Steam reforming of sulfur-containing dodecane on a Rh-Pt catalyst: Influence of process parameters on catalyst stability and coke structure

摘要

The present work offers a practical solution to the steam reforming (SR) of sulfur-containing liquid fuels, with dodecane as model compound for diesel fuel. The SR reaction is catalyzed by a Rh-Pt catalyst supported on a sulfur tolerant carrier (SiO2-ZrO2). The study highlights the influences of various process parameters such as steam to carbon (S/C) ratio, sulfur concentration, time on stream (TOS), and preemptive air regeneration on the catalytic performance and the nature of the deposited coke. Stable catalytic performance of sulfur-free dodecane was achieved with S/C ratio >1.8. Catalyst deactivation was accelerated by the addition of increased amount of sulfur from 29 to 74 ppm. The formation of graphitic carbonaceous species was observed on the spent catalyst for higher sulfur concentrations and/or longer TOS. Preemptive air regeneration allowed more sustained catalytic activity under less severe conditions than conventional air regeneration. Moreover, the frequency of air regeneration had a profound effect on the nature of the coke formed. The study provides a possible economic and energy efficient solution to the industrial production of H2 from sulfur-containing fuels.