The production of beer and spirits requires large volumes of water, for example, it takes around 50 litres of water to produce one litre of whisky. According to the 2015 Environmental Strategy Report from the Scottish Whisky Association, in 2014 the whisky industry’s total water input was 48.8 million cubic metres, of which 73% was used for cooling purposes and returned to the environment unchanged except for the temperature. Of the remaining 13 million cubic metres, process water accounted for 63% with the rest being used for cleaning and general manufacturing activities.
Reduce costs by reusing and recycling wastewater
Given that it costs twice as much to discharge water as it does to bring it on site, there is a strong financial incentive to think more creatively about how to use wastewater, particularly as these costs are likely to rise faster than inflation, and there is a growing need to reduce the pressure on local water supplies during seasons of irregular rainfall or drought. The first step is to realise that wastewater, despite its name, is not useless. In fact, reusing and recycling wastewater is one of the most effective ways, following a fall in consumption, of reducing overall water costs. However, there are plenty of on-site demands, such as boiler feed, cooling towers and some cleaning activities, that can make good use of recycled wastewater after it has been treated.
It’s important to note that, at present, recycled wastewater is not used as a water ingredient. This is not due to a deficiency in purification technology; today’s reverse osmosis systems combined with continuous elecrodeionisation are more than sufficient to bring wastewater to purity levels that are actually above the quality of the mains water supply. However, the cautious attitude towards reusing wastewater is driven by licensing agreements with liquor brands and the public’s perception, which largely ignores the reality that every single drop of mains water is itself recycled.
Breweries and distilleries can also benefit from anaerobic treatment of their high strength wastewater with moving bed biofilm reactors. Biogas is a by-product of this process and can be sent to an on-site combined heat and power (CHP) plant to provide energy (and heat) to run the facility, reducing reliance on non-renewable resources, while offering cost savings at the same time. In some cases, distilleries and breweries are able to produce an excess of biogas and electricity, which can be sold back to the grid. In addition, a second by-product, biomass, can be sold to local farmers as a nutrient-rich soil additive.
There is an extensive range of wastewater treatments available to distilleries and breweries, and every unique situation will require a tailored solution to meet the specific demands for recycling wastewater, taking into account the desired water quality, capacity requirements, the available space and budget.