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

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

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

The ultra-deep desulfurization of oil needs to be solved urgently due to various problems, including environmental pollution and environmental protection requirements. Oxidative desulfurization (ODS) was considered to be the most promising technology. The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task. In this paper, pentamethylene hexamine (PEHA) and phosphotungstic acid (HPW) were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil. The composite material exhibited excellent catalytic activity and high recyclability, which could reach a 100% dibenzothiophene (DBT) removal rate in 30 min and be recycled at least 5 times. Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW. It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role. This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts.

The regeneration of fluidized catalytic cracking (FCC) catalysts is an essential process in petroleum processing. The current study focused the regeneration reaction characteristics of spent fluidized catalytic cracking catalyst (SFCC) at different atmospheres with influences on pore evolution and activity, for a potential way to reduce emission, produce moderate chemical product (CO), and maintain catalyst activity. The results show that regeneration in air indicates a satisfaction on removing coke on the catalyst surface while giving a poor effect on eliminating the coke inside micropores. This is attributed that the combustion in air led to a higher temperature and further transformed kaolinite phase to silica-aluminum spinel crystals, which tended to collapse and block small pores or expand large pores, with similar results observed in pure O₂ atmosphere. Nevertheless, catalysts regenerated in O₂/CO₂ diminished the combustion damage to the pore structure, of which the micro porosity after regeneration increased by 32.4% and the total acid volume rose to 27.1%. The regeneration in pure CO₂ displayed low conversion rate due to the endothermic reaction and low reactivity. The coexistence of gasification and partial oxidation can promote regeneration and maintain the original structure and good reactivity. Finally, a mechanism of the regeneration reaction at different atmospheres was revealed.

Aniline is a vital industrial raw material. However, highly-toxic aniline wastewater usually deteriorated effluent quality, posed a threat to human health and ecosystem safety. Therefore, this study reported a novel internal circulation iron-carbon micro-electrolysis (ICE) reactor to treat aniline wastewater. The effects of reaction time, pH, aeration rate and iron-carbon (Fe/C) ratio on the removal rate of aniline and the chemical oxygen demand were investigated using single-factor experiments. This process exhibited high aniline degradation performance of approximately 99.86% under optimal operating conditions (reaction time = 20 min, pH = 3, aeration rate = 0.5 m³·h^-1, and Fe/C = 1:2). Based on the experimental results, the response surface method was applied to optimize the aniline removal rate. The Box-Behnken method was used to obtain the interaction effects of three main factors. The result showed that the reaction time had a dominant effect on the removal rate of aniline. The highest aniline removal rate was obtained at pH of 2, aeration rate of 0.5 m³·h^-1 and reaction time of 30 min. Under optional experimental conditions, the aniline content of effluent was reduced to 3 mg·L^-1 and the removal rate was as high as 98.24%, within the 95% confidence interval (97.84%-99.32%) of the predicted values. The solution was treated and the reaction intermediates were identified by high-performance liquid chromatography, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry, and ion chromatography. The main intermediates were phenol, benzoquinone, and carboxylic acid. These were used to propose the potential mechanism of aniline degradation in the ICE reactor. The results obtained in this study provide optimized conditions for the treatment of industrial wastewater containing aniline and can strengthen the understanding of the degradation mechanism of iron-carbon micro-electrolysis.

Water pollution regarding dyes and heavy metal ions is crucial facing the world. How to effectively separate these contaminants from water has been a key issue. Graphene oxide (GO) promises the green-water world as a long-lasting spotlight adsorbent material and therefore, harnessing GO has been the research hotspot for over a decade. The state of GO as well as its surface functional groups plays an important role in adsorption. And the way of preparation and structural modification matters to the performance of GO. In this review, the significance of the state of existence of stock GO and surface functional groups is explored in terms of preparation, structural modification, and adsorption. Besides, various adsorbates for GO adsorption are also involved, the discussion of which is rarely established elsewhere.

