Gasification and pyrolysis of waste

Nowadays, the disposal of waste is being transformed from simple landfilling into multiple methods of recycling, reusing, and recovering. Among these methods, thermochemical treatment methods, principally combustion, gasification, and pyrolysis, are prominent for their superiorities of efficiently recovering energy, remarkably decreasing pollution, and effectively reducing weight and volume of waste. Gasification and pyrolysis, in particular, can obtain high yields of energy-dense products like syngas, bio-oil, and biochar and thus are attaching more and more attention. The gasification and pyrolysis of waste have long been investigated by researchers, and now, they are standing on the edge of commercialization. In this chapter, the state of the art of gasification and pyrolysis processes is reviewed. For the gasification technique, the energy efficiency of the system and the handling of tar both remain challenging. Thus, the comprehensive tar removal technique and application of product gases are summarized while new trends are presented. Regarding pyrolysis, special attention is given to recent progress in producing high-quality products, new pyrolysis technologies, commercialized pyrolysis plants, and utilization of pyrolytic products.