It is known that salt ions are abundant in the natural environment where natural gas hydrates are located; thus, it is essential to investigate the self-preservation effect of salt ions on methane hydrates. The dissociation behaviors of gas hydrates formed from various NaCl concentration solutions in a quartz sand system at 268.15 K were investigated to reveal the microscopic mechanism of the self-preservation effect under different salt concentrations. Results showed that as the salt concentration rises, the initial rate of hydrate decomposition quickens. Methane hydrate hardly shows self-preservation ability in the 3.35% (mass) NaCl and seawater systems at 268.15 K. Combined the morphology of hydrate observed by the confocal microscope with results obtained from in situ Raman spectroscopy, it was found that during the initial decomposition stage of gas hydrate below the ice point, gas hydrate firstly converts into liquid water and gas molecules, then turns from water to solid ice rather than directly transforming into solid ice and gas molecules. The presence of salt ions interferes with the ability of liquid water to condense into solid ice. The results of this study provide an important guide for the mechanism and application of the self-preservation effect on the storage and transport of gas and the exploitation of natural gas hydrates.

In this study, the effects of reaction parameters on the deep-reduction and carbonization process of WO₂-Co to WC-Co were studied. The results indicate that the oxygen loss rate of WO₂ is positively correlated with temperature and methane partial pressure. The partial pressure of methane has no significant effect on the formation rate of WC. The carbon content and particle size of the product increase with the increase of CH₄ partial pressure. By synergistically regulating the reaction temperature to 950 ℃, the CH₄ partial pressure to 1.25%, and the reaction time to 60 min, ultrafine WC-Co powder without η phase can be obtained. The particle size of the composite powder is 128 nm, with total carbon content of 6.16%, free carbon content of 0.4%, and residual oxygen content of 0.05%, respectively. The growth rate relationship of tungsten carbide is as follows: δ(t)=1.21×10^-13 exp $ \left(-\frac{12809.72}{T}\right) \sqrt{t}$.

The hydrophilic ZSM-5 zeolite membranes are applied to separate the inorganic acid solutions and inorganic acid/inorganic salt mixtures by pervaporation, and the membrane presents good stability, dehydration, and desalination performance. Influences of inorganic acid type (H₂SO₄, H₃PO₄, HNO₃, and HCl), H₂SO₄ concentration (1-6 mol·L^-1), test temperature (60-90 ℃) and inorganic acid/inorganic salt type (2 mol·L^-1 H₂SO₄ and sulfate, 2 mol·L^-1 H₃PO₄ and phosphate) on the pervaporation performance are investigated in this work. Either for concentrating 3% (mass) H₂SO₄ solution or consecutive dehydrating 20% (mass) H₂SO₄ solution, the hydrophilic ZSM-5 zeolite membrane has a good dehydration performance and stability. Even though the H₂SO₄ concentration and test temperature are increased to 6 M and 90 ℃, only H₂O molecules could pass through the membrane and pH value of the permeation is kept neutral. Besides, the membrane has good dehydration and desalination performance for H₂SO₄/sulfates and H₃PO₄/phosphate mixtures, and the rejection of natrium salt, molysite, and magnesium is almost 100%.

The effect of the presence of trace SO₂ in industrial flue gas on the amine-scrubbing-based absorption process for CO₂ capture has been a matter of concern. This study aimed to investigate the effect of trace SO₂ on the CO₂ capture process using piperazine-based amine absorbents, focusing on SO₂-resistance capability, SO₂/CO₂ absorption selectivity, and cyclic stability. The presence of trace SO₂ not only restrains CO₂ absorption, but also promotes the formation of carbamate within the piperazine-based amine absorbents. Remarkably, the incorporation of aminoethyl group in piperazine-based amine absorbents can enhance the SO₂-resistance capability by promoting the formation of carbamate, while piperazine-based amine absorbents with hydroxyethyl group can promote the formation of bicarbonate to reduce the SO₂-resistance capability. The work offers valuable insights into the efficient application of novel amine absorbents for CO₂ capture from practical industrial flue gas.

Increasing the 1,3,5-trioxane (TOX) concentration in the equilibrated vapor phase of TOX-H₂O system has been recognized as a challenge for the azeotrope. Ionic liquids (ILs) were used to improve the relative volatility of TOX to H₂O and destroy the azeotrope in the TOX-H₂O system. The vapor-liquid equilibrium of TOX-H₂O system at 101.3 kPa was studied with the addition of 1-butyl-3-methylimidazolium hydrogen sulfate, 1-hexyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimidazolium nitrate, respectively. The results showed that the volatility of TOX increased with the increase in IL dosage. And the volatility of water decreased with the increase in IL dosage. The relative volatility of TOX to H₂O was improved with the increase in ILs dosage. The azeotrope could be destroyed with an IL mole fraction of about 0.10. A non-random two-liquid (NRTL) model was successfully used to correlate the experimental data. The interaction parameters were obtained by fitting the experimental data with the model. The results indicated that a strong interaction existed between ILs and water. The strong interaction improved the volatility of TOX and inhibited the volatility of water, and then intensified the relative volatility of TOX to H₂O. The results showed that an ILs with strong polarity and hydrophilicity may be a potential additive to improve the TOX concentration in the equilibrated vapor phase.

