Hydrogen production from catalytic steam reforming of benzene as tar model compound of biomass gasification

Tar reduction is an important issue for the development of biomass gasification process. In this work, a NiO/ceramic foam catalyst was developed and studied for catalytic steam reforming of tar model compound (benzene) using a fixed-bed reactor. Different reaction temperatures, equivalent ratios (ER), and steam/carbon (S/C) molar ratios were investigated with a space velocity of 5.6 h^-1. The introduction of the NiO/ceramic foam catalyst showed excellent production of hydrogen and carbon conversion. With the increase of reaction temperature from 700 to 900 °C, the yield of hydrogen increased from 140.67 to 182.06 (g H₂ kg^-1 benzene). The increase of ER resulted in the decrease of the H₂ yield. A stability test (including regeneration of reacted catalyst) showed that the catalyst was deactivated by the deposition of carbons (confirmed from scanning electron microscopy), which could be removed using air oxidation at 750 °C. The catalytic activity of the catalyst in relation to the hydrogen production could be regained after the regeneration process. A kinetic model study of the process showed that the apparent activation energy and the pre-exponential factor were 73.38 kJ/mol and 1.18 × 10⁵ (m³ kg^-1_catalysth^-1), respectively.