Disclosed are devices, systems, and methods for producing broad spectrum disinfectants, sanitizers, cleaner and deodorizers using chlorine dioxide compositions, and more particularly, to methods for producing chlorine dioxide compositions having improved long term stability by the proper choice of pH and through the careful choice of other product formula ingredients.

The present invention relates to a process for producing an aqueous solution containing chlorine dioxide from gaseous chlorine dioxide and from an aqueous phase. The invention additionally relates to an apparatus for producing an aqueous solution containing chlorine dioxide and/or for carrying out the process of the invention. Finally, the invention also relates to the use of an apparatus according to the invention for carrying out a process according to the invention. In the following, all statements made in respect of the process of the invention also apply correspondingly to the apparatus of the invention and the use according to the invention, and vice versa, unless indicated otherwise in the individual case.

This invention relates to aqueous solutions that contain chlorine dioxide, particularly ultrapure aqueous solutions of chlorine dioxide that can be used, for example, in the field of human and veterinary medicine to disinfect surfaces, devices and instruments, as well as a process for producing such aqueous solutions of chlorine dioxide. In particular, this invention is a process for producing an aqueous solution of chlorine dioxide in which a previously produced aqueous solution of chlorine dioxide is treated so that an ultrapure aqueous solution of chlorine dioxide is obtained. The invented process can be applied to all previously produced aqueous solutions of chlorine dioxide, regardless of the process used to produce these. The invented process can be used in particular to produce ultrapure aqueous solutions of chlorine dioxide much more easily and inexpensively from previously produced aqueous solutions of chlorine dioxide. Surprisingly, it was discovered that the aqueous solutions of chlorine dioxide produced using the invented process show a high level of purity and a surprisingly high level of stability.

Preparation of an aqueous chlorine dioxide solution that reaches a first chlorine dioxide concentration during a first time period, and reaches a terminal concentration thereafter. A dilute solution of aqueous sodium chlorite or chlorate with predetermined concentration is produced, which yields the terminal chlorine dioxide concentration once an acid activator is added. The dilute solution is transferred through a conduit into a sanitization zone. The acid activator is injected into the conduit at a rate and concentration selected to reach the first chlorine dioxide concentration at the end of the first time period, with a flow rate such that the activated dilute solution of aqueous sodium chlorite has passed through the conduit prior to reaching the first chlorine dioxide concentration, which thereby limits exposure of the conduit to levels less than the first chlorine dioxide concentration.

A gaseous species can be separated from an aqueous donor mixture and absorbed in an aqueous recipient mixture using a membrane separation apparatus while maintaining a large temperature difference (e.g. greater than 30° C.) between the two aqueous mixtures. A composite membrane is employed which comprises a non-porous membrane adjacent a porous membrane. The non-porous membrane is permeable to the gaseous species. The porous membrane has a porosity greater than 50% and is hydrophobic. In one embodiment, the composite membrane is oriented such that the porous membrane faces the aqueous recipient mixture and is impermeable thereto at the recipient mixture pressure. The invention is particularly suitable for separating chlorine dioxide from chlorine dioxide reaction liquor and absorbing in chilled water.

A chlorine dioxide gas generating agent pack includes a chlorine dioxide gas generating agent containing a mixture of chlorite powder, gas generation control agent powder, moisture-absorbent powder, water-absorbent resin powder, and activating agent powder; and a gas-permeable film container permeable to water vapor and chlorine dioxide gas and containing the chlorine dioxide gas generating agent. This chlorine dioxide gas generating agent pack is suitable for being carried to a region where sterilization, disinfection and deodorization are required.

Stable, aqueous solutions of chlorine dioxide and methods for producing stable, aqueous solutions of chlorine dioxide are disclosed. Generally, the chlorine dioxide solutions of the invention are aqueous solutions containing about 1000 ppm by weight or less of total impurities and/or 10 ppm or less of manganese and iron combined. The aqueous chlorine dioxide solutions are storage stable for at least 90 days at 25° C. and maintain at least 75% of the initial chlorine dioxide concentration. Methods of preparing, using and transporting the chlorine dioxide solutions are also disclosed.

There is disclosed a method of forming chlorine dioxide comprising passing chlorous acid through a membrane including a catalyst suitable to catalyse the formation of chlorine dioxide from chlorous acid. There is also disclosed a membrane suitable for forming an aqueous solution of chlorine dioxide comprising a catalyst suitable to catalyse the formation of chlorine dioxide from chlorous acid or alkali metal chlorite.

Chlorous acid is generated from a chlorite salt precursor, a chlorate salt precursor, or a combination of both by ion exchange. The ion exchange material facilitates the generation of chlorous acid by simultaneously removing unwanted cations from solution and adding hydrogen ion to solution. Chlorine dioxide is generated in a controlled manner from chlorous acid by catalysis. Chlorine dioxide can be generated either subsequent to the generation of chlorous acid or simultaneously with the generation of chlorous acid. For catalysis of chlorous acid to chlorine dioxide, the chlorous acid may be generated by ion exchange or in a conventional manner. Ion exchange materials are also used to purify the chlorous acid and chlorine dioxide solutions, without causing degradation of said solutions, to exchange undesirable ions in the chlorous acid and chlorine dioxide solutions with desirable ions, such as stabilizing ions, and to adjust the pH of chlorous acid and chlorine dioxide solutions.

The present invention relates to a process for producing an aqueous solution containing chlorine dioxide from gaseous chlorine dioxide and from an aqueous phase. The invention additionally relates to an apparatus for producing an aqueous solution containing chlorine dioxide and/or for carrying out the process of the invention. Finally, the invention also relates to the use of an apparatus according to the invention for carrying out a process according to the invention. In the following, all statements made in respect of the process of the invention also apply correspondingly to the apparatus of the invention and the use according to the invention, and vice versa, unless indicated otherwise in the individual case.