In this work, several HZSM-5 catalysts with different Si/Al ratios treated with acids are selected as catalysts and used for hydration of cyclohexene to cyclohexanol. The results indicated that HZSM-5 (Si/Al = 38) modified with 4 mol·L^-1 nitric acid was selected as an efficient catalyst for improving the hydration efficiency of cyclohexene. Furthermore, the microstructures and properties of fresh, used and regenerated acid-modified catalysts have been characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption/desorption isotherm, Fourier transform infrared, thermal gravimetric analyzer, ammonia temperature programmed desorption and pyridine adsorbs Fourier transform infrared. The characterization results indicated that the total surface areas and pore volume of HZSM-5 zeolite increased after nitric acid treatment due to the formation of mesoporous structure. This benefits the diffusion rate of reactants and products, which improves the hydration efficiency and stability of the catalyst. Under the catalysis of HZSM-5, the conversion of cyclohexene was found to be 9.0%. However, treatment of HZSM-5 with nitric acid enhanced the conversion of cyclohexene to 12.2%, achieving a selectivity of 99.7% for cyclohexanol under optimal reaction conditions. This work affords a mild and efficient approach for improving the hydration efficiency and has potential industrial application value.

The dynamics of vapor-liquid-solid (V-L-S) flow boiling in fluidized bed evaporators exhibit inherent complexity and chaotic behavior, hindering accurate prediction of pressure drop signals. To address this challenge, this study proposes an innovative hybrid approach that integrates wavelet neural network (WNN) with chaos analysis. By leveraging the Cross-Correlation (C-C) method, the minimum embedding dimension for phase space reconstruction is systematically calculated and then adopted as the input node configuration for the WNN. Simulation results demonstrate the remarkable effectiveness of this integrated method in predicting pressure drop signals, advancing our understanding of the intricate dynamic phenomena occurring with V-L-S fluidized bed evaporators. Moreover, this study offers a novel perspective on applying advanced data-driven techniques to handle the complexities of multi-phase flow systems and highlights the potential for improved operational prediction and control in industrial settings.

Iron tailings are a common solid waste resource, posing serious environmental and spatial challenges. This study proposed a novel hydrogen-based reduction roasting (HRR) technology for the processing of iron tailings using a combined beneficiation and metallurgy approach. Pilot-cale experiment results indicated that under the gas composition of CO:H₂ = 1:3, and optimal roasting conditions at a reduction temperature of 520 ℃, the majority of weakly magnetic hematite transforms into strongly magnetic magnetite during the reduction process. Combining roasting products with a magnetic separation–grinding–magnetic selection process yields a final iron concentrate with a grade of 56.68% iron and a recovery rate of 86.54%. Theoretical calculations suggested the annual production value can reach 29.7 million USD and a reduction of 20.79 tons of CO₂ emissions per year. This highlights that the use of HRR in conjunction with traditional beneficiation processes can effectively achieve comprehensive utilization of iron tailings, thereby reducing environmental impact.

In the extraction of potassium from salt lakes, Mg is abundant in the form of bischofite (MgCl₂·6H₂O), which is not utilized effectively, resulting in the waste of resources and environmental pressure. Anhydrous MgCl₂ prepared by the dehydration of bischofite is a high-quality raw material for the production of Mg. However, direct calcination of MgCl₂·6H₂O in industrial dehydration processes leads to a large amount of hydrolysis. The by-products are harmful to the electrolysis process of Mg, causing problems such as sludge formation, low current efficiency, and corrosion in the electrodes. To obtain high-purity anhydrous MgCl₂, different advanced dehydration processes have been proposed. In this review, we focus on the recent progress of the dehydration process. Firstly, we discuss the molecular structure of MgCl₂·6H₂O and explain the reason why much hydrolysis occurs in dehydration. Secondly, we introduce the specific dehydration processes, mainly divided into direct dehydration processes and indirect dehydration processes. The direct dehydration processes are classified into gas protection heating and molecular sieve dehydration process. Indirect dehydration processes are classified into thermal dehydration of ammonium carnallite (NH₄Cl·MgCl₂·6H₂O), thermal dehydration of potassium carnallite (KCl·MgCl₂·6H₂O), thermal decomposition of the [HAE]Cl·MgCl₂·6H₂O, organic solvent distillation, ionic liquid dehydration process and ammonia complexation process. In the meanwhile, purity of anhydrous MgCl₂ of each dehydration process, as well as the advantages and disadvantages, is discussed. The characteristics of different processes with a simple economic budget are also given in this paper. Finally, the main challenges are evaluated with suggested directions in the future, aiming to guide the synthesis of high-purity anhydrous MgCl₂.

