Methane Leaks from Buried Food Waste
research 2024-07-31
Methane Report

Methane Leaks from Buried Food Waste

About

This study proposes treatment methods, reduction strategies, and policy recommendations for food waste as a means of reducing methane emissions in South Korea.

This study specifically calculated methane emissions from food waste since it is difficult to separately identify the data from national statistics. At the same time, it assessed the methane emission factor and methane recovery factor from different treatment methods: composting, biogas production, incineration, landfilling. The results identified the treatment method with the lowest methane emissions.

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Executive summary


This study categorizes methane reduction strategies for food waste into three stages: first, reducing and preventing the generation of food waste; second, fully recovering food waste; third, processing waste in ways that do not produce methane while recovering methane during processing. This includes blocking methane emissions through proper treatment during recycling (e.g., animal feed, compost) and utilizing biogas production. Moreover, methane emissions from the transportation and processing of food waste should be monitored and measured throughout the entire process.

The most fundamental and important means of reducing methane is to obtain accurate methane data. This is a prerequisite for any methane reduction strategy and is essential for addressing the shortcomings of existing data.

This study confirms that reducing food waste is a short-term and effective means of reducing waste methane and emphasizes that reducing food waste generation, reduction policies, and major national initiatives should go in tandem with efforts to reduce methane emissions

Key findings

The methane emission factor, the kg of methane emitted per ton of food waste, is highest for landfilling at 25.71, followed by composting at 4.00 and biogas production at 1.00. This means that landfilling one ton of food waste produces methane 6 times more than composting and 25 times more than biogas production. Biogas production is the only food waste treatment method with a negative net methane emission factor, which in principle, means that methane is reduced when food waste is treated via biogas production.

Excluding feed production, which has a methane emission factor of 0 according to the IPCC Guidelines, composting generates the most methane, accounting for 51% of the total emissions from food waste. Composting has traditionally been recognized as a green food waste treatment method, but as methane naturally leaks into the atmosphere under partially anaerobic conditions, it needs to be captured and treated. The following diagram shows the amount of food waste processed and methane emissions by treatment method.