Water treatment and water management as key themes at drinktec 2013 – Focus on water recycling
Water treatment and water management will be key themes at drinktec 2013 in Munich, between September 16 and 20, 2013. Increasingly the subject of water recycling is coming under scrutiny.
All the major international brewing and soft drinks groups have long since formulated ambitious goals for reducing their 'water footprint', none of which would be achievable without in-company water recycling. What technological developments are the machine manufacturers offering? The place to find out just that and to review all the solutions is at drinktec 2013, the World´s Leading Trade Fair for the Beverage and Liquid Food Industry.
Careful, i.e. cost-efficient use of the resource of water will be a common theme covered right through the exhibition halls at drinktec 2013, in particular at the booths of the exhibitors in Halls A3, A4 and B2. Professor Dr. Stefan Schildbach from the University of Fulda, Dept. of Food Technology, describes the current situation as follows: "Sustainability most certainly also affects the subject of water processing. Savings that only a few years ago were considered too small and not cost-effective to implement, are now becoming ever more interesting. I am thinking here, for example, of the processing of water from filter backwash and of further increasing the yield in reverse osmosis plants. Also, intelligent control and monitoring strategies will start to become more important."
The membrane trend
What, then, does this mean for the separation technology being used? "For some years now the trend has been clearly towards membrane separation. That applies both to reverse osmosis for desalination of water as well as to the area of filtration," explained Wolfgang Winkler, Technical Managing Director at EUWA H.H. Eumann GmbH. There are good reasons for this development: Membrane systems operate fully automatically and continuously, they need virtually no chemicals and the waste water from water preparation has no added salt from regeneration media. Added to this is the fact that the membranes have become cheaper and more effective and the necessary pressure and therefore energy input is now much lower.
Ion exchangers and lime precipitation still have a place
However, there are still applications in which the ion exchanger or even the most traditional of all preparation methods – lime precipitation – will be fully justified, as Winkler points out: "Lime precipitation has very low operating costs and very low wastage given, for example, the right composition of untreated water. With water treatment plant with a standard 20-year lifespan these two factors are of considerable importance. In addition, lime is a natural product. Lime precipitation can therefore be an attractive alternative for businesses following strictly organic
guidelines, or for tradition-conscious craft breweries. Until now, however, the vessel sizes necessary for lime precipitation have been a disadvantage, in particular in view of current steel prices. We have therefore combined lime precipitation with membrane filtration, so do not need these vessels and we operate fully automatically."
Regenerating with the sun
Experts continue to see potential in electrodeionization (EDI) which is currently being used, for example, in semiconductor production as the final polishing stage in the preparation of ultrapure water. In the EDI process the ions in the drinking water are separated off via an exchange resin system. At the same time a DC voltage is applied, which gives rise to H2O+ and OH- ions which continuously regenerate the resin. This regeneration is also the reason why it is believed the process will soon find new applications. Because the DC voltage needed for regeneration can be generated easily with photovoltaics, this represents a further step in the direction of autonomous production.
Membranes also at the "end-of-pipe"
Modern water management does not only mean ensuring enough fresh water is prepared. It also means separating off this resource from the waste water flows produced, and returning it to the cycle. Here also more and more membrane systems are being installed, but this, according to Professor Schildbach, gives some cause for concern: "In the recycling of waste water from production there have been many R&D projects in recent years yet still the biggest problem of premature membrane blocking has not been solved comprehensively. But we are also seeing, in the increasing number of membrane systems being used, that in individual cases very successful water recycling is being implemented. In future we will be finding out a lot more about this. And it will be exciting to see what new solutions and ideas are being presented at drinktec 2013."
From biogas to natural gas
Membrane systems are not only being used to recover water from the flows of waste water. Other resources, too, are being recovered, in particular in the optimization of biogas yields from the organic load. For as an "energy drink", waste water can contribute quite considerably towards regenerative coverage of electricity and heat needs. The efficiency of this process can be improved still further using a membrane process system from a drinktec exhibitor which involves continuous separation of the CO2 content in the biogas. This gives rise to natural gas which firstly has a higher calorific value and secondly can be used in standard boilers. And, because with sustainability it´s always important to keep closing cycles, the CO2 separated from the biogas could be transformed into natural gas using solar-generated hydrogen. But that is something for a future drinktec
