Supercritical carbon dioxide (SC-CO2) is CO2 that is stored beyond its critical point of 7.4 MPa and 31.1 °C. Given the request for consumption of a green solvent for the environment, SC-CO2 is widely utilized in chemical, food, and pharmaceutical industries. To design material and drug production processes using supercritical fluid (SCF) technology, knowledge of their solubility is important. Temperature and pressure are the main factors in the study of solubility. Solubility data are then evaluated using equation of state, semi-empirical, and intelligence models to establish suitable correlations. SC-CO2 is one of the most important materials used in SCFs to study solubility. Another application of SC-CO2 is in the field of material extraction to reduce the consumption of organic solvents. Nanoparticles production in drug industry is another advantage of SC-CO2. Micro and nanoparticles can be produced using SCF techniques. In this review, the applications of SC-CO2 in drug solubility, extraction of valuable materials, and nanoparticles production for pharmaceutical processes are reported and discussed. Finally, the main challenges are explained.

CO2 emission is an important environmental issue leading to global climate change, notably an increase in global temperatures; therefore, it is so imperative to reduce CO2 emissions to the atmosphere. Absorption columns using amine-based solutions are a promising approach for CO2 removal from industrial gas streams. Many modeling and simulation research have been performed on CO2 absorption columns in which computational fluid dynamics (CFD) strategy is very appropriate and well-known. As CFD modeling and simulation is a fast-developing method, the most recent review papers do not include the core research in this field of study. In this study, numerical simulations of CO2 absorption columns using CFD strategy have been carried out applying various types of amine-based solutions. Furthermore, the effect of various types of packing mesh generation on the absorption columns' efficiency was studied. Investigation of synergetic influence such as application of various nanoparticles in different amine-based solutionsand activators, double diameter packed bed absorption columns with different packings, rotating packed columns with double diameter are proposed for future studies.

Biorefineries are facilities in which lignocellulosic biomasses are converted in a wide range of bioproducts facilitating the transition from the use of petrochemical resources to renewable ones. Organic acids are considered very attractive for their utilization in different industrial areas as building blocks or as final bioproducts leading to a considerable market growth. They are metabolites which are naturally produced by microbials. The production of these molecules by filamentous fungi are attracting more attention due to their ability to hydrolyze lignocellulosic biomasses and to contextually produce different organic acids. Contrarily to a lot of other microorganisms, fungi have the ability to ferment pentoses, broadening the substrate utilization. The integrated use of lignocellulosic biomasses as material input and fungi as biocatalyst can contribute to make biorefineries more successful. This review gives an overview about the lignocellulosic biomass structure and hydrolysis, fungal morphology, and how they are connected. Further, it describes some relevant organic acids with regard to their processes, biocatalysts, industrial applications, and market considerations.

Membrane technology promises a highly economical and efficient solution for CO2 separation. Many polymeric membranes have been reported in the past for the separation of gases specially to remove CO2 from natural gas and low-pressure flue-gas streams. The performance of membranes can be tailored by dispersing nanofillers in a polymeric matrix to produce mixed-matrix membranes (MMMs). This not only adds mechanical strength to membranes but also reduces compaction of the polymeric layer at high pressure and maintains high performance. Halloysite nanotubes (HNTs) gained attention in gas separation technology and due to their tubular structure have been used in a variety of applications in biomedical, coating, composite, and electronic industries. However, very little but conclusive literature and reviews are available to indicate that functionalized and non-functionalized HNTs can improve the performance of MMMs for efficient CO2 capture. The current status and gaps for potential applications of HNTs-based membranes for gas separation are identified and reviewed.

The goal of microphysiological systems (MPS) is to replicate the relevant functionality of human organ tissues in in vitro. MPS technology so far has been used to simulate the various human organs and with the help of sensor integration in the MPS systems the biological activities of the organ to be modeled have been translated into data to be analyzed for further considerations. Most standard characterization approaches are intrusive and detrimental, and not feasible for online monitoring of cell cultures. Microfluidic biosensors, for instant, provide non-invasive on-line detection of biomarkers and molecules under targeted indicators with a high detection extent, successfully overcoming the limits of existing approaches. Microfluidic biosensors are rapidly being incorporated into MPS and employed for real-time target identification as a result. In this review the focus is on emerging ways for miniaturizing and embedding biosensing systems in MPS also known as “organ-on-chip”. Cutting-edge microfluidic biosensors are also covered with examples, showing their key benefits in monitoring MPS and highlighting current breakthroughs, before describing the remaining problems and anticipated future improvements in integrated microfluidic biosensors.

