Plasma gasification of municipal solid waste with variable content of plastic solid waste for enhanced energy recovery

Abstract

In this work thermochemical investigation of plasma gasification of municipal solid waste (MSW) at variable plastic solid waste (PSW) content is conducted. To assess the performance of this thermochemical conversion route, various waste mixtures were used as a feedstock in an Integrated Plasma Gasification Combined Cycle (IPGCC). The IPGCC plant model is built within Aspen Plus environment. Furthermore, the impacts of different plasma gas composition were investigated using air as the main gas while using oxygen or steamas partial substitute. The most important performance metrics were calculated, showing that when pure air is used as plasma gas, the gasification of MSW without addition of further PSW showed better overall performance. However, as the oxygen steam ratio in the plasma gas is increased, a consistent improvement can be seen by increasing the PSW fraction in the waste mixture up to an optimal value. The best achieved plant performance was 38% when pure oxygen (ω=1) is used as plasma gas and for 0.7MSW:0.3PSW feedstock mixture. A slightly different trend is seen with the increase of steam ratio as the performance reach a maximum corresponding to a specific fraction of MSW-PSW mixture. The maximum plant efficiency was 21.7% and is reached at 34% steam ratio (σ) in the plasma gas when the feedstock is made of equal MSW to PSW mixture fractions.