Optimization of C5+ production by CO2 recycle at an integrated Tri-reforming and Fischer-Tropsch process

Abstract

Integration of Tri-reforming and Fischer-Tropsch processes is a novel approach for conversion of CO₂ into C₅⁺ liquid hydrocarbon. Tri-reforming converts CO₂ into syngas and does not require external heat source due to methane oxidation reaction that occurs at the beginning of reactor. Fischer-Tropsch synthesis converts produced syngas in the reformer to hydrocarbon fuels. In this research, plug reactors have been modeled in a heterogeneous and one-dimensional form, and the mass and energy equations governing them in steady state have been developed. The accuracy of models is validated with literature data. Then an optimization problem aiming at maximal C₅⁺ production is compiled with specific limitations imposed on operating conditions. Based on the modeling results, 95 % of CO₂ produced at Fischer-Tropsch and 92 % CO₂ produced at Tri-reforming process is captured and injected into Tri-reforming reactor for conversion into hydrocarbon fuels. Modeling results revealed that the mole fractions of C₂-C₄ and C₅⁺ at outlet of Fischer-Tropsch are 0.117 and 0.023 which could be purified in separators and used as clean energy carriers. The suggested integrated route for CO₂ capture and conversion into green fuels offers both environmental and technical advantages.