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.

Efficient and low-cost recycling of spent lithium iron phosphate (LiFePO₄, LFP) batteries has become an inevitable trend. In this study, an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed. An inexpensive FeCl₃ was used as leaching agent to directly substitute Fe²⁺ from LFP. 99% of Li can be rapidly leached in just 30 min, accompanied by 98% of FePO₄ precipitated in lixivium. The tri-n-butyl phosphate (TBP)-sulfonated kerosene (SK) system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li⁺ and Fe³⁺. 80.81% of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^-1 of Li⁺ under optimal conditions. And the Fe stripping liquor was recovered for LFP re-leaching, of which, Fe²⁺ was oxidized to Fe³⁺ by appropriate H₂O₂. Raffinate and lixivium were concentrated and entered into extraction process to accomplished close-loop recycling process. Overall, the results suggest that more than 99% of Li was recovered. FeCl₃ holding in solution was directly regenerated without any pollutant emission. The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.

Synthetic biotechnology has led to the widespread application of genetically modified organisms (GMOs) in biochemistry, bioenergy, and therapy. However, the uncontrolled spread of GMOs may lead to genetic contamination by horizontal gene transfer, resulting in unpredictable biosafety risks. To deal with these challenges, many effective methods have been developed for biocontainment. In this article, we summarize and discuss recent advances in biocontainment strategies from three aspects: DNA replication, transcriptional regulation, and protein translation. We also briefly introduce the efforts in the biocontainment convention, such as the recent publication of the Tianjin Biosecurity Guidelines for the Code of Conduct for Scientists.

An integrated vacuum pressure swing adsorption (VPSA) and Rectisol process is proposed for CO₂ capture from underground coal gasification (UCG) syngas. A ten-bed VPSA process with silica gel adsorbent is firstly designed to pre-separate and capture 74.57% CO₂ with a CO₂ purity of 98.35% from UCG syngas (CH₄/CO/CO₂/H₂/N₂ = 30.77%/6.15%/44.10%/18.46%/0.52%, mole fraction, from Shaar Lake Mine Field, Xinjiang Province, China) with a feed pressure of 3.5 MPa. Subsequently, the Rectisol process is constructed to furtherly remove and capture the residual CO₂ remained in light product gas from the VPSA process using cryogenic methanol (233.15 K, 100% (mass)) as absorbent. A final purified gas with CO₂ concentration lower than 3% and a regenerated CO₂ product with CO₂ purity higher than 95% were achieved by using the Rectisol process. Comparisons indicate that the energy consumption is deceased from 2.143 MJ·kg^–1 of the single Rectisol process to 1.008 MJ·kg^–1 of the integrated VPSA & Rectisol process, which demonstrated that the deployed VPSA was an energy conservation process for CO₂ capture from UCG syngas. Additionally, the high-value gas (e.g., CH₄) loss can be decreased and the effects of key operating parameters on the process performances were detailed.

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.

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.

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.

Rotating packed bed (RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area (a_e) is critical to understand the mass transfer process. By using the NaOH–CO₂ chemical absorption method, the a_e values of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence. The radius of packing is the dominant equipment factor to affect a_e value. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the a_e value. Moreover, the measured a_e/a_p (effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.

To improve the ability of diglycolamide extractants for the extraction of Sr(II) from high-level waste liquid, N,N,N',N'-tetracyclohexyldiglycolamide (TCHDGA) was proposed and studied to extract Sr(II) from nitrate media. TCHDGA was prepared and characterized by ¹H nuclear magnetic resonance spectroscopy (NMR), ¹³C NMR, and fourier transform infrared spectroscopy (FT-IR). Various factors affecting extraction were studied systematically. In just 20 s, the extraction rate can reach approximately 98.2%. The extraction capacity of cyclohexyl-substituted extractant TCHDGA is tens of times higher than that with linear or branched chain alkyl. The chemical structure of the complex has been demonstrated to be [Sr 3TCHDGA]·(NO₃)₂, based on FT-IR, X-ray photoelectron spectroscopy (XPS), and crystal structure analysis. The crystal belongs to the monoclinic system, space group P21, and a strontium ion coordinates with nine oxygen atoms, all of which contribute from TCHDGA. The stripping rate can reach over 99% when using distilled water or 0.50 mol·L^-1 oxalic acid as stripping agents.

This wok proposed the extraction distillation coupled pervaporation (ED+PV) technology process using two different solvents to separate isopropanol (IPA) and diisopropyl ether (DIPE) from DIPE/IPA/H₂O ternary heterogeneous azeotropes in industrial wastewater from the synthesis of isopropanol in this study. Based on strict design specifications, simulation and sequential iteration methods are used for process design and optimization. Compared to the ethylene glycol (EG)-EG+H₂O process and the 1,3-propanediol (PDO)-IPA+H₂O process, the total annual cost (TAC) of the EG-IPA+H₂O process decreased by 20.76% and 7.86% (PDO). Compared to the EG-EG+H₂O process, the TAC of the PDO-IPA+H₂O process reduced 14%, but the global warming potential (GWP) and human toxicity of the PDO-IPA+H₂O process increased 11.3% and 4.07% respectively. Compared to the PDO-IPA+H₂O process, the EG-IPA+H₂O process saves 7.86% (TAC), 9.78% (GWP) and 9.85% (human toxicity). The ED+PV process with EG is superior to PDO in factors of TAC, energy consumption, human toxicity and environment. The EG-IPA+H₂O process changed the separation order of the products of the multi-azeotropic system, reduced the cost and energy conservation of the system, and enhanced the environmental protection evaluation of the process, is the best process through life cycle assessment for analyzing the economy, energy conservation, environmental assessment and human toxicity, designing cleaner products, controlling waste discharge, and promoting the chemical purification industry. This work provides a new process design and optimized separation ideas, will have a good guiding significance for the research and application separation of multi-azeotropic mixture with mixed solvents in organic wastewater from the cleaner chemical production, has been up to standard wastewater discharge process, and realized the development goal of carbon peak and carbon neutrality in the sustainable development of chemical clean industry.

