When beer is brewed, there's generally tons of leftover grain that's sold or thrown out. But a researcher has come up with a plan to convert that waste into energy.
Sure, beer tastes good (most kinds, anyway). But did you know that for every batch brewed commercially, there’s a huge amount of grain left over that isn’t fit for human consumption? Some breweries sell the excess waste to farmers for use as manure, but in many cases, it’s simply thrown out. “We reached a situation in 2000 where breweries even had to pay to dispose of their spent grain,” researcher Wolfgang Bengel told LiveScience.
But Bengel, technical director of the German company BMP Biomasse Projekt, had a novel idea to prevent wastage and reduce the breweries’ energy costs. Based on his previous experiences working with the wastage from rice and sugar cane in China and Thailand, he believed that the excess grain from the brewing process could be used 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,” he said.
The process works by combining the leftover grain and water waste with bacteria, which breaks down the elements into methane gas. Next, the gas and remaining wastage are burned to boil water, which will produce steam. The pressure from the steam will go into a turbine, which will generate energy that can power as much as 60 percent of the brewery’s equipment.
Now that he’s tested the technology in breweries, Bengel is eager to find commercial brewing partners to work with. If beer companies are willing to jump on board, then green beer may soon be more than just a St. Patrick’s Day special.