Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

Renata Sadek,Jacek Rynkowski,Pawel Mierczynski,Jacek Gurgul,Stanislaw Dzwigaj,Karolina A Chalupka

doi:10.3390/catal9060497

Abstract

Co-containing Beta zeolite catalysts prepared by a wet impregnation and two-step postsynthesis method were investigated. The activity of the catalysts was examined in Fischer-Tropsch synthesis (FTS), performed at 30 atm and 260 °C. The physicochemical properties of all systems were investigated by means of X-ray diffraction (XRD), in situ XRD, temperature programmed desorption of ammonia (NH3-TPD), X-ray Photoelectron Spectroscopy (XPS), temperature programmed reduction of hydrogen (TPR-H2), and transmission electron microscopy (TEM). Among the studied catalysts, the best results were obtained for the samples prepared by a two-step postsynthesis method, which achieved CO conversion of about 74%, and selectivity to liquid products of about 86%. The distribution of liquid products for Red-Me-Co20Beta was more diversified than for Red-Mi-Co20Beta. It was observed that significant influence of the zeolite dealumination of mesoporous zeolite on the catalytic performance in FTS. In contrast, for microporous catalysts, the dealumination did not play such a significant role and the relatively high activity is observed for both not dealuminated and dealuminated catalysts. The main liquid products of FTS on both mesoporous and microporous catalysts were C10-C14 isoalkanes and n-alkanes. The iso-/n-alkanes ratio for dealuminated zeolite catalysts was three times higher than that for not dealuminated ones, and was related to the presence of different kind of acidic sites in both zeolite catalysts.

Highlights

The growing demand for high-quality energy puts new challenges for scientists in the field of alternative fuels production
The aim of our work was to investigate the effect of dealumination of Beta zeolite and presence of mesopores in the zeolite matrix on the Fischer-Tropsch synthesis
Characteristic for the Beta zeolite (Figure 1). Their presence is most likely related to the co-existence of two isomorphic forms of Beta zeolite [19]

Summary

Introduction

The growing demand for high-quality energy puts new challenges for scientists in the field of alternative fuels production. For this reason, for many years a considerable interest has been focused on technology and catalysts for Fischer-Tropsch synthesis (FTS). For many years a considerable interest has been focused on technology and catalysts for Fischer-Tropsch synthesis (FTS) This process leads to the production of sulfur and nitrogen free fuels and other valuable chemical compounds from the synthesis gas (the mixture of CO and H2 ). Co based systems are less susceptible to sintering and deactivation by carbon deposit [11]

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Conclusion