Showing papers in "Green and Sustainable Chemistry in 2019"
TL;DR: The application of the magnetic nanocatalysts is a rapidly growing field for the development of sustainable and green processes Magnetic separation not only avoids the need for catalyst filtration or centrifugation after completion of the reaction, but also provides practical techniques for recovering these catalysts as mentioned in this paper.
Abstract: The application of the magnetic nanocatalysts is a rapidly growing field for the development of sustainable and green processes Magnetic separation not only avoids the need for catalyst filtration or centrifugation after completion of the reaction, but also provides practical techniques for recovering these catalysts Multicomponent reactions are recognized as very powerful tools in synthetic organic and medicinal chemistry for the synthesis of the complex products in a single step from simple starting materials The combination of magnetic nanocatalysts and multicomponent reactions will become an emerging strategic research area and is an ideal blend for the development of sustainable methods in green synthetic chemistry This review focuses on the synthesis and application of magnetic nanocatalysts as novel task-specific catalysts for multicomponent reactions in recent years
175 citations
TL;DR: In this article, the authors review the current status of CO2 reduction and discuss very recent developments and remaining challenges from an industrial perspective, emphasizing the importance of system-level investigation and optimization of the CO2R aimed at industrialization of the technology.
Abstract: In light of the energy transition, electrochemical CO2 reduction (CO2R) has commonly been postulated as a favorable strategy for renewable energy storage and electrification of the chemical industry. However, for an effective impact of CO2R, large-scale implementation of this technology is required. The majority of research in this field has focused on fundamental and mechanistic understanding of the CO2R reaction and on the development of highly active and selective catalytic materials. Herein, we review the current status of the technology and discuss very recent developments and remaining challenges from an industrial perspective. We underscore the importance of system-level investigation and optimization of CO2R aimed at industrialization of the technology.
143 citations
TL;DR: The opinion is left on the current challenges and opportunities in this blossoming field, which are curiously aligned with the scope of today's major concerns, where DESs are called to make a valuable contribution to important areas such as clean water, clean energy, and biotechnology.
Abstract: In the last couple of years, deep eutectic solvents (DESs) have been raising a lot of attention mainly due to their versatility and their easy and speedy preparation without the need of further purification. Moreover, the vast array of very different compounds that can be selected for their preparation has led to the full tailoring of their relevant properties as solvents. We herein leave our opinion on the current challenges and opportunities in this blossoming field, which are curiously aligned with the scope of today's major concerns, where DESs are called to make a valuable contribution to important areas such as clean water, clean energy, and biotechnology.
129 citations
TL;DR: A quick summary of the state of the art on the usage of these new green solvents in analytical chemistry, particularly in liquid-phase microextraction methods (within sample preparation) and as additives or pseudostationary phases in liquid chromatography (within analytical separation methods) can be found in this paper.
Abstract: Current trends in incorporating the principles of green chemistry in analytical methods have led to the design and usage of new solvents to replace conventional organic solvents, which characterize by their high volatility, flammability, and toxicity. Among the alternatives that have emerged, amphiphilic solvents, ionic liquids, and deep eutectic solvents are the most explored candidates in this research field. Taking advantage of the solvation properties of these new solvents, together with the synthetic versatility in the case of ionic liquids and deep eutectic solvents, a wide variety of applications of these solvents within green analytical chemistry appear in the recent literature. The aim of this article is to provide a quick summary of the state of the art on the usage of these new green solvents in analytical chemistry, particularly in liquid-phase microextraction methods (within sample preparation) and as additives or pseudostationary phases in liquid chromatography (within analytical separation methods).
123 citations
TL;DR: In this paper, the authors outline recent advances in pretreating lignocellulosic biomass, including using kraft pulping, organosolv, and ionic liquid methods, to produce biofuels, renewable chemicals, and biomaterials.
Abstract: Lignocellulosic biomass is considered as a sustainable and potentially renewable resourse alternative to fossil fuels. Research into developing novel and innovative means to harness lignocellulosic biomass for fuels, energy, and materials has increased in the past decade as it has become clear that developing technologies must center around the mitigation of climate change. This article outlines recent advances in pretreating biomass, including using kraft pulping, organosolv, and ionic liquid methods, to produce biofuels, renewable chemicals, and biomaterials.
