Municipal Solid Waste Management: Waste to Energy Technologies Versus Composting—Two Sustainable Development Models

In the world, the fast growing urbanization and industrialization occasioned increases in municipal solid waste (MSW) generation and energy consumption. According to the World Bank projection, global MSW generation will increase to 2.2 billion tons per year by 2025 and the MSW management has become a major concern which aims to transform the linear economy model into a circular one, minimizing consequently environmental impacts and hence public health risks. Depending on the countries socio-economic framework, to manage MSW, several procedures have been established and practiced; these include landfilling, thermal, chemical and biological treatments. However, open dumping and landfill remain the most applied methods for MSW disposal in spite of their detrimental environmental impacts on air pollution, water and soil contaminations, and climate changes induction. At present, in developing countries, energy demand and consumption is in continuous increase. Generally, all over the world, the high-energy demands are covered through fossil fuels resources i.e. natural gas and oil. Moreover, Waste-to-Energy (WTE) technologies, specifically biodrying, incineration, pyrolysis, and gasification could be considered as sustainable processes leading to products that could be fully recovered, recycled and reused, and will be an alternative energy sources, contributing to solve the energy crisis. In developed countries, the application of the WTE project would moderate the informal landfilling as well as greenhouse gas (GHG) releases, promoting renewable energy production. The MSW management through WTE technologies may have impacts on both of the environment and human life, categorized in direct and indirect methodologies, taking into account the circular economy perspectives. The direct approach involves MSW incineration for heat recovery, while the indirect approach, including thermochemical and biochemical processes, is more complicated but attractive because of the valorized products variety—such as biochar, digestate, humus, syngas and bio-oil. The development of these technologies can lead to suitable eco-friendly approaches, and WTE technologies are important components of circular economy that will assist to achieve the demand of clean energy in the future. The present chapter focuses on the municipal solid waste management strategies and waste-to-energy conversion technologies as a model for circular economy and sustainable MSW option development. After sorting the MSW, their disposal and the technologies used to valorize this waste will be developed, presenting first the common management technologies practiced, with composting agronomic benefits, then emphasizing on waste-to-energy technology, its advantages and its challenges’ as a sustainable and clean bioresources issue, enhancing environmental sustainability, facing energetic crisis. A comparison between composting process and WTE will be considered.