Coal, a solid fossil fuel, consists of organic and inorganic matter. Its complex structure contains fused aromatic moieties, constituting a three-dimensional macromolecular coal structure network. More efficient utilisation technologies are required to ensure coal becomes a considerably cleaner source of energy in the future. Due to the increase in energy, liquid fuels, and combustible gas demands, coal utilisation is necessary for some developing countries such as Pakistan, Turkey, and India. Furthermore, coal is globally being used to produce liquid fuels and combustible gases. The benefits and drawbacks of various Fischer-Tropsch synthesis catalysts are discussed. For clean coal carbonisation, blends of coal and biomass, which are the current trends in decarbonising the coal industries, should be adopted and the chemistry of coal carbonisation should be investigated further, especially the phenomenon that occurs at the plastic layer (300–550 °C). In addition, the clean co-gasification technology presented in this work could be adopted and successfully implemented through government and industry initiatives to study and test coal/biomass for co-gasification and advanced modelling and simulation of the co-gasification plant.

The demand for renewable fuels has risen as a result of increasing human population, urbanization, industrialization, and transport systems. Biodiesel production using metal oxide-based heterogeneous catalysts is an efficient, sustainable, and environmentally friendly approach. Because of their recovery, reusability, and consistency, heterogeneous catalysts may be preferable to homogeneous catalysts. Since the last few decades, the metal oxides of alkali earth and transition metals and their composite materials have been used as nanocatalysts in the production of biodiesel fuel. Utilization of inorganic metal oxide nanoparticles (MONPs) and their composite materials in producing biodiesel has gained increased attention because of their advanced physical and chemical characteristics. In this review, the applicability of metal oxides and their nanocomposite-based catalysts in biodiesel production, transesterification reactions with nanocatalytic systems, and the important parameters that affect these reactions are discussed.

Biochar is a porous fine-grained substance produced from the pyrolysis technology of biomass that can be commercially used as a soil conditioner to promote soil fertility. Biochar is characterized by high carbon content, stability, and porosity. However, organic pollutants residue of polycyclic aromatic hydrocarbons (PAHs) is also formed during the pyrolysis of biochar. The high concentration of PAHs adversely degrades the quality of biochar for soil amendment application. Meanwhile, highly toxic-PAHs concentration may pose a potential threat to both human health and the environment. The total PAHs yield is mainly influenced by the pyrolysis condition and feedstock resource. This review aims to discuss the conversion pyrolysis technology of biochar and factors that may influence the PAHs formation. The key research findings from this literature will lead to some strategies to minimize the PAHs compound in biochar by controlling the pyrolysis conditions through higher pyrolysis temperature, carrier gas flow, and prolonged pyrolysis time or by selecting suitable feedstock with lower lignin content.

The motion of droplets in non-Newtonian fluids is widely present in ubiquitous industrial processes. Understanding the droplet motion characteristics is important for optimizing the design of related processes. Here the progress in the research on the droplet motion characteristics in non-Newtonian fluids is reviewed. The mechanism of droplet deformation in non-Newtonian fluids were elucidated, the influence of different rheological properties on droplet shape was discussed, and the empirical correlations of droplet aspect ratio were summarized. Moreover, the dimensionless correlations of drag coefficient were discussed. There are relatively few drag coefficient correlations of droplets in non-Newtonian fluids, while the correlation of drag coefficients of bubbles in non-Newtonian fluids can provide some reference. Finally, the possible prospects for future studies of the subject were proposed.

