Autocatalytic Production of 5‑Hydroxymethylfurfural from Fructose-Based Carbohydrates in a Biphasic System and Its Purification

An efficient autocatalytic process for the production of 5-hydroxymethylfurfural (HMF) from fructose-based carbohydrates has been investigated without the addition of any external catalysts in a methyl isobutyl ketone/water biphasic system, leading to elevated HMF yield through continuous extraction of HMF from an aqueous solution. The results show that both the reaction temperature and time have significant effects on fructose conversion and HMF yield; 96.8% of fructose can be converted into 73.6% of HMF with a small amount of levulinic acid and formic acid formed at a point of compromise between the reaction temperature and time (160 °C for 2 h). In addition, this autocatalytic system is suitable for other fructose-based feedstocks, such as sucrose and inulin, to achieve acceptable HMF yield. Moreover, a simple and efficient purification strategy for as-prepared HMF, viz., the NaOH neutralization method, has also been tested, achieving more than 99% of HMF recovery with more than 98% of purity correspondingly

Synthesis of Ionic Liquid-SBA-15 Composite Materials and Their Application for SO₂ Capture from Flue Gas

A series of 1,3-bispropyltriethoxysilane-imidazolium chloride (FILs)-modified SBA-15 adsorbents have been prepared, characterized, and applied in SO₂ capture for the first time. At low FILs loadings, significant levels of grafting were observed, while higher loading levels resulted in retention of a greater fraction of FILs precursors, as evidenced by FTIR spectroscopy. Textural properties gradually declined as FILs content increased, in conjunction with an apparent change in the regular nature of the SBA-15 pore structure and bulk particle morphology, as demonstrated by XRD, TEM, and SEM. SO₂ adsorption breakthrough curves indicated that all materials possessed rapid and facile adsorption properties, with <i>t</i>_0.9 values 1–2 orders of magnitude lower than those obtained over comparable materials under more favorable conditions. The largest total SO₂ adsorption was achieved over 10%FILs@SBA-15, which exhibited a maximized FILs adsorption contribution that remained constant at higher loadings. Corrections against surface area demonstrated that a continual increase in adsorption were apparent, verifying the importance of the change in nature of the FILs at higher loadings. The optimized adsorbent demonstrated few strong SO₂ binding sites, as indicated by excellent stability during adsorption–desorption cycles