Confronting the severe health threats and environmental impacts of Cr(VI) in aquatic environments demands innovative and effective remediation approaches. In this study, Graphene oxide (GO)-decorated poly(dimethyl amino ethyl methacrylate) (PDMAEMA) brush nanocomposites (GOP1, GOP2, GOP3, and GOP4) were fabricated using atom transfer radical polymerization (ATRP) by the “graft from” method. The resulting nanocomposites were utilized for removing Cr(VI) with good adsorption performance due to the electrostatic interaction of protonated nitrogen groups in the brush chains with negatively charged particles in the solution. The kinetic model of pseudo-second-order best represented the contaminants' adsorption characteristics. The Weber-Morris model further indicated that surface adsorption and intraparticle diffusion mechanisms primarily controlled the adsorption procedure. Additionally, the Langmuir and Temkin isotherm models were found to most accurately represent the adsorption characteristics of the pollutants on the nanocomposites, and GOP4 can achieve the maximum adsorption capacity of 164.4 mg·g^-1. The adsorbents' capacity maintains above 85% after five cycles of adsorption-desorption. The nanocomposites in this study demonstrate promising potential for eliminating Cr(VI) from aqueous solutions.

In the cooling crystallization process of thiourea, a significant issue is the excessively wide crystal size distribution (CSD) and the abundance of fine crystals. This investigation delves into the growth kinetics and mechanisms governing thiourea crystals during the cooling crystallization process. The fitting results indicate that the crystal growth rate coefficient, falls within the range of 10^-7 to 10^-8 m·s^-1. Moreover, with decreasing crystallization temperature, the growth process undergoes a transition from diffusion-controlled to surface reaction-controlled, with temperature primarily influencing the surface reaction process and having a limited impact on the diffusion process. Comparing the crystal growth rate, and the diffusion-limited growth rate, at different temperatures, it is observed that the crystal growth process can be broadly divided into two stages. At temperatures above 25 ℃, 1/q_d (q_d is diffusion control index) approaches 1, indicating the predominance of diffusion control. Conversely, at temperatures below 25 ℃, 1/q_d increases rapidly, signifying the dominance of surface reaction control. To address these findings, process optimization was conducted. During the high-temperature phase (35-25 ℃), agitation was increased to reduce the limitations posed by bulk-phase diffusion in the crystallization process. In the low-temperature phase (25 -15 ℃), agitation was reduced to minimize crystal breakage. The optimized process resulted in a thiourea crystal product with a particle size distribution predominantly ranging from 0.7 to 0.9 mm, accounting for 84% of the total. This study provides valuable insights into resolving the issue of excessive fine crystals in the thiourea crystallization process.

Rosin, a renewable and abundant resource, has been extensively processed and chemically modified to endow it with special properties, especially in the surfactant industry. In this study, four rosin-based quaternary ammonium asymmetric gemini surfactants (RGS-2-n) with different alkyl chain lengths (n = 12, 14, 16, 18) were synthesized using a simple two-step method based on dehydroabietylamine as the raw material. The feasibility of these surfactants for cleaning purposes was comprehensively evaluated, suggesting that the surfactants own high surface activity and good cleaning performance. Furthermore, by successfully introducing the amine group of dehydroabietylamine into the hydrophilic group of the surfactants, we avoided its potential harm to the environment and water pollution. Density functional theory proves rosin-based gemini surfactants with asymmetric structure can further improve cleaning efficiency. Overall, our findings suggests that RGS-2-n surfactants are promising and sustainable candidates for cleaning electric plates, and provide new opportunities for rosin application in the electric industry.

