Hydrogen‐Rich Syngas Production by DC Thermal Plasma Steam Gasification from Biomass and Plastic Mixtures

Abstract Recently, thermal plasma gasification has attracted much attention due to hydrogen‐rich syngas production. In this research, wood sawdust and high density polyethylene (HDPE) mixtures have been investigated under plasma steam gasification with various HDPE contents (0–100%), at different input plasma powers (16–24 kW) and varying steam flow/carbon flow (S/C) ratios (0.2–1.8). The single‐factor analysis indicates that the real H₂ yield at 80 wt% HDPE is 23.99% higher than the theoretically calculated results. This significant improvement in hydrogen yield confirms the synergetic gasification effects between HDPE and biomass. The yield and proportion of H₂ show a climbing trend with the increase of input power, while showing a trend from rising to descending with the increase of S/C ratio. Under the optimal conditions (the HDPE ratio of 80%, the input power of 22 kW, the S/C ratio of 1.0), the H₂ yield is as high as 78.55 mol kg⁻¹ and the proportion of H₂ in syngas reaches 66.91%. Redundancy analysis shows that the HDPE content, input power and S/C ratio can explain 39.8%, 12.4%, and 10.6% of the variations of syngas properties respectively. The input power has the largest correlation with the increase of H₂ yield among these three factors.