Upscaling of Ultrasonic Spray Pyrolysis for Nano

AMPT 2015, Dec 15th, Madrid

Upscaling of Ultrasonic Spray Pyrolysis for Nano-sized Particle Synthesis G. Alkan, J. Bogovic, S. Stopic, B. Friedrich

IME Process Metallurgy and Metal Recycling, RWTH Aachen University Prof. Dr.-Ing. Dr. h.c. Bernd Friedrich

Increasing demand for nanomaterials

Cosmetics

Textile

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Medicine

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Global market for nanoparticles

Electronics

optimistic conservative

5 mton

2 mton

[Nanomaterials future markets, March 2015]

Ultrasonic spray pyrolysis (USP) - theory Heating Zone Evaporation  Liquid droplet

Precipitation  Thermal Decomposition  Solid Particle Formation

Droplet

solvent vapour

Temperature

Shrinkage

Precipitate

Heating Zone  Each droplet undergoes same process steps  One particle produced per droplet

Gas Flow Rate

Gas Aerosol

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Ultrasound frequency

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Properties of precursor

 USP process is relatively inexpensive, continuous and flexible technique  Synthesis of fine metallic, oxide, composite nanoparticles; controlled morphology and defined chemical compositions

Motivation & Objective Problem: Increasing demand; restricted production rates Solution: Upscaling to provide larger amounts of powder for potential users 10 years experience in USP for the synthesis of different products with well controlled properties Cu

Ag&TiO2

Fe-Ni [Stopic et al., 2006]

[Stopic et al., 2005]

[Stopic et al.,2010]

[Bogovic et al.,2014]

[Gürmen et al., 2009]

Ag

RuO2 &TiO2

Objective

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Assessment of a well-controlled and reproducible demo USP plant for fine metal, oxide, composite nanoparticles mass production in defined chemical compositions, morphology and size that yield in industrialization Recycling

Nano equipments at IME

Horizontal USP equipment  Small production rate, 15-125 mg/h  Good for determination of process parameters for synthesis of new materials

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Technical scale USP equipment  Relatively increased production, 125-375 mg/h  Assesment of vertical system efficiency and process parameters

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Upscaling of USP process

IME Process Knowledge

Application NanoAg Elino Construction

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IOB Modelling and Optimizing

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Criteria for upscaling Scale-up

Higher Aerosol Throughput

Particle Size, Morphology

Higher Gas Flow Rate

Temp. Profile

Precursor

US Generator Geometry

Droplet size

Flow rate

Productivity

Quality

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• Residence time f (volume of reactor, gas flow, temperature profile) • Geometry of the reactor

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Demo scale USP equipment

Dimensioned: 4,7* 9,5* 5,4 m • 5 Aerosol generators (Prizma) • 5 Reactors, ø: 60 mm, L: 3600 mm • Resistance-heated Furnace (Elino) • 2 Electrostatic Filters • Vacuum System

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DFG Deutsche Forschungsgemeinschaft and Land NRW , program “Forschungsgeräte” (INST 222/874-1 FUGG)

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Set-up 1: Aerosol generator and gas system Gas lines

Ultrasonic Aerosol Generator

Gas outlet

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Prizma USP Generetors • 5*3 Transducer • Automatic Level Control • Continuous work • Prototyp (Prizma-Serbia) • Aerosol output: 6-8 l/h Recycling

Gas inlet

Set-up 2: furnace and reactors

Resistant-heated Furnace • 4 Heating zones • Temperature max. 1000°C • Power: 80kW

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• 5 Hot wall reactors, ø: 60 mm, L: 3600 mm • Possibility for on-line sampling from each heating zone

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Set up 3: electrofilter (powder collection system)

• • •

Collection of nanoparticle in dry form in electrical field Flexible working conditions: 15-120kV, 0,1-1mA, 130-250°C Redundant circuit for continuous operation

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• Each filter: 12 collecting electrodes and a hammer system for cleaning • Produced powder is collected in mobile and tight vessel at the bottom of the filter Recycling

First experimental results Precursor: AgNO3 (aq) Temperature: 500/1000/1000/1000°C Carrier Gas: Air Thermal decomposition: AgNO3 → Ag + NO2 + 1/2 O2

Ag

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• Ideally spherical silver particles • Particle size in the range of 100 nm up to submicron (starting concentration of silver nitrate solution was high) • EDS Analysis confirmed that produced particles were pure Ag Recycling

Summary Conclusion:

• Efficiency of design was assessed • Good control of significant process parameters e.g:: temperature profile, aerosol generation, pressure control, gas flow. • Successful principal transfer from lab scale equipment to this large scale equipment (5m x 12m x 6m). Future Prospective • Further optimization of the process is going to be done in order to obtain better control of nano-product characteristics and increase production rate. • The collecting and handling of the generated powder material must be optimized in order to fulfill pre-industrial standards • Synthesis of new nanomaterials

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• Open for partners from the industry for new applications and projects Recycling

Thanks for your attention!

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Q&A Recycling