Oct. 18, 2011

Kiln to make rural Kenyan village energy self-sufficient with agricultural boon

The increasing costs of fuel for transportation are hampering development of rural communities in developing countries, but an interdisciplinary team of Cornell scientists believes they may have found a sustainable solution: biochar.

The group of soil scientists, engineers and economists are on the cusp of harnessing the power of organic material to fuel an entire village in Kenya.

Launched last year after a $5 million donation to Cornell's David R. Atkinson Center for a Sustainable Future from energy expert Yossie Hollander, the Village Scale Pyrolysis project has progressed to building an experimental kiln -- the first continuous slow pyrolysis unit at a U.S. university.

"Our goal is to develop a system that can supply a village with both fuel for transportation and biochar to improve soil productivity," said project coordinator Johannes Lehmann, associate professor of crop and soil sciences.

Pyrolysis is the process of heating organic material -- byproducts from the processing of corn, tea, logs and sugarcane -- in a kiln in the absence of oxygen.

The resulting products are biochar, a charcoal-like residue that provides nutrients to crops, and a mixture of gases, which bacteria can convert into a liquid fuel suitable for powering cars and tractors.

The kiln will allow researchers -- under the leadership of Elizabeth Fisher, associate professor of mechanical and aerospace engineering, and Al Center, lecturer in chemical and biomolecular engineering -- to study the reaction dynamics and evaluate how the kiln can be scaled up to meet the needs of an entire village.

Their goal is to produce a dual kiln-bioreactor system that will be as thrifty as it is tough.

"The all-in-one unit must be rugged enough to work under the challenging conditions of the rural African landscape," said Lehmann. "This model will integrate the entire process, from feedstock drying to biofuels production, and will use the heat from one process to drive the others."

Lars Angenent, associate professor of biological and environmental engineering, has made progress in harnessing microbes to produce liquid fuel from the gases produced by slow pyrolysis. Members of his laboratory have scaled up the production process from small flasks to a six-liter, two-stage bioreactor system and have optimized the reaction conditions for a bacterium preferred in biofuel production.

Founder of Village Scale Pyrolysis on campus Oct. 19

The Village Scale Pyrolysis project is funded by philanthropist Yossie Hollander, the chairman and founder of the nonpartisan Our Energy Policy Foundation. The foundation fosters dialogue on energy policy amid changing geopolitical, national security, financial and environmental concerns.

Hollander will lead a conversation hosted by the Samuel Curtis Johnson Graduate School of Management's Center for Sustainable Global Enterprise Oct. 19 at 4:25 p.m. in B01 Sage Hall.

"The talk will be interesting to students, staff and faculty interested in energy policy, technology development and commercialization," said Mark Milstein, director of the Center for Sustainable Global Enterprise and a faculty member at Johnson. "Energy has become a big issue in industries from hospitality to agriculture."

A team led by David Lee, professor of applied economics and management, has been evaluating the economic viability of the pyrolysis technology in western Kenya. Using remote sensing and on-the-ground surveys, the team is tracking the types and amounts of biomass available in a 7,500-square-mile area.

Some of that biomass could be burned directly as fuel or used in animal feed or construction; such biomass as corn stalks left in fields could be used to help prevent erosion or perform other similar ecosystem functions, Lehmann said.

He and 12 of his peers reflected on how an improved understanding of soil biogeochemistry is crucial to the stewardship of the ecosystem, in a paper published in Nature Oct. 5.

"Soils are now in the 'front line' of global environmental change -- we need to be able to predict how they will respond to changing climate, vegetation, erosion and pollution so that we can better understand their role in the Earth system and ensure that they continue to provide for humanity and the natural world," they stated.

Amanda Garris is a freelance writer in Geneva, N.Y.