In 2017, drinktec exhibition will be highlighting the theme of water and energy management with 1,600 exhibitors from all over the world presenting sustainable solutions in this field.
For the manufacturers of bottling and packaging machinery, the economical use of energy and resources is becoming an ever more powerful commercial argument for their internal processes and their image towards their customers.
Themes such as reduced water consumption, the use of process heat, closed-loop production processes, water quality and the use of efficient components are all exercising minds in the industry.
Residue-free water
Just why the resource of water is attracting so much attention is explained by Dr. Karl Glas, of the Working Group on Water Technology at the Technical University of Munich.
He identifies four reasons: “Firstly, every liter of water and every liter of wastewater costs—and those costs are rising.”
“Secondly, the multinationals want to standardize production worldwide. And as part of that the water used has to meet very rigorous standards in terms of quality and technology. The key word here is ‘water design’.”
“Thirdly, how carefully a company uses resources has for some time been influencing consumer decisions on whether to buy or not, and it is very much a factor in authorization procedures for new and follow-on investment.”
“And not least fourthly, because of water shortages or to protect deep water, brand new approaches have to be tried.”
At the same time, there are increasing calls for ever cleaner, i.e. residue-free, water for use in table water, for brewing, mixing or diluting. And residue-free means: no undesirable substances detected with modern analytical methods, regardless of the source of the water.
This is an immense challenge in a time when even groundwater can contain traces of statins, painkillers, anti-inflammatory drugs, various analgesics, X-ray contrast media and hormones.
In terms of technology the demand for ‘residue-free’ water is met today largely through the use of membrane processes such as ultra- or nano-filtration, and through reverse osmosis.
In other applications, too, membrane processes are increasingly being used.
Apart from wastewater processing and deaeration of water, this also includes ensuring the biological quality of water, as Dirk Scheu from Krones AG observes: “This is prompted by the problem of secondary products that can arise during chlorination and that during ozonization bromide changes to bromate.”
“The World Health Organization has now reduced the limit value here to 0.01 mg/l, but many international companies are adopting much more rigorous standards. Ultrafiltration, with its log rate of six, can gain ground here.”
“The producers then either don’t have to sterilize any more or they only need to treat the headspace of the bottle with ozone,” he says.
“As a result the danger of bromate formation is correspondingly reduced, and that’s more sustainable.”
Resource recycling calls for optimization across all areas
When it comes to water recycling, there are basically two ways: In the first the water is collected and sorted according to its pH content or degree of pollution, and then re-used in similar applications.
The second way is the ‘end-of-pipe’ solution.
All the wastewater is collected in a central point and treated anaerobically.
The biogas this generates can be used to cover about 20-30% of the energy consumption of a brewery.
A downstream zero-liquid discharge stage could possibly enable about 95% of the volume of wastewater to be reused in production.
Theoretically even the water in the zero-liquid discharge stage could be treated to reach process water quality.
However, the more frequently the water is recycled, the more energy is needed.
So one resource is saved while perhaps another is being consumed.
In order to really get to grips with the issue of resource recycling, the approach has to encompass all areas; many cogs from the many different disciplines all have to fit smoothly together.