Temperature is a critical factor influencing the performance of coal catalytic hydrogasification in bubbling fluidized bed gasifiers. Numerical simulations at various temperatures (1023 K, 1073 K, 1123 K, and 1173 K) are conducted to elucidate the mechanisms by which temperature affects bubble size, global reaction performance, and particle-scale reactivity. The simulation results indicate that bubble size increases at elevated temperatures, while H₂-char hydrogasification reactivity is enhanced. Particle trajectory analyses reveal that particles sized between 100 and 250 μm undergo intense char hydrogasification in the dense phase, contributing to the formation of hot spots. To assess the impact of temperature on the particle-scale flow-transfer-reaction process, the dimensionless quantities of Reynolds, Nusselt, and Sherwood numbers, along with the solids dispersion coefficient, are calculated. It is found that higher temperatures inhibit bubble-induced mass and heat transfer. In general, 3 MPa, 1123 K, and 3–4 fluidization numbers are identified as the optimal conditions for particles ranging from 0 to 350 μm. These findings provide valuable insights into the inherent interactions between temperature and gas-particle reaction.

Under the dual-carbon background, the technological updating of traditional high-energy-consuming equipment should not be delayed, and the problem of reactor energy consumption should not be ignored. Therefore, this study is based on computational fluid dynamics (CFD) theory to simulate the spiral stirred reactor with different design parameters (distance of paddle from bottom surface to reactor height ratio h₁/H, diameter of stirring paddle to reactor diameter ratio D_s/D, length of blade section to reactor height ratio L_s/H). It was found that the reactor designed with lower L_s/H values and higher h₁/H, D_s/D values would have smaller power number (N_p) values and smaller flow field average velocity. In addition, this study also fitted the correlation equation of Np concerning Reynolds number and h₁/H, D_s/D, and L_s/H, and the conclusions of the study can be used as a reference for the design of industrial equipment.

Millimeter channel reactors (MCRs) have received increasing attention because of their ability to enhance treatment capacity in addition to the advantages of microchannels. In previous studies, less work has been conducted on the micromixing process and enhancement strategies for non-Newtonian fluids in MCRs. In this study, the micromixing efficiency in MCRs was experimentally investigated using CMC (carboxymethyl cellulose sodium) aqueous solution to simulate a non-Newtonian fluid, and the enhanced mechanism of micromixing efficiency by the addition of internals and rotation was analyzed by computational fluid dynamics (CFD) simulations. The results show that in the conventional channel, increasing the flow rate improves the micromixing efficiency when the CMC concentration is low. However, when the CMC concentration is higher, the higher the flow rate, the lower the micromixing efficiency. The highest micromixing efficiency is obtained for the rotationally coupled inner components, followed by the single rotation and the lowest is for the internals only. CFD simulations reveal that the most effective way to improve the micromixing efficiency of non-Newtonian fluids with shear-thinning behavior is to increase the shear force in the reactor, which effectively reduces the apparent viscosity. These results provide the theoretical foundation for enhancing the micromixing process of non-Newtonian fluids in small-size reactors.

