Photocatalytic Roads - ECTRI website/Session 9/YRS11... · DTU, Denmark, 8 – 10 June, 2011...

Young Researchers Seminar 2011DTU, Denmark, June 8 - 10, 2011

Young Researchers Seminar 2011DTU, Denmark, 8 – 10 June, 2011

Photocatalytic RoadsFrom

lab

tests to real

scale

applications

Dr. Eng. Elia

Boonen

Belgian

Road

Research

Centre

BRRC

2

Contents

•

Photocatalysis?•

Photocatalytic

concrete

▫

Mechanism

–

why?▫

Lab

measurements

–

important parameters

•

Pilot project

Antwerp

(2004-2005)•

New applications (2010-2011)▫

Prenormative

research

▫

PhotoPAQ

–

«

Leopold

II tunnel

»▫

ECO2Profit – « Den Hoek 3 »

•

Conclusions –

perspectives

Photocatalytic

Roads: From lab tests to real scale

applications

3

Photocatalysis?

Photocatalytic


applications

CO2 H2 O NO3

-

…

Pollutants

4

Photocatalytic

concrete: mechanism?

Pollutants UV Radiation

Adsorption and decomposition Photocatalytic Concrete Concrete with TiO2

CTG

•

Photo: phenomenon induced by (sun) light (UV-spectrum)

•

Catalyst: a compound which

initiates

a chemical

reaction, without being

used

during

this

reaction

Mostly

in the

form

of

microparticles

of

titanium

dioxide

(TiO2

) in the crystal form anatase

Photocatalytic


applications

5

Photocatalytic

concrete: why?

Photocatalytic


applications

Important pollutants in trafic

•

CO : carbon monoxide•

SO2

: sulphur dioxide•

NOx

: nitrogen oxides (NO and NO2

)•

CO2

: carbon dioxide•

PM : particulate matter

•

VOC : volatile organic compounds•

O3

: ozone (secondary pollutant) •

Pb: lead

Toxicity, smog formation, acid rain,…

6

NOx - nitrogen oxides (NO-NO2 )

Transport sector is responsible for over 50% of NOx

coming from human activity!

Example: Exhaust of NOx

by traffic during rush hour in Paris

Energy industries14%

manufacturing industries and construction

24%transport54%

other energy use6%

other 2%

Photocatalytic


applications

7

•

10.000 m²

of photocatalytic

pavement blocks as pilot project on the parking lanes of a main axe in Antwerp was constructed in 2004-2005

•

2*4.5m on a total width of 60 m!

First application in Belgium: Sideways of the “Leien” in Antwerp

Photocatalytic


applications

8

Pre-treatment: rinsing with distilled water and drying overnight at laboratory conditions

Photocatalytic pavement block

TiO2 containing top layer

Air inlet Air outlet

UV transmitting cover

Air inlet Air outlet

T: 23°C

R.H.: 50%

Air flow: 3 l/min

NO-conc.: 1 ppmV

Light intensity: 10 W/m²

Photocatalytic

concrete: how

to measure?

ISO 22197-1 (2007)

Photocatalytic


applications

9

• Semi-conductor TiO2

(anatase

form) at the surface • In the presence of UV-light (300-400nm)

• Contact with pollutants necessary•

Formed NO3

-

is adsorbed at concrete surface (alkalinity) and can

subsequently be washed away by rain

HNOOHNO 2TiO, 2hv

HNOOHNO -3

TiO,2

2hv

Lab tests: removal of NOx

Photocatalytic


applications

10

Lab tests: measurement set-up BRRC

Photocatalytic


applications

Following ISO 22197-1 (2007)

11

Example of measurement according to ISO

Photocatalytic


applications

-0,2

0,0

0,2

0,4

0,6

0,8

1,0

1,2

0:00:00 1:12:00 2:24:00 3:36:00 4:48:00 6:00:00 7:12:00

Time

Con

cent

ratio

n (p

pm)

NONO2NOX

5 hours of UV-irradation!

12

Example of short procedure according to BRRC

Photocatalytic


applications

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0:00:00 0:07:12 0:14:24 0:21:36 0:28:48 0:36:00 0:43:12

Tijd

Con

cent

ratie

(ppm

)

NONO2NOX

Start UV

Stop UV

Start UV

Stop UV

13

Increase of photocatalytic reaction by:

• Increase of contact time▫

Air flow (l/min)

▫

Turbulence▫

Contact area

•

Increase of light intensity (UV-light,W/m²)•

Decrease of relative

humidity (RH %)•

Optimum TiO2

-content (efficiency -

durability)

Photocatalytic


applications

-25%

-20%

-15%

-10%

-5%

0%

Relative humidity [%]

Red

uctio

n of

NO

x in

flow

with

1 p

pmV

NO

conc

entr

atio

n [%

]

3030 40% 50 60 70

-0,2

0

0,2

0,4

0,6

0,8

1

1,2

0:00:00 0:20:00 0:40:00 1:00:00 1:20:00 1:40:00 2:00:00

Time

conc

(ppm

) NONO2NOx

UV intensity: 1.0 mW/cm²

UV intensity: 0.5 mW/cm²

14

Important for heterogenous photocatalysis:

•

Acces to light –

light intensity, wavelength•

Acces to pollutants: air flows, contact time, relative humidity

•

Removal of deposited pollutants: by rain or washing

Photocatalytic


applications

15

Pilot project: Leien

in Antwerp

(2004-2005)

Photocatalytic


applications

16

Results: influence of washing the pavement blocks

Photocatalytic


applications

00,10,20,30,40,50,60,70,80,9

9/01

/200

6 (z

.w.)

