Search

This paper reviews the properties of methanesulfonic acid (MSA) and its potential for use in hydrometallurgy. Although MSA is much less known than sulfuric, hydrochloric or nitric acid, it has several appealing properties that makes it very attractive for the development of new circular flowsheets in hydrometallurgy. Unlike other organic acids such as acetic acid, MSA is a very strong acid (pKa = − 1.9). In addition, it is very stable against chemical oxidation and reduction, and has no tendency to hydrolyze in water. In terms of its environmental impact, MSA has low toxicity and is biodegradable. In nature, it is part of the geochemical sulfur cycle. A useful property is the high solubility of its salts in water: methanesulfonate salts have a much higher solubility in water than sulfate salts. Additionally, MSA and its salts are compatible with the electrowinning of metals because the anode reaction involves the formation of oxygen gas (unlike chlorine gas formation in chloride electrolytes) and no cathodic reduction of the anion occurs (unlike nitrate reduction in nitrate electrolytes). MSA is particularly interesting for lead hydrometallurgy, where it offers more environment-friendly alternatives to HBF4 and H2SiF6. However, MSA can also be adopted in all hydrometallurgical processes that require strong Brønsted acids. It can be used in the metallurgy of copper, zinc, cobalt, nickel, and rare earths, as well as in the recycling of metals from end-of-life products. Although MSA itself is a non-oxidizing acid, in combination with hydrogen peroxide it yields strongly oxidizing lixiviants that can leach copper from chalcopyrite or dissolve metallic silver. The global production of MSA is expected to increase rapidly in the near future thanks to both the industrialization of a new sustainable synthesis process and its many applications (cleaning fluids, electrolytes for electroplating, redox-flow batteries, catalysts in organic synthesis, and as a solvent for high-molecular-weight polymers). As a result, MSA will become more widely available and a lower price will make it an increasingly attractive option. Graphical Abstract

In this academic position paper, we propose the 12 Principles of a novel and more sustainable approach to hydrometallurgy that we call “circular hydrometallurgy.” The paper intends to set a basis for identifying future areas of research in the field of hydrometallurgy, while providing a “sustainability” benchmark for assessing existing processes and technological developments. Circular hydrometallurgy refers to the designing of energy-efficient and resource-efficient flowsheets or unit processes that consume the minimum quantities of reagents and result in minimum waste. The application of a circular approach involves new ways of thinking about how hydrometallurgy is applied for both primary and secondary resources. In either case, the emphasis must be on the regeneration and reuse of every reagent in the process. This refers not only to the acids and bases employed for leaching or pH control, but also any reducing agents, oxidizing agents, and other auxiliary reagents. Likewise, the consumption of water and energy must be reduced to an absolute minimum. To consolidate the concept of circular hydrometallurgical flowsheets, we present the 12 Principles that will boost sustainability: (1) regenerate reagents, (2) close water loops, (3) prevent waste, (4) maximize mass, energy, space, and time efficiency, (5) integrate materials and energy flows, (6) safely dispose of potentially harmful elements, (7) decrease activation energy, (8) electrify processes wherever possible, (9) use benign chemicals, (10) reduce chemical diversity, (11) implement real-time analysis and digital process control, and (12) combine circular hydrometallurgy with zero-waste mining. Although we realize that the choice of these principles is somewhat arbitrary and that other principles could be imagined or some principles could be merged, we are nevertheless convinced that the present framework of these 12 Principles, as put forward in this position paper, provides a powerful tool to show the direction of future research and innovation in hydrometallurgy, both in industry and in academia. Graphical Abstract

UNLABELLED: A hydrometallurgical process is described for conversion of an aqueous solution of lithium chloride into an aqueous solution of lithium hydroxide via a chloride/hydroxide anion exchange reaction by solvent extraction. The organic phase comprises a quaternary ammonium chloride and a hydrophobic phenol in a diluent. The best results were observed for a mixture of the quaternary ammonium chloride Aliquat 336 and 2,6-di-tert-butylphenol (1:1 molar ratio) in the aliphatic diluent Shellsol D70. The solvent extraction process involves two steps. In the first step, the organic phase is contacted with an aqueous sodium hydroxide solution. The phenol is deprotonated, and a chloride ion is simultaneously transferred to the aqueous phase, leading to in situ formation of a quaternary ammonium phenolate in the organic phase. The organic phase, comprising the quaternary ammonium phenolate, is contacted in the second step with an aqueous lithium chloride solution. This contact converts the phenolate into the corresponding phenol by protonation with water extracted to the organic phase, followed by a transfer of hydroxide ions to the aqueous phase and chloride ions to the organic phase. As a result, the aqueous lithium chloride solution is transformed into a lithium hydroxide solution. The process has been demonstrated in continuous counter-current mode in mixer-settlers. Solid battery-grade lithium hydroxide monohydrate was obtained from the aqueous solution by crystallization or by antisolvent precipitation with isopropanol. The process consumes no chemicals other than sodium hydroxide. No waste is generated, with the exception of an aqueous sodium chloride solution. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40831-022-00629-2. ispartof: JOURNAL OF SUSTAINABLE METALLURGY vol:9 issue:1 pages:107-122 ispartof: location:Netherlands status: published

ispartof: IET RENEWABLE POWER GENERATION vol:17 issue:9 pages:2411-2432 status: published

ispartof: ACS SUSTAINABLE CHEMISTRY & ENGINEERING vol:10 issue:28 pages:9123-9130 status: published

