least partially reducing carbon dioxide to generate a reduction product at the cathode.

Abstract: Methods for enhancing alkalinity and performance of ash-based detergents are disclosed. Nonhazardous ash-based detergent alkalinity is enhanced through increasing the ratio of sodium hydroxide to ash-based alkalinity. Methods according to the invention do not require the addition of chemical ingredients, do not generate additional waste streams and use the entirety of the ash-based detergent. The methods according to the invention provide alkalinity-enhanced detergent use solutions that are sufficiently concentrated for adequate cleaning capability while only requiring minimal amounts of the use solution to be dispensed for an in situ cleaning process.

Abstract: A method including electrolysis processing using sulfate-based electrolytes includes precipitating sodium sulfate decahydrate from a salt solution and then redissolving sodium sulfate decahydrate to prepare feed of electrolyte solution for the electrolysis processing. Front-end processing may be used to treat mixed salt solutions, including brine solutions. Calcium sulfate reagent may provide a sulfate source to regenerate electrolyte solution following carbon capture, and with carbon dioxide being sequestered in the form of calcium carbonate.

Abstract: One embodiment of the invention includes an electrochemical cell and an externally applied electrical potential used to drive a direct synthesis reaction to produce alane.

Abstract: A method and apparatus for producing a carbon monoxide containing product in which cathode and anode sides of an electrically driven oxygen separation device are contacted with carbon dioxide and a reducing agent, respectively. The carbon dioxide is reduced to carbon monoxide through ionization of oxygen and the reducing agent lowers the partial pressure of oxygen at the anode side to partially drive oxygen ion transport within the device through the consumption of the oxygen and to supply heat. The lowering of oxygen partial pressure reduces voltage and therefore, electrical power required to be applied to the device and the heat is supplied to heat the device to an operational temperature and to the reduction of the carbon dioxide occurring at the cathode side. The device can be used as part of an integrated apparatus in which the carbon dioxide is supplied from a waste stream of a process plant.

Abstract: An aluminium production electrolytic cell (14) comprises a bath (20) with bath contents (18), at least one cathode electrode (22) in contact with said contents (18), at least one anode electrode (16) in contact with said contents (18), and a hood (36), defining interior area (36a), covering at least a portion of said bath (20). The electrolytic cell (14) is equipped for effluent gases to be drawn from said interior area (36a). The electrolytic cell (14) also comprises at least one heat exchanger (74) for cooling at least a portion of the gases drawn from interior area (36a), prior to circulation thereof to interior area (36a) through at least one distribution device (90).

Abstract: Methods for enhancing alkalinity and performance of ash-based detergents are disclosed. Nonhazardous ash-based detergent alkalinity is enhanced through increasing the ratio of sodium hydroxide to ash-based alkalinity. Methods according to the invention do not require the addition of chemical ingredients, do not generate additional waste streams and use the entirety of the ash-based detergent. The methods according to the invention provide alkalinity-enhanced detergent use solutions that are sufficiently concentrated for adequate cleaning capability while only requiring minimal amounts of the use solution to be dispensed for an in situ cleaning process.

Abstract: Methods and systems for electrochemical conversion of carbon dioxide to organic products including formate and formic acid are provided. A method may include, but is not limited to, steps (A) to (C). Step (A) may introduce an acidic anolyte to a first compartment of an electrochemical cell. The first compartment may include an anode. Step (B) may introduce a bicarbonate-based catholyte saturated with carbon dioxide to a second compartment of the electrochemical cell. The second compartment may include a high surface area cathode including indium and having a void volume of between about 30% to 98%. At least a portion of the bicarbonate-based catholyte is recycled. Step (C) may apply an electrical potential between the anode and the cathode sufficient to reduce the carbon dioxide to at least one of a single-carbon based product or a multi-carbon based product.

Abstract: The present disclosure is a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte including carbon dioxide and contacting the second region with an anolyte including a recycled reactant. The method may further include applying an electrical potential between the anode and the cathode sufficient to produce carbon monoxide recoverable from the first region and a halogen recoverable from the second region.

Abstract: The present disclosure is a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte comprising carbon dioxide. The method may include another step of contacting the second region with an anolyte comprising a recycled reactant. The method may include a step of applying an electrical potential between the anode and the cathode sufficient to produce a first product recoverable from the first region and a second product recoverable from the second region. The second product may be removed from the second region and introduced to a secondary reactor. The method may include forming the recycled reactant in the secondary reactor.

Abstract: A method for the production of succinic acid and sulfuric acid by paired electrolytic synthesis is disclosed in the present invention. The method is described as following: in cathodic compartment of an electrochemical cell separated with cation exchange membrane, maleic acid or maleic anhydride is used as raw material, sulfuric acid as the cathodic reactant and the supporting electrolyte of the reaction system, succinic acid is thus synthesized by the electro-reduction reaction at cathode. In anodic compartment, the aqueous sulfuric acid solution containing iodide ion is used as electrolyte, iodide ion is anodized to form I2 and I3?. SO2 gas is fed into the circulated anolyte, reacting with I2 and I3? to form sulfuric acid and regenerate iodide ion. Simultaneously the evaporated hydroiodic acid and distilled water are returned to the anolyte circulation system. The cell voltage and the cost of production are reduced significantly.

