(583dt) Effects of SiO2 and Al2O3 Support, Different Operating Parameters On Performance of Fe-Cu-K Catalyst: Detailed Product and Carbon Number Distribution During FT-Synthesis

Fe-Cu-K catalysts were analyzed to investigate the influence of SiO₂ and Al₂O₃ supports on its performance, detailed product distribution and carbon number distribution during CO hydrogenation process. Different Cu promoted Fe catalysts were prepared by co-precipitation technique using SiO₂ and Al₂O₃ as support, followed by adding K promoter by wet impregnation technique. Both of the catalysts were characterized by ICP, N₂ physical adsorption, pulse chemisorptions, H₂ temperature-programmed reduction (TPR), NH₃ temperature-programmed desorption (TPD), XRD and SEM for analysis of metal components, textural properties, metal dispersion, reduction behavior, acidity, structural characteristics and surface morphology of the catalysts. The catalysts were tested in a fixed bed reactor at 245 ⁰C and 15 bar pressure, with a H₂/CO molar feed ratio of 2. Although after 130 h of run time the activity of the SiO₂ supported catalyst was found to be higher than Al₂O₃ supported catalyst. SiO₂ supported catalyst had higher gaseous hydrocarbon and lower olefin selectivity than the Al₂O₃ supported catalyst. Liquid product distribution shows a distinct shift to lighter molecular weight hydrocarbons with Al₂O₃ supported catalyst contrast with SiO₂ supported catalyst. However, SiO₂ supported catalyst has shown more percentage of higher molecular weight liquid hydrocarbons than Al₂O₃ supported catalyst. The chain growth probability for liquid hydrocarbon for SiO₂ supported catalyst is higher than Al₂O₃ supported catalyst.  Branched hydrocarbons, olefins and the aromatics content in liquid products are appreciably more in the presence of Al₂O₃. Furthermore five different Fe-Cu/SiO₂ catalysts were prepared by same techniques as mentioned already. The effect of addition of potassium promoter was studied for CO-Hydrogenation in a fixed bed reactor simultaneously with the effect of promoter on the CO-conversion, selectivity and deactivation. The maximum catalytic activity was obtained from 1% K-loading and the catalytic activity decreased thereafter. Different operating conditions were analyzed for 1% K-loading catalyst to determine the rate w.r.t temperature ranging from 215 -245 ^oC, pressure from 5-25 bar, H₂/CO molar ratio from 0.7-3.0 and GHSV from 1000-4000 CC/g.cat/h. Further the physiochemical characterization of these catalysts was performed by using N₂ adsorption, X-ray diffraction (XRD), H₂-TPR, NH₃-TPD, TEM, Inductive Couple Plasma Mass Spectroscopy (ICP-MS), and SEM-EDX to study the effect of potassium on the textural properties, structural change, reduction behavior, acidity and morphological change to the above K-loading catalysts.