The kinetic behavior of esterification between methacrylic acid and methanol catalyzed by NKC-9 resin was studied in a fixed bed reactor. The reaction was conducted in the temperature range of 323.15 to 368.15 K with the molar ratio of reactants from 0.8 to 1.4 under certain pressure. The measurement data were regression with the pseudo-homogeneous (P-H), Eley-Rideal (E-R), and Langmuir-Hinshelwood (L-H) heterogeneous kinetic models. Independent adsorption experiments were implemented to gain the adsorption equilibrium constants of four components. Among the above three models, the L-H model exhibited the best fitting results. The stability of NKC-9 was evaluated by long-term running with the yield of methyl methacrylate no decrease during 3000 h operation. The structure and physicochemical properties of the new and used catalyst were performed by several characterizations including thermogravimetric analysis (TG), scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) and so on.

The catalytic hydrogenation of 2-nitro-4-acetylamino anisole (NMA) is a less-polluting and efficient method to produce 2-amino-4-acetamino anisole (AMA). However, the kinetics of catalytic hydrogenation of NMA to AMA remains obscure. In this work, the kinetic models including power-law model and Langmuir-Hinshelwood-Hougen-Watson (LHHW) model of NMA hydrogenation to AMA catalyzed by Raney nickel catalyst were investigated. All experiments were carried out under the elimination of mass transfer resistance within the temperature range of 70–100 ℃ and the hydrogen pressure of 0.8–1.5 MPa. The reaction was found to follow 0.52-order kinetics with respect to the NMA concentration and 1.10-order kinetics in terms of hydrogen pressure. Based on the LHHW model, the dual-site dissociation adsorption of hydrogen was analyzed to be the rate determining step. The research of intrinsic kinetics of NMA to AMA provides the guidance for the reactor design and inspires the catalyst modification.

Catalytic pyrolysis of digestate to produce aromatic hydrocarbons can be combined with anaerobic fermentation to effectively transform and utilize all biomass components, which can achieve the meaningful purpose of transforming waste into high-value products. This study explored whether catalytic pyrolysis of digestate is feasible to prepare aromatic hydrocarbons by analyzing the thermogravimetric characteristics, pyrolysis characteristics, and catalytic pyrolysis characteristics of digestate. For digestate pyrolysis, an increase in temperature was found to elevate the CO, CH₄, and monocyclic aromatic hydrocarbon (benzene, toluene, and xylene; BTX) content, whereas it decreased the contents of phenols, acids, aldehydes, and other oxygenates. Furthermore, the catalytic pyrolysis process effectively inhibited the acids, phenols, and furans in the liquid, whereas the yield of BTX increased from 25.45% to 45.99%, and the selectivity of xylene was also increased from 10.32% to 28.72% after adding ZSM-5. ZSM-5 also inhibited the production of nitrogenous compounds.

Novel organo-inorganic hybrid materials (MTW-x-SO₃H) have been fabricated by immobilizing 3-mercaptopropyltriethoxysilane onto mesopore MTW zeolites, which is treated via a simple oxidation process with hydrogen peroxide as the oxidant to transform sulfhydryl group into sulfonic acid group. The organic sulfhydryl groups are covalently bonded to the external surface of MTW zeolites through the condensation between siloxane arising from organic fragments with silanol groups on the surface of MTW zeolites, the hybrids contain sulfonic acid group within the external surface of MTW zeolites and an opened mesoporous system in the matrix of MTW zeolites, which provide enough accessible Brønsted acid sites for the alkylation between phenol with tert-butyl alcohol. Through this methodology it’s possible to prepare multifunctional materials where the plenty of mesopores are benefit for the introduction of larger numbers of sulfonic acid groups that contributes to activity during reactions, resulting in high activity (>55%) of MTW-4-SO₃H and desired selectivity (>56%) of 2-TBP (2-tert-butyl phenol) in the alkylation between phenol with tert-butyl alcohol.

