Copper-based metal-organic frameworks (Cu-MOFs) are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions. However, the unpleasant odor and instability of the organosulfur, as well as the mass-transfer resistance that exists in multiphase catalysis, have often limited the catalytic application of Cu-MOFs in C-S coupling reactions. In this paper, a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide (CTAB) was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB. Concurrently, elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.

Under the pressure of carbon neutrality, many carbon capture, utilization and storage technologies have witnessed rapid development in the recent years, including oxy-fuel combustion (OFC) technology. However, the conventional OFC technology usually depends on the flue gas recirculation system, which faces significant investment, high energy consumption, and potential low-temperature corrosion problem. Considering these deficiencies, the direct utilization of pure oxygen to achieve particle fluidization and fuel combustion may reduce the overall energy consumption and CO₂-capture costs. In this paper, the fundamental structure of a self-designed 130 t·h^-1 pure-oxygen combustion circulating fluidized bed (CFB) boiler was provided, and the computational particle fluid dynamics method was used to analyze the gas-solid flow characteristics of this new-concept boiler under different working conditions. The results indicate that through the careful selection of design or operational parameters, such as average bed-material size and fluidization velocity, the pure-oxygen combustion CFB system can maintain the ideal fluidization state, namely significant internal and external particle circulation. Besides, the contraction section of the boiler leads to the particle backflow in the lower furnace, resulting in the particle suspension concentration near the wall region being higher than that in the center region. Conversely, the upper furnace still retains the classic core-annulus flow structure. In addition to increasing solid circulation rate by reducing the average bed-material size, altering primary gas ratio and bed inventory can also exert varying degrees of influence on the gas-solid flow characteristics of the pure-oxygen combustion CFB boiler.

Fault detection and diagnosis (FDD) plays a significant role in ensuring the safety and stability of chemical processes. With the development of artificial intelligence (AI) and big data technologies, data-driven approaches with excellent performance are widely used for FDD in chemical processes. However, improved predictive accuracy has often been achieved through increased model complexity, which turns models into black-box methods and causes uncertainty regarding their decisions. In this study, a causal temporal graph attention network (CTGAN) is proposed for fault diagnosis of chemical processes. A chemical causal graph is built by causal inference to represent the propagation path of faults. The attention mechanism and chemical causal graph were combined to help us notice the key variables relating to fault fluctuations. Experiments in the Tennessee Eastman (TE) process and the green ammonia (GA) process showed that CTGAN achieved high performance and good explainability.

Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical properties. Nevertheless, the storage capacity of the unmodified zeolites has been rather unsatisfactory (0.224%-1.082% (mass)) compared to its modified counterpart. Thus, the contemporary focus on enhancing hydrogen storage capacities has led to significant attention towards the utilization of modified zeolites, with studies exploring surface modifications through physical and chemical treatments, as well as the integration of various active metals. The enhanced hydrogen storage properties of zeolites are attributed to the presence of aluminosilicates from alkaline and alkaline-earth metals, resulting in increased storage capacity through interactions with the charge density of these aluminosilicates. Therefore, there is a great demand to critically review their role such as well-defined topology, pore structure, good thermal stability, and tunable hydrophilicity in enhanced hydrogen storage. This article aimed to critically review the recent research findings based on modified zeolite performance for enhanced hydrogen storage. Some of the factors affecting the hydrogen storage capacities of zeolites that can affect the rate of reaction and the stability of the adsorbent, like pressure, structure, and morphology were studied, and examined. Then, future perspectives, recommendations, and directions for modified zeolites were discussed.

A multitracer-gas method was proposed to study the secondary air (SA) mixing along the bed height in a circulating fluidized bed (CFB) using carbon monoxide (CO), oxygen (O₂), and carbon dioxide (CO₂) as tracer gases. Experiments were carried out on a cold CFB test rig with a cross-section of 0.42 m×0.73 m and a height of 5.50 m. The effects of superficial velocity, SA ratio, bed inventory, and particle diameter on the SA mixing were investigated. The results indicate that there are some differences in the measurement results obtained using different tracer gases, wherein the deviation between CO and CO₂ ranges from 42% to 66% and that between O₂ and CO₂ ranges from 45% to 71% in the lower part of the fluidized bed. However, these differences became less pronounced as the bed height increased. Besides, the high solid concentration and fine particle diameter in the CFB may weaken the difference. The measurement results of different tracer gases show the same trends under the variation of operating parameters. Increasing superficial velocity and SA ratio and decreasing particle diameter result in better mixing of the SA. The effect of bed inventory on SA mixing is not monotonic.

