Attrition Studies of an Iron Fischer–Tropsch Catalyst Used in a Pilot-Scale Stirred Tank Slurry Reactor

Abstract

Attrition resistance is a key design parameter for catalysts used in slurry phase Fischer–Tropsch (F–T) reactors, especially for industrial-scale reaction. It is well-known that iron F–T catalyst particles undergo physical attrition and chemical stresses caused by phase transformations. Here we report on attrition properties of a Fe–Cu–K–SiO2 catalyst used in a pilot-scale stirred tank slurry reactor (STSR) under low temperature F–T reaction conditions. The wax-free catalysts were characterized by SEM, EDS, BET surface area measurements, and a Mastersizer 2000 for particle size analysis. The results show that, after 408 h of reaction in an STSR, the particle size reduction due to erosion/abrasion and fracture was apparent. Large reductions in the Sauter mean diameter (93.45%) and the volume moment diameter (71.67%) were observed. The increase in the fractions of particles smaller than 5 and 10 μm was 18.25 and 30.11%, respectively. We concluded therefore that the catalyst underwent more severe attrition in industrial application and the attrition was mainly caused by the fracture of larger or smaller particles. Further study is needed to improve the catalyst attrition resistance.

Influence of Temperature on Fluidized‐Bed Catalyst Attrition Behavior

“…Attrition has been studied for many materials at room temperature, e.g., Fischer-Tropsch catalyst [19][20][21][22][23][24], coal [25,26], glass [27], oxygen carriers [3,[28][29][30], and various crystals [31][32][33]. Lin et al [21] and Bukur et al [20,22] carried out the attrition tests of an iron Fischer-Tropsch (F-T) catalyst in a stirred-tank slurry reactor. They concluded that attrition of the F-T catalyst was induced by both the mechanical stress from particles' collisions and the chemical stress due to phase transformation.…”

Perspective on Overcoming Scale-Up Hurdles for the Reductive Catalytic Fractionation of Lignocellulose Biomass

“…Physical stability issues on the other hand are mainly comprised of attrition and abrasion of catalyst pellets, especially for stirred reactors. 87 Such attrition or abrasion of the catalyst could ultimately pollute the remaining carbohydrate pulp with catalyst particles, hindering further analysis and pulp valorization. Future research should focus on maximizing the catalyst impact resistance, for instance by exploring more stable catalyst 88 supports, like niobia 89 or carbon nitrides.…”

“…However, more pronounced catalyst deactivation requires continuous addition, removal, and regeneration of the catalyst, for example, with slurry bubble column reactors. , The optimization of said regeneration processes for RCF purposes has not yet been tackled by the community and is ideally coupled with extensive catalyst deactivation studies, in close collaboration with the catalyst manufacturers. Physical stability issues on the other hand are mainly comprised of attrition and abrasion of catalyst pellets, especially for stirred reactors . Such attrition or abrasion of the catalyst could ultimately pollute the remaining carbohydrate pulp with catalyst particles, hindering further analysis and pulp valorization.…”

“…However, this strategy demands a complicated postprocess separation of the catalyst and biomass. Alternatively, catalyst pellets can be used, which are more readily retrievable, if abrasion and attrition of these pellets can be avoided. , In jet loop reactors, there are few options to prevent abrasion other than using a highly abrasion resistant catalyst . In stirred tank reactors, the catalyst can be shielded from the rotating equipment by enclosing it in a catalyst basket mitigating physical stability issues, although it could also inflict mass transfer limitations.…”

Micrometer‐Scale Mixing with Pickering Emulsions: Biphasic Reactions without Stirring

“…Owing to the incompatibility in such reaction systems, especially for biphasic reactions involving solid catalysts, vigorous stirring is required to ensure suspension of solid catalyst particles and sufficient mixing of reactants, mitigating mass‐transport resistance 2. However, such vigorous stirring not only requires a large energy input, but causes fragmentation of catalyst particles because of repeated collisions and persistent abrasion, also 3. Recently developed microfluidic and micromixing technologies open a promising avenue towards stirring‐free reactions by enforcing continuous contact between immiscible reactants and catalysts in micrometer‐sized spaces 4.…”