Arundo to gashttp://biothekecologic.com/wp-content/uploads/2014/01/IMG_08161-1024x687.jpg 1024 687 Miguel Ángel Martínez Miguel Ángel Martínez http://1.gravatar.com/avatar/11f4fa9a531983420b76e2869de6f723?s=96&d=mm&r=g
Anaerobic digesters (AD) are usually fed manure or food waste, yet other options are being tested and used in the biogas industry. On the expanding menu of feedstock possibilities are crops grown specifically for the purpose. Research conducted in Ontario, Canada, at the University of Guelph Ridgetown Campus explores the possibility of growing perennial energy crops and native grasses for biogas production. Energy crops are being considered in the biogas market for their environmental benefits, high-yielding rates and reliability.
The U of G-Ridgetown teamed up with New Energy Farms and Seacliff Energy for a project exploring energy crop potential in biogas production. Right now, the focus is on the methane yield at lab level, but the hope is to eventually test perennial feedstock crops in a 250-kW digester located at a campus research facility. “The main takeaway of the things we’ve tested so far is that some of them provide really high yields in the field, but they don’t convert very easily to biogas,” says Brandon Gilroyed, assistant professor School of Environmental Sciences at the U of G-Ridgetown. “We need to, for our future research, place more emphasis on pretreatment and things like that to unlock more of that energy.”
Paul Carver, CEO of New Energy Farms, says, “We identified a need for perennial biogas crops for a number of reasons.” NEF is involved in providing suitable cultivars of different energy crops, established through its CEEDS system and production testing. The Crop, Expansion, Encapsulation and Delivery System, creates a proxy for seed in vegetative crops, such as miscanthus, napier grass and arundo donax. The system was developed to make planting energy grasses and other vegetative crops as simple as conventional arable crops. “In areas where biogas projects have expanded rapidly, such as Germany, there is now saturation of annual biogas crops on arable land,” Carver says.
Germany has been using predominantly corn silage, among other streams, for biogas production. The plants that NEF is exploring are suitable for nonfood-quality land, which subsequently allows new plantings to occur without affecting food production. Another contributing factor to energy crop implementation is that biogas byproduct disposal requires a land base. “Sites with perennial crops on them for 10 years or more create a good logistical system for this recirculation of nutrients,” Carver says.