Simultaneous recovery of Ni and Co from Fe(III) and Al is a critical challenge in hydrometallurgical processes. Recognized solvent extraction systems often struggle with selectivity and effective performance in mixed metal ion environments. Herein, a new synergistic solvent extraction (SSX) system comprised of a novel pyridine analog, N,N-bis(pyridin-2-ylmethyl) dodecan-1-amine (BPMDA), and dinonylnaphthalene sulfonic acid (DNNSA) with tributyl phosphate as phase modifier is introduced. The SSX system demonstrates high extraction performance achieving >90% for Ni and >97% for Co in a single-stage extraction process, with high selectivity. Under optimal conditions, the selectivity sequence is observed as Co²⁺ (>97%) > Ni²⁺ (>90%) > Mn²⁺ (<20%) > Fe³⁺ (<10%) > Mg²⁺ (<5%) > Al³⁺ (<2%) > Ca²⁺ (<1%). Spectroscopic analysis evidences the preferential binding of BPMDA with Ni and Co in the presence of DNNSA, concurrently achieving a significant reduction in the co-extraction of Fe(III) and Al. The selective complexation of Ni and Co using the SSX system offers a highly efficient and selective approach for their extraction, with promising potential for applications in recovery-based processes.

With the increase in the complexity of industrial system, simply detecting and diagnosing a fault may be insufficient in some cases, and prognosing the fault ahead of time could have a certain necessity. Accurate prediction of key alarm variables in chemical process can indicate the possible change to reduce the probability of abnormal conditions. According to the characteristics of chemical process data, this work proposed a key alarm variables prediction model in chemical process based on dynamic-inner principal component analysis (DiPCA) and long short-term memory (LSTM). DiPCA is used to extract the most dynamic components for prediction. While LSTM is used to learn the relationship and predict the key alarm variables. This work used a simulation data set and a real hydrogenation process data set for applications and explained the model validity from the essential characteristics. Comparison of results with different models shows that our model has better prediction accuracy and performance, which can provide the basis for fault prognosis and health management.

The pyrolysis process of Shendong coal (SD) was first studied by combining the characteristics of thermal gravimetric (TG), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and Gray-King assay (G-K). The results show that the order of coke yields is G-K (76.35% (mass))>TG (73.11% (mass))>Py (70.03% (mass)). G-K coke yield caused by condensation reaction and secondary reaction accounts for 3.08% (mass) and 3.24% (mass), respectively. Compared with slow pyrolysis, fast pyrolysis has stronger fracture ability to coal molecules and can obtain more O-compounds, mono-ring aromatics and aliphatics. Especially, the content of phenolics increases significantly from 15.49% to 35.17%, but the content of multi-ring aromatics decreases from 23.13% to 2.36%. By comparing the compositions of Py primary tar and G-K final tar, it is found that secondary reactions occurred during G-K pyrolysis process include the cleavage of alkane and esters, condensation of mono-ring aromatics with low carbon alkene, ring opening, isomerization of tri-ring aromatics, hydrogenation of aromatics and acids.

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.

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.

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.

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

Fabric multifunctionality offers resource savings and enhanced human comfort. This study innovatively integrates cooling, heating, and antimicrobial properties within a Janus fabric, surpassing previous research focused solely on cooling or heating. Different effects are achieved by applying distinct coatings to each side of the fabric. One graphene oxide (GO) coating exhibits exceptional light-to-heat conversion, absorbing and transforming light energy into heat, thereby elevating fabric temperature by 15.4 ℃, 22.7 ℃, and 43.7 ℃ under 0.2, 0.5, and 1 sun irradiation, respectively. Conversely, a hydrogel coating on one side absorbs water, facilitating heat dissipation through evaporation upon light exposure, reducing fabric temperature by 5.9 ℃, 8.4 ℃, and 7.1 ℃ in 0.2, 0.5, and 1 sun irradiation, respectively. Moreover, both sides of Janus fabric exhibit potent antimicrobial properties, ensuring fabric hygiene. This work presents a feasible solution to address crucial challenges in fabric thermal regulation, providing a smart approach for intelligent adjustment of body comfort in both summer and winter. By integrating heating and cooling capabilities along with antimicrobial properties, this study promotes sustainable development in textile techniques.

Air pollution control poses a major problem in the implementation of municipal solid waste incineration (MSWI). Accurate prediction of nitrogen oxides (NO_x) concentration plays an important role in efficient NO_x emission controlling. In this study, a modular long short-term memory (M-LSTM) network is developed to design an efficient prediction model for NO_x concentration. First, the fuzzy C means (FCM) algorithm is utilized to divide the task into several sub-tasks, aiming to realize the divide-and-conquer ability for complex task. Second, long short-term memory (LSTM) neural networks are applied to tackle corresponding sub-tasks, which can improve the prediction accuracy of the sub-networks. Third, a cooperative decision strategy is designed to guarantee the generalization performance during the testing or application stage. Finally, after being evaluated by a benchmark simulation, the proposed method is applied to a real MSWI process. And the experimental results demonstrate the considerable prediction ability of the M-LSTM network.

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.