A team of Baylor engineers is working on more efficient, energy producing technology that could breathe new life into waste gases produced by the city of Waco landfill.
The group made up of Baylor University researchers and city of Waco partners was among 19 groups to receive stage two funding from the National Science Foundation’s Civic Innovation Challenge, a national competition co-funded by the U.S. Department of Energy meant to streamline emerging lab technologies to meet local community needs.
The group underwent a six-month planning phase during the grant’s first stage. They were then eligible to receive the $1 million grant to pilot a climate-smart waste-energy combustor project at the city’s Hannah Hill Road landfill.
“Stage one is six months of planning or preparation,” principal investigator Lulin Jiang said. “And then stage two is really the work … to establish a pilot system and to test your pilot system and then to show the scalability, sustainability and transferability to quickly benefit the local community and even society at large.”
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WATCH NOW: A team of Baylor engineers is working on more efficient, energy producing technology that could breathe new life into waste gases produced by the city of Waco landfill.
The program is driven by civic needs of the local community, with the Baylor project focusing on energy resilience in a changing climate. Jiang, an assistant professor of mechanical engineering at Baylor, said the winter storm in February 2021 that left many Waco residents without power for days showed the need for a flexible regenerative energy source that can sustain operations in extreme weather.
“We call it climate smart because of the high fuel flexibility, and also because when you have extreme cold days, for example, those fuel properties will be affected, especially for liquid fuel,” Jiang said.
Landfill gas, composed of about half methane and half carbon dioxide, is created by the decomposition of organic materials. According to the U.S. Environmental Protection Agency, methane is 28 times as potent as carbon dioxide, though both are considered greenhouse gases that trap heat in the Earth’s atmosphere.
Waco Chief Sustainability Officer Charles Dowdell said oceans, wetlands and forests are able to absorb excess carbon dioxide, giving rise to a natural cycle of increases and decreases in concentration. However, since the industrial revolution the planet’s mitigation system has not been able to keep up with rising emissions, which pose the threat of a climate crisis.
Gas produced by Waco’s landfill is captured by a system of pipes buried beneath the site before it escapes and reaches the open air. Currently the landfill gas is burned by the landfill’s flare system, replacing methane with less potent but still harmful, long-lasting carbon dioxide.
Dowdell said the current flare system operates under air permits from the state of Texas and EPA with 90-98% efficient combustion, though there is always room for improvement. Incomplete combustion in a traditional flare system results in the release of unburned methane along with other pollutants that form in the reaction, such as nitrogen oxides.
Despite systems like Waco’s, municipal landfills rank third in sources of human-related methane emissions, the EPA says.
Jiang’s project is twofold: achieve the most efficient combustion of methane produced by the landfill, and apply the same kind of technology to other fuels, making the project scalable and applicable to other waste sources.
Tinkering with the mixing of fuel and air using Baylor-patented fuel-flexible combustion technology and enabling clean flames will lead to the most efficient combustion of natural gas, Jiang said. Dowdell said when looking at flares in oil fields or landfills, a hotter blue flame is a sign of more efficient burning compared to orange or nonexistent flames.
Jiang’s atomization and combustion lab is also using components that have shown successful combustion in tests with different fuels, such as non-gaseous, very viscous liquid waste fuels. The multi-fuel component of the study could apply the combustion technology to other waste-generating processes, such as crude oil production, and produce a regenerative energy source through the burning of viscous biofuels. Many experts are currently studying how to efficiently generate biofuels from different waste sources, Jiang said.
“So that’s a uniqueness,” she said. “… We would like to demonstrate this waste to energy with high fuel flexibility for landfill gas and also possibly for other types of liquid oils generated from waste.”
The pilot program will establish the Baylor-designed flare system at the Waco landfill to assess its increased combustion efficiency. Proven positive impacts and multi-fuel capabilities could land the technology a spot at other waste-producing sites around the world.
“It’s not just the combustion technology itself. … This project will evaluate whether this can be further scaled up and further transferred to other communities like neighboring communities or even not within Texas, but maybe other states or even internationally,” Jiang said.
The heat given off by the burning of methane could be recaptured as a source of energy to be used by nearby industrial operations, Dowdell said. He said the city is also currently looking into a feasibility study for use of the landfill gas as a renewable energy source to be efficiently combusted in power generators or to be delivered directly to surrounding industries.
With Jiang leading as a principal investigator, the project is also employing experts in a variety of fields to determine its overall effectiveness and usefulness.
Co-principal investigator Yang Li, a Baylor assistant professor of environmental science, will conduct local, regional and national climate models using the new combustor’s emissions data to gauge its potential effect on air quality. Alex Yokochi, a mechanical engineering professor, will look at the idea of an external combustion system that could be integrated into the project that could use the heat for energy.
Waco-based economist Ray Perryman will analyze the economic impact the project could have for potential users and customers.
“Definitely to be able to transfer to some end users and customers who can actually put this into practice, that will also need the knowledge about the economic impact,” Jiang said.
