N-propanol (N-PRO), acetonitrile (ACN), and water form a ternary azeotropic system. To efficiently recover n-propanol (N-PRO) and acetonitrile (ACN) from wastewater, a basic extractive pressure-swing distillation (EPSD) process was designed based on pressure sensitivity analysis. Firstly, ethylene glycol (EG) was selected as the optimal extractant through relative volatility calculation. The interaction process between EG and N-PRO as well as ACN was analyzed using quantum chemical calculations, and the extractive distillation separation mechanism of EG as an extractant was revealed. Subsequently, the three integrated intensified processes were designed by incorporating heat integration, steam recompression, and pervaporation (PV) technology, namely thermal integrated extractive pressure-swing distillation (HI-EPSD), steam recompression coupled with thermal integrated extractive pressure-swing distillation (SR-EPSD), and extractive pressure-swing distillation coupled with pervaporation (EPSD-PV). For the EPSD-PV process, the polyvinyl alcohol membrane modified with nano-silica was used. Then, molecular dynamics simulations were performed to calculate the diffusion coefficients of solutes in the membrane, and a mass transfer model for the PV process was established. Finally, all processes were simulated using the Aspen Plus software. A multi-objective genetic algorithm was adopted to optimize the process parameters with the objectives of minimizing total annual cost (TAC) and minimizing gas emissions. The three integrated processes were evaluated from four dimensions: economics, environment, energy consumption, and exergy efficiency. The results show that compared with the EPSD process, the SR-EPSD process has the most significant effects in reducing energy consumption (by 29.66%) and decreasing gas emissions (by 26.8%). while the EPSD-PV process exhibits the best performance in terms of TAC reduction (by 14.18%) and exergy efficiency. This study provides a green and economical solution for the treatment of industrial wastewater containing N-PRO and ACN.

The separation of the ternary azeotrope system is still a topic worth studying. An effective method based on a mixed ionic liquids (ILs) extractant was proposed and applied to the separation of isopropanol (IPA), n-hexane (NH) and water (H2O) systems. Firstly, the organic solvent and ILs with better separation effects for the two components of the ternary azeotropic system were screened out by relative volatility calculation, quantum chemistry and molecular dynamics calculation. Based on the synergistic effect of dimethyl sulfoxide (DMSO) and 1-ethyl-3-methylimidazolium thiocyanate ([EMIMSCN]), a mixed ILs extractant was designed. It was then applied to three extractive distillation (ED) processes. Aiming at the minimum total process cost and gas emission, an optimization strategy was designed to achieve multi-objective optimization of process flow, the optimal composition and dosage of the mixed extractant were determined. The process results showed that the total annual cost (TAC) and gas emissions from mixed extractive distillation (MED) were 795406.85 $/y and 1536.84 kg/y, and the process energy consumption was 1987.99 kW. Compared with the ED process with DMSO as an extractant, the MED process can save 40.05 % TAC and reduce 30.39 % gas emission and energy consumption. The mixed extractant was carefully studied, and the addition of ILs was analyzed to increase the relative volatility between IPA and H2O separated by the extractant. The sensitivity analysis of the key variables of the MED process was carried out. The results show that the feed position of the extractant has the greatest influence on the objective function. Finally, the MED and the mixed extractive distillation under reduced pressure (RPMED) process were intensified, and the heat pump coupled thermal integrated Heat-integrated mixed extractive distillation (HPH-MED) process was determined to be the best process based on environmental pollution and energy consumption considerations. The TAC of the process is 767298.474 $/y, the gas emission is 753.84 kg/y, and the energy consumption of the process is 975.13 kW. Compared with the MED process, TAC is reduced by 3.53 %, and total gas emissions and energy consumption are reduced by 50.95 %.