To date, there is no research that deals with biological waste as fillers in polyphenylene sulfide (PPS). In this study, oyster shells were recycled and treated to prepare thermally-treated oyster shells (TOS), which were used as PPS fillers to make new bio-based antibacterial composite materials. The effect of varying the content of TOS was studied by means of structure and performance characterization. PPS/TOS composites were demonstrated to have an antibacterial effect on the growth of E coli and S. aureus. Qualitative analysis showed that when the TOS content was ≥ 30% and 40%, the composite materials had an apparent inhibition zone. Quantitative analysis showed that the antibacterial activity increased with the TOS content. Fourier transform infrared spectroscopy indicated the formation of hydrogen bonds between the molecular chains of TOS and PPS and the occurrence of a coordination reaction. At 10% TOS, the composite tensile strength reached a maximum value of 72.5 MPa, which is 9.65% higher than that of pure PPS. The trend of bending properties is the same as that of tensile properties, showing that the maximum property was reached for the composite with 10% TOS. At the same time, the crystallinity and contact angle were the highest, and the permeability coefficient was the lowest. The fatigue test results indicated that for the composite with 10% TOS, the tensile strength was 23% lower than static tensile strength, and the yield strength was 10% lower than the static yield strength. The results of the study showed that TOS not only could reduce the cost of PPS, but also could impart antibacterial properties and enhance the mechanical and, barrier properties, the thermostability, as well as the crystallinity.

To solve the environmental pollution and low yield during the sythesis of zeolitic imidazolate frameworks (ZIFs) and their derived materials, a KOH-assisted aqueous strategy is proposed to synthesize cobalt zeolitic imidazolate framework (ZIF-67) polyhedrons, which are used as precursors to prepare cobalt selenide/carbon composites with different crystal phases (Co_0.85Se, CoSe₂). When evaluated as anode material for lithium ion batteries, Co_0.85Se/C composites deliver a reversible capacity of 758.7 mA·h·g^-1 with a capacity retention rate of 90.5% at 1.0 A·g^-1 after 500 cycles, and the superior rate capability is 620 mA·h·g^-1 at 2.0 A·g^-1. The addition of KOH accelerates the production of ZIF-67 crystals by boosting deprotonation of dimethylimidazole, resulting in rapid growth and structures transition from two-dimensional to three-dimensional of ZIF-67 in aqueous solution, which greatly promotes the application of MOFs in the field of energy storage and conversion.

Struvite (MAP) crystallization technology is widely used to treat ammonia nitrogen in waste effluents of its simple operation and good removal efficiency. However, the presence of heavy metal ions in the waste effluents causes problems such as slow crystallization rate and small crystal size, limiting the recovery rate and economic value of the MAP. The present study was conducted to investigate the effects of concentrations of three heavy metal ions (Cu²⁺, Zn²⁺, and Pb²⁺) on the crystal morphology, crystal size, average growth rate, and crystallization kinetics of MAP. A relationship was established between the kinetic rate constant K_t calculated by the chemical gradient model and the concentrations of heavy metal ions. The results showed that low concentrations of heavy metal ions in the solution created pits on the MAP surface, and high level of heavy metal ions generated flocs on the MAP surface, which were composed of metal hydroxides, thus inhibiting crystal growth. The crystal size, average growth rate, MAP crystallization rate, and kinetic rate constant K_t decreased with the increase in heavy metal ion concentration. Moreover, the K_t demonstrated a linear relationship with the heavy metal concentration ln(C/C^*), which provided a reference for the optimization of the MAP crystallization process in the presence of heavy metal ions.

