Opportunities and Challenges in Reducing the Complexity of the Fischer–Tropsch Gas Loop of Smaller-Scale Facilities for the Production of Renewable Hydrocarbons

When renewable resources such as biomass, waste, or carbon dioxide together with renewable
electrical energy are used, Fischer–Tropsch (FT) synthesis is a promising option for
the sustainable production of fuels and petrochemicals conventionally derived from crude
oil. As such renewable resources generally do not occur in large point sources like fossil
fuels, future sustainable FT facilities will likely be substantially smaller in scale than their
fossil counterparts, which will have a significant impact on their design. A core topic in
the reimagination of such smaller-scale facilities will be the reduction in complexity of the
FT gas loop. To this end, three simple gas loop designs for the conversion of syngas from
biomass gasification were conceived, simulated in DWSIM, and compared regarding their
performance. Concepts only employing an internal recycle were found to be inherently
limited in terms of efficiency. To achieve high efficiencies, an external recycle with a tail
gas reformer and high tail gas recycling ratios (>3) were required. Thereby, the carbon
dioxide content of the syngas had a considerable influence on the required syngas H2/CO
... mehr
ratio, making the separation efficiency of the carbon dioxide removal unit a suitable control
parameter in this respect.