International Biomass Conference & Expo: Waste management is energy management

By Lisa Gibson
Posted May 5, 2010, at 1:45 p.m. CST

International Biomass Conference & Expo: Waste management is energy management
Lisa Gibson

The Midwest lags behind the rest of the U.S. in production and use of biogas for energy, but Wisconsin is the shining star of the industry in that region, according to Amanda Bilek, energy policy specialist for the Great Plains Institute. "Biogas is a tremendous economic opportunity," she said.

Bilek was a presenter at the International Biomass Conference & Expo in Minneapolis. "We believe there is a lot of room to grow and we're only just getting started," she said.

Barriers to scaling up biogas production and use include public policy, which is possibly the most important; few formal organizations and little advocacy presence such as the recently-formed American Biogas Council; technical research; new development models; and the fact that the emphasis now is on electricity production from biogas, but there is a much wider window of opportunity, Bilek said.

GPI is working on a policy report due in July identifying current policies that incentivize biogas production and use, recommend tweaks to current policy and introduce new and useful policies. Existing policies that Bilek called "best in class" include the Rural Energy for America Program, state renewable portfolio standards (RPS), and voluntary electricity tariff programs by utilities. One policy the report will identify that needs tweaking is the production tax credit, an extension of which is included in the American Workers, State and Business Relief Act.

Proposed policies that need a push include a federal RPS, as many in the biomass industry, along with other renewable industries, have repeatedly emphasized. But that might not be the action with the most push for biogas use, Bilek said, adding that a biogas production and incentive act could be the game changer, along with a federal climate bill. "A climate bill would no doubt make an impact on the industry," she said.

New policies that need a champion include advanced renewable and feed-in tariffs, and enhanced renewable portfolio standards, which would expand qualifying renewable resources to include biogas injected into the natural gas pipeline.

Nick Nelson, president of Midwest Biogas LLC and Welcome BioEnergy, shared some strategies Midwest has identified to optimize centralized anaerobic digestion systems, making them more appealing to a wider audience. "It's quite daunting how many factors have to be managed for a centralized anaerobic digester," he said. Areas that need to be optimized include substrate blend, process flows, construction costs, substrate procurement and delivery, and delivery of the energy produced, among others.

Developers need to consider several factors such as whether shop fabricated equipment is better for their specific project than building on the location, he said. "Will a more expensive name brand component reduce your capital cost?" he questioned. Managing substrate delivery routes is optimal, as is testing substrates and determining which kinds to use. "What wastes are others paying to get rid of?" he said. In addition, the end user of the energy needs to be close to the operation, which also allows for a competitive delivery cost basis.

Nelson concluded by telling his audience that the elements he discussed are only the tip of the iceberg in centralized AD optimization and Midwest Biogas has identified many more during the current development of its demonstration system.

Panelist Douglas Goodale, bioenergy project manager and principal investigator for SUNY Cobleskill, changed the focus from biogas to syngas in his presentation about research and development of a rotary kiln gasifier. The system, under research and development by SUNY with the help of other partners, could be a solution for using animal waste instead of just throwing it on the land, he said.

The rotary kiln, as the name suggests, has a natural rotation providing agitation of feedstock at high temperatures. In addition, the system sits horizontally with a slight slope, contrary to conventional vertically-designed gasifiers. The rotary kiln design allows for complete conversion of biomass to syngas and is able to accept a wide variety of feedstock shapes and sizes without affecting conversion efficiency, he said.

"The rotary kiln is an efficient method of turning animal waste into electricity," Goodale emphasized. One dry ton of cow manure has a value of 10 million Btu; a value nutrient supply of $56 when spread on land; and an electricity value of $70, he cited. "Think of the day when farmers are bringing their manure to the rotary kiln center," he said. In addition, that one dry ton of cow manure has a combined-heat-and-power value of $225, he said, adding that the heat produced is just as important as the syngas.

Audience members were intrigued by Goodale's presentation and the rotary kiln gasifier, asking numerous questions. According to Goodale, they're not the only ones. The U.S. Department of Defense is interested in the technology as something that can be used where troops are deployed all over the world, he said, and it can be widely applicable. "I don't' see us ever running out of waste," Goodale said.