Cattle are extremely efficient at digesting hard materials, and a proposed energy production system based, in part, on cow stomachs could generate 40 percent more energy from municipal waste streams, at a cost. reduced by 20 percent – and provide a viable alternative to sending waste to landfills.
That’s the goal of a $ 6.8 million effort to increase the efficiency of how we convert solid organic waste from waste and sewage into methane, a renewable fuel ready for pipelines.
Led by the University of Michigan, the project includes partnerships with Argonne National Laboratory, Northwestern University and others. The US Department of Energy is providing $ 5 million in funding.
“It’s time for us to change the way we think as a society. These organic materials are just waste in the sense that we bury them in landfills or compost them. We are throwing away precious raw material. We believe we have developed a highly scalable solution to meet the needs of an urbanizing world, ”said Steve Skerlos, Professor Arthur F. Thurnau and Professor of Mechanical Engineering, and co-principal investigator of the project.
The company, led by Lutgarde Raskin, Vernon L. Snoeyink, Professor Emeritus of Environmental Engineering at the University and Professor of Civil and Environmental Engineering, is going beyond technology development to establish a collaboration that will deploy the system. in the company and will train the necessary workforce to operate it.
Methane, the main component of natural gas, can be produced by bioreactors that absorb organic matter produced in our homes – the human waste that we throw down our toilets and the food waste that goes into our kitchen trash cans or is thrown into the home. the rubbish bins. Today, this is not a particularly efficient process, and advanced bioreactors only have a narrow band of material that they can break down.
Beyond that, methane is a by-product of decomposing organic waste in landfills, where it is released into the atmosphere. It’s a powerful greenhouse gas, so capturing more for energy production could be a double climate victory.
“Over the next decade, the technologies, design and operation strategies, and educational programs of this project could lead to a doubling or more of the power generated from food waste in the United States,” said Skerlos.
Mimic nature’s most efficient biodigesters
UM researchers set out to expand the types of organic waste that bioreactors can break down beyond food waste and sewage sludge, and that’s why they took inspiration from nature.
“A cow’s stomach is really good at breaking down lignocellulosic material – things like grass and hay that cattle eat,” Raskin said. “These materials cannot be digested by the anaerobic bioreactors commonly used today. We are looking to develop a new bioreactor capable of digesting garden waste and paper waste.
The cow stomach (rumen) bioreactor is a part of a two-phase anaerobic bioreactor system, called anaerobic because it does not require oxygen. The first bioreactor converts organic waste into simpler compounds like acetic acid, the main component of vinegar. The second reactor converts these simpler compounds into methane. Their combined footprint is much smaller than that of typical bioreactors currently in use, making them more affordable to build and operate, the researchers say.
The MU system is capable of efficiently generating biogas, a mixture of methane and carbon dioxide. Converting this into renewable methane ready for pipelines is the job of researchers at Argonne National Laboratory and Northwestern University. They are developing a system that also converts carbon dioxide in biogas into methane.
“Argonne’s electrochemical technology offers a route to use renewable energies to directly transform biogas into profitable renewable methane,” said Meltem Urgun-Demirtas, group leader of Argonne’s bioprocesses and reactive separations in the materials division. Argonne appliques.
The three aspects of the project will start and progress separately at first. A laboratory-scale assembly of the integrated system will be hosted by Argonne. Later, a pilot system will be built at the Great Lakes Water Authority’s water resource recovery facility in Detroit.
Utilities like the GLWA recovery facility will benefit as they currently do not have systems to recover energy from the sewage sludge and organic waste they produce. In line with GLWA’s goal of becoming energy neutral, the pilot program managed by company staff will be crucial in establishing that the system can be implemented at scale.
Training the renewable methane workforce of tomorrow
A key component of the project is creating a research and education collaboration to help train graduate and undergraduate students for a next-generation bioenergy technology workforce.
Educational partners include the University of Toronto, Universidad Nacional Autónoma de Mexico and Universidad de Monterrey. At UM, the project will partner with the university’s Center for Socially Engaged Design.
“This systematic approach is vital to ensuring that waste-to-energy technology is not only viable, but that it is deployed across North America and beyond,” said Skerlos.
The UM research team also includes the co-leaders Kuang Zhu, researcher in civil and environmental engineering, and Tim Fairley-Wax, specialist in the research laboratory in the same department.
The project is funded by the Office of Bioenergy Technology at DOE. Another $ 1.8 million for the project comes from matching funds provided by GLWA, consulting firm inCTRL Solutions, Carollo Engineers Inc. and others. Approximately $ 5.2 million will be used and distributed by UM while the Argonne National Laboratory will receive $ 1.6 million.