Purified hydrogen peroxide gas generation methods and devices
The present disclosure provides for and includes improved devices and methods for the production of Purified Hydrogen Peroxide Gas (PHPG) that is substantially non-hydrated and substantially free of ozone.
1. A device for producing non-hydrated purified hydrogen peroxide gas (PHPG) and providing at least a portion of said PHPG to a building, said device comprising:
a. an enclosure comprising a duct of a heating, ventilation, and air conditioning (HVAC) system;
b. an air distribution mechanism providing an airflow, wherein said air distribution mechanism comprises at least one fan associated with said HVAC system;
c. an air-permeable substrate structure having a catalyst on its surface and configured to produce non-hydrated purified hydrogen peroxide gas when exposed to a light source and provided an airflow,
wherein said air-permeable substrate structure is disposed within said duct of said HVAC system; and
d. a source of ultraviolet (UV) light comprising a wavelength between 190 nm and 460 nanometers (nm), wherein said source of UV light is configured to illuminate at least a portion of said catalyst on said surface of said air-permeable substrate structure;
wherein said air-permeable substrate structure is arranged in said duct of said HVAC system such that an airflow through said duct is across said air-permeable substrate structure; and
wherein said device produces PHPG that is free of ozone and directs it out of said duct and into a heated, ventilated, and air conditioned space in said building, when in operation.
2. The device of claim 1 , wherein said airflow comprises air having a humidity of at least 5%.
3. The device of claim 1 , further comprising a humidifier.
4. The device of claim 1 , wherein said air-permeable substrate structure comprises a mesh having a percentage of open area between 10% and 60%.
5. The device of claim 4 , wherein said air-permeable substrate structure comprises a mesh having a percentage of open area between 20% and 60%.
6. The device of claim 4 , wherein said air-permeable substrate structure comprises a mesh having a percentage of open area is between 30% to 40%.
7. The device of claim 1 , wherein said ultraviolet light does not include a wavelength below 187 nm.
8. The device of claim 1 , further comprising a filter that blocks ultraviolet light having a wavelength of 188 nm or less.
9. The device of claim 1 , wherein said wavelength of ultraviolet light is between 340 nm and 380 nm.
10. The device of claim 1 , wherein at least 90% of the power of said light is emitted between 340 nm and 380 nm.
11. The device of claim 1 , wherein at least 99% of the power of said light is emitted between 350 nm and 370 nm.
12. The device of claim 1 , wherein less than 1% of said light is ultraviolet B radiation having a wavelength of between 280 nm and 315 nm.
13. The device of claim 1 , wherein said ultraviolet B radiation is less than 0.1% of the total radiation.
14. The device of claim 1 , further comprising one or more filters to remove one or more contaminants from said airflow prior to flowing through said air-permeable substrate structure, wherein the contaminants are selected from one or more of nitrogen oxide (NOx), sulfur oxide (SOx), volatile organic molecules (VOM), household dust, pollen, dust-mite debris, mold spores, pet dander, smoke, smog, or bacteria.
15. The device of claim 14 , wherein said one or more filters is an organic vapor filter, a particulate filter, a high efficiency filter, a hydrophobic filter, an activated charcoal filter, or a combination thereof.
16. The device of claim 14 , wherein said one or more contaminants are selected from nitric oxide (NO), nitrogen dioxide (NO 2 ), sulfur oxide, sulfur dioxide, formaldehyde, acetaldehyde, toluene, propanol, or butene.
17. The device of claim 14 , wherein said one or more filters comprise a particulate filter capable of capturing particles between 0.3 microns and 10 microns in size.
18. The device of claim 1 , wherein said air permeable substrate is configured such that the air has a residence time of less than one second on said catalyst of said air permeable substrate, when said device is in operation.
19. The device of claim 1 , wherein said air-permeable substrate structure further comprises a hygroscopic additive.
20. The device of claim 1 , wherein said catalyst comprises a metal or metal oxide catalyst selected from the group consisting of titanium dioxide, copper, copper oxide, zinc, zinc oxide, iron, iron oxide, tungsten, tungsten trioxide, or mixtures thereof.