Membrane distillation technology is an important method for desalination, but it is susceptible to membrane contamination and wetting. In this study, PVDF membrane bottom surface was protected with polydimethylsiloxane (PDMS)-modified nonwoven fabric, and the membrane surface was hydrophilically modified with polymers formed from 1-vinyl-2-pyrrolidone (NVP) and vinyltriethoxysilane (VTES) to prepare the Janus membrane with hydrophilic and hydrophobic surfaces. By peeling off the PDMS-coated nonwoven fabric, part of the PDMS chains were transferred to the bottom surface of the PVDF membrane, which significantly improved the hydrophobicity of the bottom surface, and the hydrophobic contact angle of the membrane reached 152.0 degrees. Since the casting liquid was put into a solidification bath containing hydrophilic modifier for simultaneous phase conversion into film and hydrophilic modification, the PVP-VTES was firmly anchored to the surface of the PVDF membrane through silane coupling, which resulted in excellent superhydrophilic stability of the membrane surface, and the hydrophilic contact angle reached 0 degrees. Finally, the Janus membrane showed excellent performance in the separation of brine in DCMD. The membrane could reach a maximum flux of 43.0 kg center dot m- 2 center dot h- 1 and a salt rejection rate of 99.9 % in the separation of 3.5 wt% NaCl solution. In the separation of complex salt solution, after three cycles of experiments, the salt rejection effect remained unchanged while the flux was still stable and maintained at 31.2 kg center dot m- 2 center dot h- 1 . In the separation of 15 wt% NaCl solution, the membrane flux was maintained at 22.9 kg center dot m- 2 center dot h- 1 after three cycles of experiment, and the salt rejection rate was still at 99.9 %. Therefore, this Janus membrane has high permeated flux and better anti-fouling properties, and it is an effective material for treating complex salt and high salinity wastewater.

Active packaging, which can monitor food freshness and extend the shelf life, has gained significant attention in recent years. This study aims to develop a novel carboxymethyl cellulose (CMC)/starch/anthocyanins/ZnO active films with enhanced properties and specific functionalities. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) revealed that the addition of anthocyanins and nano-ZnO particles (ZnO-NPs) led to heterogeneous microstructures and a slight decrease in the crystallinity. Fourier transform infrared spectroscopy (FTIR) indicated that there were no chemical interactions among film components. Active films containing ZnO-NPs exhibited improved ductility, as well as enhanced light barrier and water resistance properties. Notably, a shift from hydrophilic to hydrophobic behavior of the films was observed with high ZnO-NP content, as evidenced by a significant increase in the water contact angle (from 63.44 degrees to 114.22 degrees). Furthermore, the presence of only 1 % ZnO-NPs resulted in efficient inhibition of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) growth. Moreover, active films containing both anthocyanins and ZnO-NPs were highly sensitive to pH changes in buffer solutions (pH 2-11). Based on the results, a recommended film formulation for future active packaging applications is a 80:20 CMC/starch blend with 3 % ZnO-NPs and 0.1 g anthocyanins.

Dye pollution in the aquatic environment can harm ecosystems and human health. Here, we developed a new green adsorbent by applying an improved drying process. Diatomite was embedded in a network structure formed between chitosan and polyvinyl alcohol without using any crosslinking agent to prepare chitosanpolyvinyl alcohol-diatomite hydrogel beads through alkali solidification. The beads were tested for removing a cationic dye (methylene blue (MB)) from water. The structure of the adsorbent beads was analysed using scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The adsorption capacity was investigated, and the results indicated excellent MB adsorption properties. The adsorbents had a rough surface and high swelling capacity of 66.9 g/g. The maximum MB adsorption capacity was 414.70 mg/g, and the adsorption followed the Freundlich isothermal and quasi-second-order kinetic models. The adsorption was an endothermic spontaneous process governed by both intra-particle and external diffusion processes. The proposed adsorption mechanisms involved hydrogen bonding and electrostatic interactions. These adsorbent beads have considerable application potentials owing to their high adsorption capacity, green composition, and non-polluting nature.