Multi-orifice cross-flow jet mixers (MOCJMs) are used in various industrial applications due to their excellent mixing efficiency, but few studies have focused on the micromixing performance of MOCJMs. Herein, the flow characteristics and micromixing performance inside the MOCJM were investigated using experiments and computational fluid dynamics (CFD) simulations based on the Villermaux/Dushman system and the finite-rate/modified eddy-dissipation model. The optimal A value was correlated with the characteristic parameters of MOCJMs to develop a CFD calculation method applicable to the study of the micromixing performance of the MOCJMs. Then the micromixing efficiency was evaluated using the segregation index X_S, and the effects of operational and geometric parameters such as mixing flow Reynolds number (Re_M), flow ratio (R_F), total jet area (S_T), the number of jet orifices (n), and outlet configuration on the micromixing efficiency were investigated. It was found that the intensive turbulent region generated by interactions between jets, as well as between jets and crossflows, facilitated rapid reactions. X_S decreased with increasing Re_M and decreasing R_F. Furthermore, MOCJMs with lower S_T, four jet orifices, and the narrower outlet configuration demonstrated a better micromixing efficiency. This study contributes to a deeper understanding of the micromixing performance of MOCJMs and provides valuable guidance for their design, optimization, and industrial application.

Lycopene is very susceptible to degradation once released from the protective chromoplast environment. In this study, oil-in-water (O/W) nanoemulsions coupled with spray drying technology were applied for the encapsulation and stabilization of lycopene extracted from tomato waste. Tomato extract was obtained by ultrasound-assisted extraction. Nanoemulsions were prepared by a high-speed rotor stator using isopropyl myristate as the oil phase and Pluronic F-127 as the emulsifier for the aqueous external phase. The effect of emulsification process parameters was investigated. Spray drying of the produced emulsions was attempted to obtain a stabilized dry powder after the addition of a coating agent. The effect of different coating agents (maltodextrin, inulin, gum arabic, pectin, whey and polyvinylpyrrolidone), drying temperature (120-170 ℃), and feed flow rate (3-9 ml·min^-1) on the obtained particles was evaluated. Results revealed that the emulsion formulation of 20/80 (O/W) with 1.5% (mass fraction) of Pluronic F-127 as stabilizer in the aqueous phase resulted in a stable nanoemulsion with droplet sizes in the range of 259-276 nm with a unimodal and sharp size distribution. The extract in the nanoemulsion was well protected at room temperature with a degradation rate of lycopene of about 50% during a month of storage time. The most stable emulsions were then processed by spray drying to obtain a dry powder. Spray drying was particularly successful when using maltodextrin as a coating agent, obtaining dried spherical particles with mean diameters of μm with a smooth surface. The possibility of dissolving the spray dried powder in order to repristinate. The original emulsion was also successfully verified.

The influences of particle size, shape, and catalyst distribution on the reactivity and hydrocarbon product selectivity of a cobalt-based catalyst for Fischer-Tropsch synthesis were investigated in the present work. A self-consistent kinetic model for Fischer-Tropsch reaction proposed here was found to correlate experimental data well and hence was used to describe the consumption rates of reactants and formation rates of hydrocarbon products. The perturbed-chain statistical associating fluid theory equation of state was used to describe vapor-liquid equilibrium behavior associated with Fischer-Tropsch reaction. Local interaction between intraparticle diffusion and Fischer-Tropsch reaction was investigated in detail. Results showed that in order to avoid the adverse influence of intraparticle diffusional limitations on catalyst reactivity and product selectivity, the use of small particles is necessary. Large eggshell spherical particles are shown to keep the original catalyst reactivity and enhance the selectivity of heavy hydrocarbon products. The suitable layer thickness for a spherical particle with a diameter of 2 mm is nearly 0.15 mm. With the same outer diameter of 2 mm, the catalyst reactivity and heavy product selectivity of hollow cylindrical particles with a layer thickness of 0.25 mm are found to be larger than eggshell spherical particles. From the viewpoint of catalytic performance, hollow cylindrical particles are a better choice for industrial applications.

Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge. In this work, a novel mixed-matrix membrane (MMM) (poly(arylene ether ketone) [PAEK]-containing carboxyl groups [PAEK-COOH]/UiO-66-NH₂@graphene oxide [GO]) with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method, by in-situ growth of UiO-66-NH₂ on the GO layer, and by preparing hydrophilic PAEK-COOH. On the basis of the structure and performance analysis of the MMM, the maximum water flux reached 591.25 L·m^-2·h^-1 for PAEK-COOH/UiO-66-NH₂@GO, whereas the retention rate for bovine serum albumin increased from 85.40% to 94.87%. As the loading gradually increased, the hydrophilicity of the MMMs increased, significantly enhancing their fouling resistance. The strongest anti-fouling ability observed was 94.74%, which was 2.02 times greater than that of the pure membrane. At the same time, the MMMs contained internal amide and hydrogen bonds during the preparation process, forming a cross-linked structure, which further enhanced the mechanical strength and chemical stability. In summary, the MMMs with high retention rate, strong permeability, and anti-fouling ability were successfully prepared.

Fault diagnosis is important for maintaining the safety and effectiveness of chemical process. Considering the multivariate, nonlinear, and dynamic characteristic of chemical process, many time-series-based data-driven fault diagnosis methods have been developed in recent years. However, the existing methods have the problem of long-term dependency and are difficult to train due to the sequential way of training. To overcome these problems, a novel fault diagnosis method based on time-series and the hierarchical multihead self-attention (HMSAN) is proposed for chemical process. First, a sliding window strategy is adopted to construct the normalized time-series dataset. Second, the HMSAN is developed to extract the time-relevant features from the time-series process data. It improves the basic self-attention model in both width and depth. With the multihead structure, the HMSAN can pay attention to different aspects of the complicated chemical process and obtain the global dynamic features. However, the multiple heads in parallel lead to redundant information, which cannot improve the diagnosis performance. With the hierarchical structure, the redundant information is reduced and the deep local time-related features are further extracted. Besides, a novel many-to-one training strategy is introduced for HMSAN to simplify the training procedure and capture the long-term dependency. Finally, the effectiveness of the proposed method is demonstrated by two chemical cases. The experimental results show that the proposed method achieves a great performance on time-series industrial data and outperforms the state-of-the-art approaches.

An efficient utilization strategy of ethylene tar (ET), the main by-product of the ethylene cracking unit, is urgently required to meet demands for modern petrochemical industry. On the other hand, condensed polynuclear aromatic resin of moderate condensation degree (B-COPNA) is a widely used carbon material due to its superb processability, the production of which is, however, seriously limited by the high cost of raw materials. Under such context, an interesting strategy was proposed in this study for producing B-COPNA resin using crosslinked light fractions of ethylene tar (ETLF, boiling point <260 ℃) facilitated by molecular simulation. 1,4-Benzenedimethanol (PXG) was first selected as the crosslinking agent according to the findings of molecular simulation. The effects of operating conditions, including reactions temperature, crosslinking agent, and catalyst content on the softening point and yield of B-COPNA resin products were then investigated to optimize the process. The reaction mechanism of resin production was studied by analyzing the molecular structure and transition state of ETLF and crosslinking agents. It was shown that PXG exhibited a superior capacity of withdrawing electrons and a higher electrophilic reactivity than other crosslinking agents. In addition to the highest yield and greatest heat properties, PXG-prepared resin contained the most condensed aromatics. The corresponding optimized conditions of resin preparation were 180 ℃, 1:1.9 (PXG:ETLF), and 3% (mass) of catalyst content with a resin yield of 78.57%. It was the electrophilic substitution reaction that occurred between the ETLF and crosslinking agent molecules that were responsible for the resin formation, according to the experimental characterization and molecular simulation. Hence, it was confirmed that the proposed strategy and demonstrated process can achieve a clean and high value-added utilization of ETLF via B-COPNA resin preparation, bringing huge economic value to the current petrochemical industry.

