Solubilities of d-xylose in water + (acetic acid or propionic acid) mixtures at atmospheric pressure and different temperatures
Highlights
► The solubility of d-xylose in selected solvents has been obtained in this work. ► The results show that the three models agree well with the experimental data. ► The Apelblat equation was more accurate than the λh model and ideal model. ► The standard enthalpy, standard entropy and Gibbs energy change of d-xylose were calculated from the solubility data.
Introduction
It has become a common view now that shifting the society's dependence away from fossil-based to sustainable renewable fuels and chemicals is an important contributor to the development of a sustainable industrial society and effective management of greenhouse gas emissions [1]. Currently biomass processing for the production of value-added chemicals has come to the forefront of both biological and chemical engineering research [2], [3], [4]. d-Xylose is an abundant pentoses present in lignocellulosic biomass, which can be converted into xylitol, d-xylonate, d-xylonic acid, ethanol, and bacterial cellulose [5], [6], [7], [8]. The yields and quality of d-xylose depend to a considerable extent on the purity of the raw material. For the purification of d-xylose, accurate solubility data are required. The solubility of d-xylose in (water + acetic acid or propionic acid) have not been reported at present.
In this study, the solubility of d-xylose in acetic acid (or propionic acid) + water binary mixed solvents from about T = (296.65–325.45) K at atmospheric pressure was measured using a laser monitoring observation technique. The experimental data were correlated with the Apelblat equation, the λh equation, and the ideal solution equation. The standard enthalpy, standard entropy and Gibbs energy change of solution of d-xylose were calculated from the solubility data.
Section snippets
Materials
d-Xylose (C5H10O5, molecular weight 150.14) used in the experiments was obtained from Shanghai Hualan Chemical Technology Co., Ltd., China. Its mass fraction purity was better than 99.0%. It was dried in vacuum at 313.15 K for 24 h and stored in a desiccator. The acetic acid and methanol (mass fraction purity ≥0.995) were purchased from Yantai Shuangshuang Chemical Co., Ltd., China. The propionic acid (mass fraction purity ≥0.99) was purchased from Tianjin Kermel Chemical Reagent Development
Solubility data
The measured mole fraction solubilities of d-xylose (x) in water + acetic acid and water + propionic acid solvent mixtures at temperature from 296.65 K to 325.45 K are given in Table 3, Table 4 and Fig. 1, Fig. 2. From Table 3, Table 4 and Fig. 1, Fig. 2, we can conclude that the solubility of d-xylose in all the solvents increases with increasing temperature and decrease with increasing volume fractions of acetic acid (or propionic acid) in aqueous solution.
Apelblat model
The relationship between mole fraction of
Conclusions
New experimental results for the solubility of d-xylose in binary system of water + (acetic acid or propionic acid) not previously reported in the literature have been obtained and presented in this work. The solubility data of d-xylose in binary system of water + (acetic acid or propionic acid) over the temperature range (296.65–325.45) K increases with increasing temperature, and decreases with increasing volume fractions of acetic acid (or propionic acid) in the solvent mixtures. All the Apelblat
Acknowledgement
This work was financially supported by Science and Technology Breakthrough Major Project in Henan Province (Grant No: 112101210200).
References (22)
- et al.
Bioresour. Technol.
(2010) - et al.
Bioresour. Technol.
(2005) - et al.
Metab. Eng.
(2011) - et al.
Process Biochem.
(2004) - et al.
Enzyme Microb. Technol.
(2002) - et al.
Fluid Phase Equilibr.
(2004) - et al.
J. Chem. Thermodyn.
(1999) - et al.
J. Chem. Thermodyn.
(2012) J. Fluid Phase Equilibr.
(1986)- et al.
Science
(2006)