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Greenhouse gas emissions from waste plastics have caused global warming all over the world, which has been a central threat to the ecological environment for humans, flora and fauna. Among waste plastics, waste polyethylene terephthalate (PET) is attractive due to its excellent stability and degradation-resistant. Therefore, merging China's carbon peak and carbon neutrality goals would be beneficial. In this review, we summarize the current state-of-the-art of carbon emission decrease from a multi-scale perspective technologically. We suggest that the carbon peak for waste PET can be achieved by employing the closed-loop supply chain, including recycling, biomass utilization, carbon capture and utilization. Waste PET can be a valuable and renewable resource in the whole life cycle. Undoubtedly, all kinds of PET plastics can be ultimately converted into CO2, which can also be feedstock for various kinds of chemical products, including ethyl alcohol, formic acid, soda ash, PU, starch and so on. As a result, the closed-loop supply chain can help the PET plastics industry drastically reduce its carbon footprint. [ABSTRACT FROM AUTHOR]

This paper presents an exergy and environmental assessment of a 1000 metric t/day ammonia production plant based on the steam methane reforming (SMR) process, including the syngas production, purification (CO 2 capture) and compression units, as well as the ammonia synthesis and purge gas treatment. An integrated heat recovery system produces power and steam at three pressure levels, besides exporting hot water, CO 2 and fuel gas, with no additional heat or power consumption being required. Two configurations for ammonia refrigeration process (−20 °C) are compared in terms of power consumption. Exergy cost data for upstream processing stages of natural gas is used to calculate the extended exergy cost of the products of the plant, namely ammonia, CO 2 and fuel gas. Moreover, an appropriated methodology is employed to properly allocate the renewable and non-renewable exergy costs, as well as the CO 2 emissions of the reforming, shift and furnace stack among the products of the plant. By considering that the cost reduction of the combustion gases is a linear function of the exergy flow rate reduction in each component of the heat recovery system, an improved allocation of the CO 2 emission cost along the convection train is performed. A breakdown of the total exergy destruction rate of the plant (136.5 MW) shows that about 59% corresponds to the reforming process followed far behind by the ammonia synthesis and condensation (18.3%) and the gas purification units (13.2%). The overall exergy efficiency of the ammonia plant is calculated as 66.36%, which is enhanced by recovering the hydrogen-rich and fuel gases in the purge gas treatment process. The total and non-renewable exergy costs and CO 2 emission cost of the ammonia produced are calculated as 1.7950 kJ/kJ and 0.0881 kg CO2 /MJ, respectively. In addition, a rational exergy cost of 1.6370 kJ/kJ and CO 2 emission cost of 0.0821 kg CO2 /MJ are allocated to the CO 2 gas, which can be supplied as feedstock to an associated chemical plant (urea, methanol, polymers, etc.). [ABSTRACT FROM AUTHOR]

The gasification of MSW (municipal solid wastes) using CO 2 as a gasifying agent has been object of growing interest in recent years. Although quite limited, studies have shown that CO 2 can behave as a catalyst and accelerate the thermal cracking of volatiles as well as minimize tar formation, and even give a positive contribute to environment. Despite these promising features, it is still necessary to develop mathematical models able to assist the advance of this technology. A previously published numerical model validated for numerous substrates (including MSW) and operating conditions in a pilot scale plant was used as a baseline to study MSW gasification with air-CO 2 mixtures. Real MSW data from Oporto metropolitan area were used as model inputs and numerical results were validated against experimental ones. Results demonstrate that increasing CO 2 content boosts carbon conversion, CO 2 conversion, and cold gas efficiency while mitigating tar production. Also, due to the ability to tailor H 2 /CO ratio, air-CO 2 mixtures can be used for catalyst-based Fischer–Tropsch synthesis and particularly for the production of specific chemicals such as urea, methanol and acetic acid. [ABSTRACT FROM AUTHOR]

Synthetic plant of chemicals (SPC) consumes large amounts of hydrogen and carbon-oxides while refineries require high-purity hydrogen. Coal gasification (CG) and steam methane reforming (SMR) are common industrial hydrogen production technologies. Their gas products are essentially a mixture of H2, CO, and CO2. Therefore, such gas products can provide both syngas for SPC and concentrated hydrogen for refinery through appropriate allocation. Based on the composition complementation of gas products from CG and SMR for their efficient utilization, this paper proposed an integration methodology for refinery and SPC coupling networks to conserve both fossil fuel resources and carbon emissions. A superstructure is established as a problem illustration and a nonlinear programming model (NLP) is formulated as a mathematical solution. A case study is performed, and the results show that the coupling network integration can save 19.1% and 20.2% of coal and natural gas consumption, as well as corresponding carbon emission and operation costs. [ABSTRACT FROM AUTHOR]

We report on a continuous flow synthetic process of non‐symmetrical ureas, based on the implementation of a Staudinger/aza‐Wittig reaction sequence. This flow technology allows obtaining the key urea functional group directly from the fundamental C1 building block CO2. A library of 26 derivatives, including alkyl/alkyl, alkyl/aryl and aryl/aryl ureas could be synthesised. In addition, the method was also suitable for the synthesis of S‐thiocarbamates. The potential for large‐scale reaction implementation and a first application to continuous flow 13C‐isotope labeling are shown. [ABSTRACT FROM AUTHOR]

