Light olefin production on the Co–Ni catalyst: calcination conditions, and modeling and optimization of the process conditions by a statistical method

Abstract

The present work is comprised of two main parts. In part 1 the Co–Ni/γ-Al₂O₃ catalyst was prepared using a sol–gel procedure. Then the effect of calcination variables including the calcination temperature and time on the catalytic performance for production of light olefins was investigated and optimized. The obtained results have shown that the catalyst which was calcined at 550 °C for 6 h has revealed the better catalytic performance for production of light olefins. In part 2 the effect of process conditions including the reaction temperature, H₂/CO feed ratio and total reaction pressure on the catalytic performance (CO conversion%, (C₂–C₄) selectivity% and C₅⁺ selectivity%) was investigated. Experiments were performed under a wide range of operational conditions including a reaction temperature of 473–673 K, pressure of 1–10 bar and H₂/CO ratio of 1–4. The optimization and modeling were performed using response surface methodology (RSM). For each response a quadratic polynomial was successfully fitted to the experimental data. In this study, the models, the impressive parameters of the models and the parameter interaction were investigated. The physicochemical properties of the catalysts were investigated using XRD, BET, SEM, TGA, DSC, TPR, TPD and VSM.