The past 10–20 years have seen numerous academic papers describing the benefits of ionic liquids (ILs) and deep-eutectic solvents (DESs) for leaching, solvent extraction and electrowinning. The scientific community—including the authors of this opinion article—have frequently proclaimed these neoteric solvents as game-changers in extractive metallurgy. Despite this, there have been no commercial breakthroughs. In this paper we reflect on the reasons why ILs and DESs seem to have failed to impact on the metallurgical industry. These include: (1) issues with high viscosity; (2) limited chemical stability under the conditions of metallurgical processes; (3) difficulties with recycling and reuse; (4) a lack of demonstrated unit processes and flowsheets on the pilot scale; (5) insufficient material-property data available for engineering purposes; (6) the administrative burden of obtaining licenses and safety permits; (7) very high costs for large-scale operations; and (8) minimal added value compared to state-of-the-art hydrometallurgical processes. Our belief is that innovations in hydrometallurgy based on ILs or DESs are unlikely. Instead, we should be aiming for a deeper understanding of hydrometallurgical processes at the molecular level. This is because advances are more likely to derive from the refocused efforts of experienced IL/DES researchers investigating the speciation and chemical thermodynamics of hydrometallurgical solutions, which will then hasten the transition from linear to low-energy-input, circular hydrometallurgy. Graphical Abstract

Construction laborers are constantly subjected to irregular work hours, leading to insomnia and poor sleep quality, which impacts cognitive and rational behavior. This negatively influences decision-making capabilities, resulting in accidents on site. This study determined the effect of sleep quality on the cognitive behavior and rational ability of construction laborers. A quantitative research design comprised of a questionnaire survey was conducted for data collection purposes. Respondents comprised a randomly selected sample of construction workers, and a statistical analysis of the results was performed to investigate existing correlations. Data were collected using questionnaires from 575 and 310 respondents in the initial and latter phases, respectively, from five construction companies in Southern India, and analyzed using inferential statistics. Shift work negatively affects both the early and late phases of rational abilities. A negative correlation was observed between age and disturbed rationality in the late phase, despite not being observed in the early phase. Gender, rational ability, age, shift work, sleep quality, and cognitive behavior were not correlated in either the early or late phases. Furthermore, age, shift work, and sleep quality were not correlated with cognitive behavior. Rather, sleep quality and shift schedules were associated with rational ability and cognitive behavior impairment. There was a transient relationship between insufficient sleep and the ability to make rational decisions. This study contributes to the current discourse regarding the improvement of the sleep health of construction workers to enhance their well-being and productivity.

A Life Cycle Assessment (LCA) was conducted to evaluate the total environmental impact of state-of-the-art Waste-to-Energy (WtE) in Belgium, with respect to recovered energy utilization and addition of Carbon Capture and Storage (CCS). Four energy output scenarios were modelled on Umberto LCA software using primary data of mass and energy flows surrounding the six incinerators at the considered WtE plant, and predefined processes from the Ecoinvent 3.6 database. The normalized LCA results suggest that by utilizing all the recovered energy as steam, the WtE plant can avoid an equivalent annual environmental impact value of approximately 21200, 36800, 6700, 15800, 37000 and 6900 average European citizens in the impact categories ‘climate change’, ‘freshwater and terrestrial acidification’, ‘freshwater eutrophication, ‘photochemical ozone creation’ and ‘respiratory effects, inorganics’, ‘terrestrial eutrophication’, respectively. The ‘Electricity and Steam with CCS’ scenario resulted in the most avoided environmental impact in the impact category ‘climate change’. However, in all other impact categories, it resulted in less avoided environmental impact compared to the ‘Steam’ scenario. The comparative analysis showed that 19 out of 24 of the LCA results varied by more than 50% between two energy substitution models, thus quantifying the influence of energy substitution in LCA modelling. This study exemplifies the environmental benefit WtE technology can realize by substituting conventional energy production processes that are reliant on fossil resources, whilst performing its primary function that is reducing the volume of non-recyclable waste, destroying hazardous organic components it contains and recovering useful materials from it.

ispartof: ACS SUSTAINABLE CHEMISTRY & ENGINEERING vol:10 issue:11 pages:3766-3776 status: published

ispartof: Acs Sustainable Chemistry & Engineering vol:10 issue:9 pages:3048-3056 status: published

ispartof: JOURNAL OF SUSTAINABLE METALLURGY vol:8 issue:1 pages:297-309 status: published

ispartof: JOURNAL OF RENEWABLE MATERIALS vol:11 issue:3 pages:1031-1061 status: published

Using the dihydroxylation of alkenes as a benchmark, the reactivities of fresh and aged solutions of (NH4)2S2O8 (electrochemically generated) were compared to commercially-procured peroxydisulfate and Oxone®. The study revealed that peroxymonosulfate (Caro’s acid, PMS) is the active oxidant in such reactions. Using complementary redox colorimetry and in situ IR spectroscopy to monitor the oxidants, the competitive decomposition of peroxydisulfate in an acidic solution into PMS and H2O2 can be quantified for the first time. The new insight enabled the design and implementation of both batch and flow processes to maximise the concentration of active PMS oxidant. The utility of these oxidants for organic synthesis is demonstrated by the dihydroxylation of eight styrenes and seven alkyl alkenes, where the ammonium PMS solutions performed better than Oxone® (counterion effect). Last but not least, a non-chromatographic method for isolating and purifying the water-soluble diol product was developed.

Electrolytic formic acid synthesis delivers green formic acid at the right concentration for emerging applications.

Following the initial cation formation, the synthesis of ionic liquids (ILs) often involves an anion-exchange or metathesis reaction. For hydrophobic ILs, this is generally performed through several cross-current contacts of the IL with a fresh salt solution of the desired anion. However, if a large number of contacts is required to attain an adequate conversion, this procedure is not economical because of the large excess of the reagent that is consumed. In this study, the metathesis of an IL, Aliquat 336 or [A336][Cl], to ILs with other anions ([A336][X] with X = HSO4–, Br–, NO3–, I–, and SCN–) was studied in a continuous counter-current mixer-settler setup. McCabe–Thiele diagrams were constructed to estimate the required number of stages for quantitative conversion. Significantly higher IL conversions were achieved, combined with reduced reagent consumption and waste production. This improvement in efficiency was most pronounced for anions placed low in the Hofmeister series, for example, HSO4–, Br–, and NO3–, which are difficult to exchange. The performance of the counter-current experiments was compared with the conventional multistep cross-current batch process by calculating the reaction mass efficiency (RME) and the environmental factor (E-factor). The RMEs of the cross-current experiments were notably smaller, that is, 38–78% of the values observed for the counter-current experiments. The E-factors of the counter-current experiments were a factor of 2.0–6.8 smaller than those of the cross-current experiments. These sustainability metrics indicate a highly efficient reagent use and a considerable, simultaneous decrease in waste production for the counter-current IL metathesis reactions., A counter-current flow diagram facilitates the efficient metathesis of ionic liquids and allows for a high conversion with minimal reagent consumption.