117 citations
TL;DR: This short review describes the recent research and developments on biofuel production from microalgae including production planning, cultivation strategy, and harvesting and conversion technology including economic viability study for the future prospect of micro algae as a third-generation biofuel.
Abstract: The first-generation biofuels from agricultural yields are currently not considered as a sustainable energy source. Similarly, the second-generation biofuels produced from nonfood feedstock are not economically viable for its high processing cost. In contrast, the third-generation biofuels from microalgae are considered as the feasible and sustainable solution for future energy demand by overcoming the shortcomings of the previous generations of biofuels. This short review describes the recent research and developments on biofuel production from microalgae. It includes production planning, cultivation strategy, and harvesting and conversion technology including economic viability study for the future prospect of microalgae as a third-generation biofuel.
110 citations
TL;DR: In this article, a review of recent findings on the pretreatment for the conversion of lignocellulosic materials into fuel and value-added products is presented, where different pretreatment methods have been categorized as physical, chemical, biological, physicochemical, and combined.
Abstract: Many countries in the world aim to achieve sustainable development goals by 2030 following ambitious climate change mitigation, and thus, the concept of sustainable biorefinery has attracted immense research and development around the world. The concept of the biorefinery is centrally based on the conversion of biomass into biofuels and value-added products. Nevertheless, lowering the recalcitrance of the lignocellulosic matrix in a cost-effective and environmentally benign manner is a crucial pretreatment step. Different pretreatment methods have been categorized as physical, chemical, biological, physicochemical, and combined. Recently, some novel ionic liquids have also emerged as promising sustainable pretreatment solutions for use of lignocellulosic waste on a large scale. This review briefly presents recent findings on the pretreatment for the conversion of lignocellulosic materials into fuel and value-added products.
93 citations
TL;DR: The use of water as a solvent, including the use of aqueous biphasic catalysis, micelle-enabled catalysis and biocatalysis, constitutes a viable, green and sustainable alternative to reactions in organic solvents as discussed by the authors.
Abstract: Recent developments in the evolution of more sustainable solvent use in organic synthesis are critically reviewed. Commonly used organic solvents and less common bio-based examples are assessed and ranked on the basis of waste disposal and environmental impact, health and safety parameters. The use of water as a solvent, including the use of aqueous biphasic catalysis, micelle-enabled catalysis and biocatalysis, constitutes a viable, green and sustainable alternative to reactions in organic solvents.
75 citations
TL;DR: In this paper, the use of plasmonic nanoparticles in catalysis of organic transformations is presented with a special emphasis on organic transformations. And the authors present several examples of the use in catalytic applications of PNP-based photocatalysts coupled with other metals and supports.
Abstract: Plasmonic nanoparticles (PNPs) are currently actively researched for their application towards enhancing catalytic transformations, thanks to their appealing property to strongly interact with light. Beyond the seminal application of supported gold nanoparticles towards photooxidation reactions, plasmon-mediated catalysts are promising candidates for the design of a wider range of visible-light driven reactions. Such systems include free standing gold, silver and copper nanoparticles as well as PNP-based photocatalysts coupled with other metals and supports. In this Current Opinion, recent examples of the use in catalysis of plasmonic nanoparticles are presented with a special emphasis on organic transformations.
66 citations
TL;DR: In this article, the authors examine the recent advances, challenges, and future opportunities in the field of integrated carbon capture, utilization, and storage (CCUS), particularly postcombustion capture by liquid sorbents and in situ utilizations or transformations.
Abstract: Carbon capture, utilization, and storage (CCUS), which has been proposed as a strategy to mitigate greenhouse gas emissions and simultaneously offer alternative pathways of production of chemicals, fuels, and materials, remains currently poorly deployed due to the prohibitive cost of the capture and utilization steps. In the present review, we examine the recent advances, challenges, and future opportunities in the field of integrated CCUS and particularly postcombustion capture by liquid sorbents and in situ utilizations or transformations.
64 citations
TL;DR: In this paper, a review of single-atom catalysts (SACs) in CO2 electrocatalysis is presented, with a focus on their high catalytic activity, stability, selectivity and maximum atom utilization.
Abstract: The design of highly selective, low-cost, and energy-efficient electrocatalysts is crucial for CO2 electrocatalysis to mitigate energy shortages and to lower carbon footprint. Single-atom catalysts (SACs) are emerging as intriguing catalytic materials in CO2 electrocatalysis owing to their high catalytic activity, stability, selectivity, and maximum atom utilization. This review highlights recent work in this area. Motivating factors for enhancing CO2 electroreduction by using SACs are discussed. Promising routes to facilitating transformation of CO2 into C2+ products with SACs are described.