As industrial development and the global economy grow rapidly, the consumption of resources and environmental pollution have increasingly intensified, making sustainable development an urgent necessity. This paper develops three types of low-toxicity, high-efficiency deep eutectic solvents (DESs) for the separation of isopropanol and cyclohexane. By screening and optimizing various hydrogen bond acceptors and donors, a variety of DES combinations were formed, and their performance was evaluated using the COSMO-RS model, thereby selecting solvents with significant separation effects. This study not only delved into the extraction mechanisms of these DESs through molecular dynamics simulations but also verified their practical application potential through liquid-liquid extraction experiments and quantum chemical analysis. Combining experimental data, the non-random two-liquid thermodynamic model was used to fit binary interaction parameters. An integrated liquid-liquid extraction-distillation process was established in Aspen V11, aimed at reducing the costs and harmful gas emissions of processes. Compared to conventional extractive distillation (ED) processes, this process saves nearly a quarter of the economic costs and reduces harmful gas emissions, demonstrating its tremendous potential for improving industrial production efficiency and promoting sustainable development.

In this study, a novel dynamic polyphenol polymerization method for the preparation of nanofiltration membrane intercalations was proposed. In this method, TA, PEI and Al3+ could successively form the first polyphenolamine crosslink network and the second metal-phenol cross-linked network on the surface of the support layer. The dense crosslinked layer of TA-PEI-Al3+ formed under dynamic conditions maintains high hydrophilicity compared to the crosslinked network formed under a single pH environment. Aluminum ions possess strong electronegativity since they have relatively high valence states and small ionic radius among transition metal ions. Therefore, this is the first time to incorporate Al3+ into phenol-amine crosslinked networks to form the metal-phenol tri-complexes. The tri-complexes of TA and Al3+ are more robust, promoting the coordination with more water molecules and forming more stable hydrophilic intermediate layers. When an interfacial polymerization reaction is performed on the intermediate layer, this hydrophilic intermediate layer can store aqueousphase PIP and slow down the IP reaction rate through electrostatic interactions. This process helps to form a dense PA separation layer on the support layer surface. The prepared TFC-NF membranes can be used to separate dyes, antibiotics, and compound inorganic salts. The outstanding water permeance of the TFC-NF membrane was determined as 18.7 L/m2 & sdot;h & sdot;bar and the removal rate of mixed pollutants can reach 99 %. The firm intermediate layer enables the optimized modified membrane to maintain stable flux and high rejection rate in 72 h separation test. This modification method provides a useful reference for the preparation of high-performance nanofiltration membranes with plant polyphenols.

The large-scale application of membrane distillation (MD), an important method for desalting seawater, is limited due to membrane fouling. In this study, ethyl orthosilicate (TEOS) was polymerized to obtain different nSiO2 particles. Vinyl triethoxysilane (VTES) was hydrolysed and polycondensation was used to produce spherical polyethylene-sesquioxane (PVSQ) microparticles, which were modified to construct micro/nano particles. Then grafted on the surface of polyvinylidene fluoride (PVDF) composite membrane. The low-surface-energy hydrophobic groups present on the surfaces of the vinyl and ethoxy particles greatly enhanced the membrane hydrophobicity. The particle size of nSiO2 can change the properties of the membrane. The separation performance of the membrane was tested by direct contact membrane distillation (DCMD). In the separation of a constant concentration of feed solution (3.5wt% NaCl), the membrane flux was relatively stable at 23.8kg·m−2·h−1, and the salt interception rate reached 99.99%. In the subsequent separation of a salt/humic acid solution, the flux remained stable and the good anti-fouling performance indicating that this system outperformed the unmodified membrane. Finally, the effect of different cations on the water diffusivity was studied using a molecular simulation method. Both Ca2+ and Mg2+ reduced the diffusion coefficient of water. However, when these two ions were present simultaneously, Ca2+ inhibited the binding of Mg2+ to water, and the diffusion coefficient of water increased. This study provides a novel approach for preparing hydrophobic membranes for the separation of complex brines.