21. The device of claim 20 , wherein said metal or metal oxide catalyst further comprises a co-catalyst selected from platinum, silver, gold, nickel, palladium, titanium dioxide ceramic, or extruded ceramic.
22. The device of claim 20 , wherein said air-permeable substrate structure comprises a polymer mesh with said catalyst disposed thereon at least a portion of said polymer mesh and wherein said polymer mesh comprises carbon fiber or natural fiber.
23. The device of claim 20 , wherein said air-permeable substrate structure comprises a polymer mesh with said catalyst disposed thereon at least a portion of said polymer mesh and wherein said polymer mesh is chosen from one or more of nylon, polybutylene terephthalate (PBT), polyester, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polypropylene/polyethylene (PP/PE) blends, or synthetic yarns or fibers.
24. A device for producing non-hydrated purified hydrogen peroxide gas (PHPG), said device comprising:
a. an air-permeable substrate structure having a catalyst on at least a portion of its surface and configured to produce non-hydrated purified hydrogen peroxide gas when exposed to a light source and provided with an airflow,
wherein said air-permeable substrate structure comprises a mesh formed from at least one chosen from fiberglass, polymer, or metal;
b. a source of ultraviolet (UV) light comprising a wavelength between 190 nm and 460 nanometers (nm) configured to irradiate at least a portion of said catalyst with said UV light,
wherein said device is configured for installation in a heating, ventilation, and air conditioning (HVAC) system comprising a duct, wherein said device is configured so that said airflow is across said air-permeable substrate structure when said device is installed in said duct; and
wherein said device produces PHPG that is free of ozone and wherein said device is configured to direct at least a portion of said PHPG out of said duct and into a heated, ventilated, and air conditioned space in fluid flow communication with said HVAC system, when in operation.
25. The device of claim 24 , wherein said mesh has a percentage of open area between 10% and 60%.
26. The device of claim 24 , wherein said mesh is a woven mesh.
27. The device of claim 26 , wherein said woven mesh comprises a fiberglass mesh chosen from a fiberglass cloth comprising a plain weave, long shaft satin weave, unidirectional weave, or twill weave.
28. The device of claim 1 , wherein said heated, ventilated, and air conditioned space comprises one or more rooms in a building.
29. A method for generating non-hydrated purified hydrogen peroxide gas (PHPG) using a heating, ventilation, and air conditioning (HVAC) system, said method comprising:
(a) passing a humid air stream through an air permeable structure of a PHPG generating device located within a duct of said HVAC system, wherein said air permeable structure comprises an air permeable substrate coated on at least one surface with at least one catalyst, wherein at least a portion of said passing is carried out by at least one fan associated with said HVAC system;
(b) during at least a portion of said passing of step (a), illuminating at least a portion of said catalyst on said air permeable structure with ultraviolet (UV) light having a wavelength between 190 nm and 460 nm to generate non-hydrated PHPG as said humid air contacts said catalyst of said air permeable structure; and
(c) discharging an air stream comprising PHPG from said air permeable structure and out of said duct and into a heated, ventilated, and air conditioned space.
30. The method of claim 29 , wherein said humid air stream passes through said air permeable structure at a flow rate such that said humid air stream contacts said catalyst for not more than about 1 second.
31. The method of claim 29 , wherein said humid air stream enters said air permeable structure at an angle of incidence in the range of from about 140 to about 68°.
32. The method of claim 29 , wherein said humid air stream passes through said air permeable structure in a transitional flow regime and has a Reynolds number in the range of about 2300 to about 4000 or wherein said humid air stream passes through said air permeable structure in a laminar flow regime and has a Reynolds number of less than 2300.
33. The method of claim 29 , wherein said PHPG generating device is placed in said duct during construction of said HVAC system and/or said duct.
34. The method of claim 29 , wherein said PHPG generating device is placed in an existing duct of said HVAC system.