Lithium-sulfur (Li-S) batteries are regarded as one of the most promising next-generation energy storage systems due to their high theoretical specific energy density and low cost. However, serious shuttle effect and sluggish lithium polysulfides (LiPSs) redox kinetics severely impede the practical application of Li-S batteries. Employing polar sulfur hosts is an effective strategy to alleviate the above problems. Herein, the potential of two-dimensional (2D) Ti₂B-based sulfur hosts for Li-S batteries was comprehensively explored using first-principles calculations. The results show that functional groups of Ti₂B can significantly modulate its structural properties, thus affecting its interaction with sulfur-containing species. Among S, Se, F, Cl, and Br elements, Ti₂B terminated with S and Se atoms possess stronger adsorption capability towards soluble Li₂S₈, Li₂S₆, and Li₂S₄, obviously stronger than organic electrolytes, which indicates that they can completely suppress the shuttle effect. Besides, Ti₂BS₂ and Ti₂BSe₂ can powerfully expedite the electrochemical conversion of LiPSs. Moreover, the decomposition energy barrier of Li₂S and diffusion energy barrier of single Li ion on them are also fairly low, manifesting their excellent catalytic performance towards the oxidation of Li₂S. Finally, Ti₂BS₂ and Ti₂BSe₂ always keep metallic conductivity during the whole charge/discharge process. Taking all this into account, Ti₂BS₂ and Ti₂BSe₂ are proposed as promising bifunctional sulfur hosts for Li-S batteries. Our results suggest that increasing the proportion of S and Se groups during the synthesis of Ti₂B monolayers is greatly helpful for obtaining high-performance Li-S batteries. Besides, our work not only reveals the huge potential of 2D transition metal borides in Li-S batteries, but also provides insightful guidance for the design and screening of new efficient sulfur cathodes.

The adsorption and separation of diols from dilute aqueous solution using hydrophobic materials is very challenging due to the strong diol-water hydrogen-bonding interactions. Herein, we screened hydrophobic zeolitic imidazolate frameworks (ZIFs) with chabazite (CHA) topology for separation of 2,3-butanediol (2,3-BDO) and 1,3-propanediol (1,3-PDO), which had junctional and hydrophobic traps matching the two end methyl groups of the 2,3-BDO molecule. Based on CHA-ZIFs with the same small-sized ligand 2-methylimidazole (mIm) and different large-sized ligand benzimidazole derivatives (RbIm), CHA-ZIFs with larger surface areas were obtained by the addition of excess small-sized ligand mIm in the synthesis process. We showed that all of the hydrophobic CHA-ZIFs preferentially adsorbed 2,3-BDO over 1,3-PDO by static batch adsorption and dynamic column adsorption experiments. But ZIF-301 and ZIF-300 with halogen groups exhibited better adsorptive separation performance for 2,3-BDO/1,3-PDO than ZIF-302 with methyl groups. For a typical ZIF-301, its adsorption capacity for 2,3-BDO was 116.4 mg·g^-1 and selectivity for 2,3-BDO/1,3-PDO was 3.8 in dynamic column adsorption of the binary-component system (2,3-BDO/1,3-PDO: 50 g·L^-1/50 g·L^-1). Computational simulations revealed that 2,3-BDO preferentially adsorbed in a trap at the junction between the cha and d6r cages of CHA-ZIFs, meaning the strong host-guest interactions. Therefore, the hydrophobic CHA-ZIFs with a junctional trap were promising candidate materials for adsorbing 2,3-BDO, which also provided a new perspective for separating diols in dilute aqueous solutions.

Efficiently enriching low-concentration CH₄ is pivotal for enhancing the utilization of unconventional energy sources and mitigating greenhouse gas emissions. This study focuses on modifying the overall performance of CH₄/N₂ separation membranes. A novel mixed matrix membrane (MMM) with a reinforced substrate structure was developed through a straightforward dip-coating technique. This MMM incorporates a polytetrafluoroethylene (PTFE) porous membrane as the supporting framework, while a composite of block polymer (styrene-butadiene-styrene) and metal-organic framework (Ni-MOF-74) forms the selective separation layer. Comprehensive characterization of Ni-MOF-74 and the fabricated membranes was conducted using X-rays diffraction, scanning electron microscope, Brunauer-Emmett-Teller analysis, and gas permeance tests. The findings indicate a robust integration of the PTFE porous support with the membrane layer, enhancing the mechanical stability of the MMM. Under optimal conditions, the mechanical strength of the PM20 membrane (containing 20% Ni-MOF-74) was observed to be 37.7 MPa, representing remarkable increase compared to the non-reinforced MMM. Additionally, the PM20 membrane exhibited an impressive CH₄ permeation rate of 92 barrer (1 barrer = 3.35×10^-16 mol·m·m^-2·s^-1·Pa^-1) alongside a CH₄/N₂ selectivity of 4.18. These results underscore the MMM's substantial performance and its promising potential in methane enrichment applications.

