Investigation of Catalytic Performance for the Fischer−Tropsch Synthesis over the Cobalt Catalysts Supported on γ‑Al۲O۳ Granules: Significant Improvement

A series of supported alumina were synthesized using two methods of sol-gel and oil-drop. In this work, the process of γ-Alumina, γ-alumina + Glucose supported granules and the simultaneous effects of Glucose surfactant and the promoter (cerium and boron) on catalytic activity for the Fischer-Tropsch Synthesis (FTS) were studied. The prepared cobalt catalysts are using the incipient wetness impregnation method on γ-alumina granules for FTS in a fixed-bed reactor. All conditions of the FTS operation were carried out at T=۵۰۳K, P=۱۵ bar, H۲/CO = ۲ with the space velocity of ۵.۱ NL·g−۱ ·h−۱. The obtained results clearly showed that the catalytic evaluation of the Co catalysts supported on γ-alumina, with respect to the activity and selectivity of C۵+ products were increased by the addition of cerium and boron promoters in FTS. Also, the Co catalysts supported with γ-alumina Glucose surfactant were more active than the Co catalysts supported with γ-alumina. Furthermore, the morphologies of the γ-alumina supported granules were changed by surfactant and promoters and the presence of CeO۲ on the surface of the supports favors the reducibility of cobalt oxide with a shift down in reduction temperature of about ۶۰ ˚C. Meanwhile, the addition of Glucose surfactant and cerium promoter remarkably influenced the improvement of activity, selectivity and stability of the catalyst as well. Ce promoter reduced the methane selectivity by increasing the chain-growth probability (α-value).

Keywords:

sol-gel , Cerium and Boron promoters , surfactant Glucose , γ-alumina granules , Cobalt catalyst , Fischer -Tropsch synthesis