from lab-scale experiments to pilot plant production...early pilot-scale production 0 10 20 30 40 0...

1Symposium 10yrs PTL, Vitznau, 05. July 2008

Flame Aerosol Synthesis

From Lab-Scale Experiments to Pilot Plant Production

Karsten WegnerWegner Consulting & ETH Zürich

2Symposium 10yrs PTL, Vitznau, 05. July 2008

How everything started...

Prototype diffusion flame microreactor

Material: copper, welded

Fabrication: hand-made in Cincinnati (OH)

Characteristics: 6 “concentric” tubes 1/10”, 1/6”, 7/32”, ...

3Symposium 10yrs PTL, Vitznau, 05. July 2008

The Swiss response:

Diffusion flame microreactor

Material: stainless steel 1.4435

Fabrication: machined at ETH workshop

Characteristics: 6 concentric! tubes: 2.54mm, 4.23mm, 5.56mm,...

4Symposium 10yrs PTL, Vitznau, 05. July 2008

Flame aerosol synthesis set-up

Precursor

Reaction

Collision

Sintering

Product

Collection

5Symposium 10yrs PTL, Vitznau, 05. July 2008

The first nanoparticles at ETH-PTL

Oxygen Flow Rate, L/min0 2 4 6 8 10B

ET-

equi

vale

nt P

artic

le D

iam

eter

, nm

0

20

40

60

80

100

~5 g/h silica from hexamethyldisiloxane (HMDSO)

6Symposium 10yrs PTL, Vitznau, 05. July 2008

Early pilot-scale production

0

10

20

30

40

0 200 400 600 800

Production rate, g/h

Prim

ary

part

icle

dia

met

er,

0.0

0.5

1.0

1.5

0 20 40 60 80 100

SiO2 mass concentration, g/m3

Car

bon

cont

ent,

wt.%

Hydrogen-oxygen diffusion burner obtained from German Aerospace Research Center (DLR)

Kammler, Mueller, Senn, Pratsinis, AIChE J. 47, 1533 (2001)Kammler, Mädler, Pratsinis, Chem. Eng. Technol. 24, 583 (2001)

7Symposium 10yrs PTL, Vitznau, 05. July 2008

Burner Operation Lines

Oxygen Flow Rate, L/min0 10 20 30 40 50B

ET-

equi

vale

nt P

artic

le D

iam

eter

, nm

0

20

40

60

80

100

Burner 123

Conditions:

CH4: 0.5 L/min

Ar: 0.3 L/min

SiO2: 5 g/h 27 mm

10 mm

6 mm

Wegner and Pratsinis, Chem. Eng. Sci. 58, 4581 (2003)

8Symposium 10yrs PTL, Vitznau, 05. July 2008

Ar/Prec.

CH4

O2

Coaxial Jet MixingDiffusion Flames:

treaction << tmixing

Particle Formation upon mixing of precursor and oxidant at shear layer.

Similar reactant mixing for similar velocity difference Δv = vOx - vFuel

vAr+Prec. ≈ vCH4 ≤ vOx

vFuel

Cold flow CFD profiles: Ar concentration

9Symposium 10yrs PTL, Vitznau, 05. July 2008

Single Operation Line dp = f(Δv)

Δv = vOx - vFuel, m/s

0 5 10 15 20 25 30

BE

T - e

quiv

alen

t Par

ticle

Dia

met

er, n

m

0

20

40

60

80

100

Burner 123

Silica

10Symposium 10yrs PTL, Vitznau, 05. July 2008

Δv = vOx - vFuel, m/s

0 5 10 15 20BE

T-eq

uiva

lent

Par

ticle

Dia

met

er d

p, nm

0

20

40

60

80

100

120 5 g/h SiO215 g/h25 g/h

dp,i = d0,i + (dm,i - d0,i) exp ( - 0.3 Δv)

Scaling the SiO2 Production Rate

Wegner and Pratsinis, Chem. Eng. Sci. 58, 4581 (2003)

Increase of CH4, Ar, and HMDSO flow rates

11Symposium 10yrs PTL, Vitznau, 05. July 2008

Products of Conventional Flame ProcessesH He

Li Be B C N O F NeNa Mg Al Si P S Cl ArK Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I XeCs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnFr Ra Ac Unq Unp Unh Uno Une

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb LuAc Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Few metal oxides accessible due to limited availability of low-cost precursors with high vapor pressure at moderate Temp.