Ethylene-vinyl acetate copolymer (EVA) as a kind of effective polymeric pour point depressant has been extensively used in the pipeline transportation of crude oil to inhibit wax deposition and improve the low temperature fluidity of crude oil. In this work, molecular dynamics simulations were performed to investigate the effect of EVA on wax-hydrate coexistence system to evaluate the application potentiality of EVA to the flow assurance of deep-sea oil-gas-water multiphase flow system. Our simulation results reveal that wax molecules gradually stretched and stacked from random coiling to a directional and ordered crystalline state during the process of wax solidification. The strong affinity of polar vinyl acetate side chains of EVA to neighboring water molecules made the EVA molecule prefer being in a curly state, which disrupted the ordered crystallization of surrounding wax molecules and delayed the solidification rate of wax cluster. In addition, it is found that EVA cocrystallized with wax molecules to form eutectic when the wax was fully solidified. The simulation results of hydrate nucleation and growth show that the EVA molecule displayed a two-sided effect on gas adsorption of wax crystals, which was the key factor that affected the nucleation and growth of hydrates in the methane-water system. The nonpolar hydrocarbon backbone of EVA increased the diffusion rate of methane and water, allowing more methane to diffuse to the surface of wax crystals, reducing the methane concentration in aqueous solutions and inhibiting the hydrate formation. On the other hand, the nonpolar vinyl acetate chains had a repulsive effect on methane, which reduced the adsorption area of methane on the eutectic surface and decreased the adsorption threshold value of the wax crystal. The excluded methane molecules would continue dissociating in the aqueous phase and participating in the nucleation and growth process of hydrates. Therefore, the probability of hydrate formation would be increased. It was worth noting that the inhibition performance of EVA on hydrate formation mainly played a significant role in the system with small wax crystal, while its hydrate promotion effect played a dominant role in the system with lager wax crystal. In summary, EVA could significantly inhibit both of the wax and hydrate deposition for the wax-gas-water multiphase system with low wax content. When the wax content in the system was high, the role of EVA was mainly played in the alleviation of wax crystallization rather than the gas hydrates. The results of the present work can contribute to a better understanding of EVA on wax deposition and hydrate formation, and provide theoretical support of the potential industrial applications of EVA.

The morphology characteristics of CH₄, CO₂, and CO₂+N₂ hydrate film forming on the suspending gas bubbles are studied using microscopic visual method at supercooling conditions from 1.0 to 3.0 K. The hydrate film vertical growth rate and thickness along the planar gas-water interface are measured to study the hydrate formation kinetics and mass transfer process. Adding N₂ in the gas mixture plays the same role as lowering the supercooling conditions, both retarding the crystal nucleation and growth rates, which results in larger single crystal size and rough hydrate morphology. N₂ in the gas mixture helps to delay the secondary nucleation on the hydrate film, which is beneficial to maintain the pore-throat structure and enhance the mass transfer. The vertical growth rate of hydrate film mainly depends on the supercooling conditions and gas compositions but has weak dependence on the experimental temperature and pressure. Under the same gas composition condition, the final film thickness shows a linear relationship with the supercooling conditions. The mass transfer coefficient of CH₄ molecules in hydrates ranges from 4.54×10^-8 to 7.54×10^-8 mol·cm^-2·s^-1·MPa^-1. The maximum mass transfer coefficient for CO₂ + N₂ hydrate occurs at the composition of 60% CO₂ + 40% N₂, which is 3.98×10^-8 mol·cm^-2·s^-1·MPa^-1.

Due to the high-pressure and low-temperature exploitation environment, the characteristics of hydrates are directly related to the safety of pipeline transportation, which is an important research topic for deep-sea flow assurance. In this review, six kinds of extensively used experimental equipment and three types of hot computer simulation methods, which are employed to explore the hydrate characteristics under deep-sea conditions, are comprehensively summarized, covering micro to macro research scales. The experimental equipment includes rotational rheometer, flow loop, high-pressure reactor, differential scanning calorimeter (DSC), micromechanical force (MMF) testing apparatus and microscopic morphology observation (MMO) device. The computer simulation methods involve numerical simulation, molecular dynamics (MD) simulation, Monte Carlo (MC) simulation and first-principles calculation. Their advantages and disadvantages are compared in detail, and their basic principles, main applications and the latest research progress are introduced. Some suggestions for future research methods are also provided. This work aims to help readers quickly grasp the characteristics of the most used research methods, choose suitable methods for their study and further expand these methods, so as to advance the development in hydrate research area.

Rapid and sensitive detection of dissolved gases in seawater is quite essential for the investigation of the global carbon cycle. Large quantities of in situ optical detection techniques showed restricted measurement efficiency, owing to the single gas sensor without the identification ability of multiple gases. In this work, a novel gas-liquid Raman detection method of monitoring the multi-component dissolved gases was proposed based on a continuous gas-liquid separator under a large difference of partial pressure. The limit of detection (LOD) of the gas Raman spectrometer could arrive at about 14 μl·L^-1 for N₂ gas. Moreover, based on the continuous gas-liquid separation process, the detection time of the dissolved gases could be largely decreased to about 200 s compared with that of the traditional detection method (30 min). Effect of equilibrium time on gas-liquid separation process indicated that the extracted efficiency and decay time of these dissolved gases was CO₂ >O₂ >N₂. In addition, the analysis of the relationship between equilibrium time and flow speed indicated that the decay time decreased with the increase of the flow speed. The validation and application of the developed system presented its great potential for studying the components and spatiotemporal distribution of dissolved gases in seawater.

