Chemical Engineering & Technology最新文献

We have designed a separation process of isobutyl alcohol (52.0 mol%) and isobutyl acetate (48.0 mol%) mixture using conventional extractive distillation (ED) and extractive dividing-wall column (E-DWC) with the solvent dimethyl sulfoxide (DMSO). The binary mixture exhibits a minimum boiling azeotrope that is sensitive to pressure. Thermodynamic analyses have shown that the vacuum pressures work better compared to the atmospheric pressure when DMSO is the solvent. Based on the separation with a purity of 99.9 mol%, the E-DWC process has resulted in 9.6 % and 4.8 % reductions in the total annual cost and CO₂ emission rates, respectively, in comparison to the conventional method. After further intensification using the heat pump technique, the E-DWC process with the solvent DMSO has provided more than 40.0 % reduction in energy consumption compared to the ED systems studied in the literature using the solvents butyl propionate and dimethylformamide.

System-scale computational fluid dynamics (CFD) simulations in chemical and process engineering remain limited owing to the complexity of integrating the results obtained at different scales. The present study addresses this issue by correlating the flow behaviors calculated by CFD in porous media at the micro-scale and the macro-scale using deep neural network (DNN) technology. The DNN model is trained using a dataset constructed from the results obtained for a large number of particle-scale CFD simulations that are coupled to macroscopic governing equations. Comparisons with experimental results obtained with a packed bed show that the proposed CFD-DNN method provides predictions of pressure drop with an accuracy that is 28% greater than that of a method based on the Ergun equation.

The research focuses on desalting and regenerating wastewater using membrane capacitive deionization (MCDI) systems with Prussian blue analog and activated carbon electrodes in batch experiments. The experimental results show that the optimized operational parameters for achieving superior deionization regeneration performance in membrane capacitors comprise a voltage magnitude of −1.6 V, a desorption flow rate of 30 mL min⁻¹, and an electrode regeneration duration of 25 min. The MCDI system achieves a desorption amount of 45.87 mg g⁻¹, a remarkable regeneration rate of 99.23 % under the optimized operating conditions. The MCDI system demonstrates a desorption amount and regeneration rate that are 22.56 mg g⁻¹ and 17.47 % higher, respectively, compared to the traditional capacitive deionization system.

This work aims to synthesize novel amphiphilic ionic liquids (AILs), AH-PM, and AD-PM as well as apply them to chemically demulsifying crude oil emulsions. Two AILs containing different long alkyl chains were synthesized and characterized using several techniques. The surface and interfacial indicated AILs’ surface activity and ability to form micelles. For that, the demulsification efficacy (DE) of these AILs was explored using different factors affecting, e.g., AIL dose, settling time (ST), water content, and temperature. The results indicated that the AIL hydrophobicity resulting from the longer alkyl chain could improve AIL DE. Moreover, increased AIL dose, ST, water content, and temperature improved DE.

The effect of temperature, pressure, and specific solvent consumption on extraction yield from Leptocarpha rivularis stalks was studied using a Box–Behnken design. The effect of pressure on extraction yield was the most important, followed by temperature and specific solvent consumption (p ≤ 0.05). The extraction yield correlated (p ≤ 0.05) positively with the CO₂ density. A diffusion model adequately described the cumulative extraction curve with the highest yield at the selected extraction condition. The inhibition of linoleic acid oxidation and the inhibition of lipoxygenase enzyme were higher in the supercritical (SC) extract than in the hydroethanolic extract. SC extraction could be used to isolate compounds from L. rivularis stalks with functional value.

In this study, the impact of reaction parameters, reaction kinetics, and mechanism on the esterification of oleic acid with methanol using Purolite CT151 as a heterogeneous catalyst was investigated. The effects of molar ratio, reaction time, and catalyst amount were examined. The highest oleic acid conversion of 84 % was achieved under the following conditions: methanol/oleic acid molar ratio of 12:1, 20 wt. % catalyst amounts, a reaction time of 7 h, and a reaction temperature of 67 °C. The surface characterization was performed with FTIR and scanning electron microscope analysis. The proposed reaction model was based on the Eley–Rideal mechanism, where methanol adsorbed onto the catalyst surface reacted with oleic acid before water desorption.

Photoelectrochemical (PEC) technology is a promising strategy that can directly convert sunlight into chemical energy. Direct solar water splitting through the PEC process is a desirable method for green hydrogen (H₂) production. This technology has also the potential to capture CO₂ and convert it into fuels using sunlight and water, besides converting N₂ and H₂O to produce ammonia (NH₃), which acts as transportable H₂ storage. The cracking of NH₃ to produce H₂ can also be accomplished using PEC technology. Despite improved PEC performance having been shown, stability, efficiency, and scalability issues still need to be resolved. Even so, PEC technology has much potential as a clean and sustainable solution for addressing global energy and environmental challenges.

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