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Spent grain - a valuable resource for brewers

Posted on 26 February 2016.

But what if brewers could use the spent grain left over from beer-making to run their plants? That’s Veolia’s idea and several energy recycling options are now being tested.

The problem for big global brewers is that the quantity of spent grain they produce far outweighs what can be sold to local farmers.

Spent grains or rather how to get rid of them... Produced from malt made from barley, at the end of saccharification the spent grain comes from filtering the must– the process that removes all the solid waste before fermentation. Spent grain is 80% of the byproducts from beer-making - 100 liters of beer generates 10-20 kg of spent grain! And that's a lot, when we know the global beer market been in a consolidation phase for some years and the large breweries now produce millions of hectoliters. Which means tens of thousands of tons of spent grain to remove from every site, every year!

So how can these residues be used? Rich in energy, protein and minerals, they are usually bought by farmers for cattle feed. The problem for the world's major brewers is that the quantity of spent grain they produce far outweighs what can be sold to local farmers - which means high transport costs.

Given this dilemma Veolia offers breweries alternative recycling solutions, in addition to that of animal feed. The idea? To make spent grain a source of renewable energy in a circular economy approach. In 2015, the Group launched a project to test several energy production solutions and assess their technical and economic scope in comparison with existing solutions.

To start with Veolia sent out a call for participation to breweries in order to collect samples of spent grain and information about their operations. The first samples arrived in September 2015 and were analyzed by Veolia’s R & D teams in Limay, Île-de-France. The first results allowed work to begin on the technical and economic evaluation of three spent grain energy recovery solutions: combustion, solid biogas production and percolation.

Whatever the method chosen, the project will help meet several of the needs expressed by breweries: make efficient use of spent grain; cover some of the energy needs of plants and so reduce dependence on fossil fuels; provide an outlet compatible with supplying animal feed locally - in short, improve their environmental approach and demonstrate it to the public.