Europe is renowned for the quality and variety of its beers - from a glass of Leffe or Chimay in Brussels to Budweiser Budvar in Prague, Mao in Madrid or Guinness in Dublin. The makers of our favourite beers, though, are facing a common problem: what should they do with the thousands of tonnes of grain which are left over at the end of the brewing process?
In the past, they simply sold the waste to farmers who either fed it to their animals or spread it on their fields as fertiliser, but that isn't easy nowadays given reductions in cattle breeding in Europe and stricter regulations on the content of waste allowed on land. "The prices breweries could get for waste are quite volatile since it depends on the world animal stock and the food market," says Wolfgang Bengel, a scientist who noticed the growing problem. "We reached a situation in 2000 where breweries even had to pay to dispose of their spent grain."
This is a commercial breakthrough.
INNOVAS GbR, Germany
Bengel, the technical director at German biomass company BMP Biomasse Projekt, saw a business opportunity in solving the breweries' headache. He reasoned that the leftover grain could be used to create steam and biogas, which would provide energy for the breweries, cheapening their energy costs as well as their costs of transporting grain to farms.
Bengel has successfully treated the residue from rice and sugar cane in boilers with atmospheric fluidized bed combustion systems, to produce energy in China and Thailand, and Bengel thought a similar process could be developed for the breweries' spent wet grain. Water would first have to be removed from the wet spent grain, the grain would have to be dried and then burned to produce energy. "Beer making is energy intensive - you boil stuff, use hot water and steam and then use electric energy for cooling - so if you recover more than 50 percent of your own energy costs from the spent grain that's a big saving," says Bengel.
BMP turned to a long-standing business partner, fellow German biogas plant specialist INNOVAS, which had worked with it in China, to help develop the method as a EUREKA project. Germany's BISANZ, which works on engineering projects, was also enlisted, as was Slovakian partner Adato, which designs boilers. By chance, BISANZ had been working on a boiler plant for a waste management company which entered bankruptcy, with assets being sold. The partners decided to buy the unwanted plant and to adapt the equipment to the process of burning spent grain.
They bought the plant easily and relatively cheaply 2003, but finding a location for it wasn't straightforward - it took two years for the partners to secure a licence to install the equipment and start using it for research at a location in Bavaria, Germany.
Developing the system and timing processes to meet the demands of a brewery was extremely demanding. "Of course the physics is thousands of years old, but how to combine this into a continuous process is quite complicated," says Bengel. "Big breweries discharge hot spent grain 365 days a year at temperatures of 60-80 centigrade. As long as it is hot, you can treat it easily. If you let it go cold, it sets like a pudding. You can't dewater it any more."
Researchers had to add extra cleaning and filtering equipment to the combustion equipment they had bought. There are extremely high European standards for combustion and the team had to extend the research timetable as its initial burning tests failed to meet the requirements. "We had more than 50-60 test periods of burning mixtures of spent grain," says Bengel.
Eventually the Eureka moment came - they had managed to refine the process so that the burning met the requirements. They also perfected a process for the anaerobic treatment of the waste water from breweries, thereby producing a complete system for breweries to treat their complete waste stream, wet spent grain and waste water. One of Germany's environmental protection agencies (TÜV) certified the burning process as up to standard.
If you recover more than 50 percent of your own energy costs from the spent grain that's a big saving.
The partners are now trying to attract commercial contracts and have shown some interested companies around their test plant. Those who sign up could become greener breweries, creating their own energy and cutting down on lorries travelling to and from their factories. "Out of 100,000 tonnes of wet spent grain, you have 2,000 tonnes or even less of ashes," says Bengel.
Bengel thinks there are potential markets not just here in Germany, where the idea sprang up, but throughout the world, particularly in Eastern Europe and in Africa where beer is becoming more popular as a drink. Either breweries could pay for and install the energy-producing equipment themselves or waste management companies could make the investment in return for selling back the energy to breweries. "This is a commercial breakthrough," says Bengel. "It's not yet delivering contract after contract, but that will follow."