Thermodynamic simulation of the co-gasification of biomass and plastic waste for hydrogen-rich syngas production

Abstract

Co-gasification of biomass and plastics is a waste-to-energy conversion that reduces waste volume and enhances product quality, thus improving overall process efficiency. Thermodynamic equilibrium simulation of biomass co-gasification with plastic is studied using HSC Chemistry Software. Properties of effluent products are evaluated as product gas yields, higher heating value and carbon conversion efficiency to gas. Among different plastics tested, polypropylene is the most beneficial. Increasing plastic-to-biomass ratio, up to 5, improves hydrogen and CO yields and increases the HHV of the gas from 21 to 25 MJ/kg. Using CO2 as gasifying agent lowers H2 quantity due to reverse water gas shift reaction and reduces HHV. Air gasification decreases the HHV, compared to oxygen, due to N2 dilution effect. Steam is the highly efficient gasifying agent, and steam-to-carbon ratio of unity is a good compromise for high gas yield and heating value. Finally, thermodynamic data are validated with published experimental work.

Keywords

• Co-gasification
• Hydrogen
• Biomass
• Plastic
• Thermodynamic simulation
• HSC Chemistry Software