The conventional energy source in cement industries is fossil fuels, mainly coal, which has a high environmental footprint. On average, energy expenditures account for 40% of the overall production costs per ton of cement. Reducing both the environmental impact and economic expenditure involves incorporating alternative energy sources (fuels) such as biomass, solid-derived fuel (SDF), refuse-derived fuel (RDF) etc. However, within cement plants, the substitution of conventional fossil fuels with alternative fuels poses several challenges due to the difficulty in incorporating additional fuel-saving techniques. Typically, an additional 3000 MJ of electricity per ton of clinker is required. One of the most effective solutions to this is thermal optimization through co-processing and pre-processing, which makes it possible to implement additional fossil-fuel-saving techniques. In developing nations such as Togo, waste-management systems rely on co-processing in cement factories through a waste-to-energy relationship. Also, there are some old cement plants with low-efficiency, multi-stage preheaters without pre-calciners, reciprocating huge coolers, low-efficiency motors etc., which still operate and need to be made environmentally sustainable. However, compared to modern kilns which can have up to 95% of energy recovery from waste, an old suspension preheater kiln can recover only up to 60% of its heat energy depending on the cooler type, and due to the lack of a bypass and combustion chamber (pre-calciner). This research paper evaluated the performance of a cement plant incorporating AF and presents the procedures and recommendations to optimize AF substitution in cement plants. To achieve this, a comparative performance study was carried out by assessing the alternative fuel characteristics and the equipment performance before and after the incorporation of the alternative fuel. Data were collected on the optimum substitution ratio, pre-processing and co-processing performance, raw-meal design and economic analysis. Results indicated that the cost to be covered per ton of waste input is €10.9 for solid-derived fuel (SDF), €15 for refuse-derived fuel (RDF), and that the co-processing cost optimization for the cement plant could have a cost saving of up to 7.81€/GJ. In conclusion, it is recommended that appropriate kiln and alternative-fuel models be created for forecasting production based on various AF.

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 and resource management in Togo is expected to become more difficult due to increasing socioeconomic development, industrialization, and renewable energy investments. Although there are numerous elements that affect waste and resource management, legislation and policy frameworks are essential. In response to the growing demands for environmental protection, the legal provisions and regulatory frameworks of waste and resource management, as well as the legal implementation process, must be more and more comprehensive. Some actions have been taken in Togo to improve the incorporation of more sustainable industrial processes, which include restrictions and regulations on MSW generation, decentralization of MSW management, policies and incentive systems that promote waste reduction, reuse, and recycling, improvement of enforcement through investigation and treatment of violations, and encouragement of macro-socio-economies in the management of municipal solid waste. In spite of the presence of these policies, the sector is still plagued with numerous challenges, mostly in terms of implementation and the application of these policies to develop tailor made and locally feasible solutions. This research paper highlights relevant policies relating to MSW management in Togo as well as key international conventions and policies. It also discusses the contribution that “transition management” can make to such processes, emphasizes the role of governance for sustainable development, and it suggests solutions with a long-term transformation impact such as the incorporation of waste to energy systems into industrial processes. The paper further identifies some flaws and challenges with law implementation on MSW management and suggests solutions to improve the effectiveness of law implementation and the conditions and criteria for a safe and secure way to use waste-derived materials and fuels or by-products coming from society or other industries. These policy suggestions may also be applicable globally at an individual industry level to encourage the creation of more Green Industrial Companies (GICs).

Sustainable energy projects in Africa are particularly vulnerable in terms of sourcing vital alternative fuels due to the complexity of sourcing processes, contract agreements and relationships between society managers or directors and supplier chain entities. These challenges can affect any phase of a sustainable project, and the losses can be as high as 3.2 EURO/GJ. In addition, there is reduced competition and fair trade, low profits and poor quality of the fuel purchased. Technology (mobile application) is one powerful tool that can solve the above challenges by controlling or managing the supply and demand of biomass-based fuels, agriculture residue, industrial waste and many more. Thus, the main objective of this study is to evaluate the feasibility of a developed digital platform to remove barriers in the trade of alternative fuels. Data collection began with the identification of the key production areas (sources) and quantities of three selected AFs. Secondly, data on the seasonal variations in alternative fuel (AF) quantities were obtained from the identified locations. Thirdly, the acquisition costs were calculated based on the quality and characteristics of the AFs. Results were then transferred into a mobile application where industries could assess, compare, and bargain for AF based on quality and price. Due to the introduction of competitive pricing, overall, the mobile application improved the savings on sourcing for AFs by industries by 2.89 EURO/GJ. In terms of profit optimization, the farmers have value for money and fair bargaining for their products, thus increasing their revenues for the planting season. It was also observed that the cost of the fuel was based on the proximity of the source to the demand industry. In conclusion, the mobile application facilitates a circular economy between the farmers, suppliers and industries where industries receive fair and competitive prices for their fuel whiles farmers receive extra income for farming businesses and agricultural waste is sustainably managed through a circular economy.

The process of making cement clinker uses a lot of energy and produces a lot of pollution. Currently, cement companies use a combination of traditional fossil fuels and alternative fuels (AF-Fuels) to lower their energy consumption and environmental footprint by improving the pyro-system. In a calciner, AF-Fuels can reach a thermal substitution rate (TSR) of up to 80–100%. However, a kiln burner can only achieve a TSR of 50–60%. High TSR values have been provided by improvements in multi-channel burners, proper AF-Fuel feeding point setups, and various AF pre-combustion methods. Significant modeling of the calciner burner and system has also improved TSRs. However, the cement industry has encountered operational problems such as kiln coating build-up, reduced flame temperatures, higher specific heat consumption, and incomplete combustion. There is growing interest in waste substitution, a promising source of AF-Fuel that needs to be integrated into the current cement plant design to solve the calciner operational problems of the cement industry. This study discusses the latest developments and different experimental and modeling studies performed on the direct burning/co-firing of AF-Fuel in the cement industry as well as the incorporation of gasification in cement manufacturing. Based on this, a technically and environmentally improved solution is proposed. The characteristics of both approaches towards pre-calciner function and optimization are critically assessed. The many in-line cement calciner integration technologies and their various configurations for the long-term problems of cement plants are discussed. This project report also focuses on the necessity of creating appropriate calciner models for forecasting calciner production based on various AF-Fuels and their feeding positions in the calciner.