Mexico City's Waste-to-Energy Plant Poised to Slash Emissions, Pioneer Circular Economy
Mexico City launches a pilot hydrothermal carbonization plant to convert organic waste into valuable resources. The first module processes 72 tons of waste daily, producing hydrochar (a coal alternative) and fertilizer, reducing CO2 emissions by 24,600 tons/year.
A pioneering hydrothermal carbonization plant on the western edge of Mexico City has completed its first module and begun conditioning operations, marking a significant step in the nation's fight against climate change and its pursuit of a circular economy, according to project leaders.
The facility, a collaborative effort between the National Autonomous University of Mexico (UNAM), the Ministry of Energy (SENER), and the Federal Electricity Commission (CFE), converts organic waste into valuable byproducts like hydrochar—a charcoal-like substance—and nutrient-rich water, while simultaneously reducing greenhouse gas emissions.
"Even at this conditioning stage, the plant is working and reducing emissions," said Luis Agustín Álvarez Icaza, a researcher at UNAM's Engineering Institute and leader of the project. "The important thing is that it operates at full scale because it has a substantial impact on the circular economy. The advantage is that hydrochar is a product with high added value."
The completed module can process 72 tons of organic waste daily, yielding 8.7 tons of hydrochar and mitigating 24,600 tons of carbon dioxide emissions annually. It also sequesters 9,500 tons of carbon per year. The project, launched in 2021 with backing from the Fund for Energy Transition and Sustainable Use of Energy, aims to transform Mexico City's organic waste management landscape.
Mexico generates over 20 million tons of organic waste annually, of which only a fraction is processed in composting plants. Dr. Álvarez Icaza, a recipient of the National University Award, highlighted the shortcomings of traditional composting, noting that improper practices can lead to significant methane emissions. Even when done correctly, composting still generates greenhouse gases. Furthermore, transporting compost to agricultural areas presents logistical challenges, and its efficacy as fertilizer can be inconsistent.
The hydrothermal carbonization plant, located at the Bordo Poniente landfill site on the former Lake Texcoco, offers a more sustainable and economically viable alternative. The process recovers carbon from organic waste, producing hydrochar for industrial applications. Dry waste undergoes gasification to generate electricity, while wet waste is converted into hydrochar, nutrient-rich water, and water vapor.
"Hydrochar has economic value," explained Dr. Álvarez Icaza. "The CFE pays $100 per ton of coal imported from Australia. The water from the process also has significant fertilizing power. These are two products with high commercial value."
The project aligns with Mexico City's Zero Waste strategy, part of its broader Environmental and Climate Change Program. This first module is just the beginning. The ultimate goal is to expand to 36 modules, enabling the processing of 300 tons of hydrochar per day and sequestering up to 342,000 tons of carbon annually. This ambitious scale-up could significantly reduce Mexico’s reliance on imported coal while offering a sustainable solution for its burgeoning organic waste problem. The success of this initial module provides a promising foundation for the future of waste management and sustainable energy production in Mexico.