Herein, PtO-supported GdFeO₃ (PtO/GdFeO₃) composite photocatalysts were synthesized by a solution-based technique. Extensive analysis using various analytical instruments has shown that PtO plays a crucial function in augmenting the visible light absorption capacity of composites. Better photogenerated charge carrier transport was credited with this improvement, which led to a decrease in bandgap energy as low as 2.14 eV. The PtO/GdFeO₃ nanocomposites showed remarkable photocatalytic activity when exposed to visible light, especially in the conversion of CO₂ into CH₃OH. After 9 h of light, a noteworthy yield of 1550 μmol·g^-1 of methanol was produced, demonstrating maximum efficiency at a dose of 2.0 g·L^-1 and a concentration of 5.0% PtO/GdFeO₃. This yield indicates the effectiveness of the heterostructure, which outperformed pristine GdFeO₃ by a factor of 7.85. This significant enhancement highlights the potential advantages of the modified structure in improving performance. Most significantly, the photocatalyst's durability maintained 98.0% of its initial efficacy throughout five cycles. The success of PtO/GdFeO₃ is largely due to the synergistic light absorption capabilities and enhanced photocharge carrier separation that the integration of PtO produced. It highlights the conversion of CO₂ into valuable chemicals under visible light exposure, as well as the promise of mixed oxide nanostructures in ecologically responsible material creation.

N-methyl-pyrrolidone (NMP) is an important solvent for the production of lithium batteries, which causes environmental pollution and wastes resources if it is directly discharged. The current commonly used vacuum distillation recovery process suffers from high operating costs and high energy consumption. Therefore, this paper proposes a coupled pervaporation-adsorption (PV-A) process to recover NMP solvents from lithium battery production waste streams. In this process, pervaporation is used to dewater the NMP waste liquid, it was found that the water content in the raw material liquid decreased from the initial 8.3% (mass) to 0.14% (mass) after 400 min of dewatering, but the membrane separation performance decreased significantly when the water content of the raw material liquid decreased to 0.45% (mass), and at the same time, the NMP loss rate increased rapidly. An adsorption process was used to remove trace water from the remaining liquid, and the water content in the feed liquid under the optimal adsorption process conditions was reduced from 0.45% (mass) to 0.014%, which fully meets the purity requirements of electronics-grade NMP for the production of lithium batteries. Steady-state modeling and techno-economic evaluation of the proposed coupled process were carried out, and compared with vacuum distillation and pervaporation technologies, the results showed the PV-A process yielded the best techno-economic performance and the lowest environmental impact, and it can be used as an alternative process to the traditional NMP recycling technology. This study provides a new method for the recycling of NMP in the lithium battery industry.

This study investigates the corrosion inhibition potential of Datura stramonium seed extracts on mild steel in 1.0 mol·L^-1 HCl and 0.5 mol·L^-1 H₂SO₄, utilizing both ethanolic and aqueous extracts as eco-friendly inhibitors. Electrochemical techniques, thermodynamic studies, and quantum chemical calculations were employed to evaluate the adsorption mechanism and inhibitory action at the metal/electrolyte interface. Maximum inhibition efficiencies of 93.1% in HCl and 97.7% in H₂SO₄ were achieved with the ethanolic extract at a concentration of 0.2 g·L^-1, while the aqueous extract demonstrated 93.8% inhibition in HCl and 96.6% in H₂SO₄. Polarization curves indicated mixed-type inhibition with a slight anodic bias. The thermodynamic analysis of two extracts in both environments indicated that the K_ads increased and that the ΔG_ads were close to -40 kJ·mol^-1, suggesting that the adsorption followed the Langmuir isotherm, indicating a combination of physical and chemical adsorption. SEM/EDX analysis confirmed the formation of a protective layer, while quantum chemical studies further validated strong adsorption, evidenced by a low ΔE of 2.396 eV and an adsorption energy of -878 kcal·mol^-1 (1 kcal·mol^-1 = 4.18 kJ·mol^-1). These results demonstrate that Datura stramonium extracts are promising inhibitors, particularly in sulfuric acid, for industrial applications. Reason: Improved clarity, vocabulary, and technical accuracy while maintaining the original meaning.

Optimizing chemical reaction parameters is an expensive optimization problem. Each experiment takes a long time and the raw materials are expensive. High-throughput methods combined with the parallel Efficient Global Optimization algorithm can effectively improve the efficiency of the search for optimal chemical reaction parameters. In this paper, we propose a multi-objective populated expectation improvement criterion for providing multiple near-optimal solutions in high-throughput chemical reaction optimization. An l-NSGA2, employing the Pseudo-power transformation method, is utilized to maximize the expected improvement acquisition function, resulting in a Pareto solution set comprising multiple designs. The approximation of the cost function can be calculated by the ensemble Gaussian process model, which greatly reduces the cost of the exact Gaussian process model. The proposed optimization method was tested on a S_NAr benchmark problem. The results show that compared with the previous high-throughput experimental methods, our method can reduce the number of experiments by almost half. At the same time, it theoretically enhances temporal and spatial yields while minimizing by-product formation, potentially guiding real chemical reaction optimization.