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

As an important organic, isobutyl acetate (IbAc) has been widely used in industries because of its good biodegradability, low surface tension, and other properties. The industrial production of IbAc is usually catalyzed by sulfuric acid. However, the use of sulfuric acid has the drawbacks of causing considerable corrosion to equipment and being difficult to be separated. In this work, n-sulfopropyl-3-methylpyridinium trifluoromethanesulfonate ([HSO₃-PMPY][CF₃SO₃]) Brönsted acidic ionic liquid (BAIL) was used as the catalyst and the catalytic activity, solubility, and corrosiveness were evaluated for the esterification of acetic acid with isobutanol. The reaction kinetics and chemical equilibrium were systemically studied. Compared to conventional acid catalysts, [HSO₃-PMPY][CF₃SO₃] showed higher catalytic activity, more excellent reusability, more favorable phase separation, and non-corrosiveness. Three kinetic equations based on ideal homogeneous (IH), non-ideal homogeneous (NIH), and modified non-ideal homogeneous (NIH-M) models were established and correlated with the experimental data to determine the parameters and errors. The NIH-M model exhibited the best agreement with the experimental data, owing to its prediction considering the non-ideality and the self-catalysis effect of acetic acid in this system. Besides, the error of NIH-M model fitting was mainly caused by the difference in solubility between [HSO₃-PMPY][CF₃SO₃] with reactants and products in the reaction system. Furthermore, the applicability of the NIH-M model was investigated by simulating the esterification of acetic acid with three short-chain alcohols (ethanol, n-butanol, and isobutanol) catalyzed by BAILs. The NIH-M model displayed an acceptable simulation for this type of acetic acid esterification reaction catalyzed by BAILs at different ranges of the BAILs concentration and temperature. This study confirmed the industrial prospects of [HSO₃-PMPY][CF₃SO₃] in isobutyl acetate production and the applicability of the NIH-M kinetic model in the esterification of acetic acid.

The in-situ growing approach was utilized in this article to construct the magnesium-aluminum layered double hydroxide (MgAl-LDH) film on the surface of a 1060 aluminum anodized film. To improve the corrosion resistance and friction qualities of aluminum alloy, the MgAl-LDH coating was treated using stearic acid (SA) and thiourea (TU). The aluminum substrate and anodized aluminum film layer corroded to varying degrees after 24 h of immersion in 3.5% (mass) NaCl solution, while the modified hydrotalcite film layer continued to exhibit the same microscopic morphology even after being immersed for 7 d. The results show that the synergistic action of thiourea and stearic acid can effectively improve the corrosion resistance of the MgAl-LDH substrate. The tribological testing reveals that the hydrotalcite film layer and the modified film layer lowered the friction coefficient of the anodized aluminum surface substantially. The results of the simulations and experiments demonstrate that SA forms the dense LDH-TU interlayer film layer by exchanging NO₃^- ions between TU layers on the one hand and the LDH-SA film layer by adsorption on the surface of LDH on the other. Together, these two processes create LDH-TU-SA, which can significantly increase the substrate's corrosion resistance. This synergistically modified superhydrophobic and retardant hydrotalcite film layer offers a novel approach to the investigation of wear reduction and corrosion protection on the surface of aluminum and its alloys.

A nickel hexacyanoferrate (NiHCF) film electrode was prepared with NiHCF, conductive carbon black, and polyvinylidene difluoride, which was coated on graphite plate substrate for selective extraction of Cs⁺ ions by using electrochemically switched ion exchange (ESIX) technology. A potential-responsive ion-pump system for efficient extraction of Cs⁺ ions was designed, and the effect of wet film thicknesses, charging modes, flow rates, and chamber widths on Cs⁺ ions extraction performance was investigated. In the system, the adsorption capacity and removal percentage of Cs⁺ ions on the NiHCF film electrode reached as high as 147.69 mg·g^-1 and 92.47%, respectively. Furthermore, the NiHCF film electrode showed high selectivity for Cs⁺ ions and stability. After seven cycles of adsorption/desorption, the desorption percentage could reach about 100%. The excellent Cs⁺ extraction performance should be attributed to the strong driving force produced by the potential-responsive ion-pumping effect in the ESIX process, as well as the low ion transfer resistance of the film electrode which is caused by the special crystal structure of NiHCF. In addition, the NiHCF film electrode was implemented to work together with the bismuth oxybromide (BiOBr) film electrode to accomplish the simultaneous extraction of Cs⁺ and Br^-. And the adsorption capacity and removal percentage of Br^- ions on the BiOBr film electrode reached 69.53 mg·g^-1 and 77.32%, correspondingly. It is expected that such a potential-responsive ion-pump system based on NiHCF and BiOBr film electrodes could be used for the selective extraction and concentration of Cs⁺ and Br^- ions from salt lake brine..

