Chemical Looping Reforming: Impact on the Performances Due to Carbon Fouling on Catalyst

The paper presents a numerical analysis of an autothermal chemical looping reforming (CLR)process for hydrogen production. A packed–bed reactor has been simulated, which uses a Nibasedoxygen carrier. A one-dimensional pseudo-homogeneous model, validated with dataavailable in literature is used to describe the overall process. The model accounts for thedifferent reactions taking place (methane and hydrogen oxidation, steam reforming, dryreforming, Ni and carbon oxidation by air), and simultaneously describes heat and masstransport. To take into account the catalyst fouling due to carbon deposition, CH4decomposition and carbon regasification by steam and CO2 (Boudouard reaction) have beenconsidered in the kinetic model, and a catalyst deactivation function has been introduced. Bymeans of numerical simulations we highlight that carbon deposition gradually blocks catalystactive sites, leading to a progressive loss of catalytic activity. and we quantify the effects ofcatalyst poisoning on process performances.