Effect of Relative Bed Lengths on a Platinum/Nickel Stratified Dual Bed Catalyst for the Catalytic Partial Oxidation of Methane at Millisecond Contact Times

Abstract

Stratified, dual bed catalysts composed of platinum followed by nickel have shown reactant conversions and product selectivities similar to rhodium, which has shown the highest activity for the millisecond catalytic partial oxidation reaction. The goal of the stratified catalyst is to carry out the catalytic partial oxidation in a two-step process: combustion catalyzed by platinum followed by steam and carbon dioxide reforming catalyzed by nickel. Previous studies have shown that sequential platinum and nickel beds with the same space velocity have high activity and long-term stability. In this work, the relative bed length of the platinum and nickel catalysts is investigated. Since combustion occurs much faster than reforming, the platinum bed can be much shorter than the nickel bed. Experiments show that the relative bed length of platinum can be much smaller than that of nickel in the dual bed catalyst. Reducing the amount of platinum increases the methane conversion and hydrogen selectivity while reducing the carbon monoxide selectivity. Degradation studies under harsh operating conditions show that the catalyst is stable. The number of potential experiments required to optimize this system leads one to believe a simulation-based approach will be more efficient.

Stable Rh particles in hydrotalcite-derived catalysts coated on FeCrAlloy foams by electrosynthesis

“…Indeed, noble metals, mainly Pt [12,15] and Rh [16,30], are usually the active species; although the use of bimetallic noble metal-nickel or cobalt catalysts [31] and stratified beds [32] are also reported. The amount of active species, which modifies the thermal profile [8,16,26], may be controlled by pore size [33], layer thickness [34] , and metal loading [30].…”

Short contact time catalytic partial oxidation of biogas – A comprehensive study on CO2 and N2 dilution

“…Each point on a plot represents the average of three separate experimental runs. Under similar analysis conditions, Bell and Leclerc [15] found that the uncertainty in the methane conversion and carbon selectivities was 0.5%, while the uncertainty in the hydrogen selectivities was 2%.…”

Support Effects on the Oxidative Dehydrogenation of Ethane to Ethylene over Platinum Catalysts

“…Optimization should boost the yield of the silicasupported catalyst over that of ethylene. Bell et al 15 have shown that for a similar reactor system analyzed by gas chromatography, conversions and selectivities have an uncertainty of only 0.5%. The small changes in reactor performance as measured by gas chromatography in these experiments are in fact statistically significant.…”