Forests play a key role in a bio-based economy by providing renewable materials, mitigating climate change, and accommodating biodiversity. However, forests experience massive increases in stresses in their ecological and socioeconomic environments, threatening forest ecosystem services supply. Alleviating those stresses is hampered by conflicting and disconnected governance arrangements, competing interests and claims, and rapid changes in technology and social demands. Identifying which stresses threaten forest ecosystem services supply and which factors hamper their alleviation requires stakeholders' perceptions. Stakeholder-oriented stress tests for the supply of forest ecosystem services are therefore necessary but are not yet available. This perspective presents a roadmap to develop a stress test tailored to multiple stakeholders' needs and demands across spatial scales. We provide the Cascade and Resilience Rosetta, with accompanying performance- and resilience indicators, as tools to facilitate development of the stress test. The application of the stress test will facilitate the transition toward a bio-based economy in which healthy and diverse forests provide sustainable and resilient ecosystem services.

ispartof: RENEWABLE & SUSTAINABLE ENERGY REVIEWS vol:173 status: published

The building Life Cycle Assessment (LCA) applied to buildings requires collecting and organizing large quantities of data over all building life cycles. To overcome specific difficulties related to the system boundaries definition and life cycle inventory stages, the literature recognizes that systematic building decomposition methods (SBDM) can be used to classify building components, elements and materials, as well as to increase the reliability and transparency of LCA results, particularly for embodied carbon and other environmental impacts. In this paper developed in the context of the research project IEA EBC Annex 72, the authors aim to provide a basis for understanding how different SBDMs decompose a building and classify its parts. This study analyses the implications of using different SBDM along the steps of an LCA study. Such as to support transparent and comprehensible (de)composition of the life cycle inventory (LCI), definition of service lives for different building parts or clear and comparable communication of assessment results and environmental hotspots particularly when using digital tools to conduct LCA. The study analyses 12 national SBDMs used in participating countries of IEA EBC Annex 72. To showcase the implications of SBDMs in building LCA practice, an office building was used as a common case study for applying the different SBDM approaches. Differences were identified among the decomposition levels and the consequences of these differences on the LCI organization. Thus, some of the main contributions to this study are the investigation of different SBDM approaches for improving the design workflows, by discussing BIM model definitions and the recommendation to use hierarchically based methods to allow the building elements and materials decomposition.

Economic and environmental impact assessments are increasingly being adopted in the design and implementation of emerging systems. However, their emerging nature leads to several assessment challenges that need to be addressed to ensure the validity and usefulness of results in understanding their potential performance and supporting their development. There is the need to (i) account for spatial and temporal variability to allow a broader perspective at an early stage of development; (ii) handle uncertainties to systematically identify the critical factors and their interrelations that drive the results; (iii) integrate environmental and economic results to support sound decision-making based on two sustainability aspects. To address these assessment challenges, this study presents an alternative approach with the following corresponding features: (i) multiple scenario development to conduct an exploratory assessment of the systems under varying conditions and settings, (ii) global sensitivity analysis to identify the main critical factors and their interrelations, and (iii) trade-off and ecoefficiency analysis to integrate the economic and environmental results. The integrated approach is applied to a case study on plasma gasification for solid waste management. The results of the study highlight how the approach allows the identification of the dynamic relations between project settings and surrounding conditions. For example, the choice of gasifying agent largely depends on the background energy system, which dictates the impacts of the process energy requirement and the savings from the substituted energy of the syngas output. Based on these findings, the usefulness and validity of the proposed integrated approach are discussed in terms of how the key assessment challenges are addressed and how it can provide guidance for the development of emerging systems.

We herein report a multi-step flow protocol for the synthesis of 1,4-disubstituted 1,2,3-triazoles starting from α,β-unsaturated carbonyls.

The quest for sustainable monomers and \"green\" synthetic pathways for the design, fabrication, and modification of various polymers is of great importance and attracts a great deal of attention. Here, a highly versatile and novel bio-based platform was developed by reacting castor oil with propiolic acid for performing amino-yne click reactions. Owing to the electron-deficient nature of the propiolic acid esters, amino-yne click reactions were conducted with ease at room temperature, in the absence of any catalyst and solvent (as long as the amines were low-viscosity liquids at room temperature), and within 5 min. Several primary and secondary amines were shown to react readily with the developed platform. Furthermore, thermosets were prepared by using the propiolated castor oil and multifunctional amines. The prepared thermosets displayed improved thermal properties and elastomer-like mechanical properties.

We herein report a waste minimization protocol for the β-azidation of α,β-unsaturated carbonyl compounds using TMSN3. The selection of the appropriate catalyst (POLITAG-M-F), in combination with the reaction medium, resulted in enhanced catalytic efficiency and a low environmental footprint. The thermal and mechanical stability of the polymeric support allowed us to recover the POLITAG-M-F catalyst for up to 10 consecutive runs. The CH3CN:H2O azeotrope has a 2-fold positive effect on the process, increasing the efficiency of the protocol and minimizing waste generation. Indeed, the azeotropic mixture, used as a reaction medium and for the workup procedure, was recovered by distillation, leading to an easy and environmentally friendly procedure for product isolation in high yield and with a low E-factor. A comprehensive evaluation of the environmental profile was performed by the calculation of different green metrics (AE, RME, MRP, 1/SF) and a comparison with other literature available protocols. A flow protocol was defined to scale-up the process, and up to 65 mmol of substrates were efficiently converted with a productivity of 0.3 mmol/min. ispartof: ACS SUSTAINABLE CHEMISTRY & ENGINEERING vol:11 issue:7 pages:3074-3084 ispartof: location:United States status: published

