Jean-Charles Moïse

Studies on the Dissolution of Glucose in Ionic Liquids and Extraction Using the Antisolvent Method

Biomass, the fibrous material derived from plant cell walls, is a potentially clean and renewable nonfood feedstock for liquid fuel and chemical production in future biorefineries. The capability of ionic liquids to act as selective solvents and catalysts for biomass processing has already been proven. Thus, they are considered as an alternative to conventional solvents. Nevertheless, phase equilibria with biomass derived compounds is still lacking in the literature. To overcome the lack of experimental data on phase equilibria of biomass carbohydrates in ionic liquids, the solubility of d-glucose in four ionic liquids was measured within a temperature range from 283 to 373 K. Solubility data were successfully correlated with local composition thermodynamic models such as NRTL and UNIQUAC. In this work, the possibility of extracting glucose from these ionic liquids using the antisolvent method has been also evaluated. The parameters affecting the extraction process are the ionic liquid type, ethanol/ionic liquid ratio, temperature, water content, and time. Results indicate that ethanol can be successfully used as an antisolvent to separate glucose from ionic liquids.

From the dissolution to the extraction of carbohydrates using ionic liquids

Lignocellulosic biomass is an alternative raw material for the production of biofuels. The conversion of biomass to biofuels begins with pretreatment to produce amorphous cellulose which can be hydrolysed to sugars. The use of ionic liquids has been described as a new potentially viable development in this area. Nevertheless, phase equilibria with biomass-derived compounds and also sugars, is still lacking in the literature. To overcome the lack of experimental data on phase equilibria of biomass carbohydrates in ionic liquids, the solubility of fructose, sucrose and lactose in ionic liquids was measured within a temperature range from 280 K to 390 K. Solubility data were successfully correlated using NRTL and UNIQUAC thermodynamic models. In this work, the possibility of extracting carbohydrates from ionic liquids using ethanol has also been evaluated. Results indicate that ethanol could be used as an antisolvent to separate sugars from ionic liquids.

Binary phase diagram (C14 + C25) and isopleth (C14 + wax): comparison of solubility of n-pentacosane and multiparaffinic wax in n-tetradecane

Abstract The crystallization of n-alkanes is known to be responsible for the solid deposit in flowlines of middle distillate fuels or petroleum cuts. To solve the problems of solid deposits in industrial equipment, it is essential to determine the thermodynamic and structural behaviour of the components of crude oils. The aim of the study was to determine the phase diagram of (n-tetradecane+n-pentacosane) was determined by simple and differential thermal analyses and X-ray diffraction; then it was compared with the pseudo-binary isopleth of the (n-tetradecane+multiparaffinic wax) multicomponent system. In both cases, the solid phases of compounds ( γ o (P 1 )- C 14 H 30 ; β o ( Pbcm )-C 25 H 52 ; β′-wax multiparaffinic solid solution) were observed separately, but there was co-solubility in the liquid state. In the C 25 -rich side of the diagram, the binary mixtures (C 14 +C 25 ) undergo structural changes corresponding to those of pure C 25 when the temperature increases and those of β′ orthorhombic multiparaffinic solid solution of the wax are observed for the multicomponent system (C 14 +wax) in the wax-rich side. The binary diagram (C 14 +C 25 ) displays an eutectic solidification ( liquid ↔ γ o (P 1 )- C 14 H 30 + β o (Pbcm)- C 25 H 52 ) and the isopleth (C 14 +wax), a solidification that resembles an eutectic binary equilibrium ( liquid ↔ γ o (P 1 )- C 14 H 30 + β ′- wax ). The comparison of the two diagrams, particularly the curves of the crystallisation in the heavy n-alkane-rich side, shows that the solubility in C 14 of the multiparaffinic solid solution, whose medium number of carbon atoms per molecule is equal to 25.6, is greater than that of C 25 .