A chlorine dioxide solution generating apparatus is provided for use primarily in water treatment. The apparatus has a reaction chamber supplied with metered quantities of an acidic solution and a chlorite or chlorate solution whereby a reservoir of a chlorine dioxide solution is generated and retained within the reaction chamber. A conduit is provided along which a pressurized flow of a motive fluid is fed and with which the interior of the reaction chamber communicates via a dip tube. A venturi is located in the conduit adjacent an outlet from the dip tube whereby suction is applied to the reaction chamber by the pressurized flow of motive fluid. The suction draws chlorine dioxide solution from the reservoir whereby it is entrained into the flow of motive fluid. A controller is provided to control flow of motive fluid and metering of the supply of the solutions to the reaction chamber.

Disclosed herein are methods of producing a gas at a variable rate, the methods comprising dynamically mixing dry particles comprising a precursor and dry particles comprising a proton-generating species to produce a gas and wherein the gas is produced at a rate that is varied by varying the amount of time the dry particles comprising the precursor and the dry particles comprising the proton-generating species are dynamically mixed, the rate at which the dry particles comprising the precursor and the dry particles comprising the proton-generating species are dynamically mixed, or a combination thereof.

A method of producing chlorine dioxide is disclosed. The method may include feeding a reaction mixture into a separator. The reaction mixture may follow a helical path through the separator and produce gaseous chlorine dioxide within the separator. Gaseous chlorine dioxide may be withdrawn from the separator and used to disinfect process water.

A method to optimize the chemical balance at a sulfate pulp mill, which produces at least pulp bleached with chlorine dioxide and has a chlorine dioxide plant using at least chlorate, methanol and sulfuric acid for making chlorine dioxide. The method includes: a) gases from the mill's concentrated non-condensable gas system are incinerated in order to form a gas containing sulfur dioxide, which is treated to produce concentrated sulfuric acid, and b) raw methanol from the mill processes is purified to produce methanol, and c) side streams containing sodium compounds and/or sulfur compounds produced by mill processes are used as make-up chemicals, wherein the production of chlorine dioxide uses the sulfuric acid produced in step a) and methanol purified in step b), with a sulfuric acid concentration of 94-99%, preferably 95-98%, and using in step c) sesquisulfate or sodium sulfate produced during the production of chlorine dioxide.

A chlorine dioxide solution generating apparatus is provided for use primarily in water treatment. The apparatus has a reaction chamber supplied with metered quantities of an acidic solution and a chlorite or chlorate solution whereby a reservoir of a chlorine dioxide solution is generated and retained within the reaction chamber. A conduit is provided along which a pressurized flow of a motive fluid is fed and with which the interior of the reaction chamber communicates via a dip tube. A venturi is located in the conduit adjacent an outlet from the dip tube whereby suction is applied to the reaction chamber by the pressurized flow of motive fluid. The suction draws chlorine dioxide solution from the reservoir whereby it is entrained into the flow of motive fluid. A controller is provided to control flow of motive fluid and metering of the supply of the solutions to the reaction chamber.

Disclosed herein are methods of producing a gas at a controlled rate, the methods comprising directing air through a layered bed to produce a gas. The layered bed comprises alternating layers of a layer of dry particles comprising a precursor and a layer of dry particles comprising a proton-generating species. The gas is produced at a rate that is controlled by controlling the presence or absence of air flowing though the layered bed, the amount of time the air flows through the layered bed, the total number of layers in the layered bed, the average thickness of each of the layers of dry particles comprising the precursor in the layered bed, the average thickness of each of the layers of dry particles comprising the proton-generating species in the layered bed, the temperature the method is performed at, or a combination thereof.

Disclosed herein are methods of producing a gas at a controlled rate, the methods comprising directing air through a layered bed to produce a gas. The layered bed comprises alternating layers of a layer of dry particles comprising a precursor and a layer of dry particles comprising a proton-generating species. The gas is produced at a rate that is controlled by controlling the presence or absence of air flowing though the layered bed, the amount of time the air flows through the layered bed, the total number of layers in the layered bed, the average thickness of each of the layers of dry particles comprising the precursor in the layered bed, the average thickness of each of the layers of dry particles comprising the proton-generating species in the layered bed, the temperature the method is performed at, or a combination thereof.

Disclosed herein are methods of producing a gas at a controlled rate, the methods comprising directing air through a layered bed to produce a gas. The layered bed comprises alternating layers of a layer of dry particles comprising a precursor and a layer of dry particles comprising a proton-generating species. The gas is produced at a rate that is controlled by controlling the presence or absence of air flowing though the layered bed, the amount of time the air flows through the layered bed, the total number of layers in the layered bed, the average thickness of each of the layers of dry particles comprising the precursor in the layered bed, the average thickness of each of the layers of dry particles comprising the proton-generating species in the layered bed, the temperature the method is performed at, or a combination thereof.

A device for facilitating a chemical reaction while submerged in a liquid catalyst includes an upper member, a lower member, and a dissolvable member disposed between and ultimately enclosed by said upper and lower members such that upper and lower chambers are formed having substantially equal volumes. The upper chamber may receive a dry sodium chlorite and the lower chamber may receive a dry acid mixture. In order to keep the device submerged in the liquid catalyst, an inert ballast may also be added to the upper and/or lower chamber, such as glass shards.

According to one aspect of the invention, a method of converting an oxy halide salt into a halide dioxide in a reaction zone under certain conditions is provided. More specifically, the method includes generating chlorine dioxide from a stable composition comprising an oxy halide salt by introducing said composition to a reducing agent and minimum temperature within the reaction zone. According to another aspect of the invention, a composition for a stable chlorine dioxide precursor comprising an oxy halide salt is provided.