Manganese hexacyanoferrates (MnHCF) are promising positive electrode materials for non-aqueous batteries, including Na-ion batteries, due to their large specific capacity (>130 mAh g$^{–1}$), high discharge potential and sustainability. Typically, the electrochemical reaction of MnHCF associates with phase and structural changes, due to the Jahn-Teller (JT) distortion of Mn sites upon the charge process. To understand the effect of the MnHCF structure on its electrochemical performance, two MnHCF materials with different vacancies content are investigated herein. The electrochemical results show that the sample with lower vacancy content (4 %) exhibits relatively higher capacity retention of 99.1 % and 92.6 % at 2$^{nd}$ and 10$^{th}$ cycles, respectively, with respect to 97.4 % and 79.3 % in sample with higher vacancy content (11 %). Ex-situ X-ray absorption spectroscopy (XAS) and ex situ X-ray diffraction (XRD) characterization results show that a weaker cooperative JT-distortion effect and relatively smaller crystal structure modification occurred for the material with lower vacancies, which explains the better electrochemical performance in cycled electrodes.

ispartof: ACS SUSTAINABLE CHEMISTRY & ENGINEERING vol:10 issue:1 pages:16-22 status: published

Advantages of ionic liquids (ILs) over volatile organic solvents in chemical processes include no or negligible evaporative losses and high tunability. However, the conventional production of aprotic ILs via metathesis can be unattractive (both economically and environmentally) because of its high complexity, while the performance of other synthesis routes remains unclear. Existing life-cycle assessments furthermore fail to combine the production and use phases of these solvents, leading to erroneous conclusion about their sustainability credentials. This paper compares a one-pot, halide-free production route to 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] against metathesis and two conventional fuel desulfurization solvents, namely, acetonitrile and dimethylformamide (DMF). Halide-free synthesis is predicted to reduce the cost and environmental impacts associated with the production of [BMIM][BF4] by 2–5-fold compared to metathesis. Upon including the use phase of the solvents in fuel desulfurization and accounting for the uncertainty in background data, halide-free [BMIM][BF4] consistently presents the lowest cost and environmental impacts, while DMF is the worst in class. As well as exemplifying the importance of synthesis routes of ILs on their sustainability, these results highlight the need to include the use phase of solvents for more comprehensive life-cycle assessments.

The integrated nature of the Sustainable Development Goals (SDGs) presents a challenge to implementing the 2030 Agenda. Analytical methods to support decision-makers are often developed without explicitly incorporating decision-makers’ views and experience. Here, we investigate whether existing methods are fit-for-purpose in supporting decision-makers at national and subnational levels. We identify prominent methods for SDG interaction analysis, which we then evaluate by engaging directly (via a survey and interviews) with method developers and decision-makers in Sweden. We find that decision-makers prioritize methods that are simple and flexible to apply and able to provide directly actionable and understandable results. They are less concerned with the accuracy, precision, completeness or quantitative nature of the knowledge. Prominent categories of methods include self-assessment, expert judgement, literature-based, statistical analyses and modelling. Interviewed decision-makers consider these methods in line with the features prioritized in the survey but highlight low performance on features they value highly, such as the extent to which results are actionable and overall ease of use. Methods developers have limited awareness of decision-makers’ priorities and requirements, so hindering methodological advancement. They should focus on the practical value of applications to support decision-makers, resource-constrained organizations and those seeking to evaluate multiple cases.

Floating offshore wind turbines (FOWTs) have received great attention for deep water wind energy harvesting. So far, research has been focused on a single floating rotor. However, for final deployment of FOWT farms, interactions of multiple FOWTs and potential impacts of the floating motion on power performance and wake of the rotors need to be investigated. In this study, we employ CFD coupled with an Actuator Disc model to analyze interactions of two tandem FOWTs for the scenario, where the upstream rotor is floating with a prescribed surge motion and the downstream rotor is fixed and influenced by the variations in the incoming flow created by the oscillating motion of the surging rotor. We will investigate three different surge amplitudes and analyze the fluctuations in power performance of the two rotors as well as their wake interactions. The results show a light increase in the mean power coefficient of both rotors for the surging case, compared against the case with no surge motion. The standard deviation of the transient CP of the surging rotor linearly scales with the surge amplitude, while such impact for the downstream rotor is very limited. Surging motion of the upstream rotor is found to enhance flow mixing in the wake, which therefore, accelerates the wake recovery of the downstream rotor. This finding suggests prospects for research into redesigning wind farm layout for FOWTs, aiming for more compact arrangements., peer-reviewed

Offshore wind energy has seen a steady increase in the latest years as it serves as an ideal alternative energy source to meet our renewable energy goals. Due to this increase in interest and in installations of offshore wind farms a better understanding of the impact of waves on the power production of wind farms in necessary. This wave-wind farm power production interaction has scarcely been examined, however, some exceptions of small scale large-eddy-simulations exist. Unfortunately, these studies are not able to take multiple wind farms under real weather conditions into account. Here, we show the power production and wake lengths of 1250 offshore wind turbines located in the German Bight simulated by a stand-alone atmospheric (WRF) model and a coupled atmosphere-wave (WRF-SWAN) model. The coupled atmosphere-wave model estimates larger (smaller) power production in case of waves and wind traveling in the same (opposed) direction compared to the stand-alone atmospheric model. The relative difference between the two models can be as much as 20% for the two-week averaged grid power production, while the difference in total power over this two-week period is equal to 9%. Moreover, the wind farm wake lengths of waves and wind traveling in the same (opposed) direction are longer (shorter) for the coupled atmosphere-wave model compared to the stand-alone atmospheric model. Here, the relative difference of the mean wake length between the two models can be up to 25%. This shows the importance of waves as a part of the offshore wind environment and can be an important factor in future wind assessment or power production estimation studies.

