This is the fourth blog post by Dr Frank Wayman PHD taken from his recent e-book - How will the EU Industrial Emissions Directive impact the Brewing and Drinks? (Read the first, second and third here). In this post Frank explores how BAT (Best Available Technique) technology can be used to improve water, waste and energy efficiency in the brewing and soft drinks sectors.
When we look specifically at the brewing and soft drinks sectors, there are a number of opportunities that can be used to improve their water efficiency and reduce waste emissions, as well as energy usage to achieve BAT-AELs, here we present some examples.
How to improve water efficiency in brewing
There are some fairly obvious examples of how to improve water efficiency in brewing. These vary from reusing hot water from wort cooling processes, reusing waste water from the lauter tun and the reuse of bottle pasteurising water. Cross-flow filtration is also a more water efficient technique than direct filtration.
At the end of mash separation, the residual worts in the lauter tun (which are high in TSS, lipids and polyphenols) are generally considered unacceptable for process use and are consequently discharged as effluent. This loss is significant in terms of water, energy and extract.
Effluent from the lauter tun is a significant contributor to a brewery’s total effluent, with a high pollutant load and volume. Because of the way that the brewers’ grains are separated from the wort, attempts to reduce the volume tend to increase the levels of fine solids.
The lauter tun at a UK brewery contributed approximately 20 % of the total effluent load. To enable the reuse of the weak wort from the lauter tun as process water for mashing, the removal of the very fine colloidal size particles from the wort is necessary. This can be achieved by centrifugation or filtration.
The reuse of water and separation of solids reduced the cost of treating the effluent from the lauter tun by 12-15%, and the payback on the equipment required was less than two years.