The shipping industry has reached a higher level of maturity in terms of its knowledge and awareness of decarbonization challenges. Carbon-free or carbon-neutralized green fuel, such as green hydrogen, green ammonia, and green methanol, are being widely discussed. However, little attention has paid to the green fuel pathway from renewable energy to shipping. This paper, therefore, provides a review of the production methods for green power (green hydrogen, green ammonia, and green methanol) and analyzes the potential of green fuel for application to shipping. The review shows that the potential production methods for green hydrogen, green ammonia, and green methanol for the shipping industry are (1) hydrogen production from seawater electrolysis using green power; (2) ammonia production from green hydrogen + Haber–Bosch process; and (3) methanol production from CO2 using green power. While the future of green fuel is bright, in the short term, the costs are expected to be higher than conventional fuel. Our recommendations are therefore as follows: improve green power production technology to reduce the production cost; develop electrochemical fuel production technology to increase the efficiency of green fuel production; and explore new technology. Strengthening the research and development of renewable energy and green fuel production technology and expanding fuel production capacity to ensure an adequate supply of low- and zero-emission marine fuel are important factors to achieve carbon reduction in shipping. [ABSTRACT FROM AUTHOR]

Reducing carbon dioxide emissions is one of the critical challenges to mitigate global climate change, which is having detrimental impacts on society and the environment. Fossil fuel combustion in transportation, power generation, and industrial processes is the dominant contributor to carbon emissions. Over the past decades, sustainable solutions and strategies have been investigated and developed to enable decarbonization. Catalysis plays an essential role to address this global challenge by increasing energy efficiency, reducing carbon emissions, capturing carbon dioxide, and utilizing clean energy sources to displace fossil fuels. In this Review, the role of catalysis in reducing energy demand was discussed, enhancing process efficiency, displacing carbon‐intensive feedstocks and products, and therefore, reducing carbon emissions. Recent advances in catalyst development were summarized, focusing on applications to enhance industrial processes efficiency and enable utilization of clean energy sources. Emerging approaches in catalysis were reviewed, including the manufacture of iron and steel, direct air capture of CO2, production of ethylene, ammonia, and sustainable aviation fuels, plastic recycling, and the synthesis of biobased plastics. The Review was concluded with suggested research directions to achieve a carbon net‐zero world. [ABSTRACT FROM AUTHOR]

Aurantiochytrium is a heterotrophic marine microalga that has potential industrial applications. The main objectives of this study were to isolate an Aurantiochytrium strain from Sand Cay (Son Ca) Island, Vietnam, optimize its culture conditions, determine its nutritional composition, extract polyunsaturated fatty acids (PUFAs) in the free (FFA) and the alkyl ester (FAAE) forms, and evaluate the antioxidation and neuroprotection properties of the PUFAs. Aurantiochytrium sp. SC145 can be grown stably under laboratory conditions. Its culture conditions were optimized for a dry cell weight (DCW) of 31.18 g/L, with total lipids comprising 25.29%, proteins 7.93%, carbohydrates 15.21%, and carotenoid at 143.67 µg/L of DCW. The FAAEs and FFAs extracted from Aurantiochytrium sp. SC145 were rich in omega 3–6–9 fatty acids (40.73% and 44.00% of total fatty acids, respectively). No acute or subchronic oral toxicity was determined in mice fed with the PUFAs in FFA or FAAE forms at different doses over 90 days. Furthermore, the PUFAs in the FFA or FAAE forms and their main constituents of EPA, DHA, and ALA showed antioxidant and AChE inhibitory properties and neuroprotective activities against damage caused by H2O2- and amyloid-ß protein fragment 25–35 (Aβ25-35)-induced C6 cells. These data suggest that PUFAs extracted from Aurantiochytrium sp. SC145 may be a potential therapeutic target for the treatment of neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

The catalytic hydrogenation of captured CO2 by different industrial processes allows obtaining liquid biofuels and some chemical products that not only present the interest of being obtained from a very low-cost raw material (CO2) that indeed constitutes an environmental pollution problem but also constitute an energy vector, which can facilitate the storage and transport of very diverse renewable energies. Thus, the combined use of green H2 and captured CO2 to obtain chemical products and biofuels has become attractive for different processes such as power-to-liquids (P2L) and power-to-gas (P2G), which use any renewable power to convert carbon dioxide and water into value-added, synthetic renewable E-fuels and renewable platform molecules, also contributing in an important way to CO2 mitigation. In this regard, there has been an extraordinary increase in the study of supported metal catalysts capable of converting CO2 into synthetic natural gas, according to the Sabatier reaction, or in dimethyl ether, as in power-to-gas processes, as well as in liquid hydrocarbons by the Fischer-Tropsch process, and especially in producing methanol by P2L processes. As a result, the current review aims to provide an overall picture of the most recent research, focusing on the last five years, when research in this field has increased dramatically. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) emissions contribute considerably towards increasing greenhouse effect. Carbon capture and storage can reduce CO2 emissions to a great extent but lacks economic feasibility. The economic feasibility of CO2 capture could be boosted by utilizing the captured gas to produce valuable end products. CO2 is a highly stable molecule; therefore, special catalysts and elevated conditions of temperature and pressure are required for its conversion. This review presents the current status of CO2 utilization processes from various aspects, including thermodynamic, economic, and environmental impacts. The use of process systems engineering (PSE) tools and techniques in a broad spectrum, to improve the technical, economic, and environmental feasibility of these processes, is the major focus of this review. In this regard, a framework has also been presented showing the integration of various PSE techniques. All the related information in the form of tabulated data as well as qualitative and quantitative plots have been presented and critically analyzed. [ABSTRACT FROM AUTHOR]

