Solid phase extraction is widely used in sample pretreatment, concentration and analysis processes due to high selectivity and suitability for low concentration sample system. In this review, we systematically summarized and discussed the development trends of solid phase extraction by bibliometrics method. By analyzing papers output scale, the research and development direction of solid phase extraction technology is prospected. We also give an overview on current strategies of novel solid phase extraction from the separation medium and separation technology. The paper aims to describe the global research profile and the development trends of solid phase extraction, to help researchers to accurately grasp the research trend and to provide support for scientific research institutions to formulate scientific policies and strategic plans. Furthermore, the prospect of the development and application of solid phase extraction is also discussed.

With the development of digital products, electric vehicles and energy storage technology, electronic chemicals play an increasingly prominent role in the field of new energy such as lithium-ion batteries. Electronic chemicals have attracted extensive attention in various fields. Characteristics of high-end electronic chemicals are high purity and low impurity content, which requires a very strict separation and purification process. At present, crystallization is a key technology for their separation and purification of electronic chemicals. In this work, the representative fluorine-containing compounds in cathode and anode materials, separator and electrolyte of lithium-ion batteries are introduced. The latest technologies for the preparation and purification of four kinds of fluorine-containing battery chemicals by crystallization technology are reviewed. In addition, the research prospects and suggestions are put forward for the separation of fluorine-containing battery chemicals.

The emerging one-dimensional wire-shaped supercapacitors (SCs) with structural advantages of low mass/volume structural advantages hold great interests in wearable electronic engineering. Although graphene fiber (GF) has full of vigor and tremendous potentiality as promising linear electrodefor wire-shaped SCs, simultaneously achieving its facile fabrication process and satisfactory electrochemical performance still remains challenging to date. Herein, two novel types of graphene hybrid fibers, namely ferroferric oxide dots (FODs)@GF and N-doped carbon polyhedrons (NCPs)@GF, have been proposed via a simple and efficient chemical reduction-induced fabrication. Synergistically coupling the electroactive units (FODs and NCPs) with conductive graphene nanosheets endows the fiber-shaped architecture with boosted electrochemical activity, high flexibility and structural integrity. The resultant FODs@GF and NCPs@GF hybrid fibers as linear electrodes both exhibit excellent electrochemical behaviors, including large volumetric specific capacitance, good rate capability, as well as favorable electrochemical kinetics in ionic liquid electrolyte. Based on such two linear electrodes and ionogel electrolyte, a high-performance wire-shaped SC is effectively assembled with ultrahigh volumetric energy density (26.9 mW·h·cm^-3), volumetric power density (4900 mW·cm^-3) and strong durability over 10,000 cycles under straight/bending states. Furthermore, the assembled wire-shaped SC with excellent flexibility and weavability acts as efficient energy storage device for the application in wearable electronics.

Recent years, membrane separation technology has attracted significant research attention because of the efficient and environmentally friendly operation. The selection of suitable materials to improve the membrane selectivity, permeability and other properties has become a topic of vital research relevance. Two-dimensional (2D) materials, a novel family of multifunctional materials, are widely used in membrane separation due to their unique structure and properties. In this respect, as a novel 2D material, graphitic carbon nitride (g-C₃N₄) have found specific attention in membrane separation. This study reviews the application of carbon nitride in gas separation membranes, pervaporation membranes, nanofiltration membranes, reverse osmosis membranes, ion exchange membranes and catalytic membranes, along with describing the separation mechanisms.

Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia. At present, there are a variety of products, such as slurry monoammonium phosphate (MAP), diammonium phosphate (DAP), industrial grade MAP, water soluble MAP, water soluble ammonium polyphosphate (APP) and so on. After more than 60 years of development, China’s ammonium phosphate fertilizer industry has experienced the road of from scratch and from weak to strong. The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low grade phosphate ore. The continuous, stable and large-scale production of DAP plant provides sufficient guarantee for DAP products in China. The development of new ammonium phosphate fertilizer products, such as industrial grade MAP, water soluble MAP, water soluble APP, provides technical support for the transformation and upgrading of phosphorus chemical enterprises. In this paper, the production methods, the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.