Sodium-contained compounds are promising sintering additives for the low-temperature preparation of reaction bonded SiC membranes. Although sodium-based sintering additives in various original states were attempted, their effects on microstructure and surface properties have rarely been studied. In this work, three types of sodium-based additives, including solid-state NaA zeolite residue (NaA) and liquid-state dodecylbenzene sulfonate (SDBS) and water glass (WG), were separately adopted to prepare SiC membranes, and the microstructure, surface characteristics and filtration performance of these SiC membranes were comparatively studied. Results showed that the SiC membranes prepared with liquid-state SDBS and WG (S-SDBS and S-WG) showed lower open porosity yet higher bending strength compared to those prepared with solid-state NaA (S-NaA). The observed differences in bending strength were further interpreted by analyzing the reaction process of each sintering additive and the composition of the bonding phase in the reaction bonded SiC membranes. Meanwhile, the microstructural differentiation was correlated to the original state of the additives. In addition, their surface characteristics and filtration performance for oil-in-water emulsion were examined and correlated to the membrane microstructure. The S-NaA samples showed higher hydrophilicity, lower surface roughness (1.80 μm) and higher rejection ratio (99.99%) in O/W emulsion separation than those of S-WG and S-SDBS. This can be attributed to the smaller mean pore size and higher open porosity, resulting from the originally solid-state NaA additives. Therefore, this work revealed the comprehensive effects of original state of sintering additives on the prepared SiC membranes, which could be helpful for the application-oriented fabrication by choosing additives in suitable state.

Coal gasification slag (CGS) is a type of solid waste produced during coal gasification, in which heavy metals severely restrict its resource utilization. In this work, the mineral occurrence and distribution of typical heavy metal Cr in CGS is investigated. The leaching behavior of Cr under different conditions is studied in detail. Acid leaching-selective oxidation-coprecipitation method is proposed based on the characteristics of Cr in CGS. The detoxification of Cr in CGS is realized, and the detoxification mechanism is clarified. Results show that Cr is highly enriched in CGS. The speciation of Cr is mainly residual fraction (74.47%-86.12%), which is combined with amorphous aluminosilicate. Cr³⁺ and Cr⁶⁺ account for 90.93%-94.82% and 5.18%-9.07% of total Cr, respectively. High acid concentration and high liquid-solid ratio are beneficial to destroy the lattice structure of amorphous aluminosilicate, thus improving the leaching efficiency of Cr, which can reach 97.93% under the optimal conditions. Acid leaching-selective oxidation-coprecipitation method can realize the detoxification of Cr in CGS. Under the optimal conditions, the removal rates of Fe³⁺ and Cr³⁺ in the leaching solution are 80.99%-84.79% and 70.58%-71.69%, respectively, while the loss rate of Al³⁺ is only 1.10%-3.35%. Detoxification slag exists in the form of Fe-Cr coprecipitation (Fe_1-xCr_xOOH), which can be used for smelting. The detoxification acid leaching solution can be used to prepare inorganic polymer composite coagulant poly-aluminum chloride (PAC). This study can provide theoretical and data guidance for detoxification of heavy metal Cr in CGS and achieve resource utilization of coal gasification solid waste.

Organic solvent nanofiltration (OSN) membranes have a great application prospect in organic solvent separation, but the development of OSN membranes is mainly restricted by trade-off between permeability and rejection rate. In this work, a TA/Fe³⁺ polymer was introduced into polyetherimide (PEI) ultrafiltration membranes crosslinked with hexamethylene diamine as the intermediate layer, and OSN membranes with high separation performance and solvent permeability were obtained through interfacial polymerization and solvent activation. The interlayer with high surface hydrophilicity and a fixed pore structure controlled the adsorption/diffusion of the amine monomer during interfacial polymerization, forming a smooth (average surface roughness < 5.5 nm), ultra-thin (separation layer thickness reduced from 150 to 16 nm) and dense surface structure polyamide (PA) layer. The PA--HDA/PEI membrane retained more than 94% of methyl blue (BS) in 0.1 g·L^-1 BS ethanol solution at 0.6 MPa, and the ethanol permeation reached 28.56 L^-1·m^-2·h^-1. The average flux recovery ratio (FRR) of PA--HDA/PEI membrane was found to be 84%, which has better fouling resistance than PA-HDA/PEI membrane, and it was found to have better stability performance through different solvent immersion experiments and continuous operation in 0.1 g·L^-1 BS ethanol solution. Compared with thin-film composite nanofiltration membranes, the PA--HDA/PEI membrane can be manufactured from an economical and environment-friendly method and overcomes the trade-off between permeability and rejection rate, showing great application potential in organic solvent separation systems.