Climate change and the unsustainability of fossil fuels are calling for cleaner energies such as methanol as a fuel. Methanol is one of the simplest molecules for energy storage and is utilized to generate a wide range of products. Since methanol can be produced from biomass, numerous countries could produce and utilize biomethanol. Here, we review methanol production processes, techno-economy, and environmental viability. Lignocellulosic biomass with a high cellulose and hemicellulose content is highly suitable for gasification-based biomethanol production. Compared to fossil fuels, the combustion of biomethanol reduces nitrogen oxide emissions by up to 80%, carbon dioxide emissions by up to 95%, and eliminates sulphur oxide emission. The cost and yield of biomethanol largely depend on feedstock characteristics, initial investment, and plant location. The use of biomethanol as complementary fuel with diesel, natural gas, and dimethyl ether is beneficial in terms of fuel economy, thermal efficiency, and reduction in greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Biorefineries are core units that convert biomass resources to energy and bioproducts, representing the sustainable alternative to traditional fossil-based processes. The market size of biorefineries is expected to reach U$D 52,680 million by 2027, at a compound annual growth rate of 2.2% in the period of 2021–2027 (MarketWatch, 2021). Among several types of bioresources, sugarcane is the most important source of sugar and the second source of ethanol worldwide, being also exploited as a solid fuel in an efficient cogeneration system to produce bioelectricity. Sugarcane is a prominent feedstock for other bio-based products that could be obtained from sugarcane juice or molasses, from the lignocellulosic residues of sugarcane, or from by-products of alcoholic fermentation, like vinasse and CO2. This manuscript presents the status of sugarcane biorefineries in terms of bioeconomy metrics, scientific advances, and technological development, gathering information from scientific literature and patent documents with the aim of highlighting possible paths and promising bioproducts to be obtained from this unique crop at industrial level. [ABSTRACT FROM AUTHOR]

Valorizing the fatty content of agricultural waste in material synthesis is an interesting topic. This work focused on utilizing oleic acid from the solid waste of olive mills in Saudi Arabia to synthesize biodegradable polyanhydrides based on sebacic acid which terminated with different concentrations of fatty acid (10, 30, 50, and 70 wt%), then characterize the final polymer samples and study the effects of termination on polyanhydrides properties, such as molecular weight and degradation profile. The fatty content of the solid waste was extracted, purified, and analyzed prior to and after separating the saturated and unsaturated fractions by urea crystallization, then the microwave-assisted melt polycondensation technique was used in the synthesis of the final polymers. Molecular weights were determined by gel permeation chromatography (GPC), and the degradation profile of the prepared samples was examined by determining the weight loss percentage of the polymer mass and FT-IR scanning for the anhydride bond before and after sample degradation. Results showed a linear degradation profile for most samples with no significant change in the molecular weights due to termination. [ABSTRACT FROM AUTHOR]

The development of a cost-effective heterogeneous catalytic system for the cycloaddition reaction of CO2 and epoxides is of great importance. In this manuscript, three kinds of boron and phosphorus co-doping graphitic carbon nitride (BP-CN) were prepared and characterized. Among them, BP-CN-1 displayed the optimal catalytic performance in the presence of Bu4NBr (tetrabutylammonium bromide) for the CO2 cycloaddition with propylene oxide, and 95% propylene carbonate yield was obtained under a 120 °C, 2 MPa, 6 h condition. Moreover, the BP-CN-1/Bu4NBr catalytic system is compatible with various epoxides and also exhibits excellent recycling performance under metal- and solvent-free conditions. Hence, BP-CN-1 exhibited an attractive application for the efficient fixation of CO2 due to the simple, eco-friendly synthesis route and effective catalytic activity. [ABSTRACT FROM AUTHOR]

Cyanuric acid is an organic intermediate widely used in organic synthesis, and the traditional production method of cyanuric acid is the pyrolysis urea method. Due to the shortcomings of uneven mass transfer, many by-products and poor environmental friendliness, the production of cyanuric acid is extremely limited. In this paper, an effective method has been developed to synthesize cyanuric acid with high yield in a short period of time through the addition-elimination reaction of dihydric alcohol and urea under alkaline conditions. The reaction time, molar ratio of reactants, reaction temperature and other influencing factors were studied. Under optimized conditions, the yield of cyanuric acid is over 90%. And further the proposed reaction mechanism is verified. The synthetic method provided in this article has the advantages of easy availability of raw materials and reusability, simple operation and short reaction time, which makes the method novel and environmentally friendly. [ABSTRACT FROM AUTHOR]

In recent years, electrocatalysis was progressively developed to facilitate the selective oxidation of biomass‐derived 5‐hydroxymethylfurfural (HMF) towards the value‐added chemical 2,5‐furandicarboxylic acid (FDCA). Among reported electrocatalysts, alloy materials have demonstrated superior electrocatalytic properties due to their tunable electronic and geometric properties. However, a specific discussion of the potential impacts of alloy structures on the electrocatalytic HMF oxidation performance has not yet been presented in available Reviews. In this regard, this Review introduces the most recent perspectives on the alloy‐driven electrocatalysis for HMF oxidation towards FDCA, including oxidation mechanism, alloy nanostructure modulation, and external conditions control. Particularly, modulation strategies for electronic and geometric structures of alloy electrocatalysts have been discussed. Challenges and suggestions are also provided for the rational design of alloy electrocatalysts. The viewpoints presented herein are anticipated to potentially contribute to a further development of alloy‐driven electrocatalytic oxidation of HMF towards FDCA and to help boost a more sustainable and efficient biomass refining system. [ABSTRACT FROM AUTHOR]

