Structured internals for the intensified Fischer–Tropsch synthesis in fixed-bed reactors†

To accelerate the energy transition, processes for the production of sustainable fuels are desired such as the conversion of syngas from biogenic residues into liquid fuel by using the Fischer–Tropsch synthesis (FTS). These novel conversion processes are often of smaller scale due to the feedstock for which intensified reactor concepts are required. Structured reactors present viable alternatives to conventional packed bed reactors. Structured reactors can be obtained by e.g. loading a conventional tubular reactor with structured internals. Here, two strategies were followed in an effort to obtain the highest productivity per reactor volume, namely application of 3D-printed catalysts and secondly, thermally conductive aluminium and copper contactors filled with catalyst particles. Superior productivities were obtained by applying Al foam and 3D-printed Cu contactors when packed with FTS catalyst particles, with heat duties of respectively 880 kW m⁻³ and 1238 kW m⁻³ compared with only 185 kW m⁻³ for the 3D-printed catalyst and 218 kW m⁻³ for a conventional packed bed. For the system using the ordered 3D-printed Cu contactors, it presented a productivity of at least 0.85 g_C5+ g_cat⁻¹ h⁻¹. The excellent productivities could be correlated to the high thermal conductivity of the metal contactors facilitating the heat transfer from the bed centreline to the reactor wall as revealed by laser flash analysis (LFA) thermal conductivity measurements.