Biomanufacturing, which uses renewable resources as raw materials and uses biological processes to produce energy and chemicals, has long been regarded as a production model that replaces the unsustainable fossil economy. The construction of non-natural and efficient biosynthesis routes of chemicals is an important goal of green biomanufacturing. Traditional methods that rely on experience are difficult to support the realization of this goal. However, with the rapid development of information technology, the intelligence of biomanufacturing has brought hope to achieve this goal. Retrobiosynthesis and computational enzyme design, as two of the main technologies in intelligent biomanufacturing, have developed rapidly in recent years and have made great achievements and some representative works have demonstrated the great value that the integration of the two fields may bring. To achieve the final integration of the two fields, it is necessary to examine the information, methods and tools from a bird’s-eye view, and to find a feasible idea and solution for establishing a connection point. For this purpose, this article briefly reviewed the main ideas, methods and tools of the two fields, and put forward views on how to achieve the integration of the two fields.

Since the global outbreak of COVID-19, membrane technology for clinical treatments, including extracorporeal membrane oxygenation (ECMO) and protective masks and clothing, has attracted intense research attention for its irreplaceable abilities. Membrane research and applications are now playing an increasingly important role in various fields of life science. In addition to intrinsic properties such as size sieving, dissolution and diffusion, membranes are often endowed with additional functions as cell scaffolds, catalysts or sensors to satisfy the specific requirements of different clinical applications. In this review, we will introduce and discuss state-of-the-art membranes and their respective functions in four typical areas of life science: artificial organs, tissue engineering, in vitro blood diagnosis and medical support. Emphasis will be given to the description of certain specific functions required of membranes in each field to provide guidance for the selection and fabrication of the membrane material. The advantages and disadvantages of these membranes have been compared to indicate further development directions for different clinical applications. Finally, we propose challenges and outlooks for future development.

With the continuous growth of the world population, the demand for fresh water is ever increasing. Water desalination is a means of producing fresh water from saline water, and one of the proposed solutions in the scientific community for solving the current global freshwater shortage. Adsorption is foreseen as a promising technology for desalination due to its relatively low energy requirements, low environmental impact, low cost and high salt removal efficiency. More importantly, chemicals are not required in adsorption processes. Active carbons, zeolites, carbon nanostructures, graphene and coordination framework materials are amongst the most investigated adsorbents for adsorption desalination, which show different performances regarding adsorption rate, adsorption capacity, stability and recyclability. In this review, the latest adsorbent materials with their features are assessed (using metrics) and commented critically, and the current trend for their development is discussed. The adsorption mode is also reviewed, which can provide guidance for the design of adsorbents from the engineering application point of view.

In light of the increasing demand for environmental protection and energy conservation, the recovery of highly valuable metals, such as Li, Co, and Ni, from spent lithium-ion batteries (LIBs) has attracted wide-spread attention. Most conventional recycling strategies, however, suffer from a lack of lithium recycling, although they display high efficiency in the recovery of Co and Ni. In this work, we report an efficient extraction process of lithium from the spent LIBs by using a functional imidazolium ionic liquid. The extraction efficiency can be reached to 92.5% after a three-stage extraction, while the extraction efficiency of Ni-Co-Mn is less than 4.0%. The new process shows a high selectivity of lithium ion. FTIR spectroscopy and ultraviolet are utilized to characterize the variations in the functional groups during extraction to reveal that the possible extraction mechanism is cation exchange. The results of this work provide an effective and sustainable strategy of lithium recycling from spent LIBs.

With increasing importance attached by the international community to global climate change and the pressing energy revolution, hydrogen energy, as a clean, efficient energy carrier, can serve as an important support for the establishment of a sustainable society. The United States and countries in Europe have already formulated relevant policies and plans for the use and development of hydrogen energy. While in China, aided by the “30·60” goal, the development of the hydrogen energy, production, transmission, and storage industries is steadily advancing. This article comprehensively considers the new energy revolution and the relevant plans of various countries, focuses on the principles, development status and research hot spots, and summarizes the different green hydrogen production technologies and paths. In addition, based on its assessment of current difficulties and bottlenecks in the production of green hydrogen and the overall global hydrogen energy development status, this article discusses the development of green hydrogen technologies.

