Increasingly, feed manufacturers are being required to address the issue of release of odour and harmful contaminants into the surrounding community.

1. November | December 2011
Feature title: Direct Cold Plasma: The innovative answer to odour
control in the food and feed industry
International Aquafeed is published five times a year by Perendale Publishers Ltd of the United Kingdom.
All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies,
the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of
information published.
©Copyright 2009 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form
or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058
The International magazine for the aquaculture feed industry

2. F: Direct Cold Plasma F: Direct Cold Plasma
once a month would be recommended. colds plasma module will handle around
Operating costs are very low and mostly 20.000Am³/h.
associated with the cost of electricity; Higher efficiencies may be achieved
10-20kW for a standard 20,000m³/h cold by using a final polishing module.
plasma unit. During testing, both high and low odour
A costing exercise produced by one of concentrations were experienced;
APP’s customers, is shown below. This is nonetheless cold plasma achieved real
based on a 10-year period, including both odour reductions even on very low
investment and operating cost for a volume inlet concentrations, something that
of 20,000 m³/h. The operating costs for the is not always the case on alternative
scrubber alone or scrubber biofilter do not technologies.
include cost of water. Overall the tests indicated that the
cold plasma unit operated most effectively
a modulating high voltage supply to each Testing in the petfood without a scrubber either at the inlet or
corona wire, and this process results in a and fish feed industry outlet. Dust removal was very effective (99
discharge between the corona wire and Since 2003, extensive testing with a percent reduction).
by Havard Vetrhus, Director the cell wall. The discharge promotes the pilot system both on extrusion flash-off, As a result of these tests, several pet-
Sales & Marketing, Applied emission with high-speed electrons, which driers and coolers has been carried out. All food sites have now installed cold plasma
Plasma Physics AS, Norway collide with background gas molecules cre- possible variables have been reviewed to technology for their processes.
Tel: + 47 5160 2220 ating chemically active species known as determine the optimum operating condi- As per today, 50 units are in operation
Email: havard.vetrhus@app.no radicals and charge carriers. tions for the cold plasma system. in the petfood industry, a figure that will
This is actually identical to what happens increase substantially in the years to come.
with pollution in the atmosphere. Reactions Variables tested: The experience of the environmental
occur with the odour bearing compounds • Residence time (determines volume needs of the feed industry, and APP’s
I
in the gas to be treated. Ambient air may be to be handled by a standard module) approach to innovative design is com-
ncreasingly, feed manufacturers • End of pipe solution of high voltage technology and non-thermal injected just prior to the reaction chamber • Effects of water scrubber at inlet or bined to offer a competitive alternative
are being required to address • Low running cost plasma systems for industrial processes. to optimise humidity and temperature as outlet of cold plasm solution to a problem that is of increas-
the issue of release of odour and • Minimal maintenance APP has now delivered more than 200 sys- well as adding ions to the gas stream. • Cold plasma unit operating alone ing significance to the food and feed
harmful contaminants into the • Ability to operate at normal feed tems, most running on difficult applications. In essence the cold plasma process • Adding water to humidify inlet or industry.
surrounding community. manufacturing temperatures, to avoid APP has experience on ultra-high odour encourages ‘oxidation’ of the odour bearing outlet gas
cooling costs applications – where odour levels can be compounds at low temperature by creating • Air infiltration
Local communities, special interest • High odour removal efficiency over 200,000 odour units per m³ - and the discharge (cold plasma). volume (ion
groups and government legislation all bring • No chemical additions and need to company achieved odour removal efficien- A closed-loop cooling unit ensures that enrichment)
pressure to bear on factories to minimise maintain chemistry cies of up to 97 percent. Another advantage operating conditions within the High Voltage • Intensity of
real or perceived risks of contamination. • No liquid effluent waste that is unique for this specific technology is Generator are maintained within controlled cold plasma
There are no universally applied standards • Instant on/off – no warm up time that both odour and dust are removed from limits. A proprietary control system moni- generation
for odour or Volatile Organic Compounds • Modular construction, ease of reloca- the production emissions. tors the high voltage passed to each of the • Geometry and
(VOC) emissions and to provide solu- tion if change of production location corona wires in the reaction chamber, arrangement of Our compact but powerful Aerox®-Injector uses Cold Plasma
Injection Technology to treat up to 80.000 m3/h.
tions that fit specific factory needs can be and ease the ability to add on mod- and controls the voltage modulation that reaction cells
complex. ules according to required capacity generates the cold plasma. The system also The major advantage of the Aerox®-Injector is that it radiates
There is no single solution but under- • Competitive capital cost detects arcs between the corona wire and The pilot plant clean, ambient air sourced from outside the process duct, which it
standing the feed manufacturers problems This is a tall order but there is a the cell wall, automatically shutting down is designed to then injects into the process duct.
certainly helps a great deal. technology can answer most of these electrical supply for a fraction of a second handle 1600m³/h
In recent years, needs: Cold Plasma. before power is reinstated. and tests were
there have been The reaction chamber may be oper- repeated to Suitable for saturated exhaust gas flows!
numerous changes Direct Cold Plasma ated with the gas flow passing upwards or check valid- Unit is placed outside the process duct
to
regarding where pro- – A high-tech, high- downwards depending on site layout. The ity. Independent
Cold Plasma unit remains clean exhaust
duction facilities are voltage solution unit is capable of operating on emissions olfactometry
situated. Factory closures and relocation In 2003 a global petfood manufac- with relative humidity close to 100 percent, testing was used Compact and easy to install
of manufacturing units has become com- turer tested a new technology for odour although the closer to 100 percent RH the as a means of No pressure drop
monplace. At the same time urban sprawl removal, referred to as Direct Cold unit operates, the higher the possibility determining
Easy maintenance
has resulted in residential areas being built Plasma, on drier and extruder flash-off exhausts. Cold plasma technology of arcs and consequently risks of reduced odour reduction
closer to previously remote industrial areas. The technology had obvious advantages – Nature in a box efficiency. The unit can be operated with efficiency. Runs on electricity
Another pressure companies face is over more conventional solutions. As a Odour bearing gases enter the cold emission temperatures up to 70°C. In most Test results No waste products
meeting local environmental needs. result the petfood manufacturer looked for plasma module, where care is taken to cases in the feed industry, the emission indicate that
So what does the industry need from a suitable technology partner for collabora- distribute gases evenly as it enters the temperature from dryers will be less than odour removal ambient from
its odour abatement equipment? This is a tion on the application of cold plasma on reaction chamber. The reaction chamber this temperature limitation. efficiencies of up air powerpack process
complex question and the answer needs petfood applications. comprises a cluster of hexagonal cells. Maintenance is minimal, if the unit to 90 percent are
to include: In 2003 they formed such an agreement Running centrally through each cell is a is used as a dust collector as well as achievable within
with APP (Applied Plasma Physics AS). corona wire, which is isolated from the odour abatement system, then the unit the food and feed
• A compact design minimizing space APP is both an R&D and equipment sup- rest of the chamber. would have a ‘wash-down’ maybe once industry and that
requirements ply company, specialising in the application The high voltage generator distributes per week and an internal inspection the standard WWW.AEROXINJECTOR.COM
22 | InternatIonal AquAFeed | november-December 2011 november-December 2011 | InternatIonal AquAFeed | 23

