Catalyst for disinfection, sterilization and purification of air, and preparation method thereof

Abstract

A method of utilizing a catalyst for the sterilization, disinfection and purification of indoor air. The catalyst carrier is made of inorganic porous material such as Silica, Zeolite, Diatomite, Sepiolite, Montmoroillonite, and Aluminum oxide. The catalyst carrier can also be made of Cordierite, or Mullite ceramic honeycomb. After dipping into stabilized sodium hypochlorite solution or stabilized chlorine dioxide solution, the catalyst is produced after dehydration. The catalyst is irradiated with ultraviolet lamp to generate gas-phase free radicals including reactive particles such as .OH, .ClO2, .HO2, .O, thereby sterilizing microbial air pollutants such as viruses, bacteria, fungi and other microorganisms, and remove chemical air pollutants such as formaldehyde.

Claims

1. A catalyst for disinfection, sterilization and purification of air, the catalyst comprising a porous inorganic catalyst carrier, the porous inorganic catalyst carrier comprising one or more of aluminum oxide, silica, zeolite, sepiolite, montmorillonite, and diatomite, having a density greater than 100 meshes; wherein the catalyst is capable of generating free radicals in gas phase comprising OH, .ClO.sub.2, .HO.sub.2 and .O, which absorb and oxidize viruses, bacteria, fungi and other microorganisms in the air, and clear formaldehyde and other chemical containments by oxidation, and the porous inorganic catalyst carrier has a specific surface area greater than 10 m.sup.2 per gram.

2. The catalyst according to claim 1, wherein the porous inorganic catalyst carrier is impregnated in a stabilized chlorine dioxide solution or a stabilized sodium hypochlorite solution, and the catalyst is formed after the carrier is dried at a temperature lower than 85 C.

3. The catalyst according to claim 2, wherein the porous inorganic catalyst carrier is a structured carrier having a hole density between 30 mesh and 900 mesh.

4. The catalyst according to claim 3, wherein the hole density of the porous inorganic catalyst carrier is 400 mesh.

5. The catalyst according to claim 3, the porous inorganic catalyst carrier adopts cordierite or mullite ceramic honeycomb.

6. The catalyst according to claim 2, wherein the stabilized chlorine dioxide solution is prepared by the following procedures: obtaining chlorine dioxide gas having a purity over 98% by using a purified chlorine dioxide generator, preparing an absorbing liquid by using sodium carbonate peroxyhydrate as a stabilizer, and preparing a solution having a chlorine dioxide content of 2%-5%.

7. The catalyst according to claim 2, wherein the stabilized chlorite solution comprises: a chlorite 0.1-10%; a stabilizer solution 0.1-5%; a buffer solution 0.05-15%; absorbers 0.1-75%; and the chlorite is an alkali metal salt or alkaline metal salt of chlorous acid.

8. The catalyst according to claim 7, wherein the chlorite is sodium chlorite, potassium chlorite, or lithium chlorite.

9. The catalyst for disinfection, sterilization and purification of air according to claim 2, wherein the catalyst is irradiated by ultraviolet.

10. A disinfection and purification method using the catalyst of claim 1, wherein the catalyst is pre-processed into a certain shape; when the catalyst is placed on the microenvironment of air filtration system or portable air disinfection and purification equipment, after it is activated by ultraviolet having a density greater than 30 mW/cm.sup.2, microbial contaminants and chemical pollutants are removed.

11. The disinfection and purification method according to claim 10, wherein the ultraviolet is provided by either a mercury UV lamp or an LED UV lamp.

12. The catalyst for disinfection, sterilization and purification of air according to claim 1, wherein the catalyst is irradiated by ultraviolet.

13. The catalyst for disinfection, sterilization and purification of air according to claim 1, wherein, the porous inorganic catalyst carrier has a specific surface area greater than 100 m.sup.2 per gram.

14. The catalyst according to claim 13, wherein a particle size of the porous inorganic catalyst carrier is 2-3 mm.

15. The catalyst according to claim 13, wherein a particle size of the porous inorganic catalyst carrier is 3-5 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a view of a test prototype KF-501A installed with the catalyst of this invention;

(2) FIG. 2 shows the sterilization rate using KF-501A;

(3) FIG. 3 shows the formaldehyde removal rate using KF-501A in comparison with acknowledged brand of air purification machine and high concentration of ozone;

(4) FIG. 4 shows formaldehyde removal rate using KF-501A at lowest power rating in comparison with a Swiss acknowledged brand at its highest power rating.