The utilization of CO2 as a renewable and cheap carbon resource to produce fuels, chemicals and polymers has attracted more attention. This review will summarize the developments in the production of polymers like polyureas and polyurea hybrids with CO2 as a monomer directly or indirectly. The influences of catalyst and the structure of diamine monomer on the molecular weight, thermal stability and mechanical properties of polyureas are discussed. In addition, the general properties and applications of functional CO2‐based polyureas are also described. A few examples of CO2‐based polyurea hybrids are also introduced. Finally, the future research priorities as well as the development trend of polyurea materials are depicted. [ABSTRACT FROM AUTHOR]

The paper provides an updated overview of the main achievements and ideas presented at the most recent PRES conferences and in the fields which have been covered by them. The conference history now reached a quarter of the century - from 1998 to 2022. The PRES conferences have become one of the main vehicles for spreading Process Integration (PI) into various research directions and fields of possible implementation. The PRES went successfully during the last period challenged by COVID-19 pandemics. Not all conferences managed to adapt well. However, PRES successfully implemented the hybrid mode and learned how to use it efficiently for enlarging the number of speakers as well as the audience while still keeping very intensive and beneficial cross-fertilisation and networking. Some experiences have been shared in this paper. The hybrid mode helped successfully intensify the research efforts on the research challenge, which remained as a consequence of the COVID-19 pandemics - an increased amount of waste and during the life and economy recovery also increasing environmental footprints. This short overview includes (i) Process Integration with Pinch Analysis (ii) Process Integration with another approach (iii) Development of heat exchanger systems for Process Integration (iv) Other extensions of Process Integration for wider Process Systems Engineering and recently (v) Circular economy (vi) Environmental footprints and nexuses and just (vii) COVID-19 pandemics energy and environmental consequences and recovery. This paper presents an attempt to demonstrate and make suggestions for the future growth of the Process Integration branching out during the next years. [ABSTRACT FROM AUTHOR]

The massive increase in the amount of carbon dioxide (CO2) in the atmosphere has led to serious environmental problems. One of the best ways to tackle this problem is the CO2 capture and its utilization as a C1 carbon source for the production of industrially valuable chemicals. But the thermodynamic stability of the CO2 molecule poses a great challenge in its transformation. Since the last two decades, various metal‐based and organic catalysts have been developed for the adsorption and activation of CO2. Among all the catalysts the Frustrated Lewis pairs (FLPs) have been shown great potential in CO2 capture and conversion. Thus, in the present work, Intramolecular Frustrated Lewis pairs (IFLP) based on N‐Heterocycles with boron group functionalization at the α‐position to N has been theoretically investigated for CO2 activation. Thorough orbital analysis has been carried out to investigate the reactivity of the proposed catalytic systems. The result shows that the considered IFLPs are capable of activating CO2 with minimum energy requirements. The CO2 activation energy range between 8 and 14 kcal/mol. The non‐polar solvent was found to be the suitable medium for the reaction. Also, the reversibility of the adducts formed with the IFLPs can be controlled by appropriate substitution at B atom in the IFLPs. [ABSTRACT FROM AUTHOR]

A series of functionalized ionic liquids (ILs) immobilized on B‐doped mesoporous SiO2 catalysts were fabricated for effectively converting CO2 into cyclic carbonates under metal‐absent and cocatalyst‐free conditions. Functionalized imidazolium ILs were in‐situ synthesized by Debus‐Rdziszewski imidazole reaction. Among the prepared catalysts, 5B−SiO2−NH2−3−I catalyst owing to the synergistic effects of nucleophile, Lewis acid‐base and hydroxyl hydrogen bond donors in the catalyst, presented the better catalytic activity for propylene epoxide to the product of propylene carbonate with 99% yield and selectivity at 110 °C and 2 MPa CO2. The catalyst also displayed moderate yield for various mono‐substituent epoxides. Besides, the gradual decline in the product yield during consecutive runs could be easily refreshed by aqueous acidic solution washing. [ABSTRACT FROM AUTHOR]

Chlorella has been identified as a rich source of unsaturated fatty acids. Since the antiobesity effects of unsaturated fatty acids have been well documented; therefore, we explored the antiobesity actions of chlorella unsaturated fatty acids (C.UFAs) in the current study. The obtained results demonstrated C.UFAs, which contain abundant linoleic acid, could retard body weight gain (reducing body weigh by 13.93% after 16 weeks of treatment), improve blood glucose (19.29% lower) and lipid profile (23.45% lower in TG, 8.76% lower in TC) compared to high‐fat diet‐fed C57BL/6J mice. The possible underlying mechanisms might involve reducing hepatic lipid accumulation via down‐regulation of lipogenic genes (PPARγ, C/EBPα, LPL, aP2, FAS, and SREBP‐1c) and up‐regulation of lipolytic gene (adiponectin). We also demonstrate C.UFAs could reduce HFD‐induced adipocyte hypertrophy via activation of AMPK signaling pathway in adipose tissue and liver. In summary, our study highlights the potential of C.UFAs as a functional food for obesity management. Practical Application: Chlorella has already been commercialized as a functional food antiobesity function. In the current study, the unsaturated fatty acids isolated from chlorella were found to exert beneficial effects on hyperglycemia, hyperlipidemia, hepatic steatosis, and adipocyte hypertrophy in high‐fat diet‐fed mice. This may provide theoretical foundation for developing novel chlorella‐based functional foods. [ABSTRACT FROM AUTHOR]