Two-dimensional material membranes with fast transport channels and versatile chemical functionality are promising for molecular separation. Herein, for the first time, we reported design and engineering of two-dimensional Ti₃C₂T_x MXene (called transition metal carbides and nitrides) membranes supported on asymmetric polymeric hollow fiber substrate for water desalination. The membrane morphology, physicochemical properties and ions exclusion performance were systematically investigated. The results demonstrated that surface hydrophilicity and electrostatic repulsion and size sieving effect of interlayer channels synergistically endowed the MXene hollow fiber membrane with fast water permeation and efficient rejection of divalent ions during nanofiltration process.

Soil contamination by heavy metals has presented severe risks to human health through food chain. As one of the most promising remediation technologies, in-situ immobilization strategy has been widely adopted in practice. However, considering the large quantities of contaminated soil, it is still a huge challenge to design low-cost amendments with strong and long-term immobilization ability. Layered double hydroxides (LDHs) have drawn tremendous attention in fundamental research and practical application because of their unique properties. Moreover, owing to its super-stable mineralization effect to heavy metal ions, LDHs have exhibited great potential in the field of soil remediation. In this work, we mainly focused on the scale production strategy of LDHs with low-cost, and its application in soil remediation. Besides, several key challenges in using LDHs as amendments for immobilization of heavy metal ions are presented. We hope that this mini-review could shed light on the sustainable development of LDHs as amendment for heavy metals in future research directions.

Cyclohexanol is a commonly used organic compound. Currently, the most promising industrial process for synthesizing cyclohexanol, by cyclohexene hydration, suffers from a low conversion rate and difficult separation. In this paper, a three-column process for catalytic distillation applicable in the hydration of cyclohexene to cyclohexanol was established to solve these. Simulation with Aspen Plus shows that the process has good advantages, the conversion of cyclohexene reached 99.3%, and the product purity was ≥99.2%. The stable operation of the distillation system requires a good control scheme. The design of the control scheme is very important. However, at present, the reactive distillation process for cyclohexene hydration is under investigation experimentally and by steady-state simulation. Therefore, three different plant-wide control schemes were established (CS1, CS2, CS3) and the position of temperature sensitive stage was selected by using sensitivity analysis method and singular value decomposition method. The Tyreus-Luyben empirical tuning method was used to tune the controller parameters. Finally, Aspen Dynamics simulation software was used to evaluate the performance of the three control schemes. By introducing ΔF ±20% and x_ENE ±5%, comparison the changes in product purity and yield of the three different control schemes. By comparison, we can see that the control scheme CS3 has the best performance.

This review compares the different types of membrane processes for air dehumidification. Three main categories of membrane-based dehumidification are identified – membrane contactors using porous membranes with concentrated liquid desiccants, separative membranes using dense membrane morphology with a pressure gradient to drive the separation of moisture from air, and adsorptive membranes using nanofibrous membranes which adsorb and capture moisture to realise dehumidification. Drawing upon the importance of dehumidification and humidity control for urban sustainability and energy efficacy, this review critically analyses and recognizes the three unique categories of membrane-based air dehumidification technologies. Essentially, the discussion is broken into three sections-one for each category-discriminating in terms of the driving force, membrane structure and properties, and its performance indicators. Readers will notice that despite having the same objective to dehumidify air, the polymers used amongst each category differs to suit the operating requirements and optimize dehumidification performance. At the end of each section, a performance table or summary of dehumidifying membranes in its class is provided. The final section concludes with a comparative review of the three categories on membrane-based air dehumidification technologies and draw inspiration from parallel research to rationalise the potential and innovative use of promising materials in membrane fabrication for air dehumidification.

Understanding CO₂ diffusion behavior in functional nanoporous materials is beneficial for improving the CO₂ adsorption, separation, and conversion performances. However, it is a great challenge for studying the diffusion process in experiments. Herein, CO₂ diffusion in 962 metal-organic frameworks (MOFs) with open Cu sites was systematically investigated by theoretical methods in the combination of molecular dynamic simulations and density functional theory (DFT) calculations. A specific force field was derived from DFT-D2 method combined with Grimme's dispersion-corrected (D2) density functional to well describe the interaction energies between Cu and CO₂. It is observed that the suitable topology is conductive to CO₂ diffusion, and 2D-MOFs are more flexible in tuning and balancing the CO₂ adsorption and diffusion behaviors than 3D-MOFs. In addition, analysis of diffusive trajectories and the residence times on different positions indicate that CO₂ diffusion is mainly along with the frameworks in these MOFs, jumping from one strong adsorption site to another. It is also influenced by the electrostatic interaction of the frameworks. Therefore, the obtained information may provide useful guidance for the rational design and synthesis of MOFs with enhanced CO₂ diffusion performance for specific applications.

