When crude oil was $10 a barrel, the benefits cow power can provide to farms, communities and the environment were a blip on the radar. Now that crude oil has surpassed $70 a barrel, interest in renewable energy is on the rise. However, biogas recovery from anaerobic digestion still takes a backseat to ethanol and biodiesel in the limelight. Experts in the energy field are beginning to shift this focus, pointing out the multiple benefits of using waste to produce biofuels.
An industry white paper, entitled “Turn Problems Into Solutions,” is now available on the subject. It examines the benefits of biogas recovery and biomethane vehicle fuel in terms of renewable energy, environmental protection and agriculture revitalization. The 12-page report delves into the latest information from the United States, Denmark and Sweden.
Anaerobic digestion is not a new technology. Large-scale thermophilic codigestion is also not a new technology, but after more than two decades of success in Denmark, it is now making its debut here in the U.S.
“We need to view our problems as community problems in need of a community solution and recognize that our neighbors are not our competitors,” notes codigestion expert John Kunkle. “Instead of 10 digesters of 10 farms, we’re talking about one digester and 10 farms.” As a regional director for the Pittsburgh-based Waste Energy Solutions, Kunkle has been visiting with biogas plant operators in Denmark and working closely with Danish engineers in an effort to bring codigestion technology to the U.S.
Denmark is widely acknowledged as a success story in biogas production. This small country with a population of 5.5 million people has more than 50 farm-scale digesters and more than 20 large-scale codigestion biogas plants. The large-scale biogas plants are jointly owned by groups of farmers who provide the manure plus receive drop fees for accepting industry and municipal waste.
“This was their ‘space program.’ They invested in this technology and solved the problems 30 years ahead of us because they were faced with the problems before us,” explains Kunkle. “They have developed a community solution that works by turning farms into a giant recycling program.”
“We really prefer to produce biogas using manure as the baseload because it stabilizes the (anaerobic digestion) process,” explains Niels Bahnsen, head engineer for energy development with Niras International. The Danish engineering firm has been involved in biogas projects in Denmark and worldwide since 1981. “This enables us to go thermophilic, so we not only get efficient plants, we also get much better pathogen kill than with mesophilic processes.”
Codigestion addresses these major objectives:
•farm nutrient and odor issues
•community waste issues
•input revenue for farms
•high biogas yields for clean-burning, renewable energy
In the European context, codigestion biogas plants generate electricity and heat homes and offices with hot water from cogeneration power stations through district heating networks.
Aside from generating heat and electricity, the methane gas can be converted to biomethane as a completely interchangeable substitute for natural gas. According to the California Institute for Energy and Environment at the University of California, when upgraded to vehicle quality the methane generated from the manure of five dairy cows can power one car. Gas “scrubbing” methods remove corrosive elements from the biogas which can be controlled to produce biomethane that meets a pre-determined standard of quality. This process is already in use by many U.S. landfills where the biomethane is used to fuel on-site equipment.
The consensus during the European Natural Gas Vehicle Association’s political roundtable in April of 2006 is that the future for natural gas vehicles lies with biomethane because it delivers on two counts: climate change issues and renewable energy. The U.S. is well-positioned with natural gas vehicles to bridge to biomethane transportation fuel. Since the mid-1990s, transit authorities have been gradually converting bus fleets from diesel to natural gas vehicles (NGVs).
Today, compressed natural gas (CNG) is the most widely used alternative fuel in the transit industry, according to U.S. Department of Transportation data. Liquefied biomethane is a renewable substitute for CNG.
Sweden is the recognized world leader in public use of biomethane transportation fuel. This country benefits from cheap electricity but very expensive gasoline. Sweden runs 2,300 buses on biomethane and has the world’s first biogas-fueled train.
“America is going to have to look at solutions like they have in Europe,” noted Alan McConnell, food industry specialist with Pennsylvania’s Technical Assistance Program, after learning about Denmark’s technology. “As urbanization and population increase, so does the waste we generate. What better way to deal with it than to turn it into energy?”
For a copy of the complete 12-page industry white paper (“Turn Problems Into Solutions: Understanding the Benefits of Biogas Recovery and Biomethane Vehicle Fuel”) call 724-354-3897 or e-mail firstname.lastname@example.org. ANM
References omitted due to space but are available upon request.
—From Waste Energy Solutions submission
Sherry Bunting, Waste Energy Solutions