Optimizing the catalytic performance of Ni-Ce/HZSM-5 catalyst for enriched C₆-C₈ hydrocarbons in pyrolysis oil via response surface methodology

A response surface methodology (RSM) was used to optimize the C-6-C-8 hydrocarbons in pyrolysis oil from catalytic upgrading of biomass-derived oxygenated pyrolysis vapour over the Ni-Ce/HZSM-5 catalyst via Box-Behnken design. The effect of operating factors such as pyrolysis reaction temperature, catalyst to biomass mass ratio, and nickel to cerium mass ratio on HZSM-5 was employed via in situ fixed bed reactor. The ANOVA results showed that the operating factors significantly affect the total contents of C-6-C-8 hydrocarbons in pyrolysis oil. The optimal conditions of factors within this study for the maximum contents of C-6-C-8 hydrocarbons in pyrolysis oil is attainable at a pyrolysis reaction temperature of 505 degrees C, catalyst to biomass mass ratio of 1.1:1.0, and nickel to cerium mass ratio of 3.14:2.86. The confirmation runs gave 8.83% and 8.86% of C-6-C-8 hydrocarbon contents (%) in pyrolysis oil compared with 8.90% of predicted value. The developed quadratic mathematical model is significant due to the P value < 0.05. In addition, all three factors individually influence the upgrading of oxygenated compounds into C-6-C-8 hydrocarbons due to P value < 0.05. The pyrolysis reaction temperature had the strongest effect on the content of C-6-C-8 hydrocarbons in pyrolysis oil due to higher F value than other factors.