DETAILED DESCRIPTION

(5) First, stabilized sodium chlorite solution was prepared, 5000 ml of purified water was measured, 400 g sodium chlorite with 80% purity was weighed and dissolved in water. Then, weigh 100 g sodium chloride was weighed and added in the solution, stirred till fully dissolved. Then 20 g sodium borate tetrahydrate was added, and 20 ml 30% hydrogen peroxide was added. The solution was filtered after stirring. Finally, the pH value was adjusted to the range between 8.0 and 9.5 with sodium carbonate. Then 3000 g silica with particle size between 3-5 mm was added and fully immersed into the solution, stirred for 1 to 2 hours, the remaining liquid was filtered, the catalyst was blown dry and then heated dry at 65 C. in a vacuum furnace till moisture level 8%. After cooling, the material can be used to make two air filters that are assembled in a double-sided inlet air disinfection purifier KF-501A. This purifier is not equipped with UV lamp, and the air filters are used in conjunction with H13HEPA air filter for indoor air purification, as shown in FIG. 1.

EXAMPLE 2

(6) Third party testing data for sterilization rate of the air disinfection purifier of example 1 is shown in FIG. 2, the test is carried out in a 30 m.sup.3 test chamber, and the results are recorded in the table below.

(7) TABLE-US-00001 TABLE 1 Date Received: Nov. 3, 2014 Date Analyzed: Nov. 3, 2014 Test results Control group Test group Original Bacteria Natural Original Bacteria Bacteria Count after decay Bacteria Count after Killing Test Count Treatment rate Count Treatment Rate Number of Test Time V.sub.0 V.sub.1 N.sub.1 V.sub.1 V.sub.2 K.sub.1 Sample Bacteria (min) (cfu/m.sup.3) (cfu/m.sup.3) (%) (cfu/m.sup.3) (cfu/m.sup.3) (%) WJ20144913-1 Staphylococcus 20 1.82 10.sup.5 1.67 10.sup.5 8.24 1.76 10.sup.5 5.21 10.sup.2 99.68 albus 30 1.82 10.sup.5 1.58 10.sup.5 13.19 1.76 10.sup.5 17 99.99 60 1.82 10.sup.5 1.43 10.sup.5 21.43 1.76 10.sup.5 <7 >99.99

(8) As can be concluded form FIG. 2, using the air disinfection purifier of example 1, the killing rate of Staphylococcus albus can be as high as 99.68% after 20 min test time.

EXAMPLE 3

(9) Third party testing data for removal rate of the air pollutants using the purifier of example 1 is tested, the test is carried out in a 30 m.sup.3 test chamber, under a temperature of (252) C. and a humidity of (5010)% RH.

(10) The test procedure is as follows:

(11) (1) The air purifier (test prototype) is place in the middle of the test chamber according to the requirements of GB/T 18801-2008. The air purifier is adjusted to the working state. Turn off the air purifier after checking that the machine is working properly.

(12) (2) Start the temperature and humidity control device to keep the chamber temperature in the range of 23-27 C., and the relative humidity in the range of 40-60% RH.

(13) (3) A certain amount of gaseous pollutant is added into the chamber by using the gaseous pollutant generator. The generator is closed when the initial concentration reach 8-12 times of the corresponding limitation of GB/T 18883-2002.

(14) (4) The fan of the test chamber is opened to stir the gaseous pollutant for 10 min, and then closed after evenly mixed.

(15) (5) The initial concentration of sample is collected after the fan stop working.

(16) (6) The air purifier is re-opened after the sample has been collected, and a one hour sample is collected after an hour.

(17) (7) The natural decay of pollutants is tested using the same method as mentioned above as control, with the air purifier kept closed.

(18) The calculating formulas and the test results are recorded in the table below.

(19) TABLE-US-00002 Test Results Control Group Test Group Original Natural Total concentration Final decay Original Final decay Removal Test on concentration rate concentration concentration rate rate Number of Time C.sub.0 C.sub.1 N.sub.1 C.sub.0 C.sub.1 N.sub.1 K.sub.1 Sample Pollutant (h) (mg/m3) (mg/m3) (%) (mg/m3) (mg/m3) (%) (%) WJ20144913-1 Formaldehyde 1 1.05 1.00 4.8 1.15 0.01 99.1 99.1 Natural decay rate $N_t^{}\left(\%\right)=\frac{C_0^{}-C_t^{}}{C_0^{}}100$where: C.sub.0 = the original concentration of control group; C.sub.1 = the final concentration of control group Total decay rate $N_t\left(\%\right)=\frac{C_0-C_t}{C_0}100$where C.sub.0 = the original concentration of test group; C.sub.1 = the final concentration of test group Removal rate $K_t\left(\%\right)=\frac{C_0\left(1-N_t^{}\right)--C_t}{C_0\left(1-N_t^{}\right)}100$

(20) Formaldehyde removal rate curve comparison between KF-501A and other international well-known air purifier brand in a 10 m.sup.3 test chamber is shown in FIG. 3.

(21) Formaldehyde removal rate curve comparison between KF-501A operates at its lowest power rating and a Swiss acknowledged air purifier brand operates at its highest power rating in a 10 m3 test chamber is shown in FIG. 4.