ANAEROBIC DIGESTION¦
Detroit Stoker Company ® “Our Opportunities Are Always Growing”™
Detroit® Combustion Equipment for Biomass and Refuse Fuels Providing solutions that enable industry to meet tomorrow’s energy and environmental requirements.
Detroit Stoker Line of Equipment:
METHANE BOOST: Adding corn stalks to swine manure produced the most methane per day, compared to oat and wheat straw. SOURCE: JUN ZHU, UNIVERSITY OF MINNESOTA
higher lignin content will limit the degradation of such fibers,” Zhu explains. “According to [information published by academics] the lignin content in wheat straw, corn stalks and oat straw is 18, 8.4, and 13 percent, respectively. The high lignin content in wheat straw makes its sugars more difficult to use by microbes than that of the other two residues, leading to lower productivity of biogas and methane. Interestingly, the lignin content of these crop residues appears to well explain why corn stalks performed the best in biogas and methane production, followed by oat and wheat straws.” While adding crop residue to a digester may seem like a simple concept, it isn’t that easy, as most digesters on the market today are traditional liquid-state digesters and are not designed to handle more than 15 percent solids. Günther Bochmann, a project manager at the Biogas Research & Consulting Group in Austria, says he thinks the biggest factor in utilizing ag residues or energy crops in livestock AD systems is process engineering. “Here, a lot of mistakes can be done,” he says. “Some plant manufacturers think they know everything, and that all plants match to every substrate.” A researcher at Ohio State University is taking AD system engineering to a new level, by developing a (patent-pending) AD technology that integrates a traditional liquid anaerobic digester with a solid-state anaerobic digester to allow for the expanded use of cellulosic biomass feedstocks such as crop waste and yard clippings, as well as a substantial increase in digester performance.
•Detroit Hydrograte® Stokers (water cooled vibrating grate) •Detroit RotoStoker® VCG (air cooled vibrating grate) •Detroit RotoGrate® Stoker (air cooled traveling grate) •Detroit GTS Reciprocating Grates •RDF Fuel Feed Systems •Rotary Air Locks
Renewable Fuels Include: Wood Bark • Coffee Refuse Sunflower Hulls • Eucalyptus Poultry Litter • Municipal Waste Urban Waste • Sawdust • Straw RDF (Refuse Derived Fuel) • C&D
For more information about converting biomass or other waste materials into energy, talk to the company with a proven track record.
Call Toll Free: 800.786.5374 sales@detroitstoker.com • www.detroitstoker.com MARCH 2011 | BIOMASS POWER & THERMAL 39