Design and Technoeconomic Analysis of Fischer–Tropsch Fixed-Bed Synthesis with Cobalt-Based Catalysts

Abstract

A multitubular Fischer–Tropsch (FT) reactor with gas recycle and a cobalt-based catalyst is simulated by a 2D fixed-bed model that considers the complex kinetics, all relevant mass and heat transfer aspects, and also the influence of the changing molar flow rate by the FT reaction, of pressure drop, and of formation of steam, which decreases the reaction rate of FT synthesis. Optimal values of gas velocity and single-tube diameter and length are determined by a technoeconomic analysis. The comparison of the data of the FT reactor modeled in this work with data of commercial reactors indicates that the used model reflects reality well and is reliable. A superficial gas velocity of 0.5 m s−1, a tube diameter of 3 cm, and a length in a range of 12–20 m are appropriate for a high production rate of C2+-hydrocarbons with minimal operating costs of the FT unit, even for a large range of the electricity price from 0.06 to 0.3 € kWh−1.