A thermodynamic analysis of solid waste gasification in the Plasma Gasification Melting process

Highlight
• A thermodynamic analysis was conducted to evaluate the characteristics of the PGM.
• Energy recovery using gas furnaces is suggested due to high total energy and exergy.
• Gas turbines are not recommended due to high tar yield.
• Increasing heat to the PGM is beneficial for cold gas energy and exergy efficiencies.
• A small steam addition is beneficial for PGM energy and exergy efficiencies.

Plasma Gasification Melting is a promising technology for solid waste treatment. In this work, a thermodynamic analysis has been conducted to evaluate the advantages and limitations of the PGM technology. According to the characteristics of the PGM, the whole process was divided into four sections such as drying, pyrolysis, char gasification and inorganics melting. The energy and exergy in each section has been calculated. According to different usage of syngas, two kinds of energy and exergy efficiencies are defined. The results show that the PGM process produces a tar-rich syngas. When considering the raw syngas (syngas with tar), the energy and exergy efficiency of PGM process is very high. The effects of operating conditions on the thermodynamic performance of the PGM process have been analyzed. Considering the energy and exergy of clean syngas, it is beneficial to increase sensible heat input to the PGM system. However, high sensible heat input or high steam injection is not suggested when considering the energy and exergy efficiency of raw syngas.