Gas and tar generation behavior during flash pyrolysis of wood pellet and plastic

Abstract

Fluidized bed gasifiers (FBGs) and gas engines (GEs) could be available as waste-to-energy technology, because most small- and medium-scale municipal solid waste treatment plants have low electricity generation efficiencies. As feedstock composition vary widely based on regional characteristics, clarifying the relationship between gas and tar generation behaviors and feedstock is useful for the design of the GE generation process to predict gas and tar yields and compositions. To understand the synergistic effect of feedstock characteristics in fluidized bed gasification, flash pyrolysis of wood pellet, polyethylene, and polypropylene at 900 °C was conducted. Yields and compositions of gasses and tar from single and co-pyrolysis were investigated. The results reveal that co-pyrolysis increases the gas yield because of oxygenates and moisture present in the wood pellet. Tar yields found to decrease while polycyclic aromatic hydrocarbons (PAHs) are not reduced even during co-pyrolysis. That is because most chain hydrocarbons of tar are converted to CmHn gases and PAHs.