Satisfying China’s food demand without harming the environment is one of the greatest sustainability challenges for the coming decades. Here we provide a comprehensive forward-looking assessment of the environmental impacts of China’s growing demand on the country itself and on its trading partners. We find that the increasing food demand, especially for livestock products (~16%–30% across all scenarios), would domestically require ~3–12 Mha of additional pasture between 2020 and 2050, resulting in ~−2% to +16% growth in agricultural greenhouse gas (GHG) emissions. The projected ~15%–24% reliance on agricultural imports in 2050 would result in ~90–175 Mha of agricultural land area and ~88–226 MtCO2-equivalent yr−1of GHG emissions virtually imported to China, which account for ~26%–46% and ~13%–32% of China’s global environmental impacts, respectively. The distribution of the environmental impacts between China and the rest of the world would substantially depend on development of trade openness. Thus, to limit the negative environmental impacts of its growing food consumption, besides domestic policies, China needs to also take responsibility in the development of sustainable international trade.

The environmental impacts of food are currently at unsustainable levels. Consumers undoubtedly play a central role in reducing the impacts of the food system to more sustainable levels via dietary changes and food waste reduction. Mathematical optimisation is one approach to identifying less environmentally impactful dietary patterns. A limited number of studies, however, have assessed whether impact reductions offered by optimised diets are enough to remain within planetary boundaries (i.e. attain ‘absolute’ environmental sustainability). Using UK food consumption as a case study, here we employ linear programming to identify nutritionally adequate diets that meet sociocultural acceptability criteria whilst minimising (a) environmental impact transgressions of their allocated share of the safe operating space (SoSOS) for nine planetary boundaries (PBs), (b) cost, or (c) deviation from the current diet. We show that the current diet is unsustainable as it transgresses six or seven PBs, depending on the SoSOS allocation principle. Optimising for minimum SoSOS transgressions yields diets offering significant impact reductions (66 - 95% reduction across all PBs) compared to the current average dietary pattern, but whether they completely mitigate SoSOS transgressions depends on the sharing principle adopted to assign the SoSOS to national food consumption. Additionally, by comparing least-cost and least-transgression solutions, we find a trade-off between cost and environmental sustainability indicating that more sustainable dietary patterns are not currently incentivised by the relative prices of food items in the UK. Our work demonstrates the value in embedding ‘absolute’ sustainability in diet optimisation so that solutions inherently provide a more clear-cut understanding of their broad implications on the environment., Sustainable Production and Consumption, 28, ISSN:2352-5509

Reductive Catalytic Fractionation (RCF) of lignocellulosic materials produces lignin oil rich in monomer products and high-quality cellulosic pulps. RCF lignin oil also contains lignin oligomers/polymers and hemicellulose-derived carbohydrates. The variety of components makes lignin oil a complex matrix for analytical methods. As a result, the signals are often convoluted and overlapped, making detecting and quantifying key intermediates challenging. Therefore, to investigate the mechanisms underlining lignin stabilization and elucidate the structural features of carbohydrates occurring in the RCF lignin oil, fractionation methods reducing the RCF lignin oil complexity are required. This report examines the solvent fractionation of RCF lignin oil as a facile method for producing lignin oil fractions for advanced characterization. Solvent fractionation uses small volumes of environmentally benign solvents (methanol, acetone, and ethyl acetate) to produce multigram lignin fractions comprising products in different molecular weight ranges. This feature allows the determination of structural heterogeneity across the entire molecular weight distribution of the RCF lignin oil by high-resolution HSQC NMR spectroscopy. This study provides detailed insight into the role of the hydrogenation catalyst (Raney Ni) in stabilizing lignin fragments and defining the structural features of hemicellulose-derived carbohydrates in lignin oil obtained by the H-transfer RCF process. 1

This study evaluates the performance of commercial reverse osmosis (RO) and nanofiltration (NF) membranes for the removal of metal ions from synthetic water and surface water carried from the north-west of Lake Tanganyika in the city of Uvira, in the east of the Democratic Republic of Congo. Metal ion analyses were performed by the standardized ICP-MS and ICP-OES methods. The RO membrane showed higher metal ion rejection in high-concentration solutions (synthetic samples) prepared in the laboratory as well as in low-concentration samples from real raw water collected near Lake Tanganyika. Rejection levels were higher than 98% for Cr3+, Pb2+, Cd2+, As3+, Ni2+, and Sb+3 ions in the synthetic solutions, and 99.2, 98.8, 98.6, 99.2, 98.4, and 98.8%, respectively, in the real samples. The concentrations of metals in the permeate varied depending on the feed concentration and were 0.15 to 1.02 mg/L, 0.33 to 22 mg/L, and 0.11 to 22 mg/L in RO, NF90, and NF270 membranes, respectively. Regarding the NF membranes, the rejection of Cr, Ni, and Cd ions was interesting: 98.2, 97.8, and 92.3%, respectively. However, it was lower for Pb, As, and Sb ions: 76.9, 52.5 and 64.1%, respectively. The flux of NF was 329 to 375 L/m2.h, much higher than for RO membranes, which had a flux of 98 to 132 L/m2.h. The studied membranes are thus a feasible solution to remove the studied metals from real water sources at low concentrations since they meet the standards of the World Health Organization on specific values assigned to chemicals from industrial sources and human habitation areas where these ions are present in drinking water.

Wind farm control has been a topic of research for more than two decades. It has been identified as a core component of grand challenges in wind energy science to support accelerated wind energy deployment and to transition to a clean and sustainable energy system for the 21st century. The prospect of collective control of wind turbines in an array, to increase energy extraction, reduce structural loads, improve the balance of systems, reduce operation and maintenance costs, etc. has inspired many researchers over the years to propose innovative ideas and solutions. However, practical demonstration and commercialization of some of the more advanced concepts has been limited by a wide range of challenges, which include the complex physics of turbulent flows in wind farms and the atmosphere, uncertainties related to predicting structural load and failure statistics, and the highly multi-disciplinary nature of the overall design optimization problem, among others. In the current work, we aim at providing a comprehensive overview of the state of the art and outstanding challenges, thus identifying the key research areas that could further enable commercial uptake and success of wind farm control solutions. To this end, we have structured the discussion on challenges and opportunities into four main areas: (1) insight in control flow physics, (2) algorithms and AI, (3) validation and industry implementation, and (4) integrating control with system design (co-design).

