Parametric studies over a plasma co-gasification process of biomass and coal through a restricted model in Aspen plus

Abstract

Plasma gasification is considered an emerging technology within the so-called waste-to-energy technologies. The pure equilibrium models have been failing to estimate the amounts of the syngas components, especially the methane quantity. In this investigation, a restricted or quasi-equilibrium model was developed in Aspen Plus® to evaluate the performance of the plasma co-gasification process of biomass and coal. The developed model was validated against literature data. A comprehensive parametric study was performed considering the variation of the equivalence ratio, biomass ratio, temperature, and steam to feedstock ratio on the quality of syngas and hydrogen production. Three gasifying agents (air, steam, and oxygen) were used. The syngas lower heating value and the cold gas efficiency are taken as a measure of the syngas quality and process efficiency. The developed restricted model shows to estimate the amount of methane much closer to the experimental data than pure equilibrium models. The highest amount of hydrogen was obtained for steam followed by pure oxygen and lastly for the air as gasifying agents. The use of coal in the feedstock mixture allows obtaining higher LHV of the syngas and CGE of the process. The results of this parametric study represent a humble contribution to the increase of plasma gasification technology market penetration.