Abstract: The present disclosure includes a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte comprising carbon dioxide. The method may include another step of contacting the second region with an anolyte comprising a sulfur-based reactant. Further, the method may include a step of applying an electrical potential between the anode and the cathode sufficient to produce a first product recoverable from the first region and a second product recoverable from the second region. An additional step of the method may include removing the second product and an unreacted sulfur-based reactant from the second region and recycling the unreacted sulfur-based reactant to the second region.

Abstract: The present disclosure is a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte comprising carbon dioxide. The method may include another step of contacting the second region with an anolyte comprising a recycled reactant and at least one of an alkane, haloalkane, alkene, haloalkene, aromatic compound, haloaromatic compound, heteroaromatic compound or halo-heteroaromatic compound. Further, the method may include a step of applying an electrical potential between the anode and the cathode sufficient to produce a first product recoverable from the first region and a second product recoverable from the second region.

Abstract: A process for producing basic lead carbonate is provided. The process comprises: (1) immersing neutralization slag to obtain sodium hydroxide solution; (2) leaching lead chloride slag with the aqueous solution containing sodium chloride and hydrochloric acid, adding sodium sulfide and filtering; (3) neutralizing the filtrate with sodium hydroxide solution, filtering and washing the precipitate; and (4) converting the precipitate to basic lead carbonate with ammonium bicarbonate, crystallizing and washing. Said neutralization slag and lead chloride slag are the redundant slag from fire refining bismuth. Said process makes better use of the redundant slag from fire refining bismuth, saves resources and reduces environmental pollution.

Abstract: A fuel cell system includes a solid oxide reversible fuel cell (SORFC) stack that is adapted to generate an exhaust stream containing hydrogen and water vapor from an outlet of the SORFC stack when the SORFC stack is operated in an electrolysis mode, a polymer electrolyte membrane (PEM) hydrogen pump that is adapted to separate at least a portion of the hydrogen contained in the exhaust stream, a first conduit that is adapted to provide the exhaust stream from the outlet of the SORFC stack into an inlet of the PEM hydrogen pump, and a second conduit that is adapted to provide at least a portion of remaining exhaust stream from an outlet of the PEM hydrogen pump into an inlet of the SORFC stack.

Abstract: This is an electrolytic apparatus and process for the production of Hypochlorous Acid (HClO) and Sodium Hydroxide (NaOH) in a closed-loop arrangement. A brine solution in an electrolyzer cell is subjected to an electric current, causing HClO and/or NaOH to be produced in water circulated through the cell. The produced solution is recirculated through the cell as its chemical properties are monitored by a sensor, connected by a controller which controls a recirculating pump and the electric current, until the sensor indicates that the concentration of the solution has reached a desired value, and the controller stops the process.

Abstract: An electrolysis cell is controlled for operation under varying electrical power supply conditions. A flow of feed stock to the cell includes an electrolysis reactant at a controlled concentration. A varying amount of electrical power is supplied to the cell to produce an electrolysis reaction that generates a first reaction product at a first side of the cell and a second reaction product at a second side of the cell. The reactant concentration is adjusted as the electrical power varies to substantially maintain the cell at its thermal neutral voltage during cell operation. The cell may be used in an electrolysis system powered by a renewable energy source with varying power output (e.g., wind, solar, etc.).

Abstract: A non-cylindrical electrolytic cell structure for hydrolyzing water from a saline solution into a plurality of mixed oxidant solutions is disclosed.

Abstract: A process for producing one or more chemical compounds comprising the steps of providing a bioelectrochemical system having an anode and a cathode separated by a membrane, the anode and the cathode being electrically connected to each other, causing oxidation to occur at the anode and causing reduction to occur at the cathode to thereby produce reducing equivalents at the cathode, providing the reducing equivalents to a culture of microorganisms, and providing carbon dioxide to the culture of microorganisms, whereby the microorganisms produce the one or more chemical compounds, and recovering the one or chemical compounds.

Abstract: The invention provides a process for producing chlorine, alkaline metal hydroxide, and hydrogen which comprises the following steps: (a) preparing a brine by dissolving an alkaline metal chloride source in water; (b) removing alkaline precipitates from the brine prepared in step (a) in the presence of hydrogen peroxide by means of a filter of active carbon, and recovering the resulting brine; (c) subjecting at least part of the resulting brine as obtained in step (b) to an ion-exchange step; (d) subjecting at least part of the brine as obtained in step (c) to a membrane electrolysis step; (e) recovering at least part of the chlorine, alkaline metal hydroxide, hydrogen, and brine as obtained in step (d); (f) subjecting at least part of the brine as recovered in step (e) to a dechlorination step; and (g) recycling at least part of the dechlorinated brine obtained in step (f) to step (a).

Abstract: The present invention relates to a process for the continuous preparation of diaryl carbonates from phosgene and at least one monohydroxy compound (monophenol) in the presence of catalysts, and also the use thereof for preparing polycarbonates. The hydrogen chloride formed in the reaction is converted by electrochemical oxidation into chlorine, with the chlorine being recirculated to the preparation of phosgene. In particular, the process comprises utilization of the hydrogen chloride formed for the process for preparing diphenyl carbonate (DPC process).