The need for sustainable fuels has resulted in the production of renewables from a wide range of sources, in particular organic fats and oils. The use of biofuel is becoming more widespread as a result of environmental and economic considerations. Several efforts have been made to substitute fossil fuels with green fuels. Ester molecules extracted from processed animal fats and organic plant materials are considered alternatives for the use in modern engine technologies. Two different methods have been adopted for converting esters in vegetable oils/animal fats into compounds consistent with petroleum products, namely the transesterification and the hydro-processing of ester bonds for the production of biodiesel. This review paper primarily focuses on conventional and renewable biodiesel feedstocks, the catalyst used and reaction kinetics of the production process.

Conjugated microporous polymers (CMPs) are a unique class of porous organic materials, which are constructed with π-conjugation structures leading to intrinsic micropores. The CMPs properties such as high surface area, intrinsic and rich micropores, interlocking and rigid structure, extensive π-conjugation and tunable band-gap, chemical and thermal stability, together with tailored functionalities, contribute to its abundant potential for application in fields such as photocatalysis, optoelectronics, energy storage, and chemical sensors. Recently, CMPs have gained importance in the field of membranes for chemical separation. In this review, we briefly discuss the historical development of CMPs, followed by a detailed description of the progress in state-of-the-art design, preparation, and application of CMPs in membranes. Additionally, we provide inference on the future prospects of CMPs as membranes.

Basic organic chemicals and high value–added products are mainly produced by hydrocarbon nitridation and oxidation. However, several drawbacks limit the application of the traditional oxidation and nitridation technologies in the future, such as complex processes, poor intrinsic safety, low atom utilization, and serious environmental pollution. The green nitridation and oxidation technologies are urgently needed. Hydrogen peroxide, a well–known green oxidant, is widely used in green hydrocarbon oxidation and nitridation. But its industrial production in China adopts fixed–bed technology, which is fall behind slurry–bed technology adopted by advanced foreign chemical companies, limiting the development of hydrogen peroxide industry and green hydrocarbon nitridation or oxidation industry. This article reviews the industrial production technologies of hydrogen peroxide and basic organic chemicals such as caprolactam, aniline, propene oxide, epichlorohydrin, phenol, and benzenediol, especially introduces the green production technologies of basic organic chemicals related with H₂O₂. The article also emphasis on the efforts of Chinese researchers in developing its own slurry–bed technology of hydrogen peroxide production, and corresponding green hydrocarbon nitridation or oxidation technologies with hydrogen peroxide. Compared with traditional nitridation or oxidation technologies, green production technologies of caprolactam, propene oxide, epichlorohydrin, and benzenediol with hydrogen peroxide promote the nitrogen atom utilization from 60% to near 100% and the carbon atom utilization from 80% to near 100%. The waste emissions and environmental investments are reduced dramatically. Technological blockade against the green chemical industry of China are partially broken down, and technological upgrade in the chemical industry of China is guaranteed.

Vortices motion in the anisotropic turbulent flow of cyclones makes a vital impact on flow stability and collection performance. Nevertheless, there remains a lack of clarity in the overall feature of vortices motion. In this work, a numerical analysis was conducted to clarify the complex motion of the vortex core in a cyclone separator. The validity of the numerical model was demonstrated by comparing the computational results with experimental data in the literature. As revealed by the results, the vortex core not only has a precession motion about the geometrical center axis but also does a nutation motion in the axial direction. The frequencies of the precession motions show two main peaks. And the magnitudes of the precession and nutation motions have non-uniform distributions in the cyclone. Moreover, the precession-nutation motions of the vortex cores exhibit a similar fluctuant pattern to the dust ring on the separator wall. The inlet gas velocity and the inlet solid loading show vital effects on the magnitudes and frequencies of precession and nutation motion.