VNCI Responsible Care Award 2010
SECTION 0 - Submission details
Akzo Nobel Industrial Chemicals B.V., Amersfoort
Submission title New generation anti caking agent for salt
Main contact details Name: Frank Hoks Location: Amersfoort
for administration Director Technology Salt
Tel: +31334676966 e-mail frank.hoks@akzonobel.com
Address: P.O. Box 247; Stationsstraat 77, 3800 AE Amersfoort
SECTION 1 – Brief introduction AkzoNobel Industrial Chemicals
AkzoNobel Industrial Chemicals produces salt and energy, chlor-alkali products and derivatives like
monochloroacetic acid (MCA). It is Europe’s largest producer of vacuum salt and a leading supplier of
chlorine, caustic lye, hydrochloric acid, ferric chloride and water treatment chemicals and MCA used in
the chemical, detergent, construction, food, pulp and paper and plastic industries. Its products are
essential in daily life and used in the manufacture of among others vehicles, glass, performance
plastics, pharmaceuticals, textiles and in disinfectants for swimming pools.
Employing approximately 1,800 people, Industrial Chemicals has production sites at Rotterdam,
Hengelo and Delfzijl in the Netherlands, Ibbenbüren, Frankfurt and Bitterfeld in Germany, Mariager in
Denmark, LeMoyne in the USA, and Taixing in China.
SECTION 2 – Description of improvement
The Challenge
Salt, being a very pure product, has a natural tendency to cake when it is put in stock. Caking, the
process where salt-crystals are sticking together, is an undesired process as it causes hard lumps of
salt and it hampers the handling of salt in terms of storage, loading, transport and discharging from
ships or trucks.
In order to prevent caking of salt a so called anti caking agent is added. Only very small amounts are
needed. Usually 3 to 5 parts per million (ppm) are sufficient to keep the salt free flowing, which is
crucial to keep the logistic part of the salt business in motion.
It was KNZ, one of our AkzoNobel forefathers, who in 1957 invented and patented ferro cyanide
Fe(CN)6 as a very powerful and effective anti caking agent, still today’s world wide standard.
With today’s applications and technologies however ferro cyanide has certain draw backs which made
AkzoNobel Industrial Chemicals to invest in an extensive R&D program in order to try to find an even
better successor.
Our salt is used in state of the art membrane electrolysis processes for the production of chlorine and
caustic lye. When the stable ferro cyanide complex enters the membrane cells the circumstances are
so harsh that it is broken down in parts. The free iron has distinct negative effects since it is deposited
on or in the membranes which increases the power consumption.
Delta cell voltage between electrolyzer with and without Fe(CN)64-
at 6 kA/m2
120
Start test
Delta cell voltage
100
Stop test
Out of operation
80
Delta cell voltage (mV)
60
40
20
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24-3-2006 13-5-2006 2-7-2006 21-8-2006 10-10-2006 29-11-2006 18-1-2007 9-3-2007 28-4-2007 17-6-2007 6-8-2007
The picture shows a clear increase in cell voltage/ power consumption due to deposit of iron under
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test-conditions. (ref.: Meijer, J.A.M., Next generation anti-caking: Meso Tartrate, 9 International
Symposium on Salt, Beijing, September 2009, ISBN 978-7-80251-213-9)
The cyanide is transformed into harmful nitrogentrichloride that may lead to explosions under certain
conditions, as incidents, happened in the nineties (explosion of a rail tanker in Belgium, explosion of a
vaporizer in Germany) demonstrate. (ref. Piersma, H., Nitrogen Trichloride: a Continuing Challenge,
Eurochlor Fifth technical seminar, Barcelona, 8-9 February 2001.
In another field of application of the salt, high way de-icing, where the salt reverts into the
environment, the call for biodegradability is getting louder and louder.
All excellent reasons for us, as the undisputed leader of vacuum salt for the Chemical Transformation
market and important supplier in the road salt market, to take up the challenge of developing a new
generation anti caking agent for salt!
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The improvement:
The last couple of years AkzoNobel Industrial Chemicals developed and patented a new, advanced
anti caking agent: Fe-mTA (Ferro-meso-Tartrate), in short mTA. It is a complex of iron and meso-
tartrate, working according to the same principles as the classic Ferro cyanide does: The iron (Fe) is
protected and carried by, in this case, the tartrate complex to the salt crystals where the iron can
perform its anti-caking effect by “disturbing” the crystal-grid of the salt, thus caking is prevented.
The main difference with the classic ferro cyanide is in the stability of the complex. Ferro cyanide is a
very stable molecule and hard to break down, which makes it difficult to prevent it from entering into
the membrane cells of electrolysis plants. Also in nature, though in very low concentrations, it is hardly
degradable.
The mTA however, decomposes easily whenever the salt is dissolved to brine, the iron can easily be
filtered out, the organic tartrates degrade and evaporate harmlessly.
All in all, the new product is totally free of cyanides, the iron can be prevented from entering the
sensitive membrane electrolysis processes and in nature, on the roads, the product will vanish by
simple biological degradation.
The team
As referred to above, the first initiatives and try-outs were carried out on lab scale at our Deventer
based Salt R&D department. A first scaling-up has been performed by starting delivery of the so called
mTA-salt from our Delfzijl salt producing facility to the membrane electrolysis plants of AkzoNobel
Industrial Chemicals in Rotterdam, The Netherlands.
