Upgrading of Fischer–Tropsch synthesis bio-waxes via catalytic cracking: Effect of acidity, porosity and metal modification of zeolitic and mesoporous aluminosilicate catalysts

Komvokis, V.G.; Karakoulia, Stamatia A.; Iliopoulou, Eleni F.; Papapetrou, Maria; Vasalos, I.A.; Lappas, A. A.; Triantafyllidis, Konstantinos S.

doi:10.1016/j.cattod.2012.06.029

Cited by 50 publications

(31 citation statements)

References 47 publications

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“…Mostly linear hydrocarbons and very small amounts of iso ‐paraffins were observed over the Co/SiO 2 reference catalyst (Figure , Table ). This is consistent with previous reports and could be attributed to the absence of strong acid sites in the silica support (Figure ), which would initiate formation of carbocations with subsequent skeletal isomerization, possible β‐scission, and the formation of short‐chain isomers . In agreement with previous reports, the olefin‐to‐paraffin ratio increases with an increase in the hydrocarbon chain length (Figure ).…”

Section: Resultssupporting

confidence: 93%

“…The low olefin selectivity in the bifunctional Co‐zeolite catalysts coincides with the presence of significant amounts of iso ‐paraffins in the reaction products. Previous studies suggest that paraffin isomerization on the metal‐containing zeolites proceeds by the intermediate formation of olefins. Our results show that light olefins, which are always present during FT synthesis over Co catalysts, might participate in the isomerization reaction.…”

Section: Resultsmentioning

confidence: 99%

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The Role of Steric Effects and Acidity in the Direct Synthesis of iso‐Paraffins from Syngas on Cobalt Zeolite Catalysts

et al. 2015

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This study focuses on the effects of the localization of Co species, zeolite structure, and acidity on the performance of Co bifunctional catalysts promoted with Pt for the direct synthesis of iso‐paraffins from syngas. ZSM‐5, MOR, and BEA were chosen as zeolites with different structures and pore diameters. The catalysts were prepared either by incipient wetness impregnation or by the mechanical mixing of the zeolite with a conventional silica‐supported Co catalyst. The increase in the pore size and open character of the zeolite structure from ZSM‐5 to BEA resulted in a higher fraction of Co located inside the pores of the catalysts prepared by impregnation. The catalytic performance was affected strongly by the zeolite acidity, pore structure, and Co distribution between the pores and the external surface. The selectivity to short‐chain iso‐paraffins is affected principally by the zeolite acidity, whereas the selectivity to long‐chain branched hydrocarbons mostly depends on steric effects.

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Section: Resultssupporting

confidence: 93%

Section: Resultsmentioning

confidence: 99%

The Role of Steric Effects and Acidity in the Direct Synthesis of iso‐Paraffins from Syngas on Cobalt Zeolite Catalysts

et al. 2015

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“…The formation of intracrystal meso/macropores is also verified by the evenly distributed light contrast spots that can be identified the former zeolite contains larger mesopores in the range of 15 to 90 nm (with average width of 45 nm) ( Table 3). ZSM-5 is a strongly acidic zeolite, with many applications in the cracking/pyrolysis of petroleum or biomass-derived feedstocks, containing mainly Brønsted acid sites as well as Lewis sites when extra-framework amorphous phases are present [43,[101][102][103][104]. As expected, the amount of Brønsted acid sites of the parent commercial ZSM-5 zeolites increases as the Si/Al decreases, as can be seen in Table 3.…”

Section: Characterization Data Of Zsm-5 Zeolitessupporting

confidence: 59%

Catalytic Fast Pyrolysis of Lignin Isolated by Hybrid Organosolv—Steam Explosion Pretreatment of Hardwood and Softwood Biomass for the Production of Phenolics and Aromatics

et al. 2019

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Lignin, one of the three main structural biopolymers of lignocellulosic biomass, is the most abundant natural source of aromatics with a great valorization potential towards the production of fuels, chemicals, and polymers. Although kraft lignin and lignosulphonates, as byproducts of the pulp/paper industry, are available in vast amounts, other types of lignins, such as the organosolv or the hydrolysis lignin, are becoming increasingly important, as they are side-streams of new biorefinery processes aiming at the (bio)catalytic valorization of biomass sugars. Within this context, in this work, we studied the thermal (non-catalytic) and catalytic fast pyrolysis of softwood (spruce) and hardwood (birch) lignins, isolated by a hybrid organosolv–steam explosion biomass pretreatment method in order to investigate the effect of lignin origin/composition on product yields and lignin bio-oil composition. The catalysts studied were conventional microporous ZSM-5 (Zeolite Socony Mobil–5) zeolites and hierarchical ZSM-5 zeolites with intracrystal mesopores (i.e., 9 and 45 nm) or nano-sized ZSM-5 with a high external surface. All ZSM-5 zeolites were active in converting the initially produced via thermal pyrolysis alkoxy-phenols (i.e., of guaiacyl and syringyl/guaiacyl type for spruce and birch lignin, respectively) towards BTX (benzene, toluene, xylene) aromatics, alkyl-phenols and polycyclic aromatic hydrocarbons (PAHs, mainly naphthalenes), with the mesoporous ZSM-5 exhibiting higher dealkoxylation reactivity and being significantly more selective towards mono-aromatics compared to the conventional ZSM-5, for both spruce and birch lignin.

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“…Nevertheless, over the years several studies reported on the fluid catalytic cracking of wax over FAU, MFI and BEA catalysts [ 72 , 73 , 74 , 75 , 76 ]. It is commonly noted that high wax conversion is possible leading to high C 3 -C 4 gas yields, low coke yield and low aromatic content.…”

Section: Atmospheric Residuementioning

confidence: 99%

Zeolites as Catalysts for Fuels Refining after Indirect Liquefaction Processes

Klerk

2018

Molecules

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The use of zeolite catalysts for the refining of products from methanol synthesis and Fisher–Tropsch synthesis was reviewed. The focus was on fuels refining processes and differences in the application to indirect liquefaction products was compared to petroleum, which is often a case of managing different molecules. Processes covered were skeletal isomerisation of n-butenes, hydroisomerisation of n-butane, aliphatic alkylation, alkene oligomerisation, methanol to hydrocarbons, ethanol and heavier alcohols to hydrocarbons, carbonyls to hydrocarbons, etherification of alkenes with alcohols, light naphtha hydroisomerisation, catalytic naphtha reforming, hydroisomerisation of distillate, hydrocracking and fluid catalytic cracking. The zeolite types that are already industrially used were pointed out, as well as zeolite types that have future promise for specific conversion processes.

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Upgrading of Fischer–Tropsch synthesis bio-waxes via catalytic cracking: Effect of acidity, porosity and metal modification of zeolitic and mesoporous aluminosilicate catalysts

Cited by 50 publications

References 47 publications

The Role of Steric Effects and Acidity in the Direct Synthesis of iso‐Paraffins from Syngas on Cobalt Zeolite Catalysts

The Role of Steric Effects and Acidity in the Direct Synthesis of iso‐Paraffins from Syngas on Cobalt Zeolite Catalysts

Catalytic Fast Pyrolysis of Lignin Isolated by Hybrid Organosolv—Steam Explosion Pretreatment of Hardwood and Softwood Biomass for the Production of Phenolics and Aromatics

Zeolites as Catalysts for Fuels Refining after Indirect Liquefaction Processes

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