To better understand the role of the —NH₂ group in adsorption process of phenolic wastewaters, NH₂-functionalized MIL-53(Al) composites with activated carbon (NH₂-M(Al)@(B)AC) were prepared. The results showed that the NH₂ group could increase the mesopore volume for composites, which promotes mass transfer and full utilization of active sites, because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption sites. Furthermore, the introduction of the NH₂ group can improve the adsorption capacity, decrease the activation energy, and enhance the interaction between the adsorbent and p-nitrophenol, demonstrating that the NH₂ group plays a crucial role in the adsorption of p-nitrophenol. The density functional theory calculation results show that the H-bond interaction between the —NH₂ group in the adsorbent and the NO₂ in the p-nitrophenol (adsorption energy of -35.5 kJ·mol^-1), and base-acid interaction between the primary —NH₂ group in the adsorbent and the acidic OH group in the p-nitrophenol (adsorption energy of -27.3 kJ·mol^-1) are predominant mechanisms for adsorption in terms of the NH₂-functionalized adsorbent. Both NH₂-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized composites. Among the composites, the NH₂-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g^-1.

Residue conversion by combining catalytic hydrotreating and delayed coking has been evaluated comparatively with both processes alone. Optimal operating conditions are defined to achieve the greatest economic benefit for upgrading an atmospheric residue from a heavy crude oil. A literature model was adapted to simulate the hydrotreating reactor, and for delayed coking, correlations reported in the literature were used. The results with both approaches were employed to calculate the techno-economic feasibility of the combined process scheme. The combination of hydrotreating and delayed coking presented an increase in light fractions of 29% and a reduction in coke production of 47.8%. Based on the calculated net benefit values, it was demonstrated that the combination of hydrotreating and delayed coking is technically and economically better than using each process alone, with highest benefit of 57.7 USD·m^-3.

With the vigorous development of the electronics industry, the consumption of lithium continues to increase, and more lithium needs to be mined to meet the development of the industry. The content of lithium in the solution is much higher than that of minerals, but the interference of impurity ions increases the difficulty of extracting lithium ions. Therefore, we prepared an imidazole-based ionic liquid (1-butyl-3-methylImidazolium bis(trifluoromethyl sulfonyl)imide) (IL) for efficient lithium extraction from aqueous solutions by solvent extraction. Using an extraction consisting of 10% IL, 85% tributyl phosphate (TBP), and 5% dichloroethane and an organic to aqueous phase ratio (O/A) of 2/1, over 64.23% of Li were extracted, and the extraction rate after five-stage extraction could reach more than 96%. The addition of ammonium ions to the solution inhibited the extraction of Ni, and the separation coefficient between lithium and nickel approached infinity, showing a very perfect separation effect. Fourier-transform infrared spectroscopy and slope methods were used to analyze the changes that occurred during extraction, revealing possible extraction mechanisms. In addition, the LiCl solution generated during the preparation of ionic liquids was mixed with the stripping solution, and the battery-grade lithium carbonate was prepared by Na₂CO₃ precipitation, with a purity of 99.74%. This study provides an efficient and sustainable strategy for recovering lithium from the solution.

Precise modulation of the structure and composition of electrocatalysts is critical for promoting the kinetically sluggish process of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Covalent organic frameworks (COF) offer a novel way to create highly efficient electrocatalysts due to their tunable composition, structure and surface area. Herein, we report a high-efficiency bifunctional electrocatalyst comprising Co nanoparticles embedded within N-doped carbons (Co@NCs) for Zn-air batteries (ZABs). The Co@NC is yielded via the coordination of a triazine COF with Co-containing precursors and subsequent calcination under inert atmosphere. The as-prepared Co@NC exhibits remarkable ORR/OER performance and great potential in rechargeable ZABs. The liquid ZAB constructed with Co@NC provides both high specific capacity and power density. Remarkably, the ZAB exhibits a voltage gap of 0.8 V during discharge and charge cycles and high stability for 220 h compared to the Pt/C-assembled battery. This strategy for regulating electrocatalytic activities of COF-derived carbon materials could be expanded for creating various carbon catalysts.

Environmentally friendly nature of CO₂, associated with its safety and high efficiency, has made it a widely used working fluid in heat exchangers. Since CO₂ has strange thermophysical features, specific models are required to estimate its two-phase characteristics, particularly frictional pressure drop (FPD). Herein, a widespread dataset, comprising 1195 experimental samples for two-phase FPD of CO₂ was adopted from 10 sources to fulfill this requirement. The literature correlations failed to provide satisfactory precisions and exhibited the average absolute relative errors (AAREs) between 29.29% and 67.69% from the analyzed data. By inspiring the theoretical method of Lockhart and Martinelli, three intelligent FPD models were presented, among which the Gaussian process regression approach surpassed the others with AARE and R² values of 5.48% and 98.80%, respectively in the test stage. A novel simple correlation was also derived based on the least square fitting method, which yielded opportune predictions with AARE of 19.76% for all data. The truthfulness of the newly proposed models was assessed through a variety of statistical and visual analyses, and the results affirmed their high reliability over a broad range of conditions, channel sizes and flow patterns. Furthermore, the novel models performed favorably in describing the physical attitudes corresponding to two-phase FPD of CO₂. Eventually, the importance of operating factors in controlling the FPD was discussed through a sensitivity analysis.

