Optimal modes of side-section flow in heat-pump-assisted extractive distillation systems for separating allyl alcohol–allyl acetate mixtures with butyl propionate

Objectives. To investigate the influence of side-section flow modes on the energy efficiency of a partially thermally coupled distillation sequence (PTCDS) with a vapor recompression heat pump for the extractive distillation of an allyl alcohol–allyl acetate mixture with n-butyl propionate and identify modes under which the combined use of a PTCDS and heat pump are the most efficient.Methods. Mathematical modeling in the Aspen Plus V10 software package was used as the main research method. The local composition equation of the non-random two-liquid model was used as a model for describing the vapor–liquid equilibrium, while the Redlich–Kwong model was used to consider the non-ideal vapor phase. When modeling the conventional extractive distillation scheme and PTCDS, parametric optimization was carried out according to the criterion of the total energy costs in the column reboilers. For the economical evaluation, Aspen Process Economic Analyzer V10.1 tools were used.Results. For extractive distillation of a mixture of allyl alcohol (30 wt %) and allyl acetate (70 wt %) with n-butyl propionate as an entrainer, the minimum energy consumption was achieved at the same side-section flow mode for the variants of a PTCDS with and without a heat pump. The reduction in energy costs relative to the conventional scheme was 20% for the sequence without a heat pump and 38% for that with a heat pump. An economic assessment was made of the best options in comparison with the conventional extractive distillation scheme. The PTCDS with a heat pump had an advantage over the sequence without a heat pump only for long periods of operation.Conclusions. For the extractive distillation of an allyl alcohol–allyl acetate mixture, the optimal modes for the combined use of a PTCDS with a vapor recompression heat pump coincide with the optimal modes for a PTCDS without a heat pump.

Synthesis and Antioxidant Activity of Some Novel a Zino and Pyranopyrazole Derivative

Background: Pyranopyrazole derivatives has vital role in the class of organic compounds because of their broad spectrum of biological as well as pharmacological importance.Results: Our current goal is the [3+3] Cycloaddition of benzoyl isothiocyanate and pyrazolone 1 undergo oxidation cyclization producing pyrazoloxadiazine 3. The diol 5 was obtained as a condensation of two equivalent of 1 with thiopene-2-carboxaldhyde in acetic acid above sodium acetate mixture. When the condensation carried out in presence of piperidine under fusion the unsaturated ketone 4 was obtained. The cyclocondensation of pyrazolone 1 and pyruvic acid derivative in the presence of aminotive reagent resulted in pyrazolo pyrimidine 7. The pyrazolo pyran derivative 11 was resulted from the [3+3] cycloaddition of 1 and cinnamic acid. ᴽpyrone derivative was prepared by acylation of 12 with to equivalent of acetic anhydride. Phthalic anhydride undergoes arolyation using zinc chloride as a catalyst. The cyclic keto acid 23 was synthesized by the action of succinic anhydride on 12 in acetic medium. Cinnamic acid and 12 leads to pyrazole derivative 24 through Michael reaction. All of the tested compounds showed good microbial activity against pathogenic microorganisms. Newly synthesized compounds were screened for their antioxidant activity. Some of tested compounds exhibited promising activities.Conclusions: The newly synthesized compounds were found to be potent towards antioxidant activity. Moreover, the results showed that nearly a compound 5 was found to be the most potent levels of activity. Additionally, compounds 13, 14, 16, 22, 23 and 24 were found to have moderate activity. While compound 14 was found the lowest potent levels.

Specific Structure and Properties of Composite Membranes Based on the Torlon® (Polyamide-imide)/Layered Perovskite Oxide

The use of perovskite-type layered oxide K2La2Ti3O10 (Per) as a modifier of the Torlon® polyamide-imide (PAI) membrane has led to the formation of an specific structure of a dense nonsymmetrical film, namely, a thin perovskite-enriched layer (3–5 μm) combined with the polymer matrix (~30 μm). The PAI/Per membrane structure was studied by SEM in combination with energy dispersive microanalysis of the elemental composition which illustrated different compositions of top and bottom surfaces of the perovskite-containing membranes. Measurement of water and alcohol contact angles and calculation of surface tension revealed hydrophilization of the membrane surface enriched with perovskite. The transport properties of the nonsymmetrical PAI/Per membranes were studied in the pervaporation of ethanol‒ethyl acetate mixture. The inclusion of 2 wt.% Per in the PAI gives a membrane with a high separation factor and increased total flux.

Impact of Endometallofullerene on P84 Copolyimide Transport and Thermomechanical Properties

Novel polymer composite materials, including unique nanoparticles, contribute to the progress of modern technologies. In this work, the endohedral fullerene C60 with incapsulated iron atom (endometallofullerene Fe@C60) is used for modification of P84 copolyimide. The impact of 0.1, 0.5, and 1 wt % endometallofullerene on the structure and physicochemical properties of polymer films is studied through scanning electron microscopy, thermogravimetric analysis, and thermomechanical tests. Transport properties are estimated through sorption and pervaporation techniques toward methanol and methyl acetate mixture. The inclusion of endometallofullerene into the copolyimide matrix improves membrane permeability and selectivity in the separation of methanol—methyl acetate mixtures. The maximal effect is achieved with a composite containing 0.5 wt % Fe@C60. The developed composites are effective for energy and resource saving purification of methyl acetate by pervaporation.