Herein a one-pot double C–H functionalization for constructing C8-alkyl substituted coumarins from phenols is reported. For the first time Pd/C as heterogenous catalyst was used to enable the synthesis of structurally divers coumarins.

In this study, the effects of the ratio of a motor’s axial length to its pole pitch on efficiency, magnetic flux density distribution, torque, torque/weight, and motor volume were investigated in an outer-rotor (hub) brushless direct current motor. The weight and volume of an electrical machine affects the output power, efficiency and output torque, and it is advantageous to design an electric motor at an appropriate power and high efficiency with an appropriate weight and volume. Therefore, the aim of this study was to optimize the motor’s axial length and stator outer diameter, which affects the motor volume. Initially, the axial-length-to-pole-pitch ratio of the hub BLDC motor was taken at 0.75. According to this ratio, the dimensions of the rotor outer diameter, rotor inner diameter, stator outer diameter, stator inner diameter, slot height, motor axial length, and magnet thickness were optimally determined. Then, the axial-length-to-pole-pitch ratio was considered as 1, 1.50, 2, and 3, respectively. The effects of the change in the motor’s axial-length-to-pole-pitch ratio on the efficiency, torque, speed, torque/volume, torque/weight, and cogging torque were examined in a simulation environment. According to the motor’s axial-length-to-pole-pitch ratio, the torque value in the final state was 28.65% higher than the torque value in the initial state. In the last part, the motor axial length and the stator outer diameter were defined as variables in a genetic algorithm procedure and optimized. The number of poles and the number of slots were fixed parameters. Simulation studies were carried out using the finite element method via AN-SYS/Maxwell software.

Due to the expansion in the global population, there is an increase in animal protein demand and waste generation. Currently, food waste derived from supermarkets, etc., which is used to produce biogas, is collected separately and can contain (micro)plastics deriving from food packaging, imposing potential risks to the environment. A possible solution to address protein, waste and plastic concerns can potentially be achieved by rearing black soldier fly (BSF) larvae on such substrates. In this study, we investigated the effect of polyvinyl chloride (PVC) (micro)plastics on the growth, survival, and bioconversion of BSF larvae. On the other hand, the impact of the larvae on the polymer structure and degradation was also assessed. This was carried out by rearing BSF larvae on artificial food waste spiked with micro-, meso-, and macroplastics, while measuring larval growth, survival, and bioconversion parameters. The remaining plastics were collected and analysed upon changes and degradation of their polymer structure. Generally, BSF larvae were not affected in terms of growth performance (179.9–210.4 mg), survival (77.1–87.3%), and bioconversion (FCR: 4.65–5.53) by the presence of (micro)plastics in the substrates. Furthermore, the larvae were also unable to significantly alter the polymer structure of the used plastic.

There is an environmental concern regarding the use of petroleum-based lubricants, which are generally toxic and nonbiodegradable. Biobased lubricants, such as vegetable oils, are the alternative: they show excellent lubricity, are readily biodegradable and nontoxic. However, a major disadvantage of using vegetable oils in lubricant applications is their lack of thermo-oxidative stability, which can be improved by antioxidant additives. Here, we propose the use of lignin-based additives in biolubricant formulations to improve this feature, based on lignin’s known antioxidant properties. To ensure a stable dispersion in vegetable oil, lignin was partially esterified. Antioxidant properties of lignin before and after palmitoylation were demonstrated in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Four different lignin-based fractions, commercial Protobind P1000 soda lignin from straw, solvolytically fractionated Protobind P1000 lignin and two lignin fractions from reductively catalyzed fractionation (RCF) of native birch wood, were tested in biolubricant formulations with castor oil as base oil. Those lignin fractions exhibited excellent performance compared to butylated hydroxytoluene (BHT), a commonly used petroleum-based antioxidant. Formulations of modified lignin in castor oil possess improved thermo-oxidative stability, as illustrated by their increased oxidation induction time. Additionally, rheological and tribological tests demonstrate similar, or in some cases improved, lubricating properties compared to castor oil. This study showcases the successful incorporation of lignin-based antioxidants in biolubricant formulations, tackling the major disadvantage of vegetable oils as environment-friendly lubricants.

ispartof: ACS SUSTAINABLE CHEMISTRY & ENGINEERING vol:9 issue:34 pages:11596-11603 status: published

The current design of vertical axis wind turbines (VAWTs) suffers from inevitable change in tip speed ratio, λ, in variant wind conditions due to fixed rotor speed. At relatively high wind speeds, which are promising due to high wind power potential, VAWTs operate at low λ with poor power coefficient. Morphing airfoils can be a potential solution by modifying the airfoil shape to optimal at each λ. The optimal airfoil shape for VAWTs at low λ, where dynamic stall is present, has not yet been studied in the literature, therefore, the present study addresses this gap by focusing on this regime to serve as a step towards designing morphing airfoils for VAWTs by identifying the optimal airfoil shape at low λ. The present study performs a combined analysis of three shape defining parameters, namely the airfoil maximum thickness and its position as well as the leading-edge radius, to reveal the overall design space. The analysis is based on 252 high-fidelity transient CFD simulations of 126 identical airfoil shapes. The simulations are verified and validated with three experiments. The results show that the three shape defining parameters have a fully coupled impact on the turbine power and thrust coefficients. When λ reduces from 3.0 to 2.5, the optimal airfoil changes from NACA0018–4.5/2.75 to NACA0024–4.5/3.5, that is increasing the maximum thickness from 18%c to 24%c and shifting its position from 27.5%c to 35%c, while the leading-edge radius index, I, remains 4.5. In general, reducing I from the default value of 6.0 to 4.5 is found to increase the turbine CP.