Rapidly declining costs of renewable energy technologies have made solar and wind the cheapest sources of energy in many parts of the world. This has been seen primarily as enabling the rapid decarbonization of the electricity sector, but low-cost, low-carbon energy can have a great secondary impact by reducing the costs of energy-intensive decarbonization efforts in other areas. In this study, we consider, by way of an exemplary carbon capture and utilization cycle based on mature technologies, the energy requirements of the "industrial carbon cycle", an emerging paradigm in which industrial CO2 emissions are captured and reprocessed into chemicals and fuels, and we assess the impact of declining renewable energy costs on overall economics of these processes. In our exemplary process, CO2 is captured from a cement production facility via an amine scrubbing process and combined with hydrogen produced by a solar-powered polymer electrolyte membrane, using electrolysis to produce methanol. We show that solar heat and electricity generation costs currently realized in the Middle East lead to a large reduction in the cost of this process relative to baseline assumptions found in published literature, and extrapolation of current energy price trends into the near future would bring costs down to the level of current fossil-fuel-based processes. [ABSTRACT FROM AUTHOR]

This review summarizes the performance of potential catalysts for the synthesis of dimethyl carbonate (DMC) using CO2 as a feedstock by two major processes—the direct route of carbonylation of alcohols and the indirect route of alcoholysis of urea. The reaction mechanisms and corresponding catalysts that were previously investigated are discussed. The major challenges associated with the conversion of CO2 to DMC are the low yields, low DMC selectivity, and thermodynamic limitations (alcohol carbonylation) of reversible reactions with low equilibrium constants. This occurs mainly due to the highly stable carbon dioxide molecules. The development of novel catalysts with high yields and high selectivity needs to be studied to overcome these technical challenges. In addition, to enhance the DMC yield, the use of dehydrating agents for water removal from the reaction mixture is recommended and discussed in detail in this article. This review critically examines the different catalysts used by investigators, along with their respective operating conditions and suitability in applications for the commercial synthesis of CO2-based DMC. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) layered double hydroxides (LDH) are classic materials in fundamental research and practical application. 2D LDH have unique structural features, such as high aspect ratio, high specific surface area, quantum confinement in one direction, layered structure, tunable intercalated anions/ interlayer spacing/metal-cation compositions,, which endow 2D LDH with excellent chemical and physical properties. Since rational production is the first and crucial step towards their utilization, numerous efforts have been devoted to explore innovative and effective methods for their preparation. This review is a comprehensive overview of synthesis methods and aimed to capture the features of different synthesis methods to enable the selection of a suitable method to achieve the desired LDH characteristics. Therefore, we systematically summarized various preparation methods of 2D LDH, including a top-down approach, bottom-up approach, and decomposition-regrowth strategy. Besides, we listed and compared the important parameters relating to both the synthesis process and the obtained products of various synthesis methods, such as the synthesis temperature/pressure, the used device, the utilized reactants, the presence or absence of pre/post-treatment, the yield, the crystallinity and the lateral size and thickness. Finally, some current challenges and further tasks regarding the synthesis of LDH are presented. [ABSTRACT FROM AUTHOR]

Urea has been regarded as an important chemical compound in the food‐water‐energy nexus. However, the emission of urea from human activity, industrial manufacture, and agricultural fertilization into the environment has caused an ecological nitrogen imbalance. Besides addressing the environmental pollution, the applications of clean energy conversion from urea‐rich wastewater has strong potential for resource and energy recovery. Herein, we conducted a comprehensive overview of electrochemical urea oxidation reaction (UOR) for pollution control and energy harvesting. The present mechanisms and behaviors of UOR under different water matrices have been characterized and compared in detail. Additionally, the latest development of electrochemical UOR integrated into electrolyzers and fuel cells are presented. Finally, we discuss the prospects and challenges of UOR technologies, suggesting several directions for the electrochemical conversion of urea‐abundant wastewater in the near future. [ABSTRACT FROM AUTHOR]

Abstract: Although much effort has been made in the field of membrane proteomics, the analysis of membrane proteins particularly integral membrane proteins with poor water solubility still presents a great challenge. In this paper, 2% SDS was used to extract membrane proteins and experimental conditions for the application of acetone precipitation method to the cleanup of SDS-solubilized membrane protein sample were optimized. For improving the re-dissolution and trypsinolysis of acetone-precipitated proteins, several commonly used additives, urea, methanol and sodium deoxycholate (SDC), were employed and compared. The results showed that, when the pre-cooled acetone-to-sample ratio was 6:1 (v/v) with one additional washing step, residual SDS in the protein sample could be lowered to below 0.01% and more than 90% of the proteins were precipitated and therefore recovered. 1% SDC-containing buffer could improve the re-dissolution and digestion of the acetone precipitated proteins more efficiently than the others. Using the combinative sample preparation strategy developed, 398 proteins were identified from the rat liver membrane-enriched fraction, including 188 membrane proteins. Compared with other three representative solution-based sample preparation methods commonly used in membrane proteomics, the newly developed combinative strategy increased the number of identified total proteins and membrane proteins on average by 29.2% and 28.5%, respectively. This combinative strategy was demonstrated to be easily operated at low cost and suitable for the analysis of membrane proteins varying in type and sample volume, etc. [Copyright &y& Elsevier]