A recent breakthrough in the recipe led to a further improvement of the anti-caking functionality of the
product, enabling further external roll-out.
The project can be characterized as being a real multi disciplinary project. R&D, production and
technology, marketing and sales, purchasing, IP are all highly engaged as from the early start of the
project, expressing the high degree of integration of this project throughout the whole salt – chlorine
production chain.
The benefits
In brief the following benefits are in focus:
Safety: Intrinsic safety improvement at electrolysis processes in general due to the absence of
cyanides, eliminating one source of nitrogen able to convert to nitrogentrichlorides, leading to
a potential explosion risk.
Energy: Substantial lower power consumption at membrane electrolysis processes. Potential
annual electricity saving for the European chlorine industry amounts up to ca. 350 – 500 GWh,
corresponding to 160 – 230 kton CO2e reduction, or in financial terms a saving of approx. 17
– 25 Mio. Euro (based on 50 Euro/MWh).
Profit: Next to the obvious saving on energy costs: The increased lifetime of membranes and
electrodes, reducing waste and downtime.
Environment: Environmental friendly and bio-degradable alternative for highway de-icing
applications.
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Fit to AkzoNobel’s values
The mTA project has an excellent fit with our company values. Initiated by the courage to question,
drafting the challenge, our salt-customers in primary focus, addressing their sustainability-needs of
tomorrow. Finding an innovative solution and rolling out the implementation in an entrepreneurial way.
And while doing so, in an honest and responsible manner, we continuously develop the talents of our
people in this exciting project.
Implementation details
Longer term operational and stable experiences in the electrolysis process of AkzoNobel in Rotterdam
were very positive as Fe-deposits in the membrane cells indeed could be avoided, with the result of a
considerable saving of electrical energy, as mentioned before.
Initially the anti-caking behavior of the salt was not yet as good as with the classic ferro cyanide,
resulting in some more hassle during unloading of vessels.
Transport tests with a so called self unloading vessel showed clearly the room for improvement:
A continuous effort was made in our R&D department since then, in order to find an optimized recipe.
In the summer of 2008 a breakthrough was realized in producing this improved product .
Recently performed similar transport tests show far better results:
This substantial improved anti-caking performance now enables a further roll out towards more
customers and applications down the chain, as mentioned before.
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Recognition by the chemical industry
While further testing takes place, like storage tests, test deliveries to potential customers, filtration- and
de-icing tests, market introduction is carefully prepared.
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A very successful step in this process was our presentation and launch of mTA at the 9 International
Symposium on Salt in Beijing, China, September 2009. To a broad audience of salt and chemical
producers we presented our experiences at a scientific presentation, held a press conference and
elucidated on the advantages in different applications. A lot of attention and interest was expressed by
the market.
(ref. annex 1)
A lot of interest at our booth in Beijing
In January 2010 we launched mTA in the US high way de-icing market, by a scientific presentation at
the annual meeting of the US Transport Research Board, Washington DC. The first responses from
these decision makers in winter road maintenance were positive.
(ref. annex 2)
Next to the own AkzoNobel deliveries in March 2010 the first sizeable contract with another major
European chlorine producer became reality for the delivery of half a million ton mTA salt/year. As a
consequence already in 2010 1.5 million tons of mTA salt will find its way to membrane electrolyses in
Europe.
In summary
To summarize, it can be stated that after a period of hard work and first positive experiences, an
innovative breakthrough in the performance of the product brought the project in a new phase.
A phase of materializing and implementing a sustainability driven R&D concept into real business.
Business in the highly integrated salt-chlorine chain and in highway de-icing, product stewardship “pur
sang”.
Technology pushing, in balance with a market pulling, a challenging but very exciting example of
making “Tomorrow’s Answers Today” work in AkzoNobel’s field of sustainability and responsible care.
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SECTION 3 – Contribution to AkzoNobel’s ambitions in the field of sustainability and
responsible care.
The development of the mTA-Salt supports the following sustainability and responsible care ambitions
of AkzoNobel Industrial Chemicals:
Sustainability and Responsible Care Ambitions
1 Zero approach in HSE: by eliminating Ferro cyanide mTA-salt contributes to a safe working
environment at the plants of our customers, by intrinsically minimizing the risk of explosion
due to NCl3.
2 Reduce Greenhouse Gas emissions: The usage of mTA-Salt instead of salt with Ferro
Cyanide results in lower energy consumption at the plants of our customers without having
other drawbacks. CO2 foot print of the European chlorine sector potentially improves with a
reduction of 160 - 230 kton CO2 per year.
3 Low environmental footprint: because mTA-salt is biodegradable, when applied to de-icing
salt on highways the ecological footprint of this salt is improved substantially when compared
to de-icing salt with Ferro cyanide.
4 BU Industrial Chemicals wants to be a leader in the field of sustainable solutions, and it has
clearly demonstrated this ambition with the development of mTA-salt. In the demanding
sector as the chlorine industry is, where safety is of utmost importance, it is not easy to
implement a new product. The fact that mTA-salt succeeded is a big breakthrough and this
new product will raise the bar in the industry.
Annex 1: Media Coverage ISS 2009
Annex 2: Brochure “The green alternative for anti-caking in road salt”
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