Anthracite-based activated carbon supported Ni metal element as a catalyst for carbon dioxide reforming of methane to hydrogen

Anthracite has become one of the good raw materials for the synthesis of activated carbon because of its low ash content and high fixed carbon. In this study, the effects of alkali-carbon ratio, carbonization temperature, activation temperature, and impregnation time on the properties of anthracite-based activated carbon were studied by a four-factor three-level response surface method. The iodine value and methylene blue value were used as response values and the satisfaction function was used to optimize and verify the two response values. The results show that the optimum process parameters of anthracite-based activated carbon are as follows: the ratio of alkali to carbon is 2: 1, the carbonization temperature is 700 °C, the activation temperature is 867 °C, and the impregnation time is 18.15 h. Under these conditions, the iodine value and methylene blue value of anthracite-based activated carbon reach 1232.70 mg/g and 382.49 mg/g, respectively. Three verification experiments were carried out on the optimal process. The average values of iodine value and methylene blue value of activated carbon were 1271.65 mg/g and 380.78 mg/g, respectively. The error between the measured value and the predicted value was 3.16 % and 0.44 %, respectively. The actual value of overall satisfaction (0.998) is consistent with the predicted value. At the same time, the metal-modified carbon-based catalyst was prepared by ultrasonic impregnation method. It was found that its catalytic activity was stable in CO2 and CH4 reforming reactions. When the metal nickel loading was 6 %, the conversion of CO2 and CH4 reached 91.36 % and 93.35 % respectively at 900 °C. This lays a solid foundation for the further design of the preparation of carbon molecular sieve catalysts and the promotion of the utilization of renewable energy such as biomass energy, and also provides a theoretical reference for the industrial preparation of anthracite-based activated carbon.