Carbon dioxide (CO2) is available in almost infinite amounts in our atmosphere and oceans, but its utilisation as feedstock for the chemical industry is often prevented by its thermodynamic stability. Only a few processes based on CO2as a raw material were realised in a technical scale so far, like the production of urea, methanol or salicylic acid. In the present review mainly catalytic reactions of a lactone platform chemical are described whose production is based on CO2as a feedstock. The synthesis of this highly functionalised 1was already invented in the 1970s and was optimised into miniplant‑scale in the meantime. Based on its different functional groups numerous reactions can be carried out starting from this molecule leading to versatile, interesting products: Acids, alcohols or diols as well as aldehydes, amino acids or amines are formed in high yields. Furthermore, esters, silanes or even polymers are obtained using the δ‑lactone as a building block. Thus, by applying efficient catalytic systems which lead to high selectivities a new approach for the utilisation of CO2as a reasonable feedstock for chemical reactions is described. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations of a nonpolar single-walled carbon nanotube (SWNT) solvated in aqueous solutions of urea, methanol, and trimethylamine N-oxide (TMAO) show clearly the effects of cosolvents on the hydration of the interior of the SWNT. The size of the SWNT was chosen to be small enough that water but not the cosolvent molecules can penetrate into its interior. Urea as a protein denaturant improves hydration of the interior of the SWNT, while the protein protectant TMAO dehydrates the SWNT. The interior of the SWNT is also dehydrated when methanol is added to the solution. The analysis of interaction energies of the water confined inside the SWNT pore shows that the stability of the confined water in the methanol and TMAO solutions mainly depends on electrostatic interactions. In contrast, both van der Waals and electrostatic interactions were shown to be important in stabilizing the confined water when the SWNT is immersed in the urea solution. [ABSTRACT FROM AUTHOR]

• A a novel covalent organic polymers (AB-COP) is firstly prepared. • AB-COP is firstly used to purify biflavonoids from Selaginella doederleinii. • Properties, performance and mechanism are investigated comprehensively. • 4.Compared with commonly used materials, AB-COP has excellent enrichment effect. • New purification method is developed for biflavonoids from natural products. Herein, a novel covalent organic polymers (COP) material based on acylhydrazone bond (AB-COP) was prepared as an efficient extraction material for enriching natural medicine biflavonoids from Selaginella doederleinii Hieron. The obtained AB-COP structure was characterized in detail. And it was the first time to investigate the effect of AB-COP on the adsorption of biflavonoids. The effects of initial concentration of solution, adsorption temperature, solid-liquid ratio, adsorption time on the adsorption of biflavonoids were studied. In addition, adsorption kinetic model, adsorption thermodynamic model and density functional theory (DFT) were also investigated to evaluate the adsorption mechanism. At the same time, the static desorption and reusability of AB-COP were investigated. Finally, the dynamic enrichment effect of AB-COP for biflavonoids was investigated. The results showed that AB-COP was successfully synthesized by Fourier transform infrared spectroscopy (FT-IR), solid state nuclear magnetism (NMR), X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM), laser particle size analysis and Brunner Emmet Teller (BET) specific surface area test. The optimized adsorption parameters of AB-COP were initial concentration of 0.5 mg/mL, temperature of 45 °C, solid-liquid ratio of 10:10 (mg/mL), adsorption time of 60 min. The Langmuir adsorption isotherm could effectively describe the adsorption process, the pseudo-secondary adsorption model could accurately explain the adsorption mechanism, and the DFT calculations revealed that the interaction forces of AB-COP and biflavonoids were π-π stacking and hydrogen bonding. In addition, AB-COP successfully resolved biflavonoids through urea-methanol (1.3 mol/L), and the material can be reused at least four times. Finally, the solid phase extraction (SPE) chromatographic column prepared by AB-COP was successfully applied to the enrichment of biflavonoids from S. doederleinii , and the effect was significantly better than traditional chromatography materials, andthis method was also successfully applied to the enrichment of flavonoids in other plant extracts including Flos sophorae, Pericarpium viride, Lophatheri herba, Herba cuscutae. These results provide references for further purification of bioactive ingredients from plant extracts by using AB-COP. [ABSTRACT FROM AUTHOR]

Abstract: Nitrogen incorporated diamond-like carbon (DLC:N) films with different N content were deposited on Si(100) substrates by electrolysis of urea/methanol organic solution with different mole ratios under a constant voltage of 600V. Analysis by Raman spectrometry and X-ray photoelectron spectrometry (XPS) shows that N is incorporated into the DLC films by sp3 C–N and sp2 Cnd induces graphitization of the films. The electronic field emission properties of these films have been studied using a parallel plate configuration, and the dependence on N content investigated. The turn-on field (E c) is lowered with increasing N content, and there is a simultaneous rise in the field emission current densities under the electric field of 23.5V/μm. Enhancement in field emission is attributed to the donor activity of nitrogen and the field enhancement effect of sp2 clusters. [Copyright &y& Elsevier]

Abstract: Nitrogen-doped anatase, rutile and brookite titania photocatalyst TiO2−x N y which can be excited by visible light were prepared by mixing aqueous TiCl3 solutions with urea ((NH2)2CO) and various type of alcohols followed by solvothermal treatment at 190°C. The phase composition, crystallinity, microstructure and specific surface area of titania powders greatly changed depending on the pH and type of solvents. Violet, yellowish and grayish TiO2−x N y with excellent visible light absorption and photocatalytic activity were prepared. The TiO2−x N y powders prepared in urea–methanol solution showed excellent photocatalytic ability for the oxidative destruction of nitrogen monoxide under irradiation of visible light λ >510nm. [Copyright &y& Elsevier]

