Model-based optimization of the periodic operation of the Fischer-Tropsch synthesis**This work is part of Delft Interdisciplinary Research Centre “Mastering the Molecules in Manufacturing”

Conversion of CO2-Rich Natural Gas to Liquid Transportation Fuels via Trireforming and Fischer–Tropsch Synthesis: Model-Based Assessment

“…For its integration within the complete process in Figure , the reactor is scaled-up for conversion of approximately 80% of CO, at 240 °C and 30 bar, , requiring 80 t of catalyst. The reactor volume is calculated by considering a catalyst load of 28% in volume for SBCR and a particle density of 646 kg/m 3 , resulting in 442 m 3 reactor for production of about 30t/h of FT liquids . These values are consistent with those reported by Maretto and Krishana …”

“…For instance, the products’ chain length is inversely proportional to the reactor temperature. High temperature FT synthesis (HTFT: 300–350 °C, ∼20 bar) tends to produce shorter molecules, in the range of gasoline, while low temperature FT (LTFT: 175–250 °C, 10–45 bar) generates long carbon chains, in the range of diesel, heavy oil, and wax . Conversely, the products’ chain length increases with the reactor pressure, which should thus be set at an economic optimum by considering the energy required to compress the syngas feed stream.…”

“…Due to the lack of thermodynamic information for n -paraffins with more than 30 carbons and α-olefins with more than 20 carbons, these higher compounds are represented by two pseudocomponents with formula C 30 H 62 and C 20 H 40 (eqs and ) herein. with R , the rate of species formation; P , the partial pressure of species; k , the kinetic constants for the rate-determining steps; K , the equilibrium constants for the nonrate-determining steps; α, the chain growth probabilities (eq ); and [ S ], the fraction of vacant sites (eq ). It is worth noting that expressing [ S ] in terms of the reagents partial pressures can provide more accurate predictions …”