NaY zeolites are synthesized using submolten salt depolymerized natural perlite mineral as the main silica and alumina sources in a 0.94 L stirred crystallizer. Effects of alkalinity ranging from 0.38 to 0.55 (n(Na₂O)/n(SiO₂)) on the relative crystallinity, textural properties and crystallization kinetics were investigated. The results show that alkalinity exerts a nonmonotonic influence on the relative crystallinity and textural properties, which exhibit a maximum at the alkalinity of 0.43. The nucleation kinetics are studied by fitting the experimental data of relative crystallinity with the Gualtieri model. It is shown that the nucleation rate constant increases with increasing alkalinity, while the duration period of nucleation decreases with increasing alkalinity. For n(Na₂O)/n(SiO₂) ratios ranging from 0.38 to 0.55, the as-synthesized NaY zeolites exhibit narrower crystal size distributions with the increase in alkalinity. The growth rates determined from the variations of average crystal size with time are 51.09, 157.50, 46.17 and 24.75 nm·h^-1, respectively. It is found that the larger average crystal sizes at the alkalinity of 0.38 and 0.43 are attributed to the dominant role of crystal growth over nucleation. Furthermore, the combined action of prominent crystal growth and the longer duration periods of nucleation at the alkalinity of 0.38 and 0.43 results in broader crystal size distributions. The findings demonstrate that control of the properties of NaY zeolite and the crystallization kinetics can be achieved by conducting the crystallization process in an appropriate range of alkalinity of the reaction mixture.

The nickel-rich layered cathode material LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) has high energy density, lower cost and is a promising cathode material currently under development. However, its electrochemical and structural stability is poor during cycling. Among the many modification methods, cation doping has been consistently proven to be an effective strategy for enhancing electrochemical performance. Herein, the NCM811 cathode material was modified by solid-phase reactions with Mg and Al doped. In addition, the corresponding mechanism of NCM811 cathode material-doped modification is explored by density functional theory (DFT) calculations, and we have extended this approach to other ternary cathode materials with different ratios and obtained universal laws. Combined with DFT calculations, the results show that Mg²⁺ occupies the Li⁺ site and reduces the degree of Li⁺/Ni²⁺ mixture; Al³⁺ acts as a structural support during charging and discharging to prevent structural collapse. The electrochemical properties were tested by an electrochemical workstation and the LAND system, and the results showed that the capacity retention rate increased to varying degrees from 63.66% to 69.87% and 89.05% for NCM811-Mg and NCM811-Al at room temperature after 300 cycles, respectively. This study provides a theoretical basis and design strategy for commercializing cationic-doped modification of nickel-rich cathode materials.

Natural gas hydrates, intricate crystalline structures formed by water molecules and small gas molecules, have emerged as a significant and globally impactful clean energy resource. However, their commercial exploitation faces challenges, particularly operational disruptions caused by sand-related blockages. Understanding the rheological properties of hydrate slurry, especially in the presence of micron-sized sand particles, is imperative for ensuring the flow assurance of subsea hydrate exploitation. This study extensively investigates the rheological properties of sand-containing hydrate slurries. The findings reveal that these slurries exhibit non-Newtonian fluid characteristics, including yield stress, thixotropy, and shear-thinning behavior. Solid-like elastic features are observed in sand-containing hydrate slurries before yielding, transitioning to viscous behavior after yielding. Even with a minimal amount of sand, both static yield stress and yield strain experience substantial changes, correlating with the increase in sand concentration. The research conclusively establishes the thixotropic nature of sand-hydrate slurries, where the viscosity decay rate is directly influenced by the shear rate. These insights aim to contribute comprehensively to the development of effective flow assurance strategies, ensuring the safe and stable operation of subsea hydrate exploitation.

A critical pathway towards enhancing pulp mill biorefineries is to integrate the extraction and utilization of hemicelluloses into the pulping processes. Hence, an industrial pre-extraction strategy for hemicelluloses targeting eucalyptus kraft pulping process was developed. Alkaline solution or pulping white liquor was used to pre-extract hemicelluloses before the actual pulping process. The response surface methodology (RSM) technique was applied to investigate the most suitable conditions to maximize the yield of these hemicelluloses while simultaneously minimizing the damage to pulp yields and properties. Temperature (105 to 155 ℃), alkali concentration (3% to 8%), sulfidity (20% to 30%) and retention time (19 to 221 min) were combined to evaluate their effects on hemicellulose yields and chemical structures. The optimal pre-extraction conditions identified in this work (5.75% NaOH concentration, 25% sulfidity at 135℃ for 60 min) successfully allowed recovering 4.8% of hemicelluloses (based on the wood dry mass) and limited damages to pulp yields and properties. The cellulose content in pulp can even be increased by about 10%. Hemicellulose emulsification properties were also evaluated, which were comparable to synthetic emulsifiers. This study provides an industrial pathway to effectively separate and utilize wood hemicelluloses from the pulping process, which has the potential to improve the economy and material utilization of pulp and paper mills.