In the recent past, sodium-ion batteries (SIBs) have assumed to be an alternative to lithium-ion batteries (LIBs) as sodium is abundantly available in nature. It is low cost with its storage mechanism almost similar to LIBs. The ionic radius of Na is three-fold larger than that of Li and offers a low standard electrochemical potential than Li. The built-in SIBs are better than LIBs. However, in terms of energy density, specific capacity, and rate capability, there is a lack of suitable anode materials for SIBs. Interestingly, carbon-based quantum dots are a new class of zero-dimensional (0D) material with ultra-small size having unique physicochemical properties. The utility of carbon quantum dots (CQDs), graphene quantum dots (GQDs) and graphitic carbon nitride quantum dots (g-C3N4 QDs) has drawn attention to the scientists and industrialists for the development of SIBs due to their quantum size and structural diversities, physicochemical properties, amenability for doping with heteroatoms and good electrical conductivity. This article reviews the role of various carbon quantum dots commonly used as anodes in SIBs.

Virgin coconut oil is obtained by wet processing of coconut milk using fermentation, centrifugation, enzymatic extraction, and the microwave heating method. Presently, VCO has several positive effects and benefits to human health, hence, it is regularly consumed and widely known as a unique functional food. VCO contains lauric acid (45 to 52 %). By lipase in the digestive system, VCO can undergo a breakdown into lauric acid, 1-monolaurin, and 2-monolaurin. These components have both hydrophilic and lipophilic groups and are also recognized as excellent antimicrobial lipids. Furthermore, lauric acid and monolaurin can be used as antibacterial, antifungal, and antiviral with broad-spectrum inhibition. Lauric acid and monolaurin have a strong ability to destroy gram-positive bacteria, especially S. aureus, fungi such as C. Albicans, and viruses including vesicular stomatitis virus (VSV), herpes simplex virus (HSV), and visna virus (VV). Lauric acid and monolaurin interact with certain functional groups located in the cell membrane and can cause damage to the cell. In general, the potential of VCO as healthy food is contributed by lauric acid and monolaurin which are antimicrobial agents.

The aqueous two-phase system (ATPS) is commonly known as a technique that yields high-purity products in a single step. It is particularly advantageous for purifying biomolecules like proteins, nucleic acids, enzymes, viruses etc. Currently, aqueous two-phase extraction (ATPE), i.e., liquid-liquid extraction, involves the transfer of the solute from one aqueous phase to another. In ATPE, for recovery of biomolecules, polymer-polymer and polymer-salt type systems are used. The most recent developments with respect to recovery of biomolecules by ATPS are reviewed and discussed, covering the mechanism, which controls the phase formation, the conditions of solute partitioning in ATPS processes, and factors influencing the ATPS including concentration and molecular weight (MW) of polymers, types of salt, pH, and temperature. In addition, also the increasing applications of ATPS for the recovery of high-value bioproducts, the benefits of the ATPS recovery system, and the recent developments of alternative low-cost ATPS are highlighted.

Biodiesel is produced on a large scale as an eco-friendly substitute and additive to fossil fuels. Catalytic homogeneous processes using strong acids, alkalis, and natural oils have been realized in industry. However, these traditional methods have several disadvantages, such as the generation of large volumes of waste, high water and reagent needs, use of hazardous reagents, high operation costs, and utilization of valuable feedstocks and catalysis, respectively. Different solutions have subsequently been investigated, such as cheap alternative feedstocks, co-solvents and catalysts, sustainable operational conditions, advanced reactor designs and scales, and advantageous pre- and post-reaction treatments. This review explores and analyzes the main aspects of current biodiesel technologies and opportunities. It also describes some advanced improvement strategies.

Membrane fabrication methods, mechanisms, and modification of membranes for CO2 separation are discussed. Various types of membrane materials with high CO2 separation performance are summarized. Rapid prototyping can achieve precise control of the thickness of membranes and freely design the spatial structure of membranes, which provides a new development direction for material application and process combination. Hence, a critical comparison of membrane fabrication using different methods can provide a comprehensive overview on the potential of the rapid prototyping technology in membrane fabrication. This is important to demonstrate the prospects of the membrane technology development for CO2 separation.

