Landfill Gas Composition Explained

Landfill gas composition includes; methane (50-60%), carbon dioxide (30-40%), and trace gases like nitrogen, ammonia, hydrogen, oxygen and sulfuric gases (0.1-10%) [1].

This article discusses landfill gas composition, as follows;

1). Methane (as Part of the Landfill Gas Composition)

Methane is arguably the most significant or important component of landfill gas.

It is also the highest in volumetric proportion; constituting about 50-60% of the overall volume of a LFG sample.

Methane occurs as a natural byproduct of the biodegradation of organic waste materials in a landfill [2], alongside carbon dioxide (CO2) and other materials.

Landfills are among the largest anthropogenic sources of methane in all parts the world, especially in developed countries like the United States [4].

Methane is the main energy-bearing component of landfill gas, which enables it to function as a renewable fuel.

It can be extracted using recovery wells and pipes, among other equipment that make up a landfill gas collection system.

2). Carbon Dioxide

Carbon dioxide (CO2) is one of the main compounds that constitute landfill gas composition; accounting for approximately 30-40% of total volume of a given landfill sample.

Together with methane, this component makes up to 90% of the volume of landfill gas.

Carbon dioxide is also a natural byproduct of biodegradation of landfill waste by microbes.

Landfills affect the atmosphere due to the generation and emission of such gases as carbon dioxide, which have greenhouse characteristics.

Landfills also affect the carbon cycle by acting as large-scale carbon sources that emit CO2 at a continuous and rapid rate [3].

If the effect of greenhouse emissions from landfills is not balanced by the activity of carbon sinks like forests, landfill gas can play a huge role in climate change, acid rain, desertification, and other forms of environmental degradation.

3). Trace Gases (as Part of the Landfill Gas Composition)

Landfill gas trace components are those gases that do not make up a significant portion of the total composition of landfill gas.

In some studies, landfill trace gases are said to constitute less than one percent (1%) of the overall volumetric makeup of a landfill gas sample [5].

Examples of trace gas components in landfill gas include; nitrogen, hydrogen, ammonia and sulfides.

The trace gases present, and their relative proportions in any given sample of landfill gas, depends on the original composition of the organic waste or biomass from which the landfill gas was generated, as well as on the conditions of generation.

Conclusion

Landfill gas composition typically includes;

1. Methane

2. Carbon Dioxide

3. Trace Gases (Nitrogen, Oxygen, Ammonia, Hydrogen, Sulfides)

References

1). Abushammala, M. F. M.; Basri, N. E. A., Younes, M. K. (2016). “Seasonal Variation of Landfill Methane and Carbon Dioxide Emissions in a Tropical Climate.” International Journal of Environmental Science and Development 7(8):586-590. Available at: https://doi.org/10.18178/ijesd.2016.7.8.844. (Accessed 22 November 2022).

2). Joshi, R.; Pant, D. (2018). “Landfill biodegradation process and leachate.” Waste Bioremediation (pp.233-247). Available at: https://doi.org/10.1007/978-981-10-7413-4_12. (Accessed 24 November 2022).

3). Lima, R.; Nolasco, D.; Meneses, W. A.; Salazar, J. M. L.; Hernandez, P.; Pérez, N. M. (2002). “Global Biogenic Emission of Carbon Dioxide from Landfills.” Available at: https://www.researchgate.net/publication/252450974_Global_Biogenic_Emission_of_Carbon_Dioxide_from_Landfills. (Accessed 24 November 2022).

4). Liu, Y.; Cheng, Z.; Geng, C. G.; Chen, A. Y.; Zhang, K.; Zhu, N.; Skitmore, M.; Cai, B.; Zhang, X.; Lou, Z. (2022). “Big disparities in CH4 emission patterns from landfills between the United States and China and their behind driving forces.” Fundamental Research. Available at: https://doi.org/10.1016/j.fmre.2022.08.006. (Accessed 24 November 2022).

5). Zhenhan, D.; Scheutz, C.; Kjeldsen, P. (2020). “Trace gas emissions from municipal solid waste landfills: A review.” Waste Management 119:39-62. Available at: https://doi.org/10.1016/j.wasman.2020.09.015. (Accessed 24 November 2022).