Transcript ERG presentation to STM8 - Two Technical Advances in

Two Technical Advances in Wet
Chemical Scrubbing Technology
Richard Hanson MA MEng CEng MIChemE
ERG (Air Pollution Control) Ltd
ERG (Air Pollution Control) Ltd
Introduction | Two Technical Advances
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V-texTM technology
 Development
 Process Description
 Applications and Case studies
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Zero-effluent scrubbers
 Process Description
 Applications and Case Study
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Summary
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Development
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Developed in UK by AEA Technology
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Used in difficult applications
 reliability and performance
 Eg. nuclear industry
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V-texTM technology used in
 Scrubbing
 Stripping
 Distillation
 Mixing
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Development
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V-texTM Scrubbing
 Since early 1990s in UK and
Ireland
 Mid-late 1990s in USA
 More than 400 systems installed
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Technology is now owned by ERG
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What is it…?
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Process Description
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Key features
 V-texTM chamber
 Tangential gas inlet
 Opposed jet spray nozzle
 Intense mixing
 Central gas outlet
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Process Description
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Opposed jet self-cleaning spray
nozzle
Fine droplet spray pattern
Induced swirl from tangential gas
flow
Typical droplet size 100-200 μm
Large surface area for mass
transfer
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Process Description
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Mass transfer models
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Traditional packed towers
 Tower diameter = f (gas rate)
 Efficiency = f (packed height) = f (HTU)
 HTU = f (packing type, liquor rate, gas rate)
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V-texTM
 Chamber diameter = f (gas rate)
 Efficiency = f (liquor rate, liquor pressure)
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Implications of transfer model
(1) Non-clogging
 No packing to foul
 Applications for dirty gas/liquor
 Scrubbing with slurries
 Reliable performance, lower
maintenance, guaranteed efficiency
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Implications of transfer model
(2) Significantly reduced vessel height
 High pseudo-Kga values
 Intense mixing, high turbulence
 Gas residence time reduced approx x10 for same scrubbing efficiency
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Implications of transfer model
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ERG Packed
Tower Scrubber
V-texTM
Scrubber
Example:
 1000 m3/hr air
 HCl removal efficiency
99.5%
7.4 m
2.2 m
ERG (Air Pollution Control) Ltd
www.ergapc.com
V-texTM | Case studies

ERG (Air Pollution Control) Ltd
Cl2 scrubbing
 Chemical industry
 Chlorine scrubbing from process
air stream
 NaOCl by-product for sale
www.ergapc.com
V-texTM | Case studies
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ERG (Air Pollution Control) Ltd
HCl scrubbing
 Pharmaceutical industry
 Hastelloy C276 and ECTFE/PTFE
 Pressure and explosion rating
certified
 >99.5% HCl removal efficiency,
batch scrubbing
www.ergapc.com
V-texTM | Case studies
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ERG (Air Pollution Control) Ltd
Reactive gas scrubbing + particulate
removal
 Optical Fibre Manufacturer
 Removal of HCl and SiO2
 Scrub liquor contained up to 5% weight
SiO2 with no blockage
 Constant back pressure improved
optical fibre quality
www.ergapc.com
V-texTM | Case studies
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Multi-component contaminants
 Tobacco Manufacturer
 Steam quench/sub-cooling with NH3, VOC and dust scrubbing
 Scrub liquor contained entrained dust – unsuitable for packed tower
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SO2 scrubbing ex-incinerator
 12,000Am3/hr with 5,000mg/m3 SO2
 Lime slurry scrubbing
 >99.8% removal SO2
ERG (Air Pollution Control) Ltd
www.ergapc.com
Zero-Effluent | Process Description
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Vacuum evaporation: application to scrubbing
 Established technology
 Process application innovation
 System integration – optimisation of capital and operating costs
 Minimises water usage and effluent disposal
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Simplified flowsheet
 Evaporator/condenser circuit, heat pump circuit, effluent circuit
ERG (Air Pollution Control) Ltd
www.ergapc.com
Zero-Effluent | Process Description
Schematic courtesy of H2O GmbH
ERG (Air Pollution Control) Ltd
www.ergapc.com
Zero-Effluent | Process Description
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Typical Scrubber blowdown 500 litre/hr  < 40 litre/hr concentrated
sludge waste + recovery of > 460 litre/hr process water to system
Operation at 5kPa and 40oC
Typically 0.15kW per litre water evaporated
ERG (Air Pollution Control) Ltd
www.ergapc.com
Zero-Effluent | Case study
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Aerospace industry
Chromic acid scrubber
200 litre/hr treatment rate
200 g/litre CrO3 commodity recovery
Return on investment = 9 months
ERG (Air Pollution Control) Ltd
www.ergapc.com
Zero-Effluent | Applications
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High water/effluent costs and low energy costs
Feedstock, product and by-product recovery
Minimised loading for RO and ion-exchange treatment plants
ERG (Air Pollution Control) Ltd
www.ergapc.com
Summary
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Innovations in Scrubbing technology
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V-texTM
 Solid-laden gas/liquor applications
 Space limitations
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Zero-effluent
 Feedstock/product recovery
 Utility optimisation
ERG (Air Pollution Control) Ltd
www.ergapc.com