Virgin coconut oil (VCO) has become a multifunctional material for biomedical applications due to its remarkable health benefits. The use of VCO for biomedical applications has seen tremendous growth over recent years, triggering researchers to develop various approaches for VCO utilization. Nanofibers-based structure offers promising properties to encapsulate VCO, enhancing its performance and broadening its application in the medical field. Studies of VCO-loaded polymeric nanofibers for biomedical applications are currently gradually rising. Recently, in nanofibers technology, centrifugal jet spinning (CJS) offers cost-efficient and higher production rates to yield nanofibers compared to the other methods. This review summarizes recent advances of VCO for biomedical applications. Comprehensive suggestions for encapsulating VCO into nanofibers using the CJS technique are also provided. Highlights of future challenges in utilizing the CJS technique to produce VCO-loaded nanofibers for biomedical applications are also elaborated.

The pulp and paper industry is one of the most significant industrial water polluters, generating large volumes of wastewater with high levels of organic pollutants, suspended solids, and other contaminants. Catalytic ozonation has emerged as a promising technique for the treatment of pulp and paper industry wastewater. Numerous reviews have presented the research on catalytic ozonation; however, open literature is missing a bibliometric analysis. Therefore, this article presents a bibliometric analysis of the research available on catalytic ozonation in pulp and paper industry wastewater treatment. A total of 578 documents extracted from the Scopus database have been examined via VOSviewer, MS Excel, and Rstudio to identify the research trends, influential authors, and research institutions in the field. The results reveal that the number of publications on the topic has increased significantly in recent years. This study also identified several influential authors, institutions, and highlighted future research directions in the field. Overall, the study provides insights into the state of research on catalytic ozonation in pulp and paper industry wastewater treatment and could help guide future research efforts in this area.

3D-printed porous implants have been attracting increased attention. Although pore size is thought to be an important factor affecting the biocompatibility of implants, there is still no accurate conclusion about the optimal pore size of implants. In searching the relevant literature, it was found, that the pore size of implants is not clearly defined in many studies. Additionally, the definition methods are different in a few studies, that have clearly defined the apertures. In the current review, the definitions of pore size in different experiments are summarized and the factors affecting the definitions are analyzed, to provide an important framework for future research and design.

Industrial-scale mechanical recycling of plastics has been established for years, but has technical and economic limits. Chemical recycling processes lead back to monomers or to the raw materials, so that in the end new goods can be produced for all areas of application of plastics. The variety of chemical recycling processes is large. The capacities of the plants are still low today. The profitability of the plants is strongly influenced by the price of oil; the profitability limit is currently between 50 and 60 US $ per barrel.

The field of machine learning has proven to be a powerful approach in smart manufacturing and processing in the chemical and process industries. This review provides a systematic overview of current state of artificial intelligence and machine learning and their applications in textile, nuclear power plant, fertilizer, water treatment, and oil and gas industries. Moreover, this study reveals the current dominant machine learning methods, pre and post processing of models, increased utilization of machine learning in terms of fault detection, prediction, optimization, quality control, and maintenance in these sectors. In addition, this review gives the insight into the actual benefits and impact of each method, and complications in their extensive deployment. Finally in the current impressive state, challenges, future development in terms of algorithm and infrastructure aspects are highlighted.

Cocoa liquor, butter, and powder represent derived products from a small portion of the fruits, compared with the cocoa pod husk (CPH) which accounts for ∼ 70 % of fresh weight. CPH, improperly disposed in plantations, can cause diseases threatening worldwide chocolate production. However, this biomass can be a potential source of bioactive compounds aligned with the circular economy. An overview on the different methods for extracting pectin, resulting in variable extraction yields with a critical discussion on the obtained physicochemical characteristics, is presented. Additionally, the potential applications of the extracted pectin for food and biomedical application are discussed, including thickener, stabilizer, excipient, drug-release modifier, macrophage activator, etc. Despite these potential outputs, new extraction methods need to be considered for improving efficiency and sustainability. Finally, potential approaches are introduced that can help to minimize the environmental impact, making the extraction cost- and time-efficient, and, therefore, more ssustainable for a further successful translation to industry.