Sustainable vine shoots-to-ethanol valorisation by a sequential acid/organosolv pretreatment

In this study, a fractionation and valorisation scheme for vine shoots is proposed for biofuel and lignin production. This agricultural waste was fractionated by acid/organosolv sequential pretreatment. In the first step, acid pretreatment was optimised at 150ºC and 1.2% H2SO4 to release hemicellulosic sugars, of which 76% could be recovered. This sugar stream was co-fermented by E. coli with an ethanol yield higher than 98% after detoxification with resins or NH4OH. The solid obtained under optimal acid pretreatment conditions was delignified by organosolv treatment, and a delignification rate of 43% was reached at 180ºC. This substrate with 83% enzymatic digestibility was bio-converted into ethanol by simultaneous saccharification and fermentation, with a yield of 76%. Additionally, lignin was recovered from the organosolv liquor, aiming for the full valorisation of the biomass, which showed a syringyl/guaiacyl ratio of 0.92 by nuclear magnetic resonance, complying with the data provided for Fourier transform infrared spectroscopy and confirming the aromaticity of this fraction for further valorisation.MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” Grant PID2020-112594RB-C31, PID2020-112594RB-C33. Junta de Andalucía, predoctoral contract PREDOC_01931

Dehydration of fructose to HMF in presence of (H3O)xSbxTe(2-x)O6 (x = 1, 1.1, 1.25) in H2O-MIBK

The pyrochlores (H 3 O) x Sb x Te (2-x) O 6 (x = 1, 1.1 and 1.25) obtained by ion exchange from K x Sb x Te (2-x) O 6 oxides were used as catalysts for the conversion of fructose to 5-hydroxymethylfurfural (HMF) in H 2 O/Methyl isobutyl ketone (MIBK). The structure of the resulting compounds as well as the location of the H 3 O + units inside the three-dimensional network, were determined by XRD from powder samples. The effect of factors such as reaction time and temperature on the formation of HMF was studied. A fructose conversion of 99% and a yield of 59% were achieved after 120 min of reaction time and at 150 °C temperature. The percentage of substitution of the cations Sb and Te in the position B of the pyrochlore was determinant to achieve the maximum incorporation of H 3 O + ions in the pyrochlore structure, which allowed to correlate the density of acidic sites present in the materials and their catalytic activity.Fil: Mayer, Sergio Federico. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Falcon, Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Inv. y Tecnología Química. Grupo Fisicoquímica de Nuevos Materiales; ArgentinaFil: Di Paola Naranjo, Romina Daniela. Universidad Nacional de Córdoba. Secretaría de Ciencia y Tecnología. Instituto Superior de Investigación, Desarrollo y Servicio de Alimentos; ArgentinaFil: Ribota, Pablo Daniel. Universidad Nacional de Córdoba. Secretaría de Ciencia y Tecnología. Instituto Superior de Investigación, Desarrollo y Servicio de Alimentos; ArgentinaFil: Moyano, Elizabeth Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Morales-delaRosa, S.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica. Grupo de Energía y Química Sostenibles; EspañaFil: Mariscal, R.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica. Grupo de Energía y Química Sostenibles; EspañaFil: Campos-Martín, J. M.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica. Grupo de Energía y Química Sostenibles; EspañaFil: Alonso, J. A.. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Fierro, J. L. G.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica. Grupo de Energía y Química Sostenibles; Españ

CATALYTIC EPOXIDATION OF CYCLOHEXENE WITH TERT-BUTYLHYDROPEROXIDE USING AN IMMOBILIZED MOLYBDENUM CATALYST

This work describes the synthesis of molybdenum complexes immobilized on a silica support and their performance in the epoxidation reaction of cyclohexene using tert-butylhydroperoxide (TBHP) as the oxidizing agent. The catalyst synthesis included solubilization of variable amounts of bis-oxomolybdenum (VI) acetylacetonate precursor in different solvents such as tetrahydrofuran (THF), ethanol, THF/water and ethanol/water mixtures and contact with the silica support. Characterization techniques demonstrated that the nature of the incorporated molybdenum species depends markedly on the solvent employed. If the solvent employed is an ethanol:water mixture, physical adsorption of the Mo-species onto the support surface occurs; however, when THF is used as the solvent (THF catalyst series), molybdenum is grafted on the silica surface via chemical bonding with the surface hydroxyl groups of silica. Specifically, these latter catalysts show similar performance to that of the homogeneous catalyst, although long-term experiments showed deactivation by leaching of the active phase.Peer reviewe