Steam reforming of toluene over Ni–Co/modified-activated carbon catalyst for hydrogen production: Thermodynamic and experimental analysis

Abstract

An integrated thermodynamic and experimental analysis of steam reforming of toluene (SRT) over Ni–Co/modified-palm kernel shell activated carbon (AC) catalysts for H2 production has been investigated. The catalyst samples, synthesized with different AC support modifications methods (i.e., HNO3 reflux and H2O2 aging) and impregnation, are characterized by BET, TGA, FESEM-EDX, TEM, XRD, H2-chemisorption and TPO spectroscopies. Aspen Plus® simulation software is employed to perform the thermodynamic analysis to investigate the effect of wide range of operating parameters such as temperature (373–1473 K), pressure (1–30 atm) and steam-to-carbon (S/C) molar ratio (1–9) on product distribution using Gibbs free energy minimization. Optimum conditions of SRT with 86.4% H2 yield and complete toluene conversion are attained at 973 K, S/C ratio of 5 and atmospheric pressure. Next, the catalytic performance of Ni–Co/modified-AC for enhancing SRT to H2 is conducted in a fixed-bed reactor at selected conditions. It is revealed that Ni–Co/ACP catalyst confers 82.0% and 91.7% of H2 yield and toluene conversion, respectively. The results of thermodynamic simulation and experimental testing strongly corroborate the role of Ni–Co/ACP as a high-performance catalyst to enhance catalytic conversion of SRT.