Closing the cycle for water too

Since well before the current debate on plastics, recycling raw materials has been a topical issue enjoying paramount priority at Krones. Besides a closed cycle for PET und other packaging plastics, the primary focus is on smart recycling of raw materials. And our solutions are rather impressive: at the drinktec 2013, we premiered the EquiTherm energy recovery system; four years later, we closed the energy circuit for complete breweries with Brewnomic, and now comes the next coup: a concept enabling wastewater to be recycled in its totality.

Here, without exception, all beverage producers and recyclers as well should prick up their ears, since water especially plays a substantial role in each of these production processes: breweries cause two to three litres of wastewater for every litre of beer produced, in the case of CSD bottlers it’s one to two litres, and for producing PET the average is two litres of wastewater per kilogram. So obviously there are plenty of potential savings here! A verdict shared among the team headed by Dr. Ulrich Buchhauser, who is responsible at Krones in the Plants Division for utilities-related engineering and consulting: “More and more clients were approaching us and asking whether we could help them to reduce their quantities of wastewater. Because during the course of the ongoing general discussion on sustainability in particular, there is rising pressure on beverage producers from public opinion and politicians,” he summarises. “That’s why we considered how we could reduce the quantity of wastewater. Here we had to think one step further – because the individual machines have already been pretty thoroughly optimised, you see.” We swiftly realised: wastewater recycling makes sense only on a complete-factory level. “In the bottling operation alone, not enough wastewater is created to make collecting and treating it worthwhile,” explains Ulrich Buchhauser. “So in the concept we covered all the process steps where wastewater is produced.”

Basically, in Krones’ new approach the entire process water involved in the production operation is collected via the gullies and passed to a central tank. This is where the treatment begins: first all residues are removed from the wastewater, which is then treated for re-use as process water – and only for this purpose! For the latter step, a combination of two Krones Hydronomic systems is employed, which filter out of the water even the tiniest particles, like micro-organisms or salts. Following subsequent stabilisation of the water using chlorine dioxide, it’s ready to be used again in the production operation: “This combination of process steps and the appropriate kit enables wastewater to be converted into new process water,” explains Ulrich Buchhauser.

The clever bit: not only can the system for wastewater treatment be integrated into new factories, it can also be retrofitted in existing plants. The only preconditions are these: the wastewater flows should already distinguish between process and other kinds of water, and there should likewise be sufficient space available for the requisite tanks and utilities.

“The system is an attractive option not only for all those who want to reduce the amount of wastewater entailed by their production operations, but also for those who are keen to significantly downsize their water consumption,” explains Ulrich Buchhauser. “Because with Krones’ closed-circuit wastewater concept annual water consumption can be reduced by up to 80 per cent – which of course has a perceptible effect not only on the company’s water costs, but also on its environmental performance balance.”