Wind farm flow control (WFFC) is a topic of interest at several research institutes and industry and certification agencies worldwide. For reliable performance assessment of the technology, the efficiency and the capability of the models applied to WFFC should be carefully evaluated. To address that, the FarmConners consortium has launched a common benchmark for code comparison under controlled operation to demonstrate its potential benefits, such as increased power production. The benchmark builds on available data sets from previous field campaigns, wind tunnel experiments, and high-fidelity simulations. Within that database, four blind tests are defined and 13 participants in total have submitted results for the analysis of single and multiple wakes under WFFC. Here, we present Part I of the FarmConners benchmark results, focusing on the blind tests with large-scale rotors. The observations and/or the model outcomes are evaluated via direct power comparisons at the upstream and downstream turbine(s), as well as the power gain at the wind farm level under wake steering control strategy. Additionally, wake loss reduction is also analysed to support the power performance comparison, where relevant. The majority of the participating models show good agreement with the observations or the reference high-fidelity simulations, especially for lower degrees of upstream misalignment and narrow wake sector. However, the benchmark clearly highlights the importance of the calibration procedure for control-oriented models. The potential effects of limited controlled operation data in calibration are particularly visible via frequent model mismatch for highly deflected wakes, as well as the power loss at the controlled turbine(s). In addition to the flow modelling, the sensitivity of the predicted WFFC benefits to the turbine representation and the implementation of the controller is also underlined. The FarmConners benchmark is the first of its kind to bring a wide variety of data sets, control settings, and model complexities for the (initial) assessment of farm flow control benefits. It forms an important basis for more detailed benchmarks in the future with extended control objectives to assess the true value of WFFC.

Water is one of the fundamental resources of economic prosperity, food security, human habitats, and the driver of many global phenomena, such as droughts, floods, contaminated water, disease, poverty, and hunger. Therefore, its deterioration and its inadequate use lead to heavy impacts on environmental resources and humans. Thus, we argue that to address these challenges, one can rely on hydrological management strategies. The objective of this study is to simulate and quantify water balance components based on a hydrologic model with available data at the R’Dom watershed in Morocco. For this purpose, the hydrologic model used is the Soil and Water Assessment Tool + (SWAT+) model. The streamflow model simulations were run at the monthly time step (from 2002 to 2016), during the calibration period 2002–2009, the coefficient of determination (R2) and Nash–Sutcliffe efficiency (NSE) values were 0.84 and 0.70, respectively, and 0.81 and 0.65, respectively, during the validation period 2010–2016. The results of the water balance modeling in the watershed during the validation period revealed that the average annual precipitation was about 484 mm, and out of this, 5.75 mm came from the development of irrigation in agricultural lands. The evapotranspiration accounted for about 72.28% of the input water of the watershed, while surface runoff (surq_gen) accounted for 12.04%, 11.90% was lost by lateral flow (latq), and 4.14% was lost by groundwater recharge (perco). Our approach is designed to capture a real image of a case study; zooming into other case studies with similar environments to uncover the situation of water resources is highly recommended. Moreover, the outcomes of this study will be helpful for policy and decision-makers, and it can be a good path for researchers for further directions based on the SWAT model to simulate water balance to achieve adequate management of water resources.

In this contribution, we have reported our study on the fine-tuned design and synthesis of new POLITAGs-Pd0(POLymeric Ionic TAG) catalytic systems with the intention of defining highly efficient heterogeneous palladium catalysts stabilized by ionic tags able to operate at a very low loading while being fully recoverable/reusable. By varying both the support and the ratio between the metal and immobilized ionic tag, we have accessed five different heterogeneous catalytic systems that have been fully characterized (EA, XPS, TEM, and HR-TEM) to investigate their morphological differences. The catalytic efficiency of the newly prepared POLITAGs-Pd0materials was then tested and compared in the representative Mizoroki-Heck cross-coupling reaction, a universally investigated and widely useful process. A close correlation between the catalyst support and catalytic performances has been highlighted. The best system POLITAG-Pd0-HM features a high TOF value (26,786 h-1), affording the final products in high isolated yields by using as little as only 0.0007 mol % of Pd. Moreover, this high catalytic activity coupled with the use of γ-valerolactone (GVL) as a green reaction medium has led to the definition of a very efficient waste-minimized protocol. The newly designed catalyst has been utilized in the representative synthesis of Amiloxate, a widely used sunscreen agent, that could be prepared with negligible metal contamination and very low E-factor.

Wind energy is anticipated to play a central role in enabling a rapid transition from fossil fuels to a system based largely on renewable power. For wind power to fulfill its expected role as the backbone—providing nearly half of the electrical energy—of a renewable-based, carbon-neutral energy system, critical challenges around design, development, and deployment of land and offshore technologies must be addressed. During the past three years, the wind research community has invested significant effort toward understanding the nature and implications of these challenges and identifying associated gaps. The outcomes of these efforts are summarized in a series of ten articles, some under review by Wind Energy Science (WES) and others planned for submission during the coming months. This letter explains the genesis, significance, and impacts of these efforts.

Peptides have been gaining ground in the pharmaceutical arena, with a total of 22 approvals over the last six years. These molecules are also present in antibody-drug conjugate constructs as linkers or payloads, or both. Solid-phase peptide synthesis (SPPS) is the method of choice for peptide synthesis. The introduction of an automatic synthesizer facilitated this methodology and helped in reducing the amounts of the required solvents. However, there are still concerns regarding the amounts, as well as the safety profiles, of the solvents involved in SPPS. Here, we discuss the work addressing the use of water as the greenest alternative to the common non-green solvents employed in various steps of the SPPS methodology. Various technologies were introduced which enabled the synthesis of di- and up to decapeptides in aqueous media with satisfactory yields and purities., The work in the author's laboratory is partially funded by the National Research Foundation (Blue Skies) (South Africa) and Al-Balqa Applied University, Jordan.

