Apparatus and method for low flux photocatalytic pollution control

• US 20010050218A1
• Filed: 02/12/2001
• Published: 12/13/2001
• Est. Priority Date: 04/10/1998
• Status: Active Grant

• Current Assignee: University of Central Florida (State University System of Florida)
• Original Assignee: University of Central Florida (State University System of Florida)
• Inventors: Muradov, Nazim Z., Martin, Eric, Tabatabaie-Raissi, Ali
• Granted Patent: US 6,531,035 B2
• Time in Patent Office: Days
• US Class Current: 204/157.15
• CPC Class Codes: B01D 2255/802 Photocatalytic
• CPC Class Codes: B01D 53/885 Devices in general for catalytic purification of waste gases
• CPC Class Codes: B01J 19/123 Ultraviolet light
• CPC Class Codes: B01J 19/28 Moving reactors, e.g. rotary drums B01J19/08 takes precedence
• CPC Class Codes: B01J 21/06 Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 2219/00015 Scale-up
• CPC Class Codes: B01J 2219/00191 Control algorithm
• CPC Class Codes: B01J 2219/0877 Liquid
• CPC Class Codes: B01J 2219/0879 Solid
• CPC Class Codes: B01J 2219/0892 involving catalytically active material
• CPC Class Codes: B01J 2219/1946 conical
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B01J 8/10 moved by stirrers or by rotary drums or rotary receptacles or endless belts
• CPC Class Codes: C02F 1/02 by heating methods of steam generation F22B; preheating boiler feed-water or accumulating preheated boiler feed-water F22D
• CPC Class Codes: C02F 1/325 Irradiation devices or lamp constructions
• CPC Class Codes: C02F 1/38 by centrifugal separation
• CPC Class Codes: C02F 1/725 by catalytic oxidation
• CPC Class Codes: C02F 2201/3223 : Single elongated lamp located on the central axis of a turbular reactor
• CPC Class Codes: C02F 2201/328 : Having flow diverters (baffles)
• CPC Class Codes: C02F 2305/10 : Photocatalysts
• CPC Class Codes: Y02W 10/37 : using solar energy

Abstract

A new method for design and scale-up of photocatalytic and thermocatalytic processes is disclosed. The method is based on optimizing photoprocess energetics by decoupling of the process energy efficiency from the DRE for target contaminants. The technique is applicable to both low and high-flux photoreactor design and scale-up. The low-flux method is based on the implementation of natural biopolymeric and other low-pressure drop media support for titanium dioxide and other band-gap photocatalysts. The high-flux method is based on the implementation of multifunctional metal oxide aerogels and other media in conjunction with a novel rotating fluidized particle bed reactor.

Claims

1. An apparatus for low flux photocatalytic pollution control comprising:

a low flux longitudinal light source having a first end and a second end;

a first stage photocatalytic reactor having a first length about the first end of the light source, for converting a first portion of a target pollutant to a pre-determined level of destruction and removal efficiency (DRE) by passing the target pollutant through the first stage photocatalytic reactor, and

a last stage photocatalytic reactor having a second length about the second end of the light source for converting a last portion of the target pollutant passing through the second stage photocatalytic reactor to a selected final DRE level.

2. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the low flux longitudinal light source includes:

Low-pressure mercury vapor lamp.

3. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the low flux longitudinal light source includes:

a medium to high-pressure mercury vapor lamp.

4. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the first stage reactor and the last stage reactor each comprise:

an identical catalytic material.

5. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the first stage reactor and the last stage reactor each comprise:

a different catalytic material.

6. The apparatus for low flux photocatalytic pollution control of

claim 4

, wherein the photocatalytic material includes:

an elemental composition of Carbon, Oxygen, Hydrogen and Titanium.

7. The apparatus for low flux photocatalytic pollution control of

claim 6

, wherein the composition of the catalytic media includes:

approximately 30% to approximately 50% by weight Carbon;

approximately 40% to approximately 60% by weight Oxygen;

approximately 4% to approximately 10% by weight hydrogen; and

approximately 0.1% to approximately 20% by weight Titanium.

8. The apparatus for low flux photocatalytic pollution control of

claim 7

, wherein the composition the catalytic media includes:

approximately 40% to approximately 45% by weight Carbon;

approximately 47.5% to approximately 50% by weight Oxygen;

approximately 5.5% to approximately 6% by weight Hydrogen; and

approximately 1.5% to approximately 5% by weight Titanium.

