Gamma-valerolactone (GVL) has been proposed as a biomass-based platform molecule. However, its vapor–liquid equilibrium has not been exhaustively studied yet. Antoine constants of GVL were determined and vapor–liquid equilibrium (VLE) data for water(1)–GVL(2) binary system were measured at atmospheric and reduced (50.66 and 10.1 kPa) pressures. The thermodynamic consistency was investigated by applying Herrington’s area test. It was established that no azeotropic mixture was formed for the water–GVL system in the full concentration range. Data were regressed using ChemCAD software to generate binary interaction parameters for Wilson, NRTL, and UNIQUAC activity coefficient models. Good agreements between calculated and experimental VLE data were obtained.
γ-valerolactone (GVL) has been identified as a renewable, versatile, and nontoxic building block for the chemical industry. Although several protocols were published for its synthesis, so far only a few studies concerning the separation and purification of the product were reported. Some of the procedures involve alcohols or lead to the formation of binary mixtures of alcohols and GVL, therefore the separation is of utmost importance to produce GVL. Isobaric vapor–liquid equilibria of three binary systems (methanol, ethanol, and 2-propanol) of γ-valerolactone were measured using a vapor condensate and liquid circulation VLE still. The experimental data were correlated with Wilson and UNIQUAC activity coefficient models and the results were compared with UNIFAC model calculations. Both models were found suitable for representing the VLE data. The refractive indexes of all systems were determined in the whole concentration range at T = 293.2 and 298.2 K. Good agreements between experimental and calculated VLE data were obtained.
The valorization of cheap and readily available biomass‐based wastes such as various straws, husks, shells and peels, moreover, so far unprecedented, commercial and household wastes produced on large scale, i. e. spent coffee grounds and cooked tea leaves waste were processed as raw materials for the production of levulinic acid, a C5‐platform molecule. The results obtained by applying conventional and microwave dielectric heating at 170 °C were compared. It was revealed that depending on the source, the average product yields were 10–25 wt% when 2 M aqueous sulfuric acid solution was used. By applying microwave irradiation the reaction time can be significantly reduced (30 min instead of 8 h) without a decrease in product formation. The influence of the feedstock's water content on the formation of levulinic acid was investigated revealing that the drying process having significant energy needs can be eliminated from the procedure.
Because of its outstanding physical and chemical properties, γ-valerolactone (GVL) has been identified as a promising renewable platform molecule for the chemical industry. Its synthesis can be performed via many catalytic routes; however, each method results in the formation of a different product mixture, of which components have to be separated before the subsequent utilization of GVL. The use of formic acid (FA) as a hydrogen source for producing GVL by homogeneous-transfer hydrogenation could be one of the most suitable ways, whereas the product mixture could contain FA, GVL, and water. In the present study, the isobaric vapor–liquid equilibrium data of FA and GVL was determined. The experimental data were correlated with the Wilson, NRTL, and UNIQUAC models and compared to the ideal vapor pressures as well as modified UNIFAC activity coefficient models. The refractive indexes of the mixture were also determined over the whole concentration range at T = 293.2 and 298.2 K.
γ-Valerolactone (GVL) has recently been considered as a suitable solvent for synthesis and catalysis. By the application of GVL in scaled-up processes, it can be mixed with various components, including commonly utilized polar aprotic solvents such as acetone and ethyl acetate. Herein, isobaric vapor–liquid equilibria (VLE) of acetone, ethyl acetate, and γ-valerolactone were investigated at p = 101.3 kPa with a vapor–liquid equilibrium. In addition, the VLE data series of GVL–water binary mixture was extended. The experimental data were correlated with Wilson, NRTL, and UNIQUAC activity coefficient models, whereas the results showed a greater difference to the UNIFAC model calculations. The refractive indexes of the mixture were also determined in the whole concentration range at T = 293.2 and 298.2 K.
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