Natural phosphate supported Titania as a novel solid acid catalyst for oleic acid esterification

International audienceIn the present study, a novel solid acid catalyst based on titanium dioxide (2.5-10 wt%) supported on natural phosphate (TiO2/NP) was prepared by sol-gel process, and 10wt% loaded catalyst was characterized by several physicochemical techniques. The performances of synthesized catalyst were investigated in esterification of oleic acid with methanol. The catalytic performance was screened under different reaction conditions, namely, loading amount of TiO2, calcination temperature, molar ratio of methanol to oleic acid, reaction temperature and amount of catalyst. The catalyst showed a good stability under high reaction temperature and can be reused without severe loss of activity. As a versatile application, the TiO2(10)/NP catalyst exhibits a good ability for the esterification of free fatty acids in a highly acidic feedstock

Synergistic effect of cellulose nanocrystals/graphene oxide nanosheets as functional hybrid nanofiller for enhancing properties of PVA nanocomposites

Novel functional hybrid nanofillers composed of cellulose nanocrystals (CNC) and graphene oxide nanosheets (GON), at different weight ratios (2:1; 1:1 and 1:2), were successfully prepared and characterized, and their synergistic effect in enhancing the properties of poly (vinyl alcohol) (PVA) nanocomposites was investigated. Due to the synergistic reinforcement, it was found that the Young's modulus, tensile strength and toughness of the PVA nanocomposite containing 5 wt% hybrid nanofiller (1:2) were significantly improved by 320%, 124% and 159%, respectively; and the elongation at break basically remained compared to the neat PVA matrix. In addition, the glass and melting temperatures as well as the moisture sorption of nanocomposites were also enhanced. This synergistic effect improved the dispersion homogeneity by avoiding the agglomeration phenomenon of nanofillers within the polymer matrix, resulting in nanocomposites with largely enhanced properties compared to those prepared from single nanofiller (CNC or GON). The preparation of these hybrid nanofillers and their incorporation into a polymer provided a novel method for the development of novel multifunctional nanocomposites based on the combination of existing nanomaterials

Innovative deconstruction of biomass induced by dry chemo-mechanical activation: impact on enzymatic Hydrolysis and energy efficiency

Lignocellulose fractionation to chemicals and biofuels often requires severe conditions and consume high energy. Although some of these pretreatment processes are nowadays developed at pilot scale, they are not always cost effective, and they are responsible for environmental impacts. Recently, mechanocatalysis pretreatment emerged as a promising technology for the activation and deconstruction of lignocellulosic biomass. In particular, these dry processes have the potential to limit the use of solvent and the production of liquid effluents. In this study, we propose an innovative one-pot eco-friendly approach based on the combination of dry chemical and vibro-ball-milling (VBM) for biomass activation, coupled to enzymatic conversion without an external source of heating, and without the assistance of any organic solvent. NaOH activation coupling to VBM fractionation for 10, 30, and 60 min was compared to H3PO4, H2O2, betaine, and betaine-Cl activation. NaOH-VBM-10 min appears more effective in sugar production compared to other chemical-mechanical activation. NaOH-VBM in 10 min consumed less energy, resulting in higher energy efficiency compared to that of other chemical-mechanical activation. Therefore, NaOH-VBM-10 min appears the most suitable and interesting pretreatment for the production of sugars and biofuels from corn stover biomass