9. The apparatus for low flux photocatalytic pollution control of

claim 4

, wherein the photocatalytic material includes:

an elemental composition of Carbon, Oxygen, Hydrogen, Cadmium and Sulfur.

10. The apparatus for low flux photocatalytic pollution control of

claim 9

, wherein the composition includes:

approximately 34% to approximately 45% by weight Carbon;

approximately 38% to approximately 50% by weight Oxygen;

approximately 4.75% to approximately 6.25% by weight Hydrogen;

approximately 7% to approximately 17.1% by weight Cadmium; and

approximately 0.2% to approximately 5% by weight Sulfur.

11. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the first stage reactor includes:

an outer impermeable hollow shell with an inlet end about the first end of the lght source, and an outlet end before the second end of the light source,

a first permeable photocatalytic jacket inside the outer impermeable shell having a first end connected to the inlet end of the shell and a second end connected to a first location on the lamp source, and

wherein the last stage reactor includes;

a last permeable photocatalytic jacket having a first end connected to the outlet end of the outer impermeable shell and a second end connected adjacent the second end of the light source, wherein fluid flows into the first end of the first-jacket through permeable photocatalytic sidewalls of the first jacket into a space between the first jacket and the outer impermeable shell, into the interior of the last photocatalytic jacket and outward through permeable photocatalytic sidewalls of the last jacket adjacent to the second end of the light source.

12. The apparatus for low flux photocatalytic pollution control of

claim 1

, comprising:

a second stage photocatalytic reactor between the first stage photocatalytic reactor and the last stage photocatalytic reactor.

13. The apparatus for low flux photocatalytic pollution control of

claim 12

, wherein the first stage reactor includes:

an outer impermeable hollow shell with an inlet end about the first end of the light source, and an outlet end before the second end of the light source, and

a first permeable photocatalytic jacket inside the outer impermeable shell having a first end connected to the inlet end of the shell and a second end connected to a first location on the light source,

wherein the second stage reactor includes;

a second permeable photocatalytic-jacket inside the impermeable shell having a first end connected to the shell adjacent to the second end of the first permeable photocatalytic jacket, and second end connected to a second location on the light source between the first location and the second end of the light source, and

wherein the last stage reactor includes;

a last permeable photocatalytic jacket having a first end connected to the outlet end of the outer impermeable shell and a second end connected adjacent the second end of the light source, wherein fluid flows into the first end of the first jacket and passes through permeable photocatalytic sidewalls of the first jacket into a space between the first jacket and the outer impermeable shell, into the first end of the second jacket, through permeable photocatalytic sidewalls of the second jacket into the space between the second jacket and the outer impermeable shell, into the interior of the last photocatalytic jacket and outward though permeable photocatalytic sidewalls of the last jacket adjacent the second end of the light source.

14. The apparatus for low flux photocatalytic pollution control of

claim 12

, further comprising:

a third stage photocatalytic reactor between the second stage photocatalytic reactor and the last stage photocatalytic reactor.

15. The apparatus for low flux photocatalytic pollution control of

claim 14

, wherein the first stage reactor includes:

an outer impermeable hollow shell with an inlet end about the first end of the light source, and an outlet end before the second end of the light source, and

a first permeable photocatalytic jacket inside the outer impermeable shell having a first end connected to the inlet end of the outer impermeable shell and a second end connected to a first location on the light source,

wherein the second stage reactor includes;

a second permeable photocatalytic jacket inside the outer impermeable shell having a first end connected to the shell adjacent to the second end of the first permeable photocatalytic jacket, and second end connected to a second location on the light source between the first location and the second end of the light source,

wherein the third stage reactor includes;

a third permeable photocatalytic jacket inside the outer impermeable shell having a first end connected to the outer impermeable shell adjacent the second end of the second permeable photocatalytic jacket, and a second end connected to a third location on the light source between the second location and the second end of the light source, and

wherein the last stage reactor includes;

a last permeable photocatalytic jacket having a first end connected to the outlet end of the outer impermeable shell and a second end connected adjacent the second end of the light source, wherein fluid flows into the first end of the first jacket and passes through photocatalytic sidewalls of the first jacket into a space between the first jacket and the outer impermeable shell, into the first end of the second jacket, through photocatalytic sidewalls of the second jacket into the space between the second jacket and the outer impermeable shell, into the first end of the third jacket, through photocatalytic sidewalls of the third jacket into the space between the third jacket and the outer impermeable shell, into the interior of the last photocatalytic jacket and outward through photocatalytic sidewalls of the last jacket adjacent to the second end of the light source.

16. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the first stage reactor and the last stage reactor each have unequal lengths.

17. The apparatus for low flux photocatalytic pollution control of

claim 16

, wherein the first stage reactor length is greater than the second stage reactor length.

18. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the target pollutant is chosen from at least one of:

alcohols, ketons, aldehydes, carboxylic acids, nitrate esters, arnnes, halogenated compounds, plasticizers, hydrocarbons, terpenic compounds, nitrogen oxides, and sulfur gases.

19. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the first stage reactor and the last stage reactor each have equal lengths.

20. The apparatus for low flux photocatalytic pollution control of

claim 1

, wherein the first stage reactor includes:

a first outer impermeable hollow shell with an inlet end about a first end of a first light source, and an outlet end adjacent a second end of the first light source.

a first permeable photocatalytic jacket inside the first outer impermeable shell having a first end connected to the inlet end of the first impermeable shell and a second end connected to a first location on the first light source, and

wherein the last stage reactor includes;

a last outer impermeable hollow shell with an inlet end about a first end of a last light source, and an outlet end adjacent a second end of the last light source,

a last permeable photocatalytic jacket inside the last outer impermeable shell having a first end connected to the inlet end of the last outer impermeable shell and a second end connected to a first location on the last light source, the first stage reactor in series to the last stage reactor, and wherein fluid flows into the first end of the first jacket through photocatalytic sidewalls of the first jacket in a space between the first jacket and the first outer impermeable shell, into the first end of the last jacket through photocatalytic sidewalls of the last jacket into a space between the last jacket and the last outer impermeable shell and outward therefrom.

21. The apparatus for low flux photocatalytic pollution control of

claim 20

, further comprising:

a second stage photocatalytic reactor between the first stage photocatalytic reactor and the last stage photocatalytic reactor.

22. The apparatus for low flux photocatalytic pollution control of

claim 21

, wherein the first stage reactor includes:

a first outer impermeable hollow shell with an inlet end about a first end of a first light source, and an outlet end adjacent a second end of the first light source,

a first permeable photocatalytic jacket inside the first outer impermeable shell having a first end connected to the inlet end of the first impermeable shell and a second end connected to a first location on the first light source, and

wherein the second stage reactor includes;

a second outer impermeable hollow shell with an inlet end about a first end of a second light source, and an outlet end adjacent a second end of the second light source,

a second permeable photocatalytic jacket inside the second outer impermeable shell having a first end connected to the inlet end of the second impermeable shell and a second end connected to a first location on the second light source, and

wherein the last stage reactor includes;

a last outer impermeable hollow shell with an inlet end about a first end of a last light source, and an outlet end adjacent a second end of the last light source,

a last permeable photocatalytic jacket inside the last outer impermeable shell having a first end connected to the inlet end of the last outer impermeable shell and a second end connected to a first location on the last light source, the first stage reactor in series to the second stage reactor and the last stage reactor, and wherein fluid flows into the first end of the first jacket through photocatalytic sidewalls of the first jacket into a space between the first jacket and the first outer impermeable shell, into the first end of the second jacket through photocatalytic sidewalls of the second jacket into a space between the second jacket and the second outer impermeable shell, into the first end of the last jacket through photocatalytic sidewalls of the last jacket into a space between the last jacket and the last outer impermeable shell, and outward therefrom.

23. The apparatus for low flux photocatalytic pollution control of

claim 22

, further comprising:

a third stage photocatalytic reactor between the second stage photocatalytic reactor and the last stage photocatalytic reactor.

