The solubility of calcium-l-lactate pentahydrate (CLLP) in binary ethanol + water and acetone + water solvent mixtures was measured in the temperature range of 278.15 K to 313.15 K by using a synthetic method. The solubility of CLLP increases with increasing temperature, whereas it decreases with the increase of the initial mole fraction of ethanol or acetone. The solubility data were correlated by using the modified Apelblat equation, the CNIBS/R-K equation, and the hybrid model, respectively. It was found that the modified Apelblat equation could give better correlation results both in ethanol aqueous solutions and in acetone aqueous solutions. The dissolution enthalpy, entropy, and Gibbs energy change of dissolution of CLLP in these solvent mixtures were obtained by using the modified van’t Hoff equation.
In order to minimize hemicellulose (or cellulose) waste upon the simultaneous production of furfural and 5-hydroxymethylfurfural (or furfural and levulinic acid) from the hydrolysis of lignocellulose in one-pot acid/organic solvent systems, we have developed a novel pressurized phosphoric acid-acetone-water system (PPAWS) to convert hemicellulose into furfural with a high retention of cellulose. In the PPAWS (acetone/water = 7:3, v / v ) at 150 °C under 1.5 MPa nitrogen, furfural production (yield 45.8%), delignification (lignin removal rate 89.8 wt%), and cellulose-rich residue extraction (retention rate 72.9 wt%, purity 92.5 wt%) from sugarcane bagasse were achieved simultaneously in just 5 min. Gas chromatography–mass spectrometry analysis of the liquid products revealed that pressure significantly inhibits the generation of aldol condensation products, i.e., acetone self-condensation products and 4-(2-furyl)-3-buten-2-one from the condensation of acetone and furfural, and acetone was retained in large quantities. In addition, kinetic analysis revealed that the “xylose → furfural → degradation products” pentose-hydrolysis path occurs in the PPAWS and that the rate constant of the “xylose → furfural” step is significantly increased, which is a clear departure from the reaction conducted without additional pressure. Furfural degradation experiments confirmed that adding pressure also inhibits the degradation of furfural in the initial stage of the reaction. The PPAWS exploits the benefits of acetone for lignin removal and the promotion of furfural production, and can be easily integrated into advanced jet fuel production from the aldol condensation of furans and ketones.
Cellulose acetate (CA) is a versatile biopolymer derivative widely used in consumer products such as cigarette filters, textiles, and plastics. The extensive use of CA-based products generates substantial plastic waste, which can persist in the environment for over a decade due to its low biodegradability, posing serious environmental challenges. Herein, we report a one-step conversion process that transforms CA plastic waste into 5-hydroxymethylfurfural (HMF) while simultaneously recovering acetic acid. By employing AlCl 3 as a catalyst in an acetone-water solvent system at 160°C for 50 min, CA exhibited a 53.7 % HMF yield, a threefold increase compared to untreated cellulose, while also achieving a 97.3 % theoretical yield of acetic acid. The HMF yield exceeded 50 % when cigarette filters or CA fabrics were used as substrates. Molecular dynamics simulations revealed that the acetyl groups in CA enhance its coordination with acetone molecules, reducing the probability of protonation at the C1 and C4 oxygen atoms of the CA monomer and thereby suppressing the formation of undesired byproducts. Furthermore, the in-situ regenerated acetic acid actively promotes the HMF production. This study establishes a viable pathway for upcycling CA waste while advancing sustainable management strategies for CA-based plastics, offering a promising solution to mitigate environmental impacts.
危险品化学品经营许可证（带存储）