6/09

/200

6

27/0

8/20

07(z

.w.)

27/0

8/20

07

4/04

/200

5

6/09

/200

6

27/0

7/20

06

27/0

8/20

07(z

.w.)

27/0

8/20

07

9/01

/200

6 (z

.w.)

27/0

7/20

06

9/01

/200

6(z.

w.)

30 35 37 42 48 53

Positioning (nr. Amerikalei)

Min

imum

NO

-con

cent

ratio

n (p

pmV

) m

easu

red

on 2

pav

emen

t blo

cks

30 9/01/2006 (z.w.) 30 6/09/2006 30 27/08/2007 (z.w.) 30 27/08/200735 4/04/2005 35 6/09/2006 37 27/07/2006 37 27/08/2007(z.w.)37 27/08/2007 42 9/01/2006 (z.w.) 48 27/07/2006 53 9/01/2006(z.w.)

17

Results Antwerp 2010

Photocatalytic


applications

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

9/09/2010 A 9/09/2010 B 10/10/2010 A 10/10/2010 B 10/10/2010 C

Sample Amerikalei

Min

imum

NO

-con

cent

ratio

n (p

pmV

) m

easu

red

on 2

pav

emen

t blo

cks

=> Durable activity!

18

Increasing and decreasing light intensity

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

1,1

0:00:00 0:30:00 1:00:00 1:30:00 2:00:00 2:30:00 3:00:00 3:30:00 4:00:00 4:30:00 5:00:00 5:30:00

Time

NO

x-co

ncen

tratio

n at

out

let (

ppm

)

NOSeries2

1000Lux

2000Lux

3000Lux

4000Lux

5000Lux

Stop NO0Lux

New developmentsNew and more efficient materials, also working under visible light:

Photocatalytic


applications

19

New projects (2010-2013)

“Characterisation of photocatalytic (building) materials”

Prenormative

research (NBN) into

testing

methods

PhotoPAQ

Demonstration

project

within European

Life+-programme

Application in Leopold

II-tunnel

of Brussels

ECO2PROFIT

INTERREG project in cooperation with POM Antwerp (regional development)

Application of photocatalytic

concrete with TiO2

in top layerPhotocatalytic


applications

20

Photocatalytic concrete: new testing methods•

Prenormative research project CCN/PN/NBN 706: comparative study of test methods within European normalisation actions (CEN/TC386/WG 2)

CTG

http://www.centexbel.be/

21

Photocatalytic concrete: new applications •

LIFE+

project PhotoPAQ: application of cementitious photocatalytic materials on the walls and roof of Leopold II tunnel in Brussels

and

measurement of effect on air pollution inside

Improvement

of air quality

?!

CTG

Cfr. photopaq.ircelyon.univ-lyon1.fr

Pollutants UV Radiation

Adsorption and decompositionPhotocatalytic Concrete

Concrete with TiO2

Photocatalytic


applications

22

Photocatalytic concrete: new applications (2) •

INTERREG project ECO2PROFIT: application of double layered concrete with recycled concrete aggregates (CO2

)

in the bottom layer and photocatalytic materials (TiO2

) in the top layer on industrial site “Den Hoek 3” in Wijnegem

(province of Antwerp)

CTGPhotocatalytic


applications

23

Demonstration project “Den Hoek 3”

•

Test program to optimize air purifying action in top layer:▫

Testing of different materials

▫

Influence curing compound

▫

Exposed aggregates surface

▫

Simulation of durability

•

Construction of trial sections

With conservation of other properties (workability, mechanical, frost-thaw,…)

24

•

Fundamental choice for photocatalytic concrete roads:

•

Exposed aggregates surface:

noise reduction,

comfort

•

Optimization

of concrete composition

(both layers)

Spraying on the surfaceTiO2

-dispersion:

+ direct action+ cost

(“ordinary”

cement)

-

Durability (adhesion to surface)?