Efficient separation materials with multifunctional and switchable properties are urgently needed to treat submicron-scale oily droplets. Herein, tannic acid (TA) and polyethylenimine (PEI) were blended with poly (vinylidene fluoride) (PVDF) and used to coat a polydimethylsiloxane (PDMS)-modified non-woven fabric immersed in a CuSO4/H2O2 coagulation bath. TA and PEI form a phenolamine hydrophilic network that migrates to the surface and firmly binds to the PVDF substrate. CuSO4 catalyses the H2O2 oxidation, promoting the selfpolymerisation of phenol hydroxyl group for forming a carboxyl group. Furthermore, the remaining Cu2+ ions complex with TA to form a metal-phenol cross-linked network. A double-cross-linked hydrophilic layer with polyphenols as connection points was formed on the PVDF surface. The hydrophilic contact angle of the membrane reached 0. A rough structure with PDMS micro-/nanoparticles was constructed on the PVDF underside via surface nanocasting and the hydrophobic contact angle of the membranes reached 165. In experiments, each side of the obtained Janus membranes demonstrated surface superhydrophilic and superlipophilic properties and a high flux and excellent separation efficiency for various oil-water emulsions. The integrated Janus membranes are suitable for unidirectional liquid collection, oil-water emulsion separation, cationic pigment adsorption and dealing with complex dye-emulsion pollutants. The integrated structure formed by the hydrophilic layer and the membrane enhances the fouling resistance of the membrane and the removal rate of pollutants reached >99 %. This research presents a simple approach to prepare Janus membranes with asymmetric wettability.

Multicomponent liquid mixtures, particularly azeotropes, are extensively utilized in the chemical, petroleum, pharmaceutical, and other processing industries. Energy-saving and efficient separation of azeotropes holds significant value for the design and development of sustainable industrial processes. Extractive distillation (ED) has consistently played a pivotal role in azeotrope separation. We offer a broad and comprehensive review that encompasses recent progress in multiple aspects of ED, including the screening of entrainers, process design, enhancement schemes, dynamic control strategies, and environmental assessment. Initially, we delved into the application of quantum chemistry calculations and molecular dynamics simulation for screening suitable entrainers. We then elucidate the design principles and forms of two distinct types of ED processes. Subsequently, we explore the intensification mechanisms of the ED process through coupling mechanisms, such as heat integration and the combination of ED with other distillation processes. We also summarize the recent improvements in dynamic control strategies for various ED processes. Lastly, we evaluate various aspects of ED from the perspectives of environmental impact, economic viability, and exergy analysis. This study investigates the challenges, prospects, and emerging trends of ED technology for the separation of multicomponent azeotropes.

The numerical solution of the dynamic optimization problem is often sought for chemical processes, but the discretization of control variables is a difficult problem. Firstly, based on the analysis of the seagull optimization algorithm, this paper introduces the cognitive part in the process of a seagull's attack behavior to make the group approach the best position. Secondly, the algorithm adds the mechanism of natural selection, where the fitness value is used to sort the population, and the best half is used to replace the worst half, so as to find out the optimal solution. Finally, the improved seagull optimization algorithm (ISOA) is combined with the unequal division method to solve dynamic optimization problems. The feasibility of the method is verified by three practical examples of dynamic optimization in chemical industry.

Ethyl tert-butyl ether, an environmentally friendly gasoline additive, has high industrial application value, which is very necessary to study the refined process. The development of an efficient ternary azeotropic separation and purification process promotes the establishment of an environment-friendly society. In this study, two common methods of extractive distillation and extractive pressure swing distillation and three enhanced methods of heat integration process and coupled pervaporation technology were used to efficiently separate ethyl tert-butyl ether/ethanol/water. The most effective and environmentally friendly extractants were screened by analyzing the effects of relative volatility, intermolecular interactions and biotoxicity. The multi-objective optimization method was adopted to optimize the process with the annual total cost and gas emissions as the goals and the optimal parameters and process plans for extractive distillation and extractive pressure swing distillation were obtained. Finally, five technological processes are analyzed from the aspects of economy, environment, energy and exergy. It was found that the use of pressure swing distillation would greatly increase the economic and energy loss. And compared with the conventional process, the total annual cost of the extractive distillation coupled pervaporation process was reduced by 15.12 % and the environment was reduced by 20.17%. The coupling process that is of great significance to the purification of ethyl tert-butyl ether, an environmentally friendly gasoline additive was superior to the single distillation process in terms of economy, environment and energy.

