If you're a beer drinker and you've spent any time browsing the aisles at your chosen beer store, you'll note that beer has gone environmental lately. First, we had organic beer. Next, we started seeing beer flavored with very renewable substances like hemp. Next, we were faced with lines of beer produced in kegs only - no glass bottles to litter up the world and waste fuel in transportation.
Now, German researcher Wolfgang Bengel, technical director at German biomass company BMP Biomasse Projekt, has figured out a way to make energy from beer waste - the spent grains that are left over from the brewing process - by using the leftover muck to create steam and biogas that can help offset the brewer's energy use.
Making beer burns a lot of energy, in particular because of the stringent requirements for sterility the process demands. In fact, the beer brewing process has some of the highest demands for energy of any other food product you can buy. "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," said Bengel. To offset the carbon footprint of brewing, the spent grains can be dried and used for fuel.
Bengel got the idea from work he had done in China and Thailand, treating the residue from rice and sugar cane production in boilers with atmospheric fluidized bed combustion systems to produce energy. BMP is worked in conjunction with biogas plant specialist INNOVAS to adapt the process to beer. Joining the party is German engineering firm BISANZ and Adato, a Slovakian designer of boilers.
To meet rigid European requirements for emissions, Bengel and partners had to get creative in putting in place substantial cleaning and filtering equipment to allow their combustion process to be given the green light by German environmental protection authorities.
The process, if adapted by breweries, can lower their carbon footprint even further by greatly reducing the need for transportation to carry away waste, since the waste itself is greatly reduced in volume. Said Bengel, "Out of 100,000 tonnes of wet spent grain, you have 2,000 tonnes or even less of ashes."
Even More Clever German Beer Technology
In other "green" beer news, brewing engineers from the Technische Universitaet Muenchen (TUM) in Munich (are you seeing a pattern here?) have developed a method to reduce the heat and electricity consumption of the brewing process. Scientists for years have been trying to improve on the heating process for brewing beer by using a cogeneration process of combined heat and power (CHP) - essentially capturing the heat generated by the use of electricity and sending it back into the beer-making process rather than releasing it, as is standard in most industrial processes. But researchers found that they were able to attain a maximum of 90 degrees centigrade through the CHP process. The initial boiling down process of beer making, called creating the wort, requires 110 degrees centigrade. So TUM researchers began looking for another way to make up the 20 degree shortfall by initiating a thermo-chemical process using small pellets of a silicate mineral called zeolite to created a so-called "zeolite storage system" that, once water is added, can emit temperatures of up to 250 degrees centigrade. (The principle is called adsorption if you're curious about the chemistry behind the process.) The zeolite storage system works in conjunction with the combined heat and power system to create a surprisingly energy-efficient brewing process. The result? "Green" beer. (But not literally, of course.) The happy result is that the environmentally conscious beer lover is one step closer to guilt-free beer.
Of course...the guilt involved after imbibing too much at an office party and uninhibitedly telling your co-worker how irritating you find him will remain your own problem.
- Tracey E. Schelmetic