High-efficient production of 5-hydroxymethylfurfural (HMF), a “sleeping giant” in sustainable chemistry, from cellulose depends significantly on the effective separation of cellulose from lignocellulosic biomass. Herein, we report the fractional separation of wheat straw cellulose (WSC) from wheat straw under solvothermal conditions using a mixed solvent of γ-valerolactone (GVL) and H₂O as the separating solvent, wherein the impacts of fractional separation parameters (solvent composition, temperature, and time) on removals of lignin and hemicellulose as well as purity and recovery of cellulose were studied by a Box-Behnken Design of response surface method. The optimization of the solvothermal parameters enabled an optimal fractional separation condition (V_GVL: ~60.0%, T: 205 ℃, t: ~1.7 h) that led to a higher purity (89.4%) and recovery (86.7%) of cellulose in WSC. A further correlation of the removals of lignin and hemicellulose as well as purity and recovery of cellulose with the yield of HMF excluded an independent influence of the above factors. Instead, a comprehensive contribution of high fractional separation efficiency (defined as the product of cellulose purity and recovery) and low crystallinity of WSC was found to improve the HMF yield. However, the heat- and freeze-dryings of WSC after the solvothermal separation were found to lower the HMF molar yield because it re-improved the crystallinity of WSC. A high HMF molar yield of 58.6% was achieved after reacting wet-WSC in a mixed solvent of 1,4-dioxane and H₂O at 180 ℃ for 20 min, which was 1.5 fold higher than that from microcrystalline cellulose. This work highlights the importance of enhancing the fractional separation efficiency of cellulose from lignocellulosic biomass while avoiding the drying process for future HMF biorefinery.

Circulating fluidized bed flue gas desulfurization (CFB-FGD) process has been widely applied in recent years. However, high cost caused by the use of high-quality slaked lime and difficult operation due to the complex flow field are two issues which have received great attention. Accordingly, a laboratory-scale fluidized bed reactor was constructed to investigate the effects of physical properties and external conditions on desulfurization performance of slaked lime, and the conclusions were tried out in an industrial-scale CFB-FGD tower. After that, a numerical model of the tower was established based on computational particle fluid dynamics (CPFD) and two-film theory. After comparison and validation with actual operation data, the effects of operating parameters on gas-solid distribution and desulfurization characteristics were investigated. The results of experiments and industrial trials showed that the use of slaked lime with a calcium hydroxide content of approximately 80% and particle size greater than 40 μm could significantly reduce the cost of desulfurizer. Simulation results showed that the flow field in the desulfurization tower was skewed under the influence of circulating ash. We obtained optimal operating conditions of 7.5 kg·s^-1 for the atomized water flow, 70 kg·s^-1 for circulating ash flow, and 0.56 kg·s^-1 for slaked lime flow, with desulfurization efficiency reaching 98.19% and the exit flue gas meeting the ultraclean emission and safety requirements. All parameters selected in the simulation were based on engineering examples and had certain application reference significance.

The research on the thermal property of the hydrate has recently made great progress, including the understanding of hydrate thermal conductivity and effective thermal conductivity (ETC) of hydrate-bearing sediment. The thermal conductivity of hydrate is of great significance for the hydrate-related field, such as the natural gas hydrate exploitation and prevention of the hydrate plugging in oil or gas pipelines. In order to obtain a comprehensive understanding of the research progress of the hydrate thermal conductivity and the ETC of hydrate-bearing sediment, the literature on the studies of the thermal conductivity of hydrate and the ETC of hydrate-bearing sediment were summarized and reviewed in this study. Firstly, experimental studies of the reported measured values and the temperature dependence of the thermal conductivity of hydrate were discussed and reviewed. Secondly, the studies of the experimental measurements of the ETC of hydrate-bearing sediment and the effects of temperature, porosity, hydrate saturation, water saturation, thermal conductivity of porous medium, phase change, and other factors on the ETC of hydrate-bearing sediment were discussed and reviewed. Thirdly, the research progress of modeling on the ETC of the hydrate-bearing sediment was reviewed. The thermal conductivity determines the heat transfer capacity of the hydrate reservoir and directly affects the hydrate exploitation efficiency. Future efforts need to be devoted to obtain experimental data of the ETC of hydrate reservoirs and establish models to accurately predict the ETC of hydrate-bearing sediment.

Nickel is a strategic resource in social life and defense technology, playing an essential role in many fields, such as alloys and batteries. With the decrease in nickel sulfide, it is of great significance to extract nickel from laterite. The limonitic laterite is a kind of rich nickel-cobalt-scandium resource. At present, there are few reviews on the extraction of limonitic laterite. This study reviews the hydrometallurgical processes for limonitic laterite ores and the methods of recovering valuable elements. The mineralogical characteristics are analyzed, and the typical mineral compositions are summarized. The main hydrometallurgical processes are compared and discussed, including reduction roasting-ammonia leaching, sulfuric acid pressure leaching, nitric acid pressure leaching, and the atmospheric nitric acid leaching (DNi process). The methods of recovering nickel, cobalt, scandium, and iron are emphatically outlined. Finally, reasonable suggestions are proposed for comprehensive utilization. This study can provide a reference for industrial development and diversified applications.