In order to analysis the oxygen distribution in the adsorption bed during the hydrogen purification process from oxygen-containing feed gas and the safety of device operation, this article established a non-isothermal model for the pressure swing adsorption (PSA) separation process of 4-component (H₂/O₂/N₂/CH₄), and adopted a composite adsorption bed of activated carbon and molecular sieve. In this article, the oxygen distribution in the adsorption bed under different feed gas oxygen contents, different adsorption pressures, and different product hydrogen purity was studied for both vacuuming process and purging process. The study shows that during the process from the end of adsorption to the end of providing purging, the peak value of oxygen concentration in the adsorption bed gradually increases, with the highest value exceeding 30 times the oxygen content of the feed gas. Moreover, the concentration multiplier of oxygen in the adsorption bed increases with the increase of the adsorption pressure, decreases with the increase of the oxygen content in the feed gas, and increases with the decrease of the hydrogen product purity. When the oxygen content in the feed gas reaches 0.3% (vol), the peak value of oxygen concentration in the adsorption bed exceeds 10% (vol), which will make the front part of the oxygen concentration peak fall in an explosion limit range. As the decrease of product hydrogen content, the oxygen concentration peak in the adsorption bed will gradually move forward to the adsorption bed outlet, and even penetrate through the adsorption bed. And during the process of the oxygen concentration peak moving forward, the oxygen will enter the pipeline at the outlet of the adsorption bed, which will make the pipeline space of high-speed gas flow into an explosion range, bringing great risk to the device. The preferred option for safe operation of PSA for hydrogen purification from oxygen-containing feed gas is to deoxygenate the feed gas. When deoxygenation is not available, a lower adsorption pressure and a higher product hydrogen purity (greater than or equal to 99.9% (vol)) can be used to avoid the gas in the adsorption bed outlet pipeline being in the explosion range.

A lab-scale adiabatic reactor has been self-made to characterize the coupled properties of heat and reactions during the co-thermal-processing of coal and biomass with steam or steam/O₂ gasification agents. Results showed that the synergistic effects caused by heat transfer between corncob and coal at different mixing ratios were heavily determined by coal rank and gasification agent. During steam co-processing, the heat transfer from corncob char to adjacent bituminous coal char promoted the water-gas reaction on coal char and contributed to synergistic effects; the heat transfer from anthracite char to adjacent corncob char reduced the kinetic rate of the water-gas reaction on coal char and contributed to inhibitory effects, and the inhibitory effect caused by heat transfer was greater than the promotion effects of biomass mass transfer. The introduction of O₂ diminished the impact of inter-particle heat transfer and altered the intensity of synergy, decreasing the values of synergy factor of bituminous coal/corncob blends by 17% and increasing the value of synergy factor of anthracite/corncob blends by 142.5%. This study provides sufficient support for the process conditions selection for the production of syngas with specific H₂/CO molar ratios and the desired level of gasification performance.

The exosomes hold significant potential in disease diagnosis and therapeutic interventions. The objective of this study was to investigate the potential of aqueous two-phase systems (ATPSs) for the separation of bovine milk exosomes. The milk exosome partition behaviors and bovine milk separation were investigated, and the ATPSs and bovine milk whey addition was optimized. The optimal separation conditions were identified as 16% (mass) polyethylene glycol 4000, 10% (mass) dipotassium phosphate, and 1% (mass) enzymatic hydrolysis bovine milk whey. During the separation process, bovine milk exosomes were predominantly enriched in the interphase, while protein impurities were primarily found in the bottom phase. The process yielded bovine milk exosomes of 2.0 × 10¹¹ particles per ml whey with high purity (staining rate>90%, 7.01 × 10¹⁰ particles per mg protein) and high uniformity (polydispersity index <0.03). The isolated exosomes were characterized and identified by transmission electron microscopy, zeta potential and size distribution. The results demonstrated aqueous two-phase extraction possesses a robust capability for the enrichment and separation of exosomes directly from bovine milk whey, presenting a novel approach for the large-scale isolation of exosomes.

