Microwave induced plasma for solid fuels and waste processing: A review on affecting factors and performance criteria

• Published in: Waste management (Elmsford) 2017-11, Vol.69, p.423-430
• Main Authors: Ho, Guan Sem, Faizal, Hasan Mohd, Ani, Farid Nasir
• Format: Article
• Language: English
• Subjects: Gasification; Hydrogen; Microwave plasma; Microwaves; Plasma Gases; Refuse Disposal - methods; Solid fuels; Solid waste; Syngas
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2017.08.015

•Researches on microwave-induced plasma gasification of fuel and waste are reviewed.•General setup of microwave-induced plasma gasification is reviewed.•Performance data for various operating parameters are compared and discussed.•Significant effects of various operating factors on fuel retention time are discussed.•An overview for further improvement in design of operation condition is provided. High temperature thermal plasma has a major drawback which consumes high energy. Therefore, non-thermal plasma which uses comparatively lower energy, for instance, microwave plasma is more attractive to be applied in gasification process. Microwave-induced plasma gasification also carries the advantages in terms of simplicity, compactness, lightweight, uniform heating and the ability to operate under atmospheric pressure that gains attention from researchers. The present paper synthesizes the current knowledge available for microwave plasma gasification on solid fuels and waste, specifically on affecting parameters and their performance. The review starts with a brief outline on microwave plasma setup in general, and followed by the effect of various operating parameters on resulting output. Operating parameters including fuel characteristics, fuel injection position, microwave power, addition of steam, oxygen/fuel ratio and plasma working gas flow rate are discussed along with several performance criteria such as resulting syngas composition, efficiency, carbon conversion, and hydrogen production rate. Based on the present review, fuel retention time is found to be the key parameter that influences the gasification performance. Therefore, emphasis on retention time is necessary in order to improve the performance of microwave plasma gasification of solid fuels and wastes.