Adsorption of Phenylethyl Alcohol onto Granular Activated Carbon from Aqueous Solution: Kinetics, Equilibrium, Thermodynamics, and Dynamic Studies

Comparative studies were performed toward adsorption kinetics and equilibrium of phenylethyl alcohol (PEA) onto three typical types (F400D, CAL, and 207CX) of granular activated carbons (GAC). The effective diffusion coefficients were of the order of 10^–12 m²·s^–1 for PEA adsorption on the GAC at 298 K. Desorption ratios of PEA from GAC were 92.2–99.9% achieved by methanol in batch mode at 298 K. Among the GAC employed, the carbon CAL proved to be superior in terms of physical properties as well as adsorption capacity and rate toward PEA. Dynamic adsorption was investigated using this optimal activated carbon. The maximum bed saturation capacity toward PEA was 2.471 mmol·g^–1 under optimal conditions (GAC mass 10.01 g, inlet concentration 4.391 mmol·kg^–1, flow rate 6.5 × 10^–3 kg·min^–1, temperature 298 K). The Yoon-Nelson model best described breakthrough data of PEA on GAC bed, whereas Yan and Clark models gave a relatively poor fit. The outcome of this work will facilitate adsorptive recovery of PEA from rose hydrolate byproduct using GAC

Chemical composition of essential oils and hydrosols from fresh flowers of <i>Cerasus subhirtella</i> and <i>Cerasus</i><i>serrulata</i> from East China

<div><p>Essential oils and hydrosols from fresh flowers of <i>Cerasus subhirtella</i> (Miq.) Sok. and <i>Cerasus</i><i>serrulata</i> (Lindl.) London from East China were analysed by gas chromatography and gas chromatography–mass spectrometry for the first time. The major components of the essential oils from <i>C. subhirtella</i> and <i>C.</i><i>serrulata</i> were benzaldehyde (31.2% and 42.1%, respectively), tricosane (23.1% and 27.7%, respectively) and pentacosane (23.2% and 19.0%, respectively). The main constituents of the hydrosol volatiles from <i>C. subhirtella</i> and <i>C.</i><i>serrulata</i> were benzaldehyde (67.5% and 64.3%, respectively) and mandelonitrile (12.5% and 12.4%, respectively). Benzaldehyde was the key component of the essential oils, while benzaldehyde as well as mandelonitrile was the principal compound of the hydrosols.</p></div

The Manufacture of a Homochiral 4‑Silyloxycyclopentenone Intermediate for the Synthesis of Prostaglandin Analogues

A process is described for the synthesis of kilogram quantities of homochiral 4-silyloxycyclopentenone (<i>R</i>)-<b>1</b>, a key intermediate useful for the synthesis of a plurality of prostaglandin analogue drugs. Cyclopentenone (<i>R</i>)-<b>1</b> was synthesized in 14 isolated steps from furfural. Key steps in the synthesis include a Wittig reaction, Piancatelli rearrangement, and an enzymatic resolution featuring in situ recycling of the undesired enantiomer furnishing the desired homochiral alcohol in ≥99.5% ee. As a retort to the unsatisfactory coformation of about 8% at best of the <i>trans</i>-olefin in the Wittig reaction, a change to the order of several steps and the identification of a recrystallisable, amine salt derivative, <b>2</b>, allowed the unwanted isomer to be controlled to as low as 0.2%