Emergency resources play a vital role in the emergency rescue process. The adequate and timely supply of emergency resources can effectively control the development of accidents and reduce accident losses. However, the current emergency resource allocation of chemical enterprises lacks scientific analysis of accident scenarios, and the individual allocation method of enterprises increases the cost of emergency resource allocation. Given the above problems, this paper proposes a regional collaborative allocation method of emergency resources for enterprises within the chemical industry park (CIP) based on the worst credible accident scenario (WCAS). Firstly, the concept and analysis method of the WCAS is proposed. Then, based on the characteristics and consequences of the accident, the mapping relationship between accident scenarios and emergency resources is established. Finally, an optimization model for regional collaborative allocation of emergency resources is constructed to determine the amount of emergency resource allocation for each enterprise. Through the case study, the emergency resource allocation method based on the WCAS analysis can better meet the demands of accident emergency rescue. Simultaneously, the regional collaborative allocation optimization model can strengthen the cooperation ability among enterprises, greatly reducing the cost of emergency resource allocation for each enterprise.

Carbon-supported mercury catalysts are extensively employed in calcium carbide-based polyvinyl chloride (PVC) industries, but the usage of mercury-based catalysts can pose an environmental threat due to the release of mercury into the surrounding area during the operation period. In this study, a highly active and stable mercury-based catalyst was developed, utilizing the nitrogen atom of the support as the anchor site to enhance the interaction between active sites (HgCl₂) and the carbon support (N-AC). Thermal loss rate testing and thermogravimetric analysis results demonstrate that, compared to commercial activated carbon, N-doped carbon can effectively increase the heat stability of HgCl₂. The obtained mercury-based catalysts (HgCl₂/N-AC) exhibit significant catalytic performance, achieving 2.5 times the C₂H₂ conversion of conventional HgCl₂/AC catalysts. Experimental analysis combined with theoretical calculations reveals that, contrary to the Eley-Rideal (ER) mechanism of HgCl₂/AC, the HgCl₂/N-AC catalyst follows the Langmuir-Hinshelwood (LH) adsorption mechanism. The nitrogen sites and HgCl₂ on the catalyst enhance the adsorption capabilities of the HCl and C₂H₂, thereby improving the catalytic performance. Based on the modification of the active center by these solid ligands, the loading amount of HgCl₂ on the catalyst can be further reduced from the current 6.5% to 3%. Considering the absence of successful industrial applications for mercury-free catalysts, and based on the current annual consumption of commercial mercury chloride catalysts in the PVC industry, the widespread adoption of this technology could annually reduce the usage of chlorine mercury by 500 tons, making a notable contribution to mercury compliance, reduction, and emissions control in China. It also serves as a bridge between mercury-free and low-mercury catalysts. Moreover, this solid ligand technology can assist in the application research of mercury-free catalysts.

In this study, a catalyst was synthesized using a two-step in-situ molecular beam epitaxy method to grow H₄PMo₁₁VO₄₀ (HPAV) on amination-treated SiO₂ nanoparticles, which served as both dopant and host agents. SiO₂ dopant was modified with (3-aminopropyl)triethoxysilane (APTS), facilitating the formation of ammonium ions that enhanced the overall positive charge. This modification enabled the effective dispersion and exposure of HPAV's active species and induced a structural transformation of HPAV from a triclinic to a cubic crystal phase. The two-step hosting growth process optimized the proportions of Cs⁺, H⁺ and NH₄⁺ antinuclear ions, thereby fine-tuning the synergistic catalysis of oxidation and acidity, as well as the oxidative sensitivity at HPAV catalytic interface. The resultant 8(HPAV)&4(Cs₃PAV)-NH₂-SiO₂ catalyst achieved a methacrolein (MAL) conversion rate of 84% and a methacrylic acid (MAA) selectivity of 71%. Even after 10.5 h of reaction time, the catalyst retained its high dispersion, cubic crystal structure, and Keggin configuration, demonstrating stable catalytic performance over a continuous 200-h reaction period.

