Catalysis Today, Vol.291, 133-145, 2017
Synthesis of C5+ hydrocarbons from low H-2/CO ratio syngas over silica supported bimetallic Fe-Co catalyst
In the present study, selective synthesis of C5+ hydrocarbons from a low hydrogen to carbon mono oxide ratio syngas has been studied over a novel Fe-Co bimetallic catalysts. Fe was added into Co catalyst to increase the H-2/CO ratio internally via increased water gas shift activity. Catalyst with varying Fe/Co composition (Fe/Co(w/w)=0.25,0.5,1) and varying metal loadings were prepared in the laboratory. Catalysts activity were tested in a fixed bed reactor at T-220 degrees C, P-20 bar, H-2/CO-1.48 and GHSV-1200 mL/h-g(cat). Detail characterization of the catalysts were done through different techniques. Quantitative and qualitative analysis of the liquid products were done using GCMS and CHNS analyzers, The presence of Fe in bimetallic catalyst resulted an increase in CO conversion and product selectivity in comparison to that of mono metallic Fe/Co catalysts. Formation of Fe-Co bimetallic phase was confirmed through the detail characterization of fresh and spent catalysts which facilitate the CO adsorption on active metal sites. However, phases for individual iron and cobalt were also evident at higher metal loadings. The CO conversion increases with metal loading and was maximum at 30% metal loading. Optimum ratio of Fe/Co was 0.5 at a total metal loading of 30% (Cat-2) in which maximum (65%) CO conversion was achieved. Enhancement of H-2/CO ratio through WGS reaction was examined over Cat-2 at various temperature and inlet H-2/CO ratio. At 240 degrees C, C5+ selectivity was maximum at the expense of CO2 and methane production. (C) 2016 Elsevier B.V. All rights reserved.