TL;DR: In this paper, the authors describe the recent advances in glycerol valorization to valuable products under liquid phase continuous flow systems using different types of catalysts and processes, and highlight the main biobased-chemicals obtained from glycerols, namely acrolein, lactic acid, glyceric acid, propanol, propanediols, glyceolate, solketal, acetin, and oligomers.
Abstract: This report describes the recent advances in glycerol valorization to valuable products under liquid phase continuous flow systems using different types of catalysts and processes. The main biobased-chemicals obtained from glycerol, namely acrolein, lactic acid, glyceric acid, propanol, propanediols, glycerol carbonate, solketal, acetin, and oligomers, are highlighted.
TL;DR: In this article, an overview of solvent developments toward more sustainable and green separation processes is presented, where the primary separation operation is considered, but the entire process including solvent recovery, because that is typically where the energy should be invested.
Abstract: Solvent-based separation processes can reduce the required energy input for separation, improve biocompatibility, and allow for mild responsive separation systems that are applicable when distillation is technically not feasible because of the delicate nature of (bio)molecules to be separated. Owing to the increasing awareness of the need for a green and sustainable industry, the interest in green solvents for separation processes is growing. Being able to tailor solvent properties and solvent biocompatibility are key properties for making processes sustainable and allowing flexibility regarding feed and product composition of the separation processes involved. This work aims to give an overview of solvent developments toward more sustainable and green separation processes. For all solvent systems, it is key that not only the primary separation operation is considered, but the entire process including solvent recovery, because that is typically where the energy should be invested.
TL;DR: In this paper, the advantages and disadvantages of various green solvents, including water (and supercritical or subcritical water), supercritical CO2, ionic liquids, 2-methyltetrahedronfuran (and other organic green Solvents), and switchable solvent, were discussed.
Abstract: The widespread use of solvents has long been an integral part of the fine chemical and pharmaceutical industries. However, as the conflicts between sustainable development and environmental protection becomes more prominent, the chemistry community has been increasingly aware of the importance of proactively choosing environmentally friendly solvents, as evidenced by the introduction of the 12 principles of green chemistry by Paul Anastas and John Warner over two decades ago, specifically the fifth principle “safer solvents and auxiliaries”. It has since become the guideline for practicing green development both in academia and industry. This report presented and summarized the advantages and disadvantages of various green solvents, including water (and supercritical or subcritical water), supercritical CO2, ionic liquids, 2-methyltetrahedronfuran (and other organic green solvents), and switchable solvents. The combination of solvent strategies and separation technologies was also briefly discussed. Collectively, there is no perfect solvent for all the chemical applications. Taking all aspects into consideration, water as a solvent is the greenest.
TL;DR: In this paper, the authors discuss the scientific challenges in the development of novel electric double-layer supercapacitor electrodes, and present some recent highlights, as well as a review of the current state-of-the-art.
Abstract: Electric double layer supercapacitors are a class of energy storage device whose strengths are long lifespan and high power handling. They have a niche to fill in the gradual transition to fully-electric transport systems, and are expected to have future applications in textile-based energy storage and flexible electronics. Relatively new electrode materials, based on graphene, offer an opportunity for improvement over the existing commercial standard of activated carbon, however challenges still lay ahead to bring more of these materials to market. In this review we discuss the scientific challenges in the development of novel electric double-layer supercapacitor electrodes, and present some recent highlights.
TL;DR: In this paper, the authors reviewed the recent applications of zeolites as catalysts in multicomponent reactions; initially, they modified with transition metals were discussed, followed by the modified with alkaline metals and in the final section, zeolite in the protonic form.
Abstract: Multicomponent reactions are processes in which three or more reactants are introduced concurrently to deliver a single product that contains the essential parts of the starting materials, and those have emerged in the last few years as an important tool for the development of more sustainable processes in modern synthetic organic chemistry. Still, considering the pronounced attention devoted to zeolites as efficient and selective catalysts for organic transformations, in this work we have reviewed the recent applications of zeolites as catalysts in multicomponent reactions; initially, zeolites modified with transition metals were discussed, followed by zeolites with alkaline metals and in the final section, zeolites in the