Manipulation of Fischer‐Tropsch Synthesis for Production of Higher Alcohols Using Manganese Promoters

Abstract

AbstractWhile Fischer‐Tropsch (FT) provides a commercially operated route to long‐chain alkanes for fuels, little is reported showing realistic routes to long‐chain linear alcohols and linear olefins. Linear olefins and alcohols have significant commercial value for lubricants, plasticizers, detergents and base chemicals, and in this contribution, FT has gained considerable recent attention due to the potential for bio or waste feeds for fuels and chemicals, while here we demonstrate that controlling the promotion of a cobalt catalyst with manganese can lead to major shifts in selectivity towards high value chemicals. In this contribution, we demonstrate the unusual effect of adjusting manganese from 0–10 % for making long‐chain linear alcohols and olefins using industrially relevant conditions. A full evaluation of the catalysts is provided to demonstrate catalyst changes as a result of increased promotion that gives rise to this effect. Advanced wax‐product analysis is shown to demonstrate the changes in selectivity. Temperature‐programmed reduction, transmission electron microscopy elemental mapping and in situ x‐ray diffraction show the formation of CoxMnyO4 species on titania during synthesis, with cobalt‐manganese alloys after reduction, while 2D gas chromatography (GCxGC) and 1H nmR were used to analyse the FT wax product with over 50 % alcohols at long carbon numbers.