Mixing in the mass TiO2

in cement:

+ durable action-

cost

(higher

concentration

and double layered concrete)-

indirect action

(only the TiO2

at the surface is active)

Demonstration project “Den Hoek 3” (2)

Photocatalytic


applications

25

•

W/C = 0.42, Cmin = 425 kg/m³, air content: 5-8%

=> Control consistency, air content, volumetric mass,…

Concrete 0/6,3 (top layer) - Wijnegem

0

10

20

30

40

50

60

70

80

90

1008,06,34,02,01,00,2500,1250,063

Sieve size [mm]

Cum

ulat

ive

mas

s re

tain

ed [%

]

ReferentieOCW volgens berekeningARC

Composition

Material Quantity (kg)

CEM III/A 42.5 N LA 425

Sea sand 0/4 735

Porphyry 4/6,3 973

Air-entraining agent 0,65

Plasticizer 1,5

Water 178,5

Optimization of concrete composition

Photocatalytic


applications

26

•

Simultaneous

test plates

with

concrete of

top layer and spraying of photocatalytic dispersion on the surface

•

20

days conservation

under atmospheric conditions, and subsequent storage at RH

= (60 ±

2)% and

T = (20 ±

2)°C, for

15 days

Zone 1 (with

dispersion)

Zone 2 (without

dispersion)

Construction of trial section

Photocatalytic


applications

27

=> Substantial and repeatable photocatalytic efficiency

Results for air purifying action of test plates:OCW 7366/5

00,050,1

0,150,2

0,250,3

0,350,4

0,450,5

0,550,6

0,650,7

0,750,8

0,850,9

0,951

1,051,1

0:00

:00

0:02

:00

0:04

:00

0:06

:00

0:08

:00

0:10

:00

0:12

:00

0:14

:00

0:16

:00

0:18

:00

0:20

:00

0:22

:00

0:24

:00

0:26

:00

0:28

:00

0:30

:00

0:32

:00

0:34

:00

0:36

:00

0:38

:00

0:40

:00

0:42

:00

0:44

:00

0:46

:00

0:48

:00

0:50

:00

0:52

:00

0:54

:00

0:56

:00

0:58

:00

1:00

:00

1:02

:00

1:04

:00

1:06

:00

1:08

:00

1:10

:00

1:12

:00

1:14

:00

Time (uu:mm:ss)

Con

cent

ratio

n N

Ox

(ppm

)

NO ppmNOX ppmNO2 ppm

Start UV

Stop UV

Start UV

Stop UV

21.4 ± 1.9NO

11.2 ± 1.0NOx

Average reduction (%)

Photocatalytic


applications

28

Effect of curing compound

0

5

10

15

20

25

30

35

40

45

50

A B C DPhotocatalytic sample

Red

uctio

n N

Ox

[%]

with curing

without curing

Different products in the mass

0

10

20

30

40

50

60

70

80

90

100

1 2 3Type of TiO2 product

Red

uctio

n N

O, N

Ox

[%]

reduction NO

reduction NOx

Further testing in the lab

Effect of different materials Effect of curing compound

different photocatalytic products (1,2,3) mixed in the mass (no curing compound, modified curing procedure). Curing compound = to protect against desiccation

29

Further testing in the lab (2)

Effect of surface treatment Effect of brushing/washing

Only one type of “less active” product in mass

Effect of surface treatment

0

5

10

15

20

25

exposed aggregates smooth, formwork sawnType of surface

Red

uctio

n N

O, N

Ox

[%] reduction NO

reduction NOx

Effect of brushing/washing (durability)

0

5

10

15

20

25

30

35

40

45

50

F D D'Photocatalytic sample

Red

uctio

n N

Ox

[%]

before brushing

after brushing and washing

Simulation of traffic and/or weathering

30

•

Influence of curing compound▫

Application of photocatalytic dispersion afterwards (2-3 months)

•

Optimization of concrete composition and choice of photocatalytic materials (in mass + dispersion!)

•

Effect of exposed aggregates surface finish▫

Active components at surface ↔ specific surface area

•

Durability of the photocatalytic action (in the lab)

Conclusions test program “Den Hoek 3”

Photocatalytic


applications

Final choice “Den Hoek 3” = COMBINATION:•

TiO2 in mass with curing compound & spraying

of photocatalytic dispersion after 3 months •

Provisional controls of photocatalytic efficiency

(in situ & in the lab: 2011-2012)

31

Perspectives of

photocatalytic

materials•

Promising results in the lab for NOx

abatement with several photocatalytic

(building) materials

•

Durability of the air purifying performance was shown, even after more than 6 years in service

•

Translation of results obtained in laboratory towards results in

situ remains difficult:=> Further need to demonstrate effectiveness in large scale projects, including other positive effects (O3 , VOC’s, PM,…)=> Application of photocatalytic materials is not effective everywhere, e.g. pollution source and wind are very important

Contact and/or more information:Anne Beeldens, [email protected] Boonen, [email protected]

Photocatalytic


applications

32Photocatalytic


applications

Acknowledgements

33

Thank you for your attention!

Photocatalytic Roads - ECTRI website/Session 9/YRS11... · DTU, Denmark, 8 – 10 June, 2011...

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Transcript of Photocatalytic Roads - ECTRI website/Session 9/YRS11... · DTU, Denmark, 8 – 10 June, 2011...