Preparation of nickel-loaded on lignite char for catalytic gasification of biomass

• Preparation and characterization of a novel Ni/char catalyst via ion-exchange
• NCS and SSA of the Ni/SLC depended on pH and carbonization temperature.
• Catalytic reforming of volatiles from corncob pyrolysis under Ni/SLC
• Ni/SLC is active for corncob tar decomposition at 650 °C under inert atmosphere.
• The increase in NCS above 650 °C causes the deactivation of Ni/SLC.

A novel catalyst was prepared by loading nickel on Shenli lignite char via ion-exchange. The results show that the nickel crystallite size (NCS) and specific surface area (SSA) of the catalyst significantly depended on solution pH and carbonization temperature. The catalyst prepared in pH 11 at 650 °C reached the maximum SSA of 236.3 m2/g and the nickel particles dispersed quite well in the catalyst with a NCS of 5.6 nm. The catalyst was used for corncob volatiles reforming in a two-stage fixed-bed reactor to study the effects of temperature, steam, and space velocity on gas yields and carbon distributions. It effectively improved tar decomposition at 650 °C under inert atmosphere and produced a tar-free syngas in a yield of 43.9 mmol/g, which is higher than that over a commercial Ni/Al2O3. The increase of the NCS during catalytic reforming above 650 °C leads to the catalyst deactivation for tar decomposition. The study revealed the possibility of using Ni/char as a potential catalyst for low-temperature gasification of biomass.