Oil/water mixtures from industrial and domestic wastewater adversely affect the environment and human beings. In this context, the development of a facile and improved separation method is crucial. Herein, dopamine was used as a bioadhesive to bind tea polyphenol (TP) onto the surface of a polyvinylidene fluoride (PVDF) membrane to form the first hydrophilic polymer network. Sodium periodate (NaIO4) is considered an oxidising agent for triggering self-polymerisation and can be used to introduce hydrophilic groups via surface manipulation to form the second hydrophilic network. In contrast to the individual polydopamine (PDA) and TP/NaIO4 composite coatings for a hydrophobic PVDF microfiltration membrane, a combination of PDA, TP, and NaIO4 has achieved the most facile treatment process for transforming the hydrophobic membrane into the hydrophilic state. The hierarchical superhydrophilic network structure with a simultaneous underwater superoleophobic membrane exhibited excellent performance in separating various oil-in-water emulsions, with a high water flux (1530 L.m−2 h−1.bar) and improved rejection (98%). The water contact angle of the modified membrane was 0° in 1 s. Moreover, the steady polyphenol coating was applied onto the surface, which endowed the membrane with an adequate antifouling and recovery capability and a robust durability against immersion in an acid, alkali, or salt solution. This facile scale-up method depends on in situ plant-inspired chemistry and has remarkable potential for practical applications.

Petroleum wastewater contains large amounts of methyl tert-butyl ether (MTBE) and ethanol azeotropes. Efficiently and cleanly separating these azeotropes while conserving energy and reducing the emission of petroleum wastewater is an urgent problem that needs to be solved. In this work, the process of extracting MTBE from petroleum wastewater with water and ionic liquids (ILs) mixed extractant was clarified, and a complete method of evaluating the extraction performance based on the COSMO-SAC model, liquid-liquid extraction measurement, and micro-scale analysis mechanism is proposed. The COSMO-SAC model was used to determine organic solvents and ILs with the best extraction performance from among more than 250 ILs. A mixed solvent of water and the IL 1-ethyl-2,3-dimethylimidazolium ethylsulfate ([EMMIM][EtSO4]) at different molar ratios was selected for the liquid-liquid extraction experiment. It was found that the distribution coefficients and selectivity were maximum when the molar ratio of [EMMIM][EtSO4] to water was 1:2. Combined with molecular dynamics simulations and quantum chemical calculations, the interaction mechanisms of different solvents with MTBE and ethanol were revealed on the micro-level. This work provides a prototype for the high-efficiency extraction of MTBE from petroleum wastewater using a new mixed solvent of ILs and water, and it provides an application prospect for the efficient and green recycling of MTBE.

Oil-water emulsions are types of wastewater that are difficult to treat. A polyvinylidene fluoride hydrophobic matrix membrane was modified using a hydrophilic polymer, poly(vinylpyrrolidone-vinyltriethoxysilane), to form a representative Janus membrane with asymmetric wettability. The performance parameters of the modified membrane, such as the morphological structure, the chemical composition, the wettability, the hydrophilic layer thickness, and the porosity, were characterized. The results showed that the hydrolysis, migration, and thermal crosslinking of the hydrophilic polymer in the hydrophobic matrix membrane contributed to an effective hydrophilic layer on the surface. Thus, a Janus membrane with unchanged membrane porosity, a hydrophilic layer with controllable thickness, and hydrophilic/hydrophobic layer “structural integration” was successfully prepared. The Janus membrane was used for the switchable separation of oil-water emulsions. The separation flux of the oil-in-water emulsions on the hydrophilic surface was 22.88 L·m−2·h−1 with a separation efficiency of up to 93.35%. The hydrophobic surface exhibited a separation flux of 17.45 L·m−2·h−1 with a separation efficiency of 91.47% for the water-in-oil emulsions. Compared to the lower flux and separation efficiency of purely hydrophobic and hydrophilic membranes, the Janus membrane exhibited better separation and purification effects for both oil-water emulsions.

The generation of multiple stoichiometric cocrystals from safe and nontoxic water is a rare occurrence. This study explored three different stoichiometric cocrystals (1:1, 1:2, and 2:1) of pyrazinamide-3-nitrophthalic acid cocrystals characterized by single crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectrophotometry. Besides, the hydrogen bonding interaction was analyzed by the molecular electrostatic potential surfaces and the Hirshfeld surface. The hygroscopicity and solubility of the three cocrystals and the study of cocrystal transformation revealed a strong correlation between the properties of the cocrystals and the internal arrangement of the molecules. The most stable form (1:2) showed the strongest stability and the best performance in the evaluation test and had the greatest application potential.