It is desirable to exploit biomass energy along with coal and petcoke through gasification, and understanding the differences between petroleum coke (petcoke), coal and biomass gasification behaviour becomes very essential. Consequently, present investigation compares gasification components of petcoke, sawdust and high ash coal with their physico-chemical properties under isothermal conditions in CO2 atmosphere in the temperature range of 1173–1623 K. Physico-chemical characterisation includes proximate and ultimate analyses, porous structure analysis by Brunauer-Emmett-Teller (BET) surface area from nitrogen (N2) adsorption isotherm, ash composition analysis and ash fusion temperature. The effects of temperature and nature of different solid fuels on gasification reactivity have been discussed. Gasification kinetics has been investigated using two nth-order kinetic models, such as homogeneous model (HM) and shrinking core model (SCM). Influence of diffusion resistance on gasification behaviour of different solid fuels is also reported. Thus, the present study will be helpful to realise the effects of high ash in gasification behaviour as well as in designing and modelling of the suitable gasifier and to establish optimum gasification conditions for petcoke, biomass and high ash coal. [ABSTRACT FROM AUTHOR]

Indirect carbonation as an efficient CO2 sequestration strategy has received extensive attention in recent years. This study proposes a two-step leaching indirect carbonation process using NH4Cl and CH3COOH in order to combine the advantages of the two leaching agents to obtain a better experimental outcome. The experimental results show that NH4Cl has a high pH buffering capacity, which can increase the pH of the mixed leachate to an alkaline level. Among the 21 groups of mixed leachate, 17 were alkaline (pH > 7). The mixed leachate has a high Ca2+ ions carbonation rate under low CH3COOH concentration conditions, and the carbonation rate of steel slag with a particle size of < 38 μm can reach 60% when the CH3COOH concentration is 0.1 M. SEM imaging showed that the CaCO3 formed by the reaction exists in a hexagonal calcite crystal form. [ABSTRACT FROM AUTHOR]

Aerobic, hydrogen oxidizing bacteria are capable of efficient, non-phototrophic CO2 assimilation, using H2 as a reducing agent. The presence of explosive gas mixtures requires strict safety measures for bioreactor and process design. Here, we report a simplified, reproducible, and safe cultivation method to produce Cupriavidus necator H16 on a gram scale. Conditions for long-term strain maintenance and mineral media composition were optimized. Cultivations on the gaseous substrates H2, O2, and CO2 were accomplished in an explosion-proof bioreactor situated in a strong, grounded fume hood. Cells grew under O2 control and H2 and CO2 excess. The starting gas mixture was H2:CO2:O2 in a ratio of 85:10:2 (partial pressure of O2 0.02 atm). Dissolved oxygen was measured online and was kept below 1.6 mg/L by a stepwise increase of the O2 supply. Use of gas compositions within the explosion limits of oxyhydrogen facilitated production of 13.1 ± 0.4 g/L total biomass (gram cell dry mass) with a content of 79 ± 2% poly-(R)-3-hydroxybutyrate in a simple cultivation set-up with dissolved oxygen as the single controlled parameter. Approximately 98% of the obtained PHB was formed from CO2. [ABSTRACT FROM AUTHOR]

The sulfate radical-based advanced oxidation processes (SR-AOPs) are well-established and efficient techniques for the degradation of organic pollutants. Fe2+ is used as an environmentally friendly and cost-effective catalyst for activating peroxymonosulfate (PMS) to generate sulfate radicals (SO4−˙). In some past studies, the slow process of reducing Fe3+ to Fe2+ reduced the overall reaction rate of the SR-AOP system. To overcome this challenge, in this work, we for the first time fabricated a new composite activator, FeOCl decorated by graphene quantum dots (GQDs), by a facile method for activating PMS. The experimental results demonstrate that the as-prepared FeOCl/GQD catalysts can efficiently degrade organic pollutants and kill Escherichia coli through activating PMS to generate active species. Notably, the FeOCl/(16.7 wt%) GQD composite can activate PMS to degrade organics (97.8% of RhB within 30 min) and inactivate E. coli (99.1% within 10 min) with a pH range from 3 to 11. Moreover, mechanism analyses showed that the active species were SO4−˙, ˙OH, 1O2 and O2−˙ in the FeOCl/(16.7 wt%) GQDs + PMS system, and SO4−˙ and 1O2 were proved to be the main active species. The addition of GQDs promoted the reduction of Fe3+ to Fe2+, thereby accelerating the degradation rate. Our study suggests that the promising strategy of exploiting highly efficient AOP platforms has many applications. [ABSTRACT FROM AUTHOR]

Summary: A ternary nanocatalyst consisting of nickel cobalt oxide (NiCo2O4), reduced graphene oxide (rGO), and platinum (Pt) was introduced as a promising catalyst for application in the sorbitol oxidation reaction (SOR) process for use in fuel cells. Other catalysts such as NiCo2O4, NiCo2O4‐rGO, and NiCo2O4/Pt were prepared for comparison. The structure and morphology of the synthesized nanocatalysts were examined by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The efficiency of the as‐synthesized materials was assessed by electrochemical tests of cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA). The comparison of the SOR process for the synthesized nanocatalysts showed that NiCo2O4‐rGO/Pt has the highest current density (57.2 mA cm−2, 45.04 mA/mg) at a scan rate of 10 mV/s and the lowest peak potential (0.64 V) as well as the highest cyclic stability than other materials. The superior electrocatalytic performance is attributed to the synergistic effect of the components. Moreover, the charge transfer resistance of SOR for NiCo2O4‐rGO/Pt catalyst is 702 Ω, lower than that for NiCo2O4/Pt (930 Ω). Thus, NiCo2O4‐rGO/Pt constitutes an efficient and promising nanocatalyst for SOR. [ABSTRACT FROM AUTHOR]

