Dataset on the Methanation Performance of Simulated Biomass Gasification Gas over Alkali-Modified Ni/Al₂O₃ Catalysts

The present study aims to investigate the effects of alkali modification on the performance of Ni/Al2O3 catalysts in the methanation of simulated biomass gasification gas. The dataset records the preparation parameters, physicochemical characterization results (including BET, XRD, H2-TPR, CO2-TPD, etc.), and catalytic performance data of catalysts with different modification times.BET characterization was performed using a nitrogen physisorption analyzer to determine the textural properties and pore structure of the catalysts. The instrument model used was V-Sorb 2800. Prior to the measurement, the catalyst samples were pretreated under vacuum at 300 °C for 3 hours. The specific surface area was calculated based on the BET equation, and the pore size distribution curve was obtained using the BJH theory.TEM characterization was performed using a TF20 transmission electron microscope to analyze the dispersion of active components and particle size distribution of the catalysts. The catalyst sample was carefully ground and uniformly dispersed in anhydrous ethanol. The suspension was then treated in an ultrasonic bath for 20 minutes. A droplet of the resulting suspension was deposited onto a copper grid and dried under an infrared lamp prior to observation.H₂-TPR (Hydrogen Temperature-Programmed Reduction) characterization was carried out to analyze the reduction behavior of the catalysts. The measurement was performed using a Micromeritics AutoChem II 2920 chemisorption analyzer. Specifically, 120 mg of catalyst powder was placed in a quartz tube and pretreated under a He atmosphere at 200 °C for 90 minutes. After cooling to 50 °C, a 10% H₂/He mixture gas was introduced at a flow rate of 30 mL/min. The temperature was then raised from ambient to 900 °C at a ramp rate of 10 °C/min. The hydrogen consumption during the reduction process was monitored by a thermal conductivity detector (TCD).CO₂-TPD (Carbon Dioxide Temperature-Programmed Desorption) characterization was conducted using an AutoChem II 2920 chemisorption analyzer. Specifically, 120 mg of the catalyst sample was loaded into a U-shaped quartz tube. The sample was first pretreated by heating from room temperature to 300 °C at a ramp rate of 10 °C/min under flowing helium (He). It was then purged with a He flow of 30 mL/min for 2 hours. After cooling to 50 °C, the sample was exposed to a 10% CO₂/He mixture at a flow rate of 50 mL/min until saturation adsorption was achieved. Subsequently, the gas was switched back to He at 30 mL/min for 1 hour to remove weakly physically adsorbed CO₂. Finally, the temperature was increased to 700 °C at a heating rate of 10 °C/min under He atmosphere, and the desorbed gases were monitored using a thermal conductivity detector (TCD).XRD characterization was performed using a Shimadzu X-ray diffractometer (Model: XRD-7000S) to analyze the phase composition of the catalysts. The measurement was carried out under the following conditions: Cu Kα radiation source, operating voltage of 40 kV, current of 40 mA, a 2θ scanning range from 5° to 90°, and a scanning speed of 5°/min.TG (Thermogravimetric) analysis was performed using a QMA200M thermogravimetric analyzer. During the measurement, the catalyst was heated in an O₂ atmosphere with a gas flow rate of 10 mL/min. The temperature was increased from ambient to 900 °C at a heating rate of 10 °C/min, and the weight loss curve of the catalyst was recorded.The catalytic performance data were obtained in a fixed-bed reactor under the following conditions: a reaction temperature of 400 °C, H₂/CO volume ratio of 3:1, and a space velocity of 10,000 mL/(g·h). Key metrics include CO conversion, CH₄ selectivity, and stability data over a 300-minute period.