Abstract
In order to develop an iron-based catalyst with high attrition resistance and stability for Fischer–Tropsch synthesis (FTS), a series of experiments were carried out to investigate the effects of SiO2 and its hydroxyl content and a boron promoter on the attrition resistance and catalytic behavior of spray-dried precipitated Fe/Cu/K/SiO2 catalysts. The catalysts were characterized by means of N2 physisorption, nuclear magnetic resonance (NMR), X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS), H2-thermogravimetric analysis (H2-TGA), temperature-programmed reduction and hydrogenation (TPR and TPH), and scanning and transmission electron microscopy (SEM and TEM). The FTS performance of the catalysts was tested in a slurry-phase continuously stirred tank reactor (CSTR), while the attrition resistance study included a physical test with the standard method and a chemical attrition test under simulated reaction conditions. The results indicated that the increase in SiO2 content enhances catalysts’ attrition resistance and FTS stability, but decreases activity due to the suppression of further reduction of the catalysts. Moreover, the attrition resistance of the catalysts with the same silica content was greatly improved with an increase in hydroxyl number within silica sources, as well as the FTS activity and stability to some degree. Furthermore, the boron element was found to show remarkable promotion of FTS stability, and the promotion mechanism was discussed with regard to probable interactions between Fe and B, K and B, and SiO2 and B, etc. An optimized catalyst based on the results of this study was finalized, scaled up, and successfully applied in a megaton industrial slurry bubble FTS unit, exhibiting excellent FTS performance.
Highlights
Introduction published maps and institutional affilFischer–Tropsch synthesis (FTS) is the major route for converting syngas (CO+H2 )made from coal or natural gas into a wide variety of hydrocarbons
The FTS reaction performance data (Table 2) showed that the CO conversion rate of the catalyst decreased with the increase in silica content, while the methane selectivity increased, which was consistent with the law obtained by Cheng-Hua
A systematic research on physical attrition resistance and reaction stability has been carried out, a novel catalyst with highly attrition resistance and stablity based on binder and promoter optimization has been developed and verified by industrial-scale performance
Summary
Fischer–Tropsch synthesis (FTS) is the major route for converting syngas (CO+H2 ). Made from coal or natural gas into a wide variety of hydrocarbons. Stringent environmental regulations are pushing the drive for clean fuels (low-sulfur, low-aromatics), and concerns about the huge consumption of liquid fuel make FTS an environmentally friendly and promising route for coal- or gas-rich regions. The industrial catalysts for FTS are mainly iron- and cobalt-based catalysts [1]. Ironbased catalysts are relatively inexpensive, possess reasonable activity for FTS, and have lower sensitivity towards poisons and excellent water gas shift (WGS) activity compared with cobalt catalysts, which makes iron-based catalysts the preferred catalysts for hydrocarbon production via FTS using coal-derived syngas [1,2,3,4]. Iron-based catalysts can be divided into precipitated iron catalysts for low-temperature FTS and molten iron catalysts iations
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