At ETH-PTL: SiO2, TiO2 - but also first flame-made catalysts: vanadia/titania at small and pilot scale.Stark, Wegner, Pratsinis, Baiker, J. Catal. 197, 182 (2001)Stark, Baiker, Pratsinis, Part. Part. Sys. Char. 19, 306 (2002)

12Symposium 10yrs PTL, Vitznau, 05. July 2008

vacuum pump

burner chamberwith filter

precursor

OFIC

2

4CH

O or air

2

FICFIC

FIC

flamelet ring

spray flame

PI

syringepump

M

FIC

FICOsheath flow

2

nozzlecooling (H O)

FIC

2

capillarycooling (H O)

gas exit gap

heatedbox

22

2

Mädler, Kammler, Mueller, Pratsinis, J. Aerosol Sci. 33, 369 (2002). Liquid 2O2O 4CH

Flame Spray Pyrolysis (FSP) Technology

13Symposium 10yrs PTL, Vitznau, 05. July 2008

Accessible Products by FSP

Noble metals and oxides of almost all periodic table elements

Flame synthesis using vaporous precursors

H HeLi Be B C N O F NeNa Mg Al Si P S Cl ArK Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I XeCs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnFr Ra Ac Unq Unp Unh Uno Une

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb LuAc Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

14Symposium 10yrs PTL, Vitznau, 05. July 2008

Benefits of the FSP ProcessBroad range of product materials

Multi-component particles

Good control of particle properties

High purity powders

Thermally stable powders

Environmentally friendly process

Short process chain

Standard equipment and materials

Low cost energy source

Recent review article: Strobel and Pratsinis, J. Mater. Chem. 17, 4743 (2007).

15Symposium 10yrs PTL, Vitznau, 05. July 2008

Scale-up from 10 to ~500 g/h

ETH Pilot SystemZÜNDENDE PROJEKTE FÜR MASSGE-SCHNEIDERTE NANOPARTIKEL.

JAHRESBERICHT 2003

ETH Lab-Scale

Mueller, Mädler, Pratsinis, Chem. Eng. Sci. 58, 1969 (2003).Mueller, Jossen, Pratsinis, J. Am. Ceram. Soc. 87, 197 (2004).

16Symposium 10yrs PTL, Vitznau, 05. July 2008Tokyo Nanotech 2008

17Symposium 10yrs PTL, Vitznau, 05. July 2008

Process Flow Diagram

18Symposium 10yrs PTL, Vitznau, 05. July 2008

1 kg/h Pilot Plant at FlamePowders

5 kg ZnO nanoparticles

19Symposium 10yrs PTL, Vitznau, 05. July 2008

Process Design Considerations

Filtration area?Flow fieldNanopowder dischargeOff-gas treatmentProduct or clean sidefilter change?Product change?Containment! Safety!

FilterReactantDelivery FSP Reactor

Chemicals used?Batch/continuous?Precursor preparation?Precursor stability?Quality control?Cleanability?Safety!

Flow-/production rates?Auxiliary gases?Stability of combustion?Process Control?Energy utilisationCO2 reductionContainment!Safety!

Nanoparticle containment and safety concept.Process automatization

Product specs., production rate, raw materialsPurity requirementsAvailable infrastructure

20Symposium 10yrs PTL, Vitznau, 05. July 2008

100 g/h Pilot Plant for NanoCentral

Location: Johnson Matthey Research Center, UK www.nanocentral.eu

21Symposium 10yrs PTL, Vitznau, 05. July 2008

Automated FSP Unit at L’Urederra

Production rate 0.5 – 1.0 kg/h, continuous operationProcess control by PLC

Fundación L’UrederraLos Arcos (Navarra), Spain

22Symposium 10yrs PTL, Vitznau, 05. July 2008

Under construction: 1 kg/h unit

23Symposium 10yrs PTL, Vitznau, 05. July 2008

Back to the small scale:Combined FSP-cluster beam deposition

Aerodynamic lens system

Skimmer

Depositionchamber

Expansionchamber

Vacuum systeminlet

Interfacechamber

Aerodynamic lens system

Skimmer

Depositionchamber

Expansionchamber

Vacuum systeminlet

Interfacechamber

1 μm1 μm Patterned deposition

Nanostructured particulate films

24Symposium 10yrs PTL, Vitznau, 05. July 2008

Thank you very much! Questions?