A large amount of waste liquids containing methanol/acetone/water mixtures are produced in the synthesis of methyl methacrylate (MMA). Under the advocacy of green chemical industry, it is urgent to develop an efficient, economic and energy-saving mixture separation process. Through thermodynamic azeotropic behavior and pressure sensitivity analysis, pressure-swing distillation was determined and the optimal separation pressure of each column in the process was obtained. Due to the composition of waste liquids produced were quite different in MMA production, the pressure-swing distillation separation process was designed to fully achieve the accurate waste liquids treatment. Taking the total annual cost (TAC) as the target, the sequential iteration method was used to optimize the process, and the impact of composition on economy was compared. In order to further realize the energy-saving of the separation process, the pervaporation membrane module was introduced to pretreat the waste liquid in the pressure-swing distillation. The results showed that the TAC of the coupling process was 46% higher than that of the pressure-swing distillation process, and the thermodynamic efficiency was 30% higher. This study provides waste liquid treatment technology for enterprises and analyzes its economic and energy efficiency, which has reference significance for the development of coupled separation technology.

Antibacterial and pH-responsive composite films for active food packaging were fabricated based on polyvinyl alcohol (PVA), cassava starch, ethyl lauroyl arginate (LAE), and mulberry anthocyanin. With the incorporation of LAE and mulberry anthocyanin, the PVA/starch blend films exhibited a less compact and more heterogeneous surface structure. The tensile strength and elongation at break of the active films were not significantly affected when the mulberry anthocyanin content was less than 20%. Moreover, the incorporation of mulberry anthocyanin effectively improved the UV barrier property of the blend films. Notably, while mulberry anthocyanin showed obvious color changes in buffer solutions with different pH values, the changes were indistinguishable for the PVA/starch/mulberry anthocyanin films. By contrast, the color changes of the PVA/starch/LAE/mulberry anthocyanin films were more noticeable, indicating the addition of LAE increased the pH sensitivity of the blend films. Furthermore, the PVA/starch/LAE/mulberry anthocyanin films efficiently inhibited the growth of both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) due to the strong antibacterial activity of LAE. According to the spoilage test, the active films containing 5% mulberry anthocyanin and 5% LAE effectively indicated and slowed down the spoilage process of dairy milk. Our results demonstrate that PVA/starch/LAE/mulberry anthocyanin films have high potential as bioactive packaging materials applied in the food industry.

工程教育专业认证理念对高等院校的高质量发展,尤其是对大学生未来就业有着重要的意义.民族院校的学生由于生源等原因,加上化工原理实验课程教学存在的问题,工科类专业课程教学如何结合工程教育专业认证理念和自身实际情况改进教学,跟上时代的步伐,是许多教育工作者需要考虑的问题.文章对开展工程教育专业认证的重要性,化工原理实验课程教学的意义、存在的问题、教学改革现状和探索进行了阐述.

The separation and purification of methyl-chlorosilanes play an important role in the organosilicon industry. NSGA-II algorithm was applied to the multi-objective optimization of traditional organosilicon distillation. In order to save energy, pinch technology and vapor recompression technology were introduced. Two heat integration enhancement schemes, which were heat integrated distillation process (HIDP) and vapor recompression assisted heat integrated distillation process (VRC-HIDP), were designed. The results show that the key to reducing energy consumption lies on the energy saving of M1/M2 separation column. Hence, the pressure-regulating heat integrated distillation process (PR-HIDP) and the vapor recompression assisted pressure-regulating heat integrated distillation process (VRC-PR-HIDP) were proposed. The pressure of M1/M2 separation column was increased to make better use of overhead steam to exchange heat for other columns in the PR-HIDP and VRC-PR-HIDP. The results show the gas emissions and total annual cost (TAC) of the four improved energy-saving schemes are reduced significantly. The VRC-PR-HIDP has the best economic and environmental performance, with TAC reduced by 44.46 % and gas emissions reduced by 70.96 % compared with the traditional distillation process (TDP).