Effect of time on stream and temperature on upgraded products from Fischer–Tropsch synthesis when zeolite is added to iron-based activated-carbon-supported catalyst

Conversion of Syngas to LPG and Aromatics Over Commercial Fischer-Tropsch Catalyst and HZSM-5 in a Dual Bed Reactor

“…Contrarily, Freitez et al (2011) reported a decrease in cracking activity with a ZSM-5 temperature increase. In addition, the observed effect of maximum selectivity of aromatics at 573 K is in agreement with the results obtained by Varma et al (1985), Varma and Bakhshi (1987), and Karre et al (2013), who also reported an increase of aromatization reactions with a HZSM-5 temperature increase up to 573 K. A negative effect of a HZSM-5 temperature increase was also observed for the selectivity toward CH 4 and C 2 , which increased up to 10.8% and 1.1%, correspondingly. Figure 1 shows the effect of HZSM-5 temperature on the individual product selectivities of DB reaction, C 3 -C 4 paraffins ( Figure 1a) and aromatics ( Figure 1b).…”

Recent Advances in Direct Synthesis of Value‐Added Aromatic Chemicals from Syngas by Cascade Reactions over Bifunctional Catalysts

“…On the contrary, few researchers found that a dual‐bed catalyst arrangement displayed a higher aromatic yield and a possibility to regenerate zeolite catalysts and to suppress the migration of metal/alkali species to the surfaces of HZSM‐5 . It is worthy to mention that the catalysts for an olefin synthesis such as the Fe‐ or Co‐ based catalysts are normally prone to convert the formed olefin intermediates into its corresponding alkanes in a dual‐bed reactor .…”

“…Both redox and acid components are typically involved to both reactors for the successive and parallel transformations to the target value‐added products. For instance, methanol, DME and olefins intermediates formed from syngas on metal components by COx hydrogenation are converted into aromatics exclusively on the HZSM‐5 either by a single‐bed catalyst, where two catalytic components are constructed under the same working conditions or dual‐bed catalysts in which two catalytic components separated through quartz wool spacer in a same tubular reactor ( Figure a) . Besides, a dual catalytic‐bed arrangement with separate reactors, where the active metal and zeolite components can work in different temperatures, are also reported in order to regenerate both components independently .…”

Effect of proximity and support material on deactivation of bifunctional catalysts for the conversion of synthesis gas to olefins and aromatics

“…[12,13] The supplemento fa nH -ZSM-5 zeolite facilitatesc racking of the C 12 + fraction to hydrocarbonsi nt he gasoline range (C 5 -C 12 )w ith at otal carbon selectivityo fc lose to 60 %. [14][15][16] Combining an unpromoted iron-based FTS catalyst forming olefins with az eolite enables the formation of aromatics to a certain degree [17,18] relatedt ot he higher reactivity of olefins compared with paraffins and the variability in reaction temperature of iron catalysts. [19][20][21] According to the hydrogen transfer mechanism, three paraffin molecules are produced from olefins for every aromatic molecule that is formed.…”