Cities in developing countries continue to struggle with mounting waste management challenges. Within a circular economy framework, energy recovery is mostly nonexistent. Against that background, this study aimed to design and assess the viability of a hybrid waste-to-energy facility for the Greater Accra Metropolitan Area (GAMA) in Ghana by 2030. The proposed plant integrates solar PV, anaerobic digestion and pyrolysis to treat unsegregated municipal solid waste. Three cases were developed for different product combinations. Material flow analysis was performed with STAN software 2.7.101. The results indicate that 1.6 million tons of MSW will be generated, to be potentially converted to 271 GWh of electricity, 6400 tons of hydrogen or 4400 tons of bio-compressed natural gas per year, along with additional products: compost, refuse-derived fuel and bio-oil. The economic indicators show that all cases are potentially viable in terms of the net present value (EUR 397 to 1030 million), internal rate of return (14–22%) and levelized cost of energy (0.11–0.18 EUR/kWh). As such, this study proves that waste to energy is a viable waste management solution for large metropolitan areas, with the potential to supply energy, alternative fuels and material products within a circular economy, though it requires the buy-in of policy makers.

In developing countries like Ghana, the conversion of waste into energy is gaining greater interest among policy makers and researchers. The present study investigates the feasibility of producing electricity and/or fuels from a hybrid waste-to-energy pilot plant located in the Ashanti Region of Ghana. The plant integrates three technologies: anaerobic digestion, pyrolysis and solar PV. The plant has the potential to produce both energy and fuels such as green hydrogen, refuse derived fuels, bio-compressed natural gas and compost. Thus, this study compares the financial feasibility of three scenarios—generating electricity and fuels, generating electricity alone and generating fuels alone—by modelling their energy output and financial performance using RETSCREEN expert 6.0.7.55 and Microsoft Excel 2019 softwares. The results indicate that the multiple products of electricity and fuels provide higher investment interest with a Net Present Value in excess of EUR 13 million and a payback period of 12 years compared to the electricity-only model. Also, converting electricity into fuels alone also provides substantial benefits which can be explored. However, the Levelized Cost of Energy, ranging from 0.3 to 0.68 EUR/kWh, is far above the average residential End User tariff. Overall, this study provides an important methodology for assessing the potential products of future projects.

Waste management in most parts of Africa is characterized by the disposal of mixed waste in unengineered landfills. The aim of this study is to assess the environmental impact of mixed waste received at a waste-to-energy plant in Ghana relative to the current model of landfilling. A Life Cycle Assessment was conducted using OpenLCA software version 2.3.1 based on the ReCiPe Midpoint method. For landfilling, LandGEM software version 3.03 was used. The results indicate that waste-to-energy has the potential to provide carbon savings of 3.52 tCO₂eq/ton of waste treated compared to landfilling. Pyrolysis is observed to have high avoided burden across all impact categories, with the lowest Global Warming Potential of −2.3 kgCO₂eq. Anaerobic digestion shows a near neutral environmental impact with the highest value of 47.56 kg 1,4DCB for Terrestrial Ecotoxicity, while Refuse-Derived Fuel and segregation processes show low environmental burdens. The net avoided burden is highest for global warming and non-carcinogenic human toxicity potential. Overall, the hybrid waste-to-energy model is concluded to be an environmentally preferred waste management option compared to conventional landfilling methods, and we recommend that decision-makers facilitate investments into it. It is also recommended for the development of local inventories and databases to encourage more country-specific environmental impact studies and to reduce uncertainty.

In this study, Taguchi approach was used to determine the influence of waste composition for the optimization of moisture content (MC) and calorific value (CV) of food waste via bio-drying process. The objective was to reduce MC and increase CV of the bio-dried material. The effect of three different levels of four factors including food (FW), paper (Pa), plastic (Pl) waste, and bulking agent (BA) were studied and optimized. The moisture content of the bio-dried material varied between 8.59 and 50.93%, whereas that of the calorific value was 11–25 MJ/kg. The results revealed optimum configurations for MC and CV as FW₁Pa₃Pl₃BA₃ and FW₁Pa₁Pl₃BA₁, respectively. Regression analysis revealed MC as a positive function of FW and BA with plastic positively correlated with calorific value. ANOVA analysis indicated that FW had more prominent effect on both MC and CV. The predicted and measured values were very close to each other. Additionally, the results realized in the confirmatory experiments at optimized conditions of CV was found to be higher than the test runs of Taguchi design, suggesting that Taguchi method was very successful in the optimization of bio-drying factors for MC and CV.

Plastic pollution poses a critical global environmental threat, with Nigeria being particularly vulnerable to this due to its rapid industrialization, urbanization, and inadequate waste management infrastructure. This study investigated public awareness and perceptions of plastic pollution in Nigeria, emphasizing the ecological impacts and potential economic opportunities associated with plastic waste. Using a comprehensive questionnaire administered from June to December 2023, the study evaluated the extent of public awareness, perceptions of responsibility, and key factors influencing attitudes towards the management of plastic waste. The findings revealed a high level of public awareness about plastic pollution, with 66.5% of respondents having participated in environment-related gatherings and 56.5% were familiar with the concept of a circular economy. A significant majority (79.2%) believed in the wealth-generating potential of plastic waste, highlighting methods such as recycling, energy generation, and manufacturing new products. The study also identified significant associations between socio-demographic factors and perceptions of responsibility for plastic pollution management. The study underscores the need for targeted education and policy interventions to address disparities influenced by socio-demographic factors. The potential for economic development through recycling and innovative waste management solutions, such as pyrolysis and gasification, is emphasized. Effective collaboration among government agencies, businesses, NGOs, and local communities is essential to develop infrastructure, implement supportive policies, and promote responsible waste disposal practices. The results highlight the dual opportunity for economic growth and environmental protection through sustainable waste management. Advancing circular economy initiatives in Nigeria requires innovative solutions, stakeholder collaboration, and policies that leverage the wealth-generating potential of plastic waste while safeguarding the environment.

The potential for thermal recovery of waste is increasingly gaining impetus among researchers and industries across the globe especially in many developed countries. However, in processing waste for energy recovery, the type and nature of input waste materials particularly those with high moisture content have a significant impact in determining the quality, environmental profile of the waste as well as the thermal properties of the final product. Bio-drying, as a waste to energy conversion technology, tends to reduce moisture content of waste while maintaining the energy content of the processed waste. The current study investigates the effect of input materials (biogenic and non-biogenic materials) on the energy and biogenic contents of waste material by bio-drying process. The results indicated a positive correlation between biogenic and energy contents of the input materials with some variations observed. Further analysis showed that, high proportion of food waste in the waste mix indicated a slight difference in biogenic and energy contents. Conversely, the same proportion of paper in the waste mix showed similar biogenic content with slight variation in energy content.