Kinetics of Steam Gasification of Glucose as a Biomass Surrogate over Ni/Ce–Mesoporous Al₂O₃ in a Fluidized Bed Reactor

Abstract

This study reports the kinetics of steam gasification of glucose as a biomass surrogate over a new Ni(x)/Ce-doped Al 2 O 3 (x = 5, 10, 15, and 20 wt %) catalyst in a fluidized bed reactor. The presence of ceria plus successive nickel impregnation helped in conserving the catalyst's high surface area (i.e., 102 m 2 /g at 20 wt % nickel loading). Incorporation of ceria dopant suppressed coke formation during steam gasification of 15 wt % glucose in the fluidized bed reactor at 650 °C and 1 atm in the order Ni(20) < Ni(15) < Ni(10) < Ni(5)/Ce-doped Al 2 O 3 . The detailed kinetic model comprises reactant adsorption, surface reaction, and product desorption steps, involving the water gas shift reaction (WGS), steam reforming of methane (SRM), and reverse dry reforming of methane (RDRM). Ni(20)/Ce-doped Al 2 O 3 with the best performance in terms of syngas production, and the least tendency for coking, was used for the kinetic studies (for T = 550− 700 °C and t = 5−25 s). The results of the model simulation indicate that the rate of water gas shift was the highest (7.76 × 10 −2 mmol/g of cat.•s•bar 2 ) followed by steam reforming of methane (4.13 × 10 −2 mmol/g of cat.•s•bar 2 ) and then reverse dry reforming of methane (3.57 × 10 −2 mmol/g of cat.•s•bar 2 ). The high reaction rates signify the suitability of the new Ni(x)/Ce− mesoporous Al 2 O 3 catalytic system applied in this work. The modeling procedure could be applied conveniently for a different catalytic system in a similar reactor to obtain the necessary kinetic parameters.

Kinetics of Oxidative Cracking of n‐Hexane to Light Olefins using Lattice Oxygen of a VOx/SrO‐γAl2O3 Catalyst

“…The oxidative cracking of n‐hexane experiments were performed under a gas‐phase free oxygen environment using the lattice oxygen of VO x /SrO‐Al 2 O 3 in a CREC (Chemical Reactor Engineering Center) Riser Simulator. The CREC Riser Simulator is a well‐mixed bench‐scale batch reactor with a total volume of 53 cm 3 [31] . The full operational procedures of this reactor are reported elsewhere [32] …”

Oxidative Dehydrogenation of Propane to Propylene over VOx on Mixed θ-Al2O3/Alkaline Earth Metal Oxide Supports

“…The ODH catalytic activity of the V, VM, VC, and VB catalyst systems was evaluated using a fluidized CREC Riser Simulator. ,, Detailed information on the fluidized bed CREC reactor has been reported in our previous reports . Succinctly, the fluidized bed reactor (capacity of 53 mL) is a batch unit that mimics the fluidized bed reactor operation condition.…”

Conversion of Biomass-Derived Tars in a Fluidized Catalytic Post-Gasification Process

“…While tar reforming in the CREC Riser Simulator under steam and CO 2 was already shown by others [29,33,50,51], these authors did not address the important issue of the performance of these catalysts under syngas compositions as observed at the outlet of a gasifier unit. To address this important issue, the present study establishes, with the developed catalysts, the valuable basis of a tar post-gasification step, where both tar removal and a desirable H 2 /CO ratio are achieved, yielding a syngas with a H 2 /CO ratio larger than 2.…”