The removal of H₂S from coke oven gas (COG) is an important issue for the further utilization of COG. Zeolites could be used for industrial desulfurization owing to their high thermal stability and regenerability. However, further analysis on the kinetics of deep desulfurization using zeolites is necessary to provide relevant information for industrial design. In this study, the desulfurization breakthrough curves of faujasite (FAU) zeolite in COG were measured using a fixed bed reactor. The adsorption isotherm was investigated using the Langmuir, Freundlich, Temkin, Dubinin-Radushkevich models. The adsorption saturated capacity of H₂S was inversely related to the temperature. The results show that the Langmuir model best fits the adsorption isotherm with a lower value of root-mean-square-error (RMSE) and Chi-Square (χ²), and the calculated activation energy is 14.62 kJ·mol^-1. The adsorption kinetics were investigated using pseudo-first-order (PFO), pseudo-second-order (PSO), Bangham and Weber-Morris models. The Bangham model fitted the kinetic data well, indicating that pore diffusion is an influential factor in the adsorption process. The Weber-Morris model suggests that the adsorption rate was not solely determined by the pore diffusion, but was also influenced by the active site on the FAU zeolite. The adsorption breakthrough curves under different gas flow rates were fitted using the bed depth service time (BDST) model, and it provides an accurate prediction of the breakthrough time with a small relative error. The results of thermodynamic analysis demonstrated the feasibility and spontaneity (ΔG<0) and exothermic (ΔH<0) nature of the adsorption process of the FAU zeolite for H₂S under COG.

Weak cementation between natural gas hydrates and mud–sand seriously affects the solid-fluidized mining of natural gas hydrates. In this study, we analyze the debonding of natural gas hydrate sediment (NGHS) particles by applying the principle of spiral-cyclone coupling separation. To achieve this, weakly cemented NGHS particle and mechanical models were established. In the flow field of the spiral-cyclone flow-coupling separator, the motion characteristics of the weakly cemented NGHS particles and the destruction process of the cementation bond were analyzed. The destruction of the bonds mainly occurred in the spiral channel, and the destruction efficiency of the bonds was mainly affected by the rotational speed. Collision analysis of the particles and walls showed that when the velocity is 10–16 m·s^-1, the cementation bond can be broken. The greater the speed, the better the effect of the bond fracture. The breaking rate of the cementation bonds was 85.7%. This study is significant for improving the degumming efficiency in natural gas hydrate exploitation, improving the recovery efficiency of hydrates, and promoting the commercialization of hydrate solid fluidization exploitation.

In the current era of renewable energy prominence, the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants. However, attaining ultra-low nitrogen oxides (NO_x) emissions during periods of low-load operations presents a significant and persistent challenge for coal power enterprises. While techniques such as biomass re-burning and advanced re-burning have shown promise in enhancing NO reduction efficiency above 800 ℃, their elevated levels of chlorine (Cl) and alkali metals pose potential risks to boiler equipment integrity. Therefore, this study proposes the utilization of biomass char derived from pyrolysis as a dual-purpose solution to enhance NO reduction efficiency while safeguarding boiler integrity during low-load operations. Findings indicate that pyrolysis treatment effectively reduces the Cl and alkali metal content of biomass. Specifically, it was determined that biomass char produced through deeply pyrolysis at 300 ℃ achieves the highest NO reduction efficiency while minimizing the presence of harmful components. At a reduction temperature of 700 ℃, both re-burning and advanced re-burning techniques exhibit NO reduction efficiencies of 55.90% and 62.22%, which is already an ideal deficiency at low temperatures. The addition of water vapor at 700-800 ℃ obviously avoids the oxidation of ammonia to NO in advanced re-burning. Upon further analysis, denitrification efficiency in biomass char re-burning and advanced re-burning is influenced not only by volatile content but also by physicochemical properties such as porosity and surface functional group distribution under certain reaction conditions. This study provides a theoretical framework for the industrial implementation of biomass char for NO control in coal-fired power plants, offering insights into optimizing NO reduction efficiency while mitigating potential risks to boiler equipment.