In recent years, scientists have become increasingly concerned in recycling electronic trash, particularly waste printed circuit boards (WPCBs). Previous research has indicated that the presence of Cu impacts the pyrolysis of WPCBs. However, there may be errors in the experimental results, as printed circuit boards (PCBs) with copper and those without copper are produced differently. For this experiment, we blended copper powder with PCB nonmetallic resin powder in various ratios to create the samples. The apparent kinetics and pyrolysis properties of four resin powders with varying copper concentrations were compared using nonisothermal thermogravimetric analysis (TG) and thermal pyrolysis-gas chromatography mass spectrometry (Py-GC/MS). From the perspective of kinetics, the apparent activation energy of the resin powder in the pyrolysis reaction shows a rise (0.1＜α＜0.2)-stable (0.2＜α＜0.4)-accelerated increase (0.4＜α＜0.8)- decrease (0.8＜α＜0.9) process. After adding copper powder, the apparent activation energy changes more obviously when (0.2＜α＜0.4). In the early stage of the pyrolysis reaction (0.1＜α＜0.6), the apparent activation energy is reduced, but when α = 0.8, it is much higher than that of the resin sample without copper. Additionally, it is discovered using thermogravimetric analysis and Py-GC/MS that copper shortens the temperature range of the primary pyrolysis reaction and prevents the creation of compounds containing bromine. This inhibition will raise the temperature at which compounds containing bromine first form, and it will keep rising as the copper level rises. The majority of the circuit board molecules have lower bond energies when copper is present, according to calculations performed using the Gaussian09 software, which promotes the pyrolysis reaction.

The development of efficient systems for the catalytic oxidation of 2-nitro-4-methylsulfonyltoluene (NMST) to 2-nitro-4-methylsulfonyl benzoic acid (NMSBA) with atmospheric air or molecular oxygen in alkaline medium presents a significant challenge for the chemical industry. Here, we report the synthesis of FeOOH/Fe₃O₄/metal-organic framework (MOF) polygonal mesopores microflower templated from a MIL-88B(Fe) at room temperature, which exposes polygonal mesopores with atomistic edge steps and lattice defects. The obtained FeOOH/Fe₃O₄/MOF catalyst was adsorbed onto glass beads and then introduced into the microchannel reactor. In the alkaline environment, oxygen was used as oxidant to catalyze the oxidation of NMST to NMSBA, showing impressive performance. This sustainable system utilizes oxygen as a clean oxidant in an inexpensive and environmentally friendly NaOH/methanol mixture. The position and type of substituent critically affect the products. Additionally, this sustainable protocol enabled gram-scale preparation of carboxylic acid and benzyl alcohol derivatives with high chemoselectivities. Finally, the reactions can be conducted in a pressure reactor, which can conserve oxygen and prevent solvent loss. Moreover, compared with the traditional batch reactor, the self-built microchannel reactor can accelerate the reaction rate, shorten the reaction time, and enhance the selectivity of catalytic oxidation reactions. This approach contributes to environmental protection and holds potential for industrial applications.

Direct-Z-scheme g-C₃N₄/Ti₃C₂/TiO₂ photocatalyst with giant internal electric field was prepared by one-step aqueous sonication self-assembly method using g-C₃N₄ and MXene of Ti₃C₂ as the source materials. The chemical composition and structure of the catalysts was characterized by FT-IR, XRD, SEM, TEM, and XPS. The XPS characterization indicated that Ti₃C₂ was partially oxidized to TiO₂ during the composite process. As a result, an efficient direct-Z-scheme heterojunction structure consisting of the g-C₃N₄ and TiO₂ with Ti₃C₂ as an electron bridge was constructed. The photocatalytic performance of the prepared catalysts was evaluated by degrading the Rhodamine B (RhB) wastewater. Compared with the single g-C₃N₄, the g-C₃N₄/Ti₃C₂/TiO₂ composite photocatalyst exhibited efficient and stable photocatalytic degradation ability, with a degradation efficiency as high as 99.2% for RhB under optimal conditions (2% Ti₃C₂, pH = 3). The high degradation performance of g-C₃N₄/Ti₃C₂/TiO₂ for RhB was attributed to the combination of Ti₃C₂, TiO₂, and g-C₃N₄ components, forming a direct-Z-scheme heterojunction with a high-speed electron transport channel structure. The role of Z-scheme heterojunctions in electron transport is verified by photoelectrochemical characterization, along with photoluminescence (PL). Our research provides a simple method to design photocatalysts by constructing direct-Z-scheme electron transport channels for highly efficient treatment of dye wastewater.

