Colorado State University wins DOE grant for biomass stove work

By Colorado State University | October 30, 2012

The U.S. DOE has awarded Colorado State University’s Engines and Energy Conversion Laboratory—one of the most advanced cookstove laboratories in the nation—a $1 million grant to build a more efficient biomass cookstove that could further reduce indoor air pollution around the globe.

Morgan DeFoort, co-director of the laboratory, will lead a team of researchers from CSU, Lawrence Berkeley National Laboratory, Princeton University and Envirofit International to build a semi-gasifier cookstove.

A semi-gasifier stove uses a two-step process to combust solid biomass instead of one currently used in the rocket-elbow stove that CSU engineers have improved in collaboration with spinoff company Envirofit International. Most clean cookstoves that burn wood have combustion chambers that use a rocket-elbow design.

Envirofit is a private, non-profit technology leader using sustainable, scalable business models to solve global health and environmental problems. The Federal Laboratory Consortium has honored CSU, Envirofit and Oak Ridge National Laboratory for designing and disseminating the biomass cookstove. About 500,000 of the stoves have been sold to date in developing countries including India, Nigeria, Kenya, Liberia, Ghana, Zambia, Tanzania, Uganda, Republic of Congo, Ethiopia, Honduras and others.

The technology on the biomass cookstoves reduces carbon dioxide emissions by 65 percent and fuel consumption by 50 percent.

The semi-gasifier stoves will have even lower emissions, said Jessica Tryner, a second-year doctoral student working with Professor Anthony Marchese in the cookstoves lab.

“It separates the combustion process into two phases. In the first phase, combustible gasses are released from solid biomass. In the second phase, those combustible gasses are mixed with air and create a secondary flame,” Tryner said.

The project will employ high-fidelity computational fluid dynamics, or CFD, modeling for cookstoves using embedded boundary and detailed chemistry. This represents a significant stride towards improving computational simulations for biomass cookstoves and enabling accurate and reliable numerical tools for the engineering design and optimization far beyond that attempted previously. This CFD work will be led by Xinfeng Gao and Azer Yalin, both professors in the Department of Mechanical Engineering.

Indoor air pollution is a leading cause of death for women and children under age 5 around the globe. Two-thirds of the world’s population use biomass to cook their food and heat their homes, but CSU’s efforts in this program will focus on designing the stoves for China and India.

“As the health data grows, it is more and more apparent that emissions reductions of improved stoves using rocket-elbow technology are not adequate,” DeFoort said. “With nearly 360 million and 690 million users respectively, China and India use more wood for cooking than any other countries. Collectively, nearly 50 percent of the global population who primarily rely on wood for cooking can be found in these two countries.”

CSU engineers are among the best in the world at developing international cookstove testing protocols, creating international standards, testing and analyzing dozens of stoves from manufacturers throughout the world and field-testing more than a dozen commercially available products and their health impacts and performance.

Led by DeFoort, students and faculty at CSU will continue to improve cookstove technology with the DOE grant by creating generic technology that could be applied to a variety of stove designs.

“The design and configuration of a cookstove is highly location specific,” DeFoort said. “Critical design choices must be made to ensure that a stove is appropriate for the fuel type, cooking tasks, and cultural habits of a particular region.”

Founded in 1992, the Engines and Energy Conversion Laboratory has developed solutions to reduce emissions from large industrial engines, supported dozens of companies with new engine technology, made important contributions to basic combustion science, worked to define the architectures for the future electric grid, developed advanced biofuels, and brought clean energy solutions to the developing world. The laboratory has pioneered the use of undergraduate students in research programs, employed hundreds of students from across the university and helped develop a new generation of energy leaders.

Most recently, lab researchers announced they will collaborate with RTI International and others to develop a waterless toilet that converts human waste into burnable fuel and disinfected, non-potable water. The “Reinvent the Toilet Challenge,” which is made possible by a grant from the Bill & Melinda Gates Foundation to RTI International, could significantly improve public health and quality of life among people in developing countries.