Kenics static mixers (KSM) are extensively used in industrial mixing-reaction processes by virtue of high mixing efficiency, low power homogenization and easy continuous production. Resolving liquid droplet size and its distribution and thus revealing the dispersion characteristics are of great significance for structural optimization and process intensification in the KSM. In this work, a computational fluid dynamics-population balance model (CFD-PBM) coupled method is employed to systematically investigate the effects of operating conditions and structural parameters of KSM on droplet size and its distribution, to further reveal the liquid-liquid dispersion characteristics. Results indicate that higher Reynolds numbers or higher dispersed phase volume fractions increase energy dissipation, reducing Sauter mean diameter (SMD) of dispersed phase droplets and with a shift in droplet size distribution (DSD) towards smaller size. Smaller aspect ratios, greater blade twist and assembly angles amplify shear rate, leading to smaller droplet size and a narrower DSD in the smaller range. The degree of impact exerted by the aspect ratio is notably greater. Notably, mixing elements with different spin enhance shear and stretching efficiency. Compared to the same spin, SMD becomes 3.7-5.8 times smaller in the smaller size range with a significantly narrower distribution. Taking into account the pressure drop and efficiency in a comprehensive manner, optimized structural parameters for the mixing element encompass an aspect ratio of 1-1.5, a blade twist angle of 180°, an assembly angle of 90°, and interlaced assembly of adjacent elements with different spin. This work provides vital theoretical underpinning and future reference for enhancing KSM performance.

Tuning Strong Metal-support Interactions (SMSI) is a key strategy to obtain highly active catalysts, but conventional methods usually enable TiO encapsulation of noble metal components to minimize the exposure of noble metals. This study demonstrates a catalyst preparation method to modulate a weak encapsulation of Pt metal nanoparticles (NPs) with the supported TiO₂, achieving the moderate suppression of SMSI effects. The introduction of silica inhibits this encapsulation, as reflected in the characterization results such as XPS and HRTEM, while the Ti⁴⁺ to Ti³⁺ conversion due to SMSI can still be found on the support surface. Furthermore, the hydrogenation of cinnamaldehyde (CAL) as a probe reaction revealed that once this encapsulation behavior was suppressed, the adsorption capacity of the catalyst for small molecules like H₂ and CO was enhanced, which thereby improved the catalytic activity and facilitated the hydrogenation of CAL. Meanwhile, the introduction of SiO₂ also changed the surface structure of the catalyst, which inhibited the occurrence of the acetal reaction and improved the conversion efficiency of C=O and C=C hydrogenation. Systematic manipulation of SMSI formation and its consequence on the performance in catalytic hydrogenation reactions are discussed.

The amino-functionalization of TS-1 zeolite followed by immobilization of phosphotungstic acid (HPW) was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterification of citric acid and n-butanol. γ-Aminopropyltriethoxysilane (APTES) was first grafted on the TS-1 zeolite via the condensation reactions with surface hydroxyl groups, and subsequently the HPW was immobilized via the reaction between the amino groups and the protons from HPW-forming strong ionic bonding. The Keggin structure of HPW and MFI topology of TS-1 zeolite were well maintained after the modifications. The amino-functionalization generated abundant uniformly distributed active sites on TS-1 for HPW immobilization, which promoted the dispersity, abundance, as well as the stability of the acid sites. The tetrahedrally coordinated framework titanium and non-framework titania behaved as weak Lewis acid sites, and the protons from the immobilized HPW acted as the moderate or strong Brønsted acid sites. An optimized TBC yield of 96.2% (mol) with a conversion of -COOH of 98.1% (mol) was achieved at 150 ℃ for 6 h over the HPW immobilized on amino-functionalized TS-1. The catalyst exhibited good stability after four consecutive reaction runs, where the activity leveled off at still a relatively high level after somewhat deactivation possibly caused by the leaching of a small portion of weakly anchored APTES or HPW.