Pd-based catalysts are extensively employed to catalyze CO oxidative coupling to generate DMO, while the expensive price and high usage of Pd hinder its massive application in industrial production. Designing Pd-based catalysts with high efficiency and low Pd usage as well as expounding the catalytic mechanisms are significant for the reaction. In this study, we theoretically predict that Pd stripe doping Co(1 1 1) surface exhibits excellent performance than pure Pd(1 1 1), Pd monolayer supporting on Co(1 1 1) and Pd single atom doping Co(1 1 1) surface, and clearly expound the catalytic mechanisms through the density functional theory (DFT) calculation and micro-reaction kinetic model analysis. It is obtained that the favorable reaction pathway is COOCH₃-COOCH₃ coupling pathway over these four catalysts, while the rate-controlling step is COOCH₃+CO+OCH₃→2COOCH₃ on Pd stripe doping Co(1 1 1) surface, which is different from the case (2COOCH₃→DMO) on pure Pd(1 1 1), Pd monolayer supporting on Co(1 1 1) and Pd single atom doping Co(1 1 1) surface. This study can contribute a certain reference value for developing Pd-based catalysts with high efficiency and low Pd usage for CO oxidative coupling to DMO.

Ionic liquids (ILs), because of the advantages of low volatility, good thermal stability, high gas solubility and easy recovery, can be regarded as the green substitute for traditional solvent. However, the high viscosity and synthesis cost limits their application, the hybrid solvent which combining ILs together with others especially water can solve this problem. Compared with the pure IL systems, the study of the ILs-H₂O binary system is rare, and the experimental data of corresponding thermodynamic properties (such as density, heat capacity, etc.) are less. Moreover, it is also difficult to obtain all the data through experiments. Therefore, this work establishes a predicted model on ILs-water binary systems based on the group contribution (GC) method. Three different machine learning algorithms (ANN, XGBoost, LightBGM) are applied to fit the density and heat capacity of ILs-water binary systems. And then the three models are compared by two index of MAE and R². The results show that the ANN-GC model has the best prediction effect on the density and heat capacity of ionic liquid-water mixed system. Furthermore, the Shapley additive explanations (SHAP) method is harnessed to scrutinize the significance of each structure and parameter within the ANN-GC model in relation to prediction outcomes. The results reveal that system components (X_IL) within the ILs-H₂O binary system exert the most substantial influence on density, while for the heat capacity, the substituents on the cation exhibit the greatest impact. This study not only introduces a robust prediction model for the density and heat capacity properties of IL-H₂O binary mixtures but also provides insight into the influence of mixture features on its density and heat capacity.

The sulfate radical-based photocatalytic process is supposed to be the most promising way to degrade organic pollutants. However, the development of a suitable and efficient photocatalyst is very challenging. The 40LaFeO₃-CuFe₂O₄ (40LFO-CFO) nanocomposite was constructed and its catalytic performance was studied using Rhodamine B (RhB) as the target pollutant. 40LFO-CFO exhibited excellent RhB degradation by the persulfate (PS)-assisted photocatalytic process compared to the pristine LFO and CFO. The degradation rate constant for RhB by 40LFO-CFO in the Vis/PS system was 2.22 h^-1 which is 3.04 times and 5.05 times higher than the pristine LFO (0.73 h^-1) and CFO (0.44 h^-1), respectively. Furthermore, the trapping experiments and EPR spectra proved that h⁺ plays a leading role in the bleaching of RhB for the 40LFO-CFO/PS/Vis system. The enhanced photocatalytic oxidation activity of 40LFO-CFO could be attributed to the unique charge carriers flow in 40LFO-CFO due to the Z-scheme and the cooperation effect between photocatalysis and PS activation. The recycle tests confessed the stability of 40LFO-CFO. Additionally, the intermediates and products of RhB are detected by liquid chromatography-mass spectrometry (LC-MS), and the photocatalytic degradation routes of RhB for the 40LFO-CFO/Vis/PS system were proposed. Moreover, the 40LFO-CFO nanocomposite has a superior catalytic performance for other organics, suggesting that it is a promising heterocatalyst because of its high catalytic activity and stability for the PS-assisted photocatalytic process.

