Deep eutectic solvents (DESs), as a green alternative technology, exhibit great potential to recycle valuable elements from spent lithium-ion batteries (LIBs). However, due to the weak reducing power ...of DESs, raising the temperature and extending the duration of processing are not efficient for screening suitable DESs for the recycling of LIBs. Here, we propose a novel, simple and robust experimental method to identify suitable DESs for recycling spent LIBs. Based on electrochemical principles, the method proposed in this study can be used to quickly determine the reducing power of DESs. As an example, a choline chloride (ChCl) and urea mixture as a DES was found to possess strong reducing power, with a Li and Co extraction efficiency of 95% from spent LIBs obtained at a reduced reaction temperature of 180 °C and reaction time of 12 h. The results are in good agreement with the results from Fukui functions calculations. The kinetic experiments revealed that the Li and Co extraction is controlled by solution and electron diffusion through the DES. Furthermore, a cubic cobalt oxide spinel (Co
3
O
4
) was obtained from the loaded DES using H
2
C
2
O
4
and NaOH in the dilution-precipitation-calcination process. The current strategy demonstrates great potential for rapid and reliable screening of suitable DESs for the effective recycling of spent LIBs.
Deep eutectic solvents (DESs), as a green alternative technology, exhibit great potential to recycle valuable elements from spent lithium-ion batteries (LIBs).
Trace elements such as mercury, arsenic and selenium present in coal are known to be of concern for public health. Coal-fired power plants have resulted in emission of several tons of TEs in ...environment. These elements mostly evaporate during combustion and condense either homogeneously as sub-micron ash or heterogeneously onto already existing fine ash. The coal–mineral and mineral–mineral associations play an important role in the formation of fine particles and in subsequent condensation of trace elements in various phases. Any retention of these elements in fly ash particles is strongly influenced by their association with other minerals in individual coal and mineral grains. Clean coal technology development is, therefore, a priority area for research and needs continuous improvements in increased efficiency and decreased pollutant emission. The paper will include trace elements in different coals from around the world. It will consider different modes of occurrences present in coals, the ash formation and evaporation of trace elements and emissions. The typical emissions from typical power stations will be presented. The paper will also review different approaches adopted in estimating the deportment of these elements. The paper at the end would discuss control strategies for reducing emissions and future directions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
With the ever increasing demand for energy to meet the needs of growth in population and improvement in the living standards in particular in developing countries, the abundant unconventional oil ...reserves (about 70% of total world oil), such as heavy oil, oil/tar sands and shale oil, are playing an increasingly important role in securing global energy supply. Compared with the conventional reserves unconventional oil reserves are characterized by extremely high viscosity and density, combined with complex chemistry. As a result, petroleum production from unconventional oil reserves is much more difficult and costly with more serious environmental impacts. As a key underpinning science, understanding the interfacial phenomena involved in unconventional petroleum production, such as oil liberation from host rocks, oil-water emulsions and demulsification, is critical for developing novel processes to improve oil production while reducing GHG emission and other environmental impacts at a lower operating cost. In the past decade, significant efforts and advances have been made in applying the principles of interfacial sciences to better understand complex unconventional oil-systems, while many environmental and production challenges remain. In this critical review, the recent research findings and progress in the interfacial sciences related to unconventional petroleum production are critically reviewed. In particular, the chemistry of unconventional oils, liberation mechanisms of oil from host rocks and mechanisms of emulsion stability and destabilization in unconventional oil production systems are discussed in detail. This review also seeks to summarize the current state-of-the-art characterization techniques and brings forward the challenges and opportunities for future research in this important field of physical chemistry and petroleum.
With the ever increasing demand for energy to meet the needs of growth in population and improvement in the living standards, in particular in developing countries, the abundant unconventional oil reserves (about 70% of total world oil), such as heavy oil, oil/tar sands and shale oil, are playing an increasingly important role in securing global energy supply.
Electrochemical reduction of CO2 (CO2RR) provides great potential for intermittent renewable energy storage. This study demonstrates a predominant shape-dependent electrocatalytic reduction of CO2 to ...CO on triangular silver nanoplates (Tri-Ag-NPs) in 0.1 M KHCO3. Compared with similarly sized Ag nanoparticles (SS-Ag-NPs) and bulk Ag, Tri-Ag-NPs exhibited an enhanced current density and significantly improved Faradaic efficiency (96.8%) and energy efficiency (61.7%), together with a considerable durability (7 days). Additionally, CO starts to be observed at an ultralow overpotential of 96 mV, further confirming the superiority of Tri-Ag-NPs as a catalyst for CO2RR toward CO formation. Density functional theory calculations reveal that the significantly enhanced electrocatalytic activity and selectivity at lowered overpotential originate from the shape-controlled structure. This not only provides the optimum edge-to-corner ratio but also dominates at the facet of Ag(100) where it requires lower energy to initiate the rate-determining step. This study demonstrates a promising approach to tune electrocatalytic activity and selectivity of metal catalysts for CO2RR by creating optimal facet and edge site through shape-control synthesis.
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Abstract
Recently, carbon dioxide capture and conversion, along with hydrogen from renewable resources, provide an alternative approach to synthesis of useful fuels and chemicals. People are ...increasingly interested in developing innovative carbon dioxide hydrogenation catalysts, and the pace of progress in this area is accelerating. Accordingly, this perspective presents current state of the art and outlook in synthesis of light olefins, dimethyl ether, liquid fuels, and alcohols through two leading hydrogenation mechanisms: methanol reaction and Fischer-Tropsch based carbon dioxide hydrogenation. The future research directions for developing new heterogeneous catalysts with transformational technologies, including 3D printing and artificial intelligence, are provided.
