Fischer-Tropsch synthesis over the Co-Ni/Al2O3 nanocatalyst: influence of process variables, modeling and optimization using response surface methodology

BACKGROUND: Light olefins production greatly influenced by the process conditions. In the present work Al2O3 supported Co-Ni nanocatalysts were evaluated for production of light olefins. Incipient wetness impregnation procedure was used for catalyst synthesis. Catalysts were characterized for determining the physicochemical properties using various techniques of XRD, SEM, EDS, H-2-TPR, TPD, TEM, XPS, TGA, DSC, FT-IR, and BET. The influence of process conditions (Pressure, Temperature and H-2/CO inlet feed molar ratio) was investigated on the catalytic performance of Co-Ni/gamma Al2O3 nanocatalyst toward lower olefins. Temperature, pressure, and feed ratio factors were changed in wide ranges of 250-450 degrees C, 1-12 bar, and 1-4 respectively. The Response Surface Methodology (RSM) method was employed for modeling and optimization.RESULTS: The optimum process conditions were obtained using the RSM method (T = 383 degrees C, P = 4 bar, and H-2/CO = 1.92). The highest selectivity of light olefinic products and conversion of carbon monoxide and the lowest selectivity toward methane were obtained concurrently under the optimized conditions with desirability of 0.896.CONCLUSION: The impact of inlet feed ratio, temperature, and pressure factors was investigated and it was found that the performance of the catalyst greatly depends on the operational parameters. (c) 2023 Society of Chemical Industry.

Automated summary

This study evaluated Al2O3 supported Co-Ni nanocatalysts for the production of light olefins under different process conditions. Various techniques were used to characterize the catalysts and the impact of temperature, pressure, and feed ratio on the catalytic performance was investigated. The optimum process conditions were obtained using the Response Surface Methodology with the highest selectivity of light olefins achieved at a desirability value of 0.896.