Naphthenic base oil is an important lubricating base oil and very scarce in the global petroleum resources. Herein, a series of alkylated tetralin fluids similar to naphthenic base oils were produced by the alkylation of tetralin and α-olefins (n-hexene, n-octene, n-decene) with ionic liquid Et₃NHCl/AlCl₃ as the catalyst, where the applied raw materials are totally derived from the coal chemical industry. The product composition could be controlled by adjusting the feeding ratio of tetralin and olefin. The synthetic fluids were evaluated as lubricating base oils to reveal the structure-property correlations. Their principal physicochemical and tribological properties depend on the chain-length of α-olefins and the number of alkyl groups onto the aromatic rings. Bis-(octyl- or decyl-) alkyl tetralin exhibited good properties in terms of viscosity, thermo-oxidation stability and pour point, as well as friction-reducing and anti-wear performance, showing great potential for producing naphthenic base synthetic oils from coal-based chemicals.

Copper was extracted from methylchlorosilane slurry residue by a direct hydrogen peroxide leaching method. A number of experimental parameters were analyzed to determine the extraction efficiency of copper. The extraction efficiency of copper reached 98.5% under the optimal leaching conditions, such as the hydrogen peroxide concentration of 1.875 mol·L^-1, the leaching temperature of 323 K, the liquid-solid ratio of 20 ml·g^-1, and the stirring speed of 300 r?min^-1. The leaching kinetics of the copper extraction process was then described by the shrinking core model. There were two stages. The first stage was controlled by chemical reactions, while the second stage was controlled by interface transfer and product layer diffusion. The activation energy and kinetic control equations were determined, as well as an explanation of the leaching mechanism of copper extraction based on kinetic analysis and materials characterization. Copper resources can be recovered from the methylchlorosilane slurry residue efficiently and inexpensively with the methods used in this study.

In this study, ferric nitrate modified carbon nanotube composites (FCNT) were prepared by isovolumetric impregnation using carbon nanotubes (CNTs) as the carrier and ferric nitrates the active agent. The batch experiments showed that FCNT could effectively oxidize As(III) to As(V) and react with it to form stable iron arsenate precipitates. When the dosage of FCNT was 0.1 g·L^-1, pH value was 5-6, reaction temperature was 35 ℃ and reaction time was 2 h, the best arsenic removal effect could be achieved, and the removal rate of As(V) could reach 99.1%, which was always higher than 90% under acidic conditions. The adsorption results of FCNT were found to be consistent with Langmuir adsorption by static adsorption isotherm fitting, and the maximum adsorption capacity reached 118.3 mg·g^-1. The material phase and property analysis by scanning electron microscopy, Brunauer-Emmett-Teller, Fourier transform infrared spectoscopy, X-ray photoelectron spectroscopy and other characterization methods, as well as adsorption isotherm modeling, were used to explore the adsorption mechanism of FCNT on arsenic. It was found that FCNT has microporous structure and nanostructure, and iron nanoparticles are loosely distributed on CNTs, which makes the material have good oxidation, adsorption and magnetic separation properties. Arsenic migrates on the surface of FCNT composites is mainly removed by forming insoluble compounds and co-precipitation. All the results show that FCNT treats arsenic at low cost with high adsorption efficiency, and the results also provide the experimental data basis and theoretical basis for arsenic contamination in groundwater.

The development of green solvents for enhancing aqueous solubility of drug curcumin remains a challenge. This study explores the enhancing effect of deep eutectic solvents (DESs) on the aqueous solubility of curcumin (CUR) via experiment and theoretical calculation. Choline chloride-based DESs with polyols 1,2-propanediol (1,2-PDO), 1,3-propanediol, ethylene glycol, and glycerol as hydrogen bond donors were prepared and used as co-solvents. The CUR aqueous solubility increased with increasing the DESs content at temperature of 303.15-318.15 K, especially in aqueous ChCl/1,2-PDO (mole ratio 1:4) solutions. The positive apparent molar volume values and reduced density gradient analysis confirmed the existence of strong interactions between CUR and solvent. The van der Waals interactions and hydrogen bonding coexisted in DESs monomer retained the stability of DESs structure after introducing CUR. Moreover, the lower interaction energy of DESs…CUR system than that of the counterpart DESs further proved the strong interaction between CUR and DESs. The lowest interaction energy of ChCl/1,2-PDO…CUR system indicated that this system was the most stable and ChCl/1,2-PDO was promising for CUR dissolution. This work provides efficient solvents for utilizing curcumin, contributing to a deep insight into the interactions between DES and CUR at the molecular level, and the role of DESs on enhancing drugs solubility.

