Sorption-enhanced reaction process in Fischer–Tropsch synthesis for production of gasoline and hydrogen: Mathematical modeling

• Mathematical model for Fischer–Tropsch synthesis with in-situ water adsorption.
• Introduction of flowing solids as water adsorbent to the three phase system.
• Higher gasoline production in comparison with zero solid mass flux condition.
• Production of hydrogen and benzene as additional valuable products.

This work proposes a sorption enhanced-thermally coupled reactor (SE-TCR) for simultaneous production of gasoline and hydrogen in which Zeolite 4A, with the composition of Na12(Si12Al12O48)·27H2O, is considered as water adsorbent. For this purpose, in the exothermic side of proposed configuration, a gas-flowing solids-fixed bed reactor (GFSFBR) is used. The main advantage of GFSFBR over the conventional sorption-enhanced reaction process is the continuous adsorbent regeneration in this novel configuration. SE-TCR takes the advantages of adsorption and couple technique simultaneously. The new configuration is designed as a double pipe reactor where exothermic Fischer–Tropsch synthesis (FTS) reactions in the exothermic side are coupled with dehydrogenation of cyclohexane. Simulation result demonstrates that selective adsorption of water from FTS in SE-TCR leads to 45% and 57% enhancement in gasoline and hydrogen yields and 84% reduction in CO2 production in comparison with the zero solid mass flux condition, respectively. This paper shows how the concept of in-situ water adsorption is feasible and beneficial for gasoline production in thermally coupled reactor.