Ethylene glycol (EG), synthesized from coal-based syngas, is frequently contaminated with refractory impurities 1,2butanediol (BDO) and 1,2-propanediol (PDO), which affect the quality of EG for polyester production. Distillation, one of the existing methods employed, is still difficult for separation and purification due to the close boiling points. Melt crystallization is an effective technology to obtain high-purity organic compounds based on the difference in the melting points of each component in the mixture. Thus, in this work, we have explored the feasibility of the static melt crystallization on the separation of these two binary systems, EG/BDO and EG/PDO, respectively. For this purpose, a jacketed crystallization tube was adopted and the process was divided into three stages: seed generation, crystallization, and sweating. The crystallization parameters were investigated and fractal porous media theory was used to describe the state of the crude crystals. Furthermore, sweating was applied as a finishing treatment. The purity of ethylene glycol was recorded using gas chromatography, and its corresponding UV transmittance spectrum was studied. The results showed that the purity of ethylene glycol could reach ≥99.8% from the two binary systems studied and its UV transmittance at 220 nm was significantly improved by the tertiary separation process. Overall, melt crystallization has been proved as an effective way to solve the difficulty of separating these short-chain glycols.
A convenient, scalable, benign, and efficient epoxidation method based on farringtonite, without the use of transition metals, was developed for the first time.
A new series of bio‐based sulfonate gemini surfactants was synthesized through esterification of renewable linoleic acid with various alcohols and subsequent sulfonation with readily available sodium hydrogensulfite (NaHSO3). Organocatalytic sulfonation of methyl linoleate with NaHSO3 by the triethylamine and tert‐butyl peroxybenzoate catalyst system was investigated, where a methyl linoleate conversion of 96.4% could be achieved while generating high purity product without tedious purification. Three resulting sodium alkyl linoleate disulfonates (SALDs) have been characterized by Fourier transform infrared, high‐performance liquid chromatography, LC–MS, high‐resolution mass spectrometry (HR–MS), nuclear magnetic resonance techniques, and thermogravimetric analysis. The physicochemical properties and surface properties of the SALDs at various concentrations were investigated. The results showed that the SALDs exhibited low Krafft temperature, high water solubility, foam stability (foam half‐life time could reach 15 min), emulsifying ability (emulsification time of 2.0 g/L is 192 s), and good thermal stability. This study enriches the family of anionic gemini surfactants and provides reference data for facile preparation of gemini surfactants.
A new class of ricinoleic acid-derived branched surfactant with a Y-shaped structure (ethoxylated monohydroxy stearic acid methyl ester, 12-HMEEn) was synthesized and characterized by introducing a polyoxyethylene head group in...
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