In order to improve the catalytic performance of the nitrobenzene hydrogenation rearrangement to prepare p-aminophenol, a bimetallic Pt-Ni/C (PNC) catalyst was synthesized. Taking advantage of the synergistic effect of Ni and Pt to enhance product selectivity and catalytic performance stability, the electrons in Ni are moved to Pt by the electron effect, which affects the catalyst's ability to activate H₂ as well as the amount of hydrogen activated. Furthermore, due to the strong Pt(5d)-Ni(3d) coupling effect, Ni can effectively maintain Pt stability in the acidic system and reduce Pt dissolution. The stability of the PNC can be found to be greatly enhanced compared to the Pt/C (PC) catalyst, and p-aminophenol selectivity is greatly enhanced, showing excellent catalytic performance.

Pervaporation desalination by highly hydrophilic materials such as poly(vinyl alcohol) (PVA) based separation membrane is a burgeoning technology of late years. However, the improvement of membrane flux in pervaporation desalination has been a difficult task. Here, a novel hybrid membrane with doped graphene oxide quantum dots (GOQDs) which is rich in hydrophilic groups and small size into the matrix of PVA was prepared to improve the membrane flux. The membranes structures were described by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). And more, Water contact angle, swelling degree, and pervaporation properties were carried out to explore the effect of GOQDs in PVA matrix. In addition, GOQDs content in the hybrid membrane, NaCl concentration, and feed temperature were investigated accordingly. Moreover, the hydrogen bonds between PVA chains were weakened by the interaction between GOQDs and PVA chains. Significantly, the hybrid membrane with optimized doped GOQDs content, 200 mg·L^-1, displays a high membrane flux of 17.09 kg·m²·h¹ and the salt rejection is consistently greater than 99.6%.

Redox catalysts play a vital role in the interconversion of two significant greenhouse gases, CO₂ and CH₄, via chemical looping methane dry reforming technology. Herein, a series of transition metals-alloyed and core-shell structured Ni-M/SiO₂@CeO₂ (M = Fe, Co, Cu, Mn, Zr) redox catalyst were fabricated and evaluated in a gas-solid fixed-bed reactor for cycling CH₄ partial oxidation (POx) and CO₂ splitting. The catalysts are composed of spherical SiO₂ core and CeO₂ shell, and the highly dispersed Ni alloy nanoparticles are the interlayer between core and shell. The oxygen vacancy concentration of Ni-M/SiO₂@CeO₂ followed the order of Co > Cu > Fe > Mn > Zr, and Ni alloying with transition metals significantly enhanced oxygen storage capacity (OSC). Ni-Co/SiO₂@CeO₂ catalyst with abundant oxygen vacancies and a high OSC showed the lowest temperatures of CH₄ activation (610 ℃) and CO₂ decomposition (590 ℃), thus demonstrating excellent redox reactivity. The catalyst exhibited superior activity and structural stability in the continuous CH₄/CO₂ redox cycles at 615 ℃, achieving 87% CH₄ conversion and 83% CO selectivity. The proposed catalyst shows great potential for the utilization of CH₄ and CO₂ in a redox mode, providing a new sight for design redox catalyst in chemical looping or related fields.

The structure of the pressure swirl nozzle is an important factor affecting its spray performance. This work aims to study pressure swirl nozzles with different structures by experiment and simulation. In the experiment, 10 nozzles with different structures are designed to comprehensively cover various geometric factors. In terms of simulation, steady-state simulation with less computational complexity is used to study the flow inside the nozzle. The results show that the diameter of the inlet and outlet, the direction of the inlet, the diameter of the swirl chamber, and the height of the swirl chamber all affect the atomization performance, and the diameter of the inlet and outlet has a greater impact. It is found that under the same flow rate and pressure, the geometric differences do have a significant impact on the atomization characteristics, such as spray angle and SMD (Sauter mean diameter). Specific nozzle structures can be customized according to the actual needs. Data analysis shows that the spray angle is related to the swirl number, and the SMD is related to turbulent kinetic energy. Through data fitting, the equations for predicting the spray angle and the SMD are obtained. The error range of the fitting equation for the prediction of spray angle and SMD is within 15% and 10% respectively. The prediction is expected to be used in engineering to estimate the spray performance at the beginning of a real project.