Thermodiffusion is the phenomenon by which molecules in a mixture present concentration gradients in response to an imposed temperature gradient. Despite decades of investigations, this effect remains poorly understood at a molecular level. A common, phenomenological approach is to individuate the molecular factors that influence the Soret coefficient, the parameter that quantifies the resulting concentration-gradient. Experimental studies, often performed on organic mixtures, as well as simulations of model particle systems have evidenced that the difference in masses between the mixture components has an important effect on the amplitude of the Soret coefficient. Here, we use molecular dynamics simulations of a thermophoretic setting to investigate the mass dependence of the Soret coefficient in dilute aqueous solutions. An advantage of simulation approaches is that they are not limited in the range of explored molecular masses, which is often limited to isotopic substitutions in the experiments. Our simulations reveal that the mass dependence of the Soret coefficient in these solutions is in agreement with previous experimental and simulation work on molecular-size systems. In particular, it is sensitive to the relative mass difference between the solute and the solvent, but not to their absolute mass. Adjusting the mass of the solvent and of the solute can turn a thermophobic solution into a thermophilic one, where solute accumulation is reversed. This demonstrates that the mass effect can indeed compensate for the other contributions to the Soret coefficient. Finally, we find that changing the molecular moments of inertia has a much more limited impact as compared to a change in the total molecular mass. [ABSTRACT FROM AUTHOR]

This paper is about a package of infrastructure investment, the China-Pakistan Economic Corridor (CPEC). This paper uses a range of theoretical perspectives (buttressed by historical and contemporary evidence) to think about the likely impact of CPEC on economic (especially industrial) growth in Pakistan. The theory includes crowding in of private by public investment, social savings, spillovers and the leading sector, and industrial policy. Theory points to some likely growth promoting effects of CPEC, on corporate logistics, shorter transport routes to China, and greater local production of cement. The impact of CPEC is unlikely to be transformative. There is little evidence that CPEC has improved corporate logistics in Pakistan. CPEC may reduce physical distances for overland trade with China but trade is likely to remain seaborne. CPEC construction activity has generated positive spillovers in local construction employment and cement production but no spillovers in either bitumen or steel production. Pakistan lacks a capable state and commitment to an industrial policy that historically have proved important in leveraging transport infrastructure into domestic industrialisation. The most important reason is that Pakistan is a middle-income country and CPEC is too small to create more than modest economic growth benefits for Pakistan. [ABSTRACT FROM AUTHOR]

The increase in partial pressure of CO2 in the oceans directly affects the productivity and survival of coastal industries and ecosystems. For marine aquaculture, the decreased alkalinity of seawater results in reduced availability of carbonates for marine organisms to build their shells, leading to decreased aquaculture quality and productivity. The industry has been implementing recirculating aquaculture systems (RASs) to reduce CO2 in feedwaters, but recent interest in ocean-based CO2 capture has led to additional strategies that may be relevant. The new methods in addition to CO2 removal offer capture options for enhanced aquaculture sustainability. Here, we review and compare early-stage and commercially available technologies for deacidification of seawater and their suitability for aquaculture. Most methods considered rely on a voltage-induced pH swing to shift the carbonate/bicarbonate equilibrium toward the release of CO2, with subsequent capture of the released CO2 as a gas or as solid mineral carbonates. The modular design and distributed deployment potential of these systems offers promise, but current demonstrations are limited to bench scale, highlighting the need for sustained research and development before they can be implemented for marine aquaculture. [ABSTRACT FROM AUTHOR]

The nanostructured composite catalyst of potassium compounds-Al2O3, or briefly K/Al2O3, was prepared by using the sol-gel urea combustion method using potassium and aluminum nitrates as precursors, which was applied in the transesterification reaction of sunflower and waste cooking oils to produce biodiesel. The molar ratio of potassium nitrate to aluminum nitrate of 0.5 in the synthesizing solution of the catalyst and calcination temperature of 650 °C were obtained from the optimization experiments of the catalyst. The optimized K/Al2O3 catalyst was characterized by ICP, XRD, SEM, and TGA. Gas chromatography-mass spectrometry analysis of the produced biodiesel confirmed the formation of methyl esters. The effects of the operating conditions like methanol to oil molar ratio, catalyst dose, reaction temperature, and time on the biodiesel production were investigated, modeled, and optimized using the response surface methodology. The results of statistical analysis of the experimental model showed that linear term of temperature and interaction term of temperature and time had the strongest effect on the biodiesel yield. The optimized operating conditions were methanol to oil molar ratio of 17:1, catalyst dose of 8.25 wt.%, temperature of 70 °C, and time of 7 h. Under these conditions, the experimental yield of biodiesel production was 88.74% from sunflower oil and 82.01% from waste cooking oil. The properties of the produced biodiesels like density, pour point, cloud point, cetane number, and acid value were measured, which were comparable with the standards. [ABSTRACT FROM AUTHOR]