With the increasing demand for high-purity products, the industrial application of melt crystallization technology has been highly concerned. In this study, the purification process of nitrochlorobenzene binary eutectic system (NBES) and naphthalene–benzothiophene solid solution system (NBSSS) in tower melting crystallizer is analyzed, and a mathematical model of crystallization process is established. The key parameters in terms of feed concentration, crystal bed height, reflux ratio and stirring speed efficiency on purification effects were discussed by the established model. The results show that the concentration of p-nitrochlorobenzene was purified from 90.85% to 99.99%, when the crystal bed height is 600 mm, the reflux ratio is 2.5, and the stirring speed is 12 r·min^-1. The naphthalene concentration is purified from 95.89% to 99.99%, when the crystal bed height is 400 mm, the reflux ratio is 1.43, and the stirring speed is 16 r·min^-1. The quality of the model is evaluated by the ARD (average relative deviation). The minimum ARD values of the NBES and NBSSS are 2.39% and 5.22%, respectively, indicating the model satisfactorily explains the purification process.

As a significant index to evaluate the mixing efficiency, studying the concentration distribution is directly related to the intensity of segregation (I_s). In this work, the I_s of the mixture composed of NaCl solution-water was investigated experimentally in a rotating bar reactor (RBR) by the conductivity method. The results showed that the mixing efficiency was improved along the axial direction from the bottom to the top in the RBR. The concentration distribution at the bottom section was more uneven, and I_s was higher compared with the top section, which decreased from 6.53×10^-5 to 1.57×10^-7. With the increase of rotational speed from 0 to 700 r·min^-1, I_s at the bottom and top sections decreased from 4.27×10^-3 to 7.10×10^-5 and from 1.93×10^-3 to 7.29×10^-7, respectively. The increases flow rate of solution A, and the decreases of concentration of NaCl and flow rate of solution B gave rise to the reduction of I_s, signifying an improved mixing efficiency. The results revealed that the conductivity method used in this paper has high efficiency and low cost to measure the, which indicates a promising prospect for estimating reactors’ mixing performance.

Direct epoxidation of propylene with H₂/O₂, being the dream reaction for propylene oxide (PO) production, has raised wide scientific and industrial interests. Fundamentally understanding the formation mechanism of acrolein, as the main by-product of this epoxidation process, is very important to achieve the high yield of PO. In this study, we perform the spin-polarized density functional theory (DFT) calculations to investigate the reaction pathway from propylene to acrolein over two representative Au surfaces, that is, Au(1 1 1) and Au(1 0 0), which incorporates propylene adsorption, methyl hydrogen activation and acrolein formation. The results show that the oxygenated species (mainly O^*, OH^* and OOH^*) are able to stabilize the adsorption of propylene to decrease the energy barrier for its activation. It is demonstrated that the OOH^* on Au(1 1 1) surface emerges as the most easily formed oxygenated species via the H-assisted O₂ dissociation, which is also the most active for the cleavage of methyl C-H bond in propylene. Furthermore, three pathways of acrolein formation activated by O^*/OH^*/OOH^* are analyzed, in which O^* is found as the key species to form acrolein. Finally, Bader charge analysis was conducted to explore the reasons behind the promotion effect of the oxygenated species. The insights reported here could be valuable in the design and optimization of gold catalysts for the direct epoxidation of propylene.