24. The apparatus for low flux photocatalytic pollution control of

claim 23

, wherein the first stage reactor includes:

a first outer impermeable hollow shell with an inlet end about a first end of a first light source, and an outlet end adjacent a second end of the first light source,

a first permeable photocatalytic jacket inside the first outer impermeable shell having a first end connected to the inlet end of the first impermeable shell and a second end connected to a first location on the first light source, and

wherein the second stage reactor includes;

a second outer impermeable hollow shell with an inlet end about a first end of a second light source, and an outlet end adjacent a second end of the second light source,

a second permeable photocatalytic jacket inside the second outer impermeable shell having a first end connected to the inlet end of the second impermeable shell and a second end connected to a first location on the second light source, and

wherein the third stage reactor includes;

a third outer impermeable hollow shell with an inlet end about a first end of a third lamp light, and an outlet end adjacent a second end of the third light source,

a third permeable photocatalytic jacket inside the third outer impermeable shell having a first end connected to the inlet end of the third impermeable shell and a second end connected to a first location on the third light source, and

wherein the last stage reactor includes;

a last outer impermeable hollow shell with an inlet end about a first end of a last light source, and an outlet end adjacent a second end of the last light source,

a last permeable photocatalytic jacket inside the last outer impermeable shell having a first end connected to the inlet end of the last outer impermeable shell and a second end connected to a first location on the last light source, the first stage reactor in series to the second stage reactor and the third stage reactor and the last stage reactor, and wherein fluid flows into the first end of the first jacket through photocatalytic sidewalls of the first jacket into a space between the first jacket and the first outer impermeable shell, into the first end of the second jacket through photocatalytic sidewalls of the second jacket into a space between the second jacket and the second outer impermeable shell, into the first end of the third jacket through photocatalytic sidewalls of the third jacket into a space between the third jacket and the third outer impermeable shell, into the first end of the last jacket through photocatalytic sidewalls of the last jacket into a space between the last jacket and the last outer impermeable shell, and outward therefrom.

25. An apparatus for low flux photocatalytic pollution control comprising:

first low flux longitudinal lamps positioned parallel to each other;

last low flux longitudinal lamps positioned parallel to each other, and in series with the first low flux longitudinal lamps;

first stage photocatalytic reactors, positioned parallel to each other, each of the first stage photocatalytic reactors housing each of the first stage flow flux longitudinal lamps, wherein the first stage photocatalytic reactors converts a first portion of a target pollutant passing therethrough; and

a last stage photocatalytic reactors, positioned parallel to each other, each of the last stage photocatalytic reactors including each of the last stage low flux longitudinal lamps, wherein the last stage photocatalytic reactors converting a last portion of the target pollutants passing through the last stage photocatalytic reactors to a selected final DRE level.

26. The apparatus for low flux photocatalytic pollution control of

claim 25

, wherein the first stage reactors and the second stage reactors each include:

approximately 2 to approximately 32 lamps.

27. The apparatus for low flux photocatalytic pollution control of

claim 25

, wherein the first stage reactors include:

a single first outer impermeable hollow shell with inlet ends about first ends of the first parallel lamps and outlet ends adjacent second ends of the first parallel lamps;

first permeable photocatalytic jackets inside the first outer permeable hollow shell, each of the jackets having first ends connected to the inlet ends of the first shell and second ends connected to the outlet ends of the first shell; and

wherein the last stage reactors include;

a single last outer impermeable hollow shell with inlet ends about first ends of the last parallel lamps, and outlet ends adjacent second ends of the last parallel lamps; and

last permeable photocatalytic jackets inside the last outer impermeable hollow shell, each of the last jackets having first ends connected to the inlet ends of the last shell and second ends connected to the outlet ends of the last hollow shell, wherein fluid flows into the first ends of the first jackets adjacent the first ends of the first lamps and out through the permeable photocatalytic sidewalls of the first jackets surrounding the first lamps into a space between the first jackets and the first outer impermeable shell, and through an interconnect joining an exit port of the first shell to an inlet port of the last shell and into each of the last photocatalytic jackets surrounding the last lamps and outward through permeable photocatalytic sidewalls of the last jackets and into a space between the last jackets and the last outer impermeable shell and out of the pollution control apparatus through an exit port of the last hollow shell.

28. The apparatus for low flux photocatalytic pollution control of

claim 25

, wherein the length of each of the first stage reactors and each of the last stage reactors are equal to one another.

29. The apparatus for low flux photocatalytic pollution control of

claim 25

, wherein the length of each of the first stage reactors and each of the last stage reactors are unequal to one another.

