Effect of reduction and reaction conditions on the catalytic performance of Co-Ni/Al2O3 catalyst in CO hydrogenation: modeling of surface reaction rate

The effect of reduction and reaction conditions on catalytic performance and surface reaction rate of Fischer-Tropsch synthesis over Co-Ni/Al2O3 catalyst was studied in a stainless steel fixed-bed micro-reactor. Experiments were done over a collection of different reduction and reaction conditions, including reduction temperature (250-450 degrees C), reduction time (2-10 h), reducing agent (H-2, CO and mixing of H-2 and CO), reaction temperature (150-240 degrees C), H-2/CO (1-4) and reaction pressure (1-5 bar). In particular, the modeling of the effect of reduction and reaction conditions on the CO consumption rate was studied by response surface methodology. The surface reaction rates are important in scale-up of a FT reactor, industrial design, and simulation. The accuracy of created models was proved by ANOVA and diagnostic plots. According to the obtained quadratic polynomial equations, the order of parameters influence on CO consumption rate response was argued. Regard to results obtained, the main effective reduction and reaction parameters on CO consumption rate were reducing agent and reaction pressure, respectively. Furthermore, the precursor and catalysts before and after the test were characterized by XRD and SEM.