Carbon capture and storage (CCS) is gaining momentum as a means for combating climate change. It is viewed as an important bridging technology, allowing emission targets to be met during fossil fuel ...dependence while sufficient renewable energy generation is installed. Mineral carbon sequestration is the only known form of permanent carbon storage and has the potential to capture and store CO
2 in a single step. It is based on the geologic process of natural rock weathering where CO
2 dissolved in rain water reacts with alkaline rocks to form carbonate minerals. While the reactions are thermodynamically favourable, in nature the process occurs over thousands of years. The challenge of mineral carbon sequestration is to accelerate carbonation and exploit the heat of reaction with minimal energy and material losses. Minerals commonly selected for carbonation include calcium and magnesium silicates. These minerals require energy-intensive pre-treatments, such as fine grinding, heat treatment, and chemical activation with strong acids, to provide adequate conversions and reaction kinetics. Industrial waste residues present alternative sources of mineral alkalinity that are more reactive than primary minerals and are readily and cheaply available close to CO
2 sources. In addition, the carbonation of waste residues often improves their environmental stability. This paper provides an overview of the types of industrials wastes that can be used for mineral carbon sequestration and the process routes available.
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A novel interfacially active and magnetically responsive nanoparticle is designed and prepared by direct grafting of bromoesterified ethyl cellulose (EC‐Br) onto the surface of amino‐functionalized ...magnetite (Fe3O4) nanoparticles. Due to its strong interfacial activity, ethyl cellulose (EC) on the magnetic nanoparticles enables the EC‐grafted Fe3O4 (M‐EC) nanoparticles to be interfacially active. The grafting of interfacially active polymer EC on magnetic nanoparticles is confirmed by zeta‐potential measurements, diffuse reflectance infrared Fourier‐transform spectroscopic (DRIFTS) characterization, and thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) images show a negligible increase in particle size, confirming the thin silica coating and grafted EC layer. The magnetization measurements show a marginal reduction in saturation magnetization by silica coating and EC grafting of original magnetic nanoparticles, confirming the presence of coatings. The M‐EC nanoparticles prepared in this study show excellent interfacial activity and highly ordered features at the oil/water interface, as confirmed using the Langmuir–Blodgett technique and atomic force microscopy (AFM). The magnetic properties of M‐EC nanoparticles at the oil/water interface make the interfacial properties tunable by or responsive to an external magnetic field. The occupancy of M‐EC at the oil/water interface allows rapid separation of the water droplets from emulsions by an external magnetic field, demonstrating enhanced coalescence of magnetically tagged stable water droplets and a reduced overall volume fraction of the sludge.
A novel interfacially active and magnetically responsive nanoparticle is designed and prepared by directly grafting bromoesterified ethyl cellulose (EC‐Br) onto the surface of amine‐functionalized magnetite (Fe3O4) nanoparticles. The tagging of stable emulsified water droplets by the resulting nanoparticles enhances coalescence and rapid separation of the emulsified water droplets by an external magnetic field.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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Surfactants with temperature-sensitive polyoxyethylene (POE) chains are widely used to prepare nanoemulsions by the phase inversion temperature (PIT) method. It is therefore ...anticipated that surfactants with temperature-sensitive polyoxypropylene (POP) chains could also be used to prepare nanoemulsions by the PIT method.
POP surfactants were synthesized through electrostatic interactions between hydrophilic POP diamines and hydrophobic long-chain fatty acids. The synthesized POP surfactants were used as emulsifiers to prepare n-tetradecane-in-water nanoemulsions by the PIT method. Electrical conductivity measurements were used to determine the PITs of the water/POP surfactant/n-tetradecane systems. The effects of surfactant concentration, NaCl concentration, number of POP units, and degree of unsaturation of hydrocarbon chains on the PIT and the nanoemulsion droplet size were investigated. The droplet size and morphology of the nanoemulsions were characterized by dynamic light scattering and cryogenic transmission electron microscopy, respectively.
Nanoemulsions are formed by the PIT method using POP surfactants when the POP chains are short (∼2.5–6.1 POP units). The formation of nanoemulsions with droplet radii of 20–300 nm and spherical morphology occurs because of the temperature-dependent hydration of the short POP chains.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The drainage of thin liquid films between colliding bubbles is strongly influenced by the boundary conditions at the air–liquid interface. Theoretically, the interface should not resist any ...tangential stress (fully mobile) in a clean water system, resulting in very fast film drainage and coalescence between bubbles within milliseconds. In reality, under most experimental and industrial conditions, the presence of impurities or surfactants can immobilize the interface and significantly hinder bubble coalescence by several orders of magnitude. In this opinion, we introduce the recent progress on understanding the boundary conditions at the air–water interface, and how they may affect the outcome of bubble collisions. The transition from mobile to immobile boundary conditions in the presence of contaminations is discussed. Despite the considerable recent progress, there are still experimental and theoretical challenges remaining on this topic, for example, finding the mechanism for hindered bubble coalescence by high salt concentrations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The asphaltene fraction of crude oil is commonly considered to be responsible for the formation of highly undesirable, stable water-in-crude oil emulsions and rag layers. We developed a new procedure ...for subfractionation of asphaltenes based on their interfacial activity. The most interfacially active asphaltene (IAA) subfraction was extracted as an interfacial material from emulsified water droplets in asphaltene solution. The IAA subfraction represents less than 2 wt % of whole asphaltenes (WA), but its removal had a profound effect on interfacial and thin emulsion film properties. It was found that the IAA subfraction is a main contributor to emulsion stabilization and formation of rigid oil−water interfaces. IAA adsorbed irreversibly at the oil−water interface and formed interfacial layers of low compressibility. Thin emulsion films of toluene stabilized by IAA were thicker and exhibited severe aging effects in contrast to the films stabilized with remaining asphaltene fractions, which were thin and less rigid, without any noticeable aging effects.
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