Glycerol monolaurate (GML) is a widely used industrial chemical with excellent emulsification and antibacterial effect. The direct esterification of glycerol with lauric acid is the main method to synthesize GML. In this work, the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst. A complete kinetic model of consecutive esterification reaction has been established, and the kinetic equation of acid catalysis was deduced. The isomerization reactions of GML and glycerol dilaurate were investigated. It was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification reaction. The kinetic equations of the consecutive esterification reaction were obtained by experiments as k₁ = (276+92261X_cat)exp(-37720/RT) and k₂ = (80 +4413X_cat)exp(-32240/RT). The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.

Porous silica nano-flowers (KCC-1) immobilized Pt-Pd alloy NPs (Pt-Pd/KCC-1) with different mass ratios of Pd and Pt were successfully prepared by a facile in situ one-step reduction, using hydrazinium hydroxide as a reducing agent. The as-synthesized silica nanospheres possess radial fibers with a distance of 15 nm, exhibiting a high specific surface area (443.56 m²·g^-1). Meanwhile, the obtained Pt-Pd alloy NPs are uniformly dispersed on the silica surface with a metallic particle size of 4-6 nm, which exist as metallic Pd and Pt on the surface of monodisperse KCC-1, showing the transfer of electrons from Pd to Pt. The as-synthesized 2.5%Pt-2.5%Pd/KCC-1 exhibited excellent catalytic activity and stability for the continuous dehydrogenation of 2-methoxycyclohexanol to prepare guaiacol. Compared with Pt or Pd single metal supported catalysts, the obtained 2.5%Pt-2.5%Pd/KCC-1 shows 97.2% conversion rate of 2-methoxycyclohexanol and 76.8% selectivity for guaiacol, which attributed to the significant synergistic effect of bimetallic Pt-Pd alloy NPs. Furthermore, turn over frequency value of the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs achieved 4.36 s^-1, showing higher catalytic efficiency than other two monometallic catalysts. Reaction pathways of dehydro-aromatization of 2-methoxycyclohexanol over the obtained catalyst are proposed. Consequently, the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs prove their potential in the dehydrogenation of 2-methoxycyclohexanol, while the kinetics and mechanistic study of the dehydrogenation reaction over the catalyst in a continuous fixed-bed reactor may provide valuable information for the development of green, outstanding and powerful synthetic pathway of guaiacol.

Ethylene glycol (EG) plays a pivotal role as a primary raw material in the polyester industry, and the syngas-to-EG route has become a significant technical route in production. The carbon monoxide (CO) gas-phase catalytic coupling to synthesize dimethyl oxalate (DMO) is a crucial process in the syngas-to-EG route, whereby the composition of the reactor outlet exerts influence on the ultimate quality of the EG product and the energy consumption during the subsequent separation process. However, measuring product quality in real time or establishing accurate dynamic mechanism models is challenging. To effectively model the DMO synthesis process, this study proposes a hybrid modeling strategy that integrates process mechanisms and data-driven approaches. The CO gas-phase catalytic coupling mechanism model is developed based on intrinsic kinetics and material balance, while a long short-term memory (LSTM) neural network is employed to predict the macroscopic reaction rate by leveraging temporal relationships derived from archived measurements. The proposed model is trained semi-supervised to accommodate limited-label data scenarios, leveraging historical data. By integrating these predictions with the mechanism model, the hybrid modeling approach provides reliable and interpretable forecasts of mass fractions. Empirical investigations unequivocally validate the superiority of the proposed hybrid modeling approach over conventional data-driven models (DDMs) and other hybrid modeling techniques.

Raman spectroscopy has found extensive use in monitoring and controlling cell culture processes. In this context, the prediction accuracy of Raman-based models is of paramount importance. However, models established with data from manually fed-batch cultures often exhibit poor performance in Raman-controlled cultures. Thus, there is a need for effective methods to rectify these models. The objective of this paper is to investigate the efficacy of Kalman filter (KF) algorithm in correcting Raman-based models during cell culture. Initially, partial least squares (PLS) models for different components were constructed using data from manually fed-batch cultures, and the predictive performance of these models was compared. Subsequently, various correction methods including the PLS-KF-KF method proposed in this study were employed to refine the PLS models. Finally, a case study involving the auto-control of glucose concentration demonstrated the application of optimal model correction method. The results indicated that the original PLS models exhibited differential performance between manually fed-batch cultures and Raman-controlled cultures. For glucose, the root mean square error of prediction (RMSEP) of manually fed-batch culture and Raman-controlled culture was 0.23 and 0.40 g·L^-1. With the implementation of model correction methods, there was a significant improvement in model performance within Raman-controlled cultures. The RMSEP for glucose from updating-PLS, KF-PLS, and PLS-KF-KF was 0.38, 0.36 and 0.17 g·L^-1, respectively. Notably, the proposed PLS-KF-KF model correction method was found to be more effective and stable, playing a vital role in the automated nutrient feeding of cell cultures.

