Development of an Iron-Based Fischer—Tropsch Catalyst with High Attrition Resistance and Stability for Industrial Application

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.

Effects of Potassium Loading over Iron–Silica Interaction, Phase Evolution and Catalytic Behavior of Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis

“…SiO 2 has been considered as a proper structural promoter for iron-based catalysts [4]. The formula 100Fe/5Cu/4.2K/25SiO 2 from Ruhrchemie A. G. in Germany [14] was one of the classical recipes, which acts as the basic formula of precipitated iron-based FTS catalysts, has been widely used as a benchmark for basic research and industrial catalyst development [15][16][17][18]. In the research works related to SiO 2 -incorporation effects, some works have indicated that its promotion of the attrition property, FTS activity/stability and selectivity/hydrocarbon productivity of Fe catalyst seemed to some extent to exhibit contrary correlation [19,20].…”

Direct Construction of K-Fe3C@C Nanohybrids Utilizing Waste Biomass of Pomelo Peel as High-Performance Fischer–Tropsch Catalysts

“…As of now, FTS has attracted renewed attention as a well-known and long-established commercial technical route to produce a wide range of synthetic paraffins and olefins from syngas comprising primarily H 2 and CO, derived from non-petroleum carbon sources, such as coal, biomass and natural gas [1][2][3][4]. In particular, for coal-based FTS processes with low H 2 /CO ratio syngas, iron-based catalysts are preferentially applied in industrial implementation, depending largely on abundant reserves, low price, adequate catalytic performance for H 2 -poor syngas and impressive selectivity for α-olefin production [5][6][7].…”

The Use of Iron Ore as a Catalyst in Fischer–Tropsch Synthesis—A Review

“…It is imperative to have an optimized catalyst to make the overall FT application economical for the practitioner by ensuring high production of the desired hydrocarbons [3,10,16,20,25]. Catalytic performance is defined as a function of its activity, selectivity, and stability [9,16,19,20,[26][27][28][29][30][31]. These principles are also applicable to iron ore catalysts used in FT, which will be scrutinized to improve the current research on this type of iron catalyst.…”

“…It is observed that most of the research work carried out on the use of iron ore as a catalyst in FTS did not give significant attention to its stability. Apart from looking at the activity and selectivity of the iron ore as a catalyst in FTS, its stability is a very crucial aspect for the development of a practical reaction system [1,3,19,24,25,27,30,32,33]. A catalyst's stability can be defined as a function of the chemical and physical aspects [18,24,27,29,34].…”

“…A catalyst's stability can be defined as a function of the chemical and physical aspects [18,24,27,29,34]. The chemical element focuses on its durability during reactions before it starts losing its functionality, while the latter emphasizes maintaining its physical structure throughout the reactions [11,24,30,35]. The deactivation of catalysts is dependent on these two aspects.…”