Context
Over 500,000 tonnes of solid wastes are landfilled annually in Mauritius, out of which more than 50% are organic wastes. With its only existing Mare Chicose landfill being close to saturation, this poses a significant challenge. Moreover, over 87% of the total primary energy requirements of the island are met through fossil fuels making the small island developing state extremely exposed to the volatility of import prices.
Mauritius needs to identify solutions for its Municipal Solid Waste (MSW) and has identified anaerobic digestion as a promising solution for the organic fraction of the MSW, a process in which biogas as an electricity source and digestates as organic fertilizer can be generated. The treatment of organic waste through anaerobic digestion is considered a highly beneficial alternative instead of disposing organic waste on landfills. This circular economy approach to use organic waste for energy generation results in a reduced usage and reliance of fossil fuels and a reduction of greenhouse gas (GHG) emissions from the use of fossil fuels.
CTCN Support
Prior to implementation of anaerobic digestion on a large scale, an in-depth feasibility study needed to be carried out. This CTCN Technical Assistance thus addressed this gap through the development of a technical and economic feasibility study for anaerobic digestion of the organic fraction of solid waste from households, hotels and markets in Mauritius. With the completion of this Technical Assistance, Mauritius had a technical and economic feasibility study as well as a proposal for a public-private partnership at hand that allows the country to move towards the implementation phase of the project.
Expected Impact
The feasibility assessment has demonstrated that biogas production is economically and technically viable and the plant could process up to 100 tons of organic waste per day, corresponding to around 30,000 tons per year. This volume of waste has the potential to generate enough biogas to produce approximately 1.5 to 2 megawatt-hours (MWh) of electricity daily. That is sufficient to power between 1,500 to 2,000 households, depending on energy consumption patterns. The plant will also produce valuable by-products like compost and liquid fertilizer, helping close the nutrient loop in agriculture and reducing reliance on chemical inputs.