Reducing methane emissions has become a critical focus in the fight against climate change. Methane, a greenhouse gas, has over 25 times the effect of carbon dioxide at trapping heat in the atmosphere over a 100-year period. One solution gaining momentum is the production of Renewable Natural Gas (RNG) or biomethane. This approach addresses methane emissions and provides a sustainable energy source, serving as a direct alternative to conventional natural gas and helping companies meet their climate goals.
The June 12, 2024, announcement of the “National Strategy for Reducing Food Loss and Waste and Recycling Organics” by the U.S. Environmental Protection Agency (EPA), the U.S. Department of Agriculture (USDA), and the U.S. Food and Drug Administration (FDA) shows that the government is taking a comprehensive, whole-of-government approach to tackling climate change, feeding people, addressing environmental justice, and promoting a circular economy. While the strategy includes objectives such as preventing food loss and waste, it also emphasizes the need to increase the recycling rate for organic waste and support policies that encourage these practices.
This strategy is bolstered by nearly $200 million in funding from the Bipartisan Infrastructure Law, which supports projects that include organics recycling, composting, and anaerobic digestion, an essential component of RNG production. The increase in funding to the RNG industry is an opportunity to develop new production facilities that can help meet these new strategy goals.
Understanding Renewable Natural Gas and Anaerobic Digesters
RNG is produced from organic materials such as agricultural waste, food waste, and animal manure. Unlike traditional natural gas extracted from fossil fuel reserves, RNG derived from the anaerobic digestion of organic waste captures methane that would otherwise be released into the atmosphere and turns it into a usable energy source.
Anaerobic digestion is a biological process where microorganisms break down organic materials in the absence of oxygen, producing biogas primarily composed of methane and carbon dioxide. Food waste anaerobic digesters specifically target food waste as the feedstock for this process.
Here are some of the benefits associated with Food Waste RNG production:
- Significant Methane Capture Potential
Food waste decomposition in landfills is a significant contributor to methane emissions. Recent EPA research shows that 58% of methane emissions from landfills are due to food waste. While landfill gases can typically be captured to generate RNG, diverting food waste to anaerobic digesters provides greater capture of this feedstock by processing it earlier in the decomposition process, leading to higher methane generation and lowering fugitive methane emissions. - Enhanced Waste Management
Food waste anaerobic digesters offer an effective solution for managing one of the most prevalent and challenging waste streams. Food waste comprises up to 24% of municipal solid waste or more in urban areas. Utilizing anaerobic digesters reduces landfill burden while converting waste into a valuable resource, contributing to a circular economy where waste is continuously repurposed. - Reduction of Greenhouse Gas Emissions and Air Quality Pollutants
RNG generated from food waste provides a significant opportunity to reduce overall greenhouse gas (GHG) emissions by capturing the methane it generates. Each year in the U.S., food loss and waste create potent GHG pollutants equivalent to the emissions of 60 coal-fired power plants. Additionally, the carbon dioxide produced during anaerobic digestion is biogenic, meaning it originates from the natural carbon cycle and does not contribute to net atmospheric CO2 levels when managed properly. The RNG production process also removes other pollutants, improving overall air quality. - Renewable Energy Generation
The biogas produced by food waste anaerobic digesters can be refined into RNG. This renewable energy source can replace conventional natural gas in various applications, including heating, electricity generation, and transportation. RNG helps lower reliance on fossil fuels and supports the transition to a sustainable energy future. - Nutrient-Rich Digestate
Besides biogas, anaerobic digesters produce digestate, a nutrient-rich byproduct that can be used as a fertilizer. This digestate can return valuable nutrients to the soil, enhancing agricultural productivity and reducing the need for synthetic fertilizers. This contributes to more sustainable agricultural practices and closes the nutrient loop. - Economic and Community Benefits
Implementing food waste anaerobic digesters can create economic opportunities, particularly in urban and suburban areas where food waste is abundant. These facilities can provide jobs, stimulate local economies, and support waste management infrastructure. Furthermore, by turning waste into a resource, communities can reduce waste disposal costs and generate revenue from selling RNG and digestate.
Conclusion
Government initiatives like the National Strategy for Reducing Food Loss and Waste and Recycling Organics support the development of new food waste RNG facilities by providing funding and driving technology forward in this industry. The production of RNG from food waste anaerobic digesters offers a multifaceted solution to corporate environmental goals and broader climate challenges. Food waste-derived RNG stands out by providing a renewable energy source that also reduces GHG emissions, improves air quality, and increases waste management efficiency, all while creating economic opportunities and reducing our dependence on fossil fuels.
About the Author
Tim Sperfslage, Project Director Environmental Consulting Services, Alliance Technical Group
With a strong background in air permitting and compliance across multiple industries, Tim brings more than 15 years of experience in air quality to his client’s environmental projects. Supporting clients with regulatory and technical air quality knowledge, Tim proficiently manages complex permitting projects with cross-discipline teams, conducting technical audits, and directing environmental compliance projects.
More About RNG: Tackling the Challenges of RNG Testing, Together