Sorption-enhanced Fischer–Tropsch synthesis with continuous adsorbent regeneration in GTL technology: Modeling and optimization

Abstract

Fischer–Tropsch synthesis (FTS) plays an important role in the production of clean liquid transportation fuels, chemicals, and other hydrocarbon products. This work proposes a novel configuration of FTS reactor in which zeolite 4A, with the composition of Na12(Si12Al12O48)·27H2O, is considered as water adsorbent. For this purpose, a gas-flowing solids-fixed bed reactor (GFSFBR) is used instead of conventional reactor. The main advantage of GFSFBR over the conventional sorption-enhanced reaction process is the continuous adsorbent regeneration in this novel configuration. Simulation result demonstrates that selective adsorption of water from FTS in GFSFBR leads to significant enhancement in the gasoline yield and reduction in CO2 production in comparison with the zero solid mass flux condition. Subsequently, the aforementioned reactor is optimized using differential evolution (DE) algorithm as an effective and robust optimization method. Optimization results show that there are optimum values for eight decision variables under which the highest gasoline productivity can be achieved. Afterwards, the simulation and optimization results are compared with the ones in conventional reactor. This paper shows how the concept of in situ water adsorption is feasible and beneficial for FTS.