Occurrence of neurofibrillary tangles of the tau protein is a hallmark of tau-related neurodegenerative diseases, i.e. Alzheimer's disease (AD) and frontotemporal dementia. The pathological mechanism underlying AD remains poorly understood, and effective treatments are still unavailable to mitigate the disease. Inhibiting of tau aggregation and disrupting the existing fibrils are key targets in drug discovery towards preventing or curing AD. In this study, grape seed proanthocyanidins (GSPs) was found to effectively inhibit the repeat domain of tau (tau-RD) aggregation and disaggregate tau-RD fibrils in a concentration-dependent manner by inhibiting β-sheet formation of tau-RD. In cells, GSPs relieved cytotoxicity induced by tau-RD aggregates. Molecular dynamics simulations indicated that strong hydrogen bonding, hydrophobic interaction and π-π stacking between GSPs and tau-RD protein were major reasons why GSPs had high inhibitory activity on tau-RD fibrillogenesis. These results provide preliminary data to develop GSPs into medicines, foodstuffs or nutritional supplements for AD patients, suggesting that GSPs could be a candidate molecule in the drug design for AD therapeutics.

Catalytic wet air oxidation (CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing free radicals, the stability of catalysts is often insufficient, which has become a bottleneck in the application of CWAO. In this paper, a copper-based catalyst with excellent hydrothermal stability was designed and prepared. TiO₂ with excellent stability was used as the carrier to ensure the long-term anchoring of copper and reduce the leaching of the catalyst. The one pot sol–gel method was used to ensure the super dispersion and uniform distribution of copper nanoparticles on the carrier, so as to ensure that more active centers could be retained in a longer period. Experiments show that the catalyst prepared by this method has good stability and catalytic activity, and the catalytic effect is not significantly reduced after 10 cycles of use. The oxidation degradation experiment of m-cresol with the strongest biological toxicity and the most difficult to degrade in coal chemical wastewater was carried out with this catalyst. The results showed that under the conditions of 140 ℃, 2 MPa and 2 h, m-cresol with a concentration of up to 1000 mg·L^-1 could be completely degraded, and the COD removal rate could reach 79.15%. The biological toxicity of wastewater was significantly reduced. The development of the catalyst system has greatly improved the feasibility of CWAO in the treatment of refractory wastewater such as coal chemical wastewater.

Tungsten (W) incorporated mobil-type eleven (MEL) zeolite membrane (referred to as W-MEL membrane) with high separation performance was firstly explored for the separation of oil/water mixtures under the influence of gravity. W-MEL membranes were grown on stainless steel (SS) meshes through in-situ hydrothermal growth method facilitated with (3-aminopropyl)triethoxysilane (APTES) modification of stainless steel meshes, which promote the heterogeneous nucleation and crystal growth of W-MEL zeolites onto the mesh surface. W-MEL membranes were grown on different mesh size supports to investigate the effect of mesh size on the separation performance of the membrane. The as-synthesized W-MEL membrane supported on 500 mesh (25 μm) (W-MEL-500) exhibit the hydrophilic nature with a water contact angle of 11.8° and delivers the best hexane/water mixture separation with a water flux and separation efficiency of 46247 L·m^-2·h^-1 and 99.5%, respectively. The wettability of W-MEL membranes was manipulated from hydrophilic to hydrophobic nature by chemically modifying with the fluorine-free compounds (hexadecyltrimethoxysilane (HDTMS) and dodecyltrimethoxysilane (DDTMS)) to achieve efficient oil-permselective separation of heavy oils from water. Among the hydrophobically modified W-MEL membranes, W-MEL-500-HDTMS having a water contact angle of 146.4° delivers the best separation performance for dichloromethane/water mixtures with a constant oil flux and separation efficiency of 61490 L·m^-2·h^-1 and 99.2%, respectively along with the stability tested up to 20 cycles. Both W-MEL-500-HDTMS and W-MEL-500-DDTMS membranes also exhibit similar separation performances for the separation of heavy oil from sea water along with a 20-fold lower corrosion rate in comparison with the bare stainless-steel mesh, indicating their excellent stability in seawater. Compared to the reported zeolite membranes for oil/water separation, the as-synthesized and hydrophobically modified W-MEL membranes shows competitive separation performances in terms of flux and separation efficiency, demonstrating the good potentiality for oil/water separation.