The simulated moving bed (SMB) chromatographic separation is a continuous compound separation process based on the differences in adsorption capacity exhibited by distinct constituents of a mixture on the fluid phase and stationary phase. The prediction of axial concentration profiles along the beds in a unit is crucial for the operating optimization of SMB. Though the correlation shared by operating variables of SMB has an enormous impact on the operational state of the device, these correlations have been long overlooked, especially by the data-driven models. This study proposes an operating variable-based graph convolutional network (OV-GCN) to enclose the underrepresented correlations and precisely predict axial concentration profiles prediction in SMB. The OV-GCN estimates operating variables with the Spearman correlation coefficient and incorporates them in the adjacency matrix of a graph convolutional network for information propagation and feature extraction. Compared with Random Forest, K-Nearest Neighbors, Support Vector Regression, and Backpropagation Neural Network, the values of the three performance evaluation metrics, namely MAE, RMSE, and R², indicate that OV-GCN has better prediction accuracy in predicting five essential aromatic compounds' axial concentration profiles of an SMB for separating p-xylene (PX). In addition, the OV-GCN method demonstrates a remarkable ability to provide high-precision and fast predictions in three industrial case studies. With the goal of simultaneously maximizing PX purity and yield, we employ the non-dominated sorting genetic algorithm-II optimization method to perform multi-objective optimization of the PX purity and yield. The outcome suggests a promising approach to extracting and representing correlations among operating variables in data-driven process modeling.

Isosorbide is a novel bio-based material derived as a secondary dehydration product of sorbitol. This work focuses on the kinetics of sulfuric acid-catalyzed dehydration of sorbitol under conditions of nonconstant volume. Herein, the effects of stirring rate, catalyst dosage, reaction temperature, and reaction time on the dehydration reaction of sorbitol were investigated. The yield of isosorbide up to 77.13% was obtained after 1.5 h of reaction time under conditions of 2 kPa, 1.0% (mass) catalyst dosage, and 413.15 K. Based on the sorbitol dehydration reaction mechanism and a simplified reaction network, a kinetic model was developed in this work. A good agreement was accomplished between kinetic modeling and experiments between 393.15 and 423.15 K. The fitting results indicate that side reactions with higher activation energies are more affected by reaction temperatures, and the main side reaction that influences the selectivity of isosorbide is the oligomerization reaction among the primary dehydration products of sorbitol. The model fitting of the catalyst amounts effect shows that the effective concentration of sulfuric acid would be reduced with the increase of dosage due to the molecular agglomeration effect. Hopefully, the kinetic experiments and modeling results obtained in this work will be helpful to the design and optimization of the industrial sorbitol dehydration process.

Neural networks are often viewed as pure ‘black box’ models, lacking interpretability and extrapolation capabilities of pure mechanistic models. This work proposes a new approach that, with the help of neural networks, improves the conformity of the first-principal model to the actual plant. The final result is still a first-principal model rather than a hybrid model, which maintains the advantage of the high interpretability of first-principal model. This work better simulates industrial batch distillation which separates four components: water, ethylene glycol, diethylene glycol, and triethylene glycol. GRU (gated recurrent neural network) and LSTM (long short-term memory) were used to obtain empirical parameters of mechanistic model that are difficult to measure directly. These were used to improve the empirical processes in mechanistic model, thus correcting unreasonable model assumptions and achieving better predictability for batch distillation. The proposed method was verified using a case study from one industrial plant case, and the results show its advancement in improving model predictions and the potential to extend to other similar systems.

At present, many countries are becoming more and more stringent in terms of sulfur content in fuel oil. S Zorb is a kind of desulfurization technology with advantages of exceptional desulfurization efficiency and small impact on octane number. To meet the needs of environmental requirements and the trend of digitalization in the petrochemical industry, a first-principle model of S Zorb was established based on industry data. In order to describe the desulfurization and the other side reactions, a reaction network was designed and the kinetic parameters were estimated by the particle swarm optimization algorithm. Two hybrid models based on the first-principle model and support vector regression method were established to correct the mass fraction of sulfur and predict the research octane number of the refined gasoline respectively. The results indicate that the hybrid models can predict the mass fraction of PIONA, sulfur content and research octane number of the refined gasoline accurately, of which the mean absolute percentage errors are less than 6%. Hybrid models were then applied to optimize the decision variables to minimize the research octane number loss. Optimization results show that the average reduction of the loss of research octane number is 21.8%, which suggests that the models developed hold promise for guiding practical production.

Modern industrial processes are typically characterized by large-scale and intricate internal relationships. Therefore, the distributed modeling process monitoring method is effective. A novel distributed monitoring scheme utilizing the Kantorovich distance-multiblock variational autoencoder (KD-MBVAE) is introduced. Firstly, given the high consistency of relevant variables within each sub-block during the change process, the variables exhibiting analogous statistical features are grouped into identical segments according to the optimal quality transfer theory. Subsequently, the variational autoencoder (VAE) model was separately established, and corresponding T² statistics were calculated. To improve fault sensitivity further, a novel statistic, derived from Kantorovich distance, is introduced by analyzing model residuals from the perspective of probability distribution. The thresholds of both statistics were determined by kernel density estimation. Finally, monitoring results for both types of statistics within all blocks are amalgamated using Bayesian inference. Additionally, a novel approach for fault diagnosis is introduced. The feasibility and efficiency of the introduced scheme are verified through two cases.