(216d) Parametric Sensitivity and Runaway in Fixed-Bed Reactors: Example of Methanol Selective Oxidation over Pt-Bi Catalysts

Exothermic reactions are important in various fields, such as petroleum refining and chemical industries. When conducted in fixed-bed reactors, thermal runaway may occur under certain conditions, which should be avoided. Bimetallic catalysts, typically containing a noble metal and a non-noble metal promoter, are widely used in exothermic reactions e.g. alcohol selective oxidation, CO oxidation to CO 2 in H 2 -rich gas. Following our prior study on methanol low-temperature oxidation over Pt-Bi bimetallic catalysts, investigations for parametric sensitivity of reactor thermal behavior were performed in the present work. Experimental measurements and modeling for reaction kinetics, temperature profiles and selectivity to target products were conducted and compared. It was found that values from kinetic modeling match experimental data well, and the onset of thermal runaway behavior in the reactor is always correctly predicted using the developed model. The generalized sensitivity criterion was utilized to predict critical values of feed temperature and oxygen pressure for runaway, which are also consistent with experimental measurements. For bimetallic catalysts used in alcohol selective oxidation, to achieve high selectivity towards target product and stable thermal performance of reactor, it was found that promoter addition amount should be carefully controlled. We believe that the present study will benefit both scientific advances and industry in terms of catalyst design and safe reactor operation for exothermic reactions carried out in fixed-bed reactors.