30. The apparatus for low flux photocatalytic pollution control of

claim 25

, further comprising:

second low flux longitudinal lamps positioned parallel to each other;

second stage photocatalytic reactors, positioned parallel to each other, each of the second stage photocatalytic reactors including each of the second low flux longitudinal lamps for converting a second portion of the target pollutant passing.

31. The apparatus for low flux photocatalytic pollution control of

claim 25

, further comprising:

second low flux longitudinal lamps positioned parallel to each other;

second stage photocatalytic reactors, positioned parallel to each other, each of the second stage photocatalytic reactors including each of the second low flux longitudinal lamps for converting a second portion of the target pollutant passing; and

third low flux longitudinal lamps positioned parallel to each other;

third stage photocatalytic reactors, positioned parallel to each other, each of the third stage photocatalytic reactors including each of the third low flux longitudinal lamps for converting a third portion of the target pollutant passing therethrough to the pre-determined final level of destruction and removal efficiency (DRE).

32. An apparatus for low flux photocatalytic pollution control comprising:

a first stage photocatalytic reactor having a first single low flux longitudinal lamp for converting a first portion of a target pollutant passing; and

a last stage photocatalytic reactor having a last single low flux longitudinal lamp for converting a last portion of the target pollutant passing therethrough to the pre-determined final level of destruction and removal efficiency (DRE).

33. The apparatus for low flux photocatalytic pollution control of

claim 32

, wherein each of the first stage photocatalytic reactor and the second stage photocatalytic reactor include:

a single jacket.

34. The apparatus for low flux photocatalytic pollution control of

claim 32

, further comprising:

a second stage photocatalytic reactor having a second single low flux longitudinal lamp for converting a second portion of the target pollutant passing.

35. The apparatus for low flux photocatalytic pollution control of

claim 34

, further comprising:

a third stage photocatalytic reactor having a third single low flux longitudinal lamp for converting a third portion of the target pollutant passing therethrough.

36. A method of low flux photocatalytic pollution control comprising the steps of:

passing a target pollutant into a first photocatalytic reactor, a first catalytic media and a second catalytic media, and at least one low flux light source; and

converting the target pollutant that passes through the first catalytic media and the second catalytic media to a selected level of destruction and removal efficiency (DRE).

37. The method of low flux photocatalytic pollution control of

claim 36

, wherein the passing step further comprises the step of:

orienting the fist catalytic media and the second catalytic media in series to one another.

38. The method of low flux photocatalytic pollution control of

claim 36

, wherein the passing step further comprises the step of:

orienting the catalytic media and the second catalytic media in parallel to one another.

39. The method of low flux photocatalytic pollution control of

claim 36

, wherein at least one light source further includes:

a single low flux light source for both the first catalytic media and the second catalytic media.

40. The method of low flux photocatalytic pollution control of

claim 36

, wherein the at least one light source further includes:

a first low flux lamp for the first catalytic media and a second low flux lamp for the second catalytic media.

41. The method of low flux photocatalytic pollution control of

claim 36

, further comprising the steps of:

passing the target pollutant into a second photocatalytic reactor having at least one catalytic media, and at least one low flux light source; and

converting the target pollutants that pass through the second photocatalytic reactor to a second selected level of destruction and removal efficiency (DRE).

42. The method of low flux photocatalytic-pollution control of

claim 41

, further comprising the step of:

orientating the first photocatalytic reactor in series with the second photocatalytic reactor.

43. The method of low flux photocatalytic pollution control of

claim 41

, further comprising the step of:

orientating the first photocatalytic reactor in parallel with the second photocatalytic reactor.

44. The method of low flux photocatalytic pollution control of

claim 36

, wherein the first catalytic media and the second catalytic media have different lengths.

45. The method of low flux photocatalytic pollution control of

claim 36

, wherein the first catalytic media and the second catalytic media have identical lengths.

46. The method of low flux photocatalytic pollution control of

claim 41

, wherein the first reactor and the second reactor have different lengths.

47. The method of low flux photocatalytic pollution control of

claim 41

, wherein the first reactor and the second reactor have identical lengths.

48. A method of low flux photocatalytic pollution control, comprising the steps of:

passing a target pollutant into a photocatalytic reactor having at least one organic catalytic jacket and at least one low flux light source; and

converting the target pollutant that passes through the first catalytic media at a selected level of destruction and removal efficiency (DRE).