Chlorotrifluoroethylene (CTFE) is a vital fluorinated olefinic monomer produced through the catalytic hydrodechlorination of trichlorotrifluoroethane (CFC-113), an eco-friendly process. However, hydrodechlorination catalysts for olefin production often suffer from poor stability. The Pd/AC catalyst and Pd-Cu/AC catalyst prepared by co-impregnation method exhibited poor stability, Pd-Cu/AC catalyst with CFC-113 conversion dropping to around 37% after 50 h of hydrodechlorination reaction. Brunauer-Emmett-Teller, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction of fresh and deactivated Pd/AC catalysts indicate that the deactivation of Pd/AC catalysts is due to high-temperature agglomeration of Pd. Comparative analysis of fresh and deactivated Pd-Cu/AC catalysts using Brunauer-Emmett-Teller, transmission electron microscopy, and thermogravimetric analysis techniques revealed decreased dispersion of active sites, reduced surface area, catalyst aggregation deactivation, and a significant decrease in Cu content. Furthermore, the results of NH₃-TPD revealed that the acid sites of the catalyst increased significantly. X-ray diffraction spectra indicated the formation of new species, basic copper chloride (Cu₂(OH)₃Cl), during the reaction. As the reaction progressed, these new species agglomerated, leading to a gradual loss of catalyst activity. Moreover, the deactivated catalyst was successfully reactivated using a simple alkaline washing method.

Recently, azobenzene-4,4'-dicarboxylic acid (ADCA) has been produced gradually for use as an organic synthesis or pharmaceutical intermediate due to its eminent performance. With large quantities put into application in the future, the thermal stability of this substance during storage, transportation, and use will become quite important. Thus, in this work, the thermal decomposition behavior, thermal decomposition kinetics, and thermal hazard of ADCA were investigated. Experiments were conducted by using a SENSYS evo DSC device. A combination of differential iso-conversion method, compensation parameter method, and nonlinear fitting evaluation were also used to analyze thermal kinetics and mechanism of ADCA decomposition. The results show that when conversion rate α increases, the activation energies of ADCA's first and main decomposition peaks fall. The amount of heat released during decomposition varies between 182.46 and 231.16 J·g^-1. The proposed kinetic equation is based on the Avrami-Erofeev model, which is consistent with the decomposition progress. Applying the Frank-Kamenetskii model, a calculated self-accelerating decomposition temperature of 287.0 ℃ is obtained.

High alumina fly ash (FA_HAl) is a kind of bulk solid waste unique to China, whose availability of high-value aluminum and the threat to the environment makes its high-value utilization urgent. In this work, the alumina containing leaching solution obtained from Na₂CO₃ roasting and HCl leaching of FA_HAl was used as the mother liquor to prepare layered boehmite in situ. The preparation process with AlCl₃ as the raw material was also compared. The formation process and mechanism of boehmite, the choice of solvent, along with the adsorption capability of Congo red were analyzed by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller method and adsorption experiments. Results showed that during the preparation of layered boehmite, the precursor Al(OH)₃ from the reaction of Al³⁺ and OH^- is transformed into boehmite γ-AlOOH. The existence of ethanol is beneficial to regulate and promote the growth of boehmite crystal effectively. When water and ethanol are mixed with a volume ratio of 2:1 and used as the solvent, the maximum specific surface area of the boehmite is obtained at 135.7 m²·g^-1, and 99.16% of Congo red can be absorbed after 10 min when AlCl₃ is used as a raw material. As purified leaching solution is used as the mother liquid, the crystallinity of boehmite decreases slightly when the pH value decreases from 12.5 to 11. When pH is 11, the removal efficiency of Congo red reaches a maximum of 72.25%. This process not only achieves the extraction of aluminum and high-value utilization of FA_HAl but also provides a thought to prepare layered boehmite with adsorption properties.