Upcoming biorefineries, such as lignin-first provide renewable aromatics containing unique aliphatic alcohols. In this context, a Cu-ZrO2 catalyzed hydrogen borrowing approach was established to yield tertiary amine from the lignin model monomer 3-(3,4-dimethoxyphenyl)-1-propanol and the actual lignin-derived monomers, (3-(4-hydroxyphenyl)-1-propanol and dihydroconiferyl alcohol), with dimethylamine. Various industrial metal catalysts were evaluated, resulting in nearly quantitative mass balances for most catalysts. Identified intermediates, side and reaction products were placed into a corresponding reaction network, supported by kinetic evolution experiments. Cu-ZrO2 was selected as most suitable catalyst combining high alcohol conversion with respectable aliphatic tertiary amine selectivity. Low pressure H2 was key for high catalyst activity and tertiary amine selectivity, mainly by hindering undesired reactant dimethylamine disproportionation and alcohol amidation. Besides dimethylamine model, diverse secondary amine reactants were tested with moderate to high tertiary amine yields. As most active catalytic site, highly dispersed Cu species in strong contact with ZrO2 is suggested. ToF-SIMS, N2 O chemisorption, TGA and XPS of spent Cu-ZrO2 revealed that imperfect amine product desorption and declining surface Cu lowered the catalytic activity upon catalyst reuse, while thermal reduction readily restored the initial activity and selectivity demonstrating catalyst reuse. ispartof: CHEMSUSCHEM vol:15 issue:19 ispartof: location:Germany status: published

Grid-scale inter-seasonal energy storage and its ability to balance power demand and the supply of renewable energy may prove vital to decarbonise the broader energy system. Whilst there is a focus on techno-economic analysis and battery storage, there is a relative paucity of work on grid-scale energy storage on the system level with the required temporal resolution. Here, we evaluate the potential of power-to-gas-to-power as inter-seasonal energy storage technology. Our results suggest that inter-seasonal energy storage can reduce curtailment of renewable energy, and overcapacity of intermittent renewable power. Importantly, grid scale energy storage assumes a critical role especially when the technology options for dispatchable power are limited. It appears that neither high CAPEX nor low round-trip efficiency preclude the value of the technology per se, however the rate of charge and discharge of the technology emerges as key technical characteristic. This study emphasises the rising importance of balancing seasonality in energy systems characterised by a high penetration of renewable energy, and prompts questions regarding sector integration and resilient decision-making toward a zero-carbon economy.

The treatment of dementia-related diseases is a global issue. Taiwan is facing a more serious dementia problem due to the combination of an aging society and a declining birthrate. A great portion of healthcare resources has been utilized for dementia among the aged population. In order to understand how dementia develops in rural areas in Taiwan, a cooperated effort between the university and a regional hospital was formed to develop a customized medical information system to collect and track dementia patients. This efficient customized system compiled information on 768 patients with dementia-released diseases. Big data technology and data mining approaches were then applied to analyze the relevant information. Using statistical analysis, we then extracted useful medical findings from the large amounts of collected medical data. Some of the findings indicate that the patients’ education level and care practices have a major effect on the dementia severity in these local senior populations.

Recent research suggests that atmospheric gravity waves can affect offshore wind-farm performance. A fast wind-farm boundary layer model has been proposed to simulate the effects of these gravity waves on wind-farm operation by Allaerts and Meyers (2019). The current work extends the applicability of that model to free atmospheres in which wind and stability vary with altitude. We validate the model using reference cases from literature on mountain waves. Analysis of a reference flow shows that internal gravity-wave resonance caused by the atmospheric non-uniformity can prohibit perturbations in the atmospheric boundary layer (ABL) at the wavelengths where it occurs. To determine the overall impact of the vertical variations in the atmospheric conditions on wind-farm operation, we consider 1 year of operation of the Belgian–Dutch wind-farm cluster with the extended model. We find that this impact on individual flow cases is often of the same order of magnitude as the total flow perturbation. In 16.6 % of the analyzed flows, the relative difference in upstream velocity reduction between uniform and non-uniform free atmospheres is more than 30 %. However, this impact is small when averaged over all cases. This suggests that variations in the atmospheric conditions should be taken into account when simulating wind-farm operation in specific atmospheric conditions.

Peer-to-peer, community or collective self-consumption, and transactive energy markets offer new models for trading energy locally. Over the past five years, there has been significant growth in the amount of academic literature examining how these local energy markets might function. This systematic literature review of 139 peer-reviewed journal articles examines the market designs used in these energy trading models. A modified version of the Business Ecosystem Architecture Modelling framework is used to extract market model information from the literature, and to identify differences and similarities between the models. This paper examines how peer-to-peer, community self-consumption and transactive energy markets are described in current literature. It explores the similarities and differences between these markets in terms of participation, governance structure, topology, and design. This paper systematises peer-to-peer, community self-consumption and transactive energy market designs, identifying six archetypes. Finally, it identifies five evidence gaps which require future research before these markets could be widely adopted. These evidence gaps are the lack of: consideration of physical constraints; a holistic approach to market design and operation; consideration about how these market designs will scale; consideration of information security; and, consideration of market participant privacy.

Thermal water splitting by redox reactants could contribute to a hydrogen-based energy economy. The authors previously assessed and classified these thermo-chemical water splitting redox reactions. The Mn3O4/MnO/NaMnO2 multi-step redox cycles were demonstrated to have high potential. The present research experimentally investigated the MnOx/Na2CO3 redox water splitting system both in an electric furnace and in a concentrated solar furnace at 775 and 825 °C, respectively, using 10 to 250 g of redox reactants. The characteristics of all reactants were determined by particle size distribution, porosity, XRD and SEM. With milled particle and grain sizes below 1 µm, the reactants offer a large surface area for the heterogeneous gas/solid reaction. Up to 10 complete cycles (oxidation/reduction) were assessed in the electric furnace. After 10 cycles, an equilibrium yield appeared to be reached. The milled Mn3O4/Na2CO3 cycle showed an efficiency of 78% at 825 °C. After 10 redox cycles, the efficiency was still close to 60%. At 775 °C, the milled MnO/Na2CO3 cycles showed an 80% conversion during cycle 1, which decreased to 77% after cycle 10. Other reactant compounds achieved a significantly lower conversion yield. In the solar furnace, the highest conversion (>95%) was obtained with the Mn3O4/Na2CO3 system at 775 °C. A final assessment of the process economics revealed that at least 30 to 40 cycles would be needed to produce H2 at the price of 4 €/kg H2. To meet competitive prices below 2 €/kg H2, over 80 cycles should be achieved. The experimental and economic results stress the importance of improving the reverse cycles of the redox system.