3. Photograph © Fred Jonny Hammeroe
Welcome to ISFNF 2012 in Molde, Norway
4-7. June 2012
Welcome to Molde in 2012 for the 15th consecutive
International Symposium of Fish Nutrition and Feeding
Key areas:
■ Sustainable resources
■ Health, welfare and ethics
■ New methods and working-tools
Amino Acids
■ Feed technology and feeding regime
■ Nutrigenomics
■ ‘omics’ data and system biology models Headquarters Choosing the right nutrients for your Aquafeed
Evonik Industries AG
■ Nutritoxicology Health & Nutrition
feed additives Our amino acids help to
Rodenbacher Chaussee 4 • replace costly and scarce raw materials
■ Nutrition in whole life cycle
63457 Hanau-Wolfgang, Germany
phone +49 6181 59-2256 • improve protein balance and production efficiency
fax +49 6181 59-6734 • reduce environmental pollution
Europe & Middle East Africa +49 6181 59-6766
Latin America +49 6181 59-6761
Photograph © Terje Rakke
Some conference ingredients: feed-additives@evonik.com | www.evonik.com/feed-additives
North America +1 678 797-4300
Asia North +86 10 85 27-6400
■ Get updated on the latest research on fish nutrition and Asia South +65 6890-6861
feeding
■ Mingle with the 500 leading fish nutritionists in the world
■ Pre symposium tour to visit industry
■ 4 post symposium sight seeing tours in the beautiful Nofima will host the event along with the Aquaculture
coastal fjords Protein Centre (APC), the National Institute of Nutrition
and Seafood Research (NIFES), the Norwegian
School of Veterinary Science (NVH) and the
Norwegian University of Life Sciences (UMB).
Please submit your abstract at www.isfnf.org by 20th January 2012
18 | InternatIonal AquAFeed | november-December 2011

4. Content from the magazine is available to view free-of-charge, both as a full online magazine on our
website, and as an archive of individual features on the docstoc website.
LINKS
This digital re-print is part of the November | December 2011 edition of International Aquafeed magazine.
Please click here to view our other publications on www.docstoc.com.
VO L U M E 1 4 I S S U E 6 2 0 1 1
• See the full issue
• Visit the International Aquafeed website
BioMarine Business Convention
• Contact the International Aquafeed Team
Ecobiol Aqua
– A unique and highly effective single strain probiotic
Evaluation of probiotic bacteria in
tilapia production
Marine based protein hydrolysate
- Improve the performance of feeds containing
• Subscribe to International Aquafeed
a low level of fish meal
THE INTERNATIONAL MAGAZINE FOR THE AQUACULTURE FEED INDUSTRY
IAF11.06.indd 1 04/11/2011 08:40
To purchase a paper copy of the magazine, or to subscribe to the paper edition please contact
our Circulation and Subscriptions Manager on the link above.
INFORMATION FOR ADVERTISERS - CLICK HERE
www.aquafeed.co.uk