When carrying out biogas construction and implementation, there are key areas that need to be considered before setting up the project. One of them is where the site will be set up for biogas plant construction. This article highlights the factors influencing the selection of the biogas plant construction site. The site selection for biogas production should be convenient for both biogas production and for consumers.
An Overview
Selecting a site for biogas construction is very important, if not vital. It is crucial to assess biomass at a high geographic resolution to control supply risks and find the best plant locations for producing sustainable biofuels and co-products (Sahoo, Mani, Das, & Bettinger, 2018).
Selecting a site to position the plant involves factors such as convenience, presence of existing structures, terrain, cost, safety, and environmental conditions. The spatial distribution and characteristics of different energy sources are driving factors towards site selection and plant scaling (Soha, Papp, Csontos, & Munkácsy, 2021). Suitable sites are plots of land where all of the components of a biogas plant (digesters, storage systems, and CHP plants) may be constructed under favorable technical and legal conditions, such as adequate area and good road access (Epp, Rutz, Kottner & Finsterwalder, 2008).
Geographic Information Systems (GIS) have been used in previous studies because geographical data and spatial factors (biomass availability, transportation distances, urbanization of the area, road infrastructure, protected areas, and environmental features), all play a critical role in identifying optimal locations for siting biogas plants (Díaz-Vázquez, Alvarado-Cummings, Meza-Rodríguez, Senés-Guerrero, de Anda, & Gradilla-Hernández, 2020). These mechanisms enable architects to select a good area for siting a biogas plant. However, such systems are used for large-scale commercial biogas plants.
Factors Affecting Site Selection of Biogas Plants
a) Biogas demand: The term biogas demand means an economically justifiable use of the biogas produced at a scale large enough to equal the output. Biogas demand is one of the most important considerations in selecting the site of a biogas plant.
b) Size of the plant: The area for the installation of the biogas plant is determined by its size. If the biogas plant is large, it will need a bigger and more free location.
c) Convenience to the biogas plant and its utilities: The position of the site should be convenient to feed the digester. It should be placed in consideration of other structures that are to be connected to the plant such as the kitchen stove and cowshed.
d) Land terrain: The terrain should also be considered because of the nature of the slurry and the gas in and out of the plant.
e) Biogas plant construction cost: Cost is an optimal factor in selecting the site of the biogas plant. The site should facilitate easy construction works and minimize the cost. It should also allow easy access to the building materials.
f) Interaction with the environment: Site safety should also be put into consideration when positioning the plant. The site location should be considerate of the activities that are present in the area. Children’s playgrounds should be avoided.
g) Temperature of the area: Right temperatures ranging between (20-35°C) should be considered, preferably a sunny site. Warm temperatures promote more microbial activity in the dome ensuring more gas production.
h) Proximity to nearby water sources: It is not advisable to have a biogas plant 10 meters within any source of water. Pollution is contained since bio-slurry water is more likely to infiltrate into the nearby water bodies.
i) Nearness to raw materials: It is tough to feed the plant on a daily basis if it is located far from the supply of feed material. The expense of the pipeline will rise as it gets further away from the gas consumption point. In addition, the site’s water supply is a vital element to consider. It is always preferable to choose a location on the side of the animal enclosure that is closer to the source of feed material. (Sangha, 2013).
j) Feedstock availability: The proximity of the feedstock supply increases the chances of obtaining big quantities without incurring additional logistics costs. Many published studies back up the relevance of feedstock supply (e.g. Epp et al., 2008; Ma et al., 2005; Wellinger et al., 2013). In most situations, the feedstock is a major consideration when deciding where to build a biogas plant, and proximity to a source of feedstock is especially crucial for biomass with high moisture content (Feiz, Metson, Wretman & Ammenberg, 2022).
k) Digestate demand: Digestate demand refers to the ability to supply the produced digestate to its customers in a cost-effective manner; commonly, as a biofertilizer in agriculture. Digestate has a high moisture content (about 95% water), making handling and shipment a relatively expensive issue. (Feiz et al., 2022). Therefore, the site has to be strategically positioned in order to handle the slurry from digestion and to transport it efficiently.
Note: Once a site has been selected, it must be carefully marked and cleared, with any stumps and trees uprooted but not felled.
Conclusion
A suitable site is a piece of land on which all of the components of a biogas plant are built in a safe, legal, and productive manner. Therefore, a good biogas site has to be chosen for optimum production considering the factors of site selection. Failure to consider such factors may lead to technical-related issues in biogas plant construction and installation.
References
Díaz-Vázquez, D., Alvarado-Cummings, S. C., Meza-Rodríguez, D., Senés-Guerrero, C., de Anda, J., & Gradilla-Hernández, M. S. (2020). Evaluation of biogas potential from livestock manures and multicriteria site selection for centralized anaerobic digester systems: The case of Jalisco, Mexico. Sustainability, 12(9), 3527.
Epp, C., Rutz, D., Kottner, M., & Finsterwalder, T. (2008). Guidelines for selecting suitable sites for biogas plants. Romania: 1-18.
Feiz, R., Metson, G., Wretman, J., & Ammenberg, J. (2022). Key Factors for Site-Selection of Biogas Plants in Sweden. Available at SSRN 4023474.
SKG Sangha (January 2013) Biogas Plant Construction Manual. Retrieved from https://www.build-a-biogas-plant.com/PDF/SKGConstrution%20manual2013.pdf
Soha, T., Papp, L., Csontos, C., & Munkácsy, B. (2021). The importance of high crop residue demand on biogas plant site selection, scaling and feedstock allocation–A regional-scale concept in a Hungarian study area. Renewable and Sustainable Energy Reviews, 141, 110822.
Sahoo, K., Mani, S., Das, L., & Bettinger, P. (2018). GIS-based assessment of sustainable crop residues for optimal siting of biogas plants. Biomass and Bioenergy, 110, 63-74.
This article is an excerpt from the book “The Blue Flame: Biogas Training Blueprint”
Suggested Citation in APA
Wanjohi, A.M. (2022). The Blue Flame: Biogas Training Blueprint. Nairobi: Kenya Projects Organization
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