Gasification char as a functional reactor material for tar reforming and hydrogen‐enriched syngas production

Abstract

Abstract Biomass gasification produces raw syngas containing tar and light hydrocarbons, which reduce carbon‐conversion efficiency and increase the complexity of downstream cleaning and utilization. This study investigates gasification char as an in situ reforming medium for primary syngas upgrading under realistic high‐temperature conditions (800–1000°C), with a comparison among an empty reformer, a fixed bed containing alumina and char, and dilute transported‐char injection. Gravimetrically measured tar reduction increased by approximately 30–40% relative to thermal reforming alone under the tested conditions, with the strongest tar removal observed in the upper part of the investigated temperature range. First‐order kinetic analysis gave apparent activation energies of 113 and 98 kJ mol −1 from laminar‐flow and plug‐flow interpretations, respectively, confirming the strong temperature dependence of tar reforming. In the fixed‐bed configuration, methane conversion approached about 30% near 925°C, whereas dilute transported‐char injection did not produce a comparable hydrocarbon‐conversion effect. In addition, transported‐char experiments showed increased CO 2 formation and a rise in outlet H 2 /CO ratio from about 1.48 to 2.08 across the investigated char‐concentration range, indicating a stronger water–gas shift‐related response. These results show that gasification char can function as a useful reactor material for tar reforming and syngas upgrading rather than merely as a residual solid.