Iron‐Based Fischer‐Tropsch Catalysts for Higher Alcohol Synthesis

Abstract

A short overview over state‐of‐the‐art synthesis routes to higher alcohols from syngas is given. The literature shows that iron‐based catalysts offer the potential for higher alcohol production but cannot fully compete with catalyst systems based on molybdenum and cobalt so far. However, the results presented in this short communication show that by proper choice of reaction conditions and promotion of the catalysts a promising selectivity to higher alcohols and other oxygenates can also be reached for low‐priced iron‐based catalysts.

Development and Up‐scaling of Iron‐based Catalysts for Fischer‐Tropsch Synthesis of Higher Alcohols

“…In this study supported and shaped monometallic Fe-based FTS catalysts for the production of HA have been synthesized and tested, outperforming the state-of-the-art bulk Fe powder catalysts by means of HA STY. [5,30] For this purpose, in a first step favorable support materials were identified and tested on powder scale. The influence of support properties like S BET on catalyst performance were examined.…”

“…[45][46][47] In addition to application of the state-of-the-art promoters K, Cu, Mo in HA synthesis an extended promoter screening for Fe-based LTFTS catalysts was conducted applying different concentrations and combinations of promoters. [5] Conclusive results are given in Figure 4A and Figure S9.…”

“…[4] A higher value-added potential results from the FTS due to almost complete production of unbranched alcohols and operation at milder conditions. [5] In addition to alcohols, long-chain alkanes, alkenes and other oxygenates are also formed, which can be fed to existing petrochemical production pathways. [14] Depending on the operating conditions and catalyst composition, the product spectrum of FTS can vary significantly.…”

“…[15] In general, selectivity to HA decreases with increasing reaction temperatures, decreasing total pressures, and decreasing CO or increasing CO 2 partial pressure in the syngas. [5,16] At low flow rates, lower olefin/paraffin (OP) and alcohol/paraffin (AP) ratios are observed, since a longer residence time within the catalyst bed implies an increasing probability of secondary reactions mainly in form of hydrogenations. [17] Although CO conversion is limited at low reaction temperatures (200-220 °C), low-temperature FTS (LTFTS) should be pursued considering the strongly temperature-dependent selectivity to HA.…”

“…One example frequently discussed in literature are higher alcohols (HA). [4,5] These can be used as fuel additives and solvents as well as for the production of surfactants, cosmetics and pharmaceuticals. [6] In this paper, HA are deliberately defined as linear 1-alcohols with more than four carbon atoms per molecule (C � 5 ), in line with the definition of Schaller et al [5] This is in contrast to the widely applied definition of HA as alcohols with two and more carbon atoms.…”