Acid functionalized coal fly ashes: New solid catalysts for levulinic acid esterification

Peixoto, Andreia F.; Silva, Sónia M.; Costa, Paula Cristina Pereira da; Santos, Ana Cláudia; Valentim, Bruno; Lázaro-Martínez, Juan Manuel; Freire, Cristina

doi:10.1016/j.cattod.2019.07.038

Cited by 18 publications

(5 citation statements)

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“…This can severely reduce the activity of the catalyst for consecutive cycles [50]. Comparing with data from literature (Table S1, supplementary information), the catalyst SiO 2 NPs10_CSPTMS allowed an improvement of up to 100% for BL and PL products in shorter reaction time (40-60 min), only comparable with our previous results obtained in the esterification of LA and n-butanol using sulfonic acid functionalized coal fly ashes and the same reaction conditions, Table S1 [51]. These results show the potential of SiO 2 NPs10_CSPTMS, as solid acid catalysts for the preparation of n-alkyl levulinates fuel additives.…”

Section: Catalytic Performance In the Esterification Reaction Of Lasupporting

confidence: 83%

Highly active organosulfonic aryl-silica nanoparticles as efficient catalysts for biomass derived biodiesel and fuel additives

Peixoto

Soliman

Pinto

et al. 2021

Biomass and Bioenergy

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Post-grafting methodologies were used to prepare aryl-organosulfonic acid functionalized silica nanoparticles (SO 3 H-aryl-SiO 2 NPs) as highly active heterogeneous acid catalysts for catalytic esterification of free fatty acids (FFA) and levulinic acid (LA), and aldol condensation of furfural with 3-methylfuran, well known renewable feedstocks for biodiesel and fuel additives production. The chemical and structural characterization of the SO 3 Haryl-SiO 2 NPs confirmed the success of the functionalization. Complete conversion for all FFA was observed using SO 3 H-aryl-SiO 2 NPs after 2 h of reaction. SiO 2 NPs_CSPTMS showed to be the most active and stable catalyst with no significant loss of activity in the first 5 cycles. In the LA esterification in the presence of an alcohol, complete conversion and selectivity and high reusability were observed (e.g., 83.2% yield after 10 cycles in the presence of 1-propanol, SiO 2 NPs10_CSPTMS, at 120 • C and 2h reaction). Finally, aldol condensation of furfural and 3-methylfuran had been performed using SiO 2 NPs_CSPTMS catalysts with almost 100% yield after 10 min at 65 • C, high stability and reusability for 7 catalytic cycles.In general, the prepared SO 3 H-aryl-SiO 2 NPs have demonstrated promising catalytic performance for transformation of biomass-derived feedstocks into biodiesel and fuel additives.

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Section: Catalytic Performance In the Esterification Reaction Of Lasupporting

confidence: 83%

Highly active organosulfonic aryl-silica nanoparticles as efficient catalysts for biomass derived biodiesel and fuel additives

Peixoto

Soliman

Pinto

et al. 2021

Biomass and Bioenergy

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“…Alkyl levulinates can be produced via the alcoholysis of sugar monomers or LA esterification [7,8,22]. The latter route can be done via homogenous [23], heterogeneous [24][25][26][27][28][29][30] or enzymatic catalysis [31][32][33][34][35][36][37]. The use of heterogeneous catalysts such as resins, zeolite or immobilized enzymes should be favored to avoid additional separation stages [23].…”

Section: Introductionmentioning

confidence: 99%

Biocatalyst and continuous microfluidic reactor for an intensified production of n-butyl levulinate: Kinetic model assessment

Cordier

Klinksiek

Held

et al. 2023

Chemical Engineering Journal

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“…The graphitized demineralised char concentrates were characterised by means of XRD, Raman microspectroscopy, SEM/EDS, and petrographic analyses. The graphitized samples could not be examined using ss-NMR due to their magnetic susceptibilities that affect both the relaxation of the nuclei ( 1 H or 13 C) and the instability of the spinning of the sample at the magic angle under high power pulses during the excitation or decoupling steps [77,78,82].…”

Section: Characterisation Of Graphitized Demineralised Char Concentratesmentioning

confidence: 99%

Assessment of Graphitized Coal Ash Char Concentrates as a Potential Synthetic Graphite Source

et al. 2020

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Coal ash char concentrates from four countries (Portugal, Poland, Romania, and South Africa) were prepared, characterised, and graphitized under the scope of the Charphite project (Third ERA-MIN Joint Call (2015) on the Sustainable Supply of Raw Materials in Europe). Coal ash chars may be a secondary raw material to produce synthetic graphite and could be an alternative to natural graphite, which is a commodity with a high supply risk. The char concentrates and the graphitized material derived from the char concentrates were characterised using proximate analysis, X-ray fluorescence, X-ray diffraction (structural), Raman microspectroscopy, solid-state nuclear magnetic resonance, scanning electron microscopy, and petrographic analyses to determine if the graphitization of the char was successful, and which char properties enhanced or hindered graphitization. Char concentrates with a lower proportion of anisotropic particles and a higher proportion of mixed porous particles showed greater degrees of graphitization. It is curious to see that embedded Al2O3 minerals, such as glass and clay, influenced graphitization, as they most likely acted as catalysts for crystal growth in the basal direction. However, the graphitized samples, as a whole, do not compare well against a reference natural graphite sample despite some particles in select char concentrates appearing to be graphitized following graphitization.

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Acid functionalized coal fly ashes: New solid catalysts for levulinic acid esterification

Cited by 18 publications

References 50 publications

Highly active organosulfonic aryl-silica nanoparticles as efficient catalysts for biomass derived biodiesel and fuel additives

Highly active organosulfonic aryl-silica nanoparticles as efficient catalysts for biomass derived biodiesel and fuel additives

Biocatalyst and continuous microfluidic reactor for an intensified production of n-butyl levulinate: Kinetic model assessment

Assessment of Graphitized Coal Ash Char Concentrates as a Potential Synthetic Graphite Source

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