Review on the Suitability of Waste for Appropriate Waste-to- Energy Technology

The proper treatment of waste to utilise them as a feedstock for resource harvesting is gaining increasing popularity. The Waste to energy (WtE) technology is the process that can produce solids, liquid or gaseous fuels from waste, which can be utilised to generate electricity and thermal energy. The WtE technology can be divided into two treatments, which are the thermal treatment (incineration, gasification, pyrolysis, refuse derived fuels) and the biological treatment (anaerobic digestion, composting). The municipal solid waste (MSW) is an attractive feedstock for WtE technology for resource harvesting due to their high organic content. MSW is heterogenous in nature. MSW can be categorised into mixed MSW and segregated MSW, which includes segregated food waste, green waste, paper waste, plastic waste and more. Different categories of waste exhibits different characteristics, such as variation in the moisture content, caloric value, C/N ratio, particle size and pH. These characteristics can be viewed interchangeably as the parameters for the WtE technology. Different technologies require appropriate waste with certain characteristic to serve as the suitable feedstock for the optimal performance. This paper aims to review the characteristics of different categories of waste under the MSW and propose a suitability matching between these waste with the available WtE technology. As a result, mixed MSW is suitable for incineration process whereas segregated MSW like food waste which is rich in labile organic matter, is more suitable for biological treatment. Plastic waste is suitable for the gasification and pyrolysis process due to its high calorific value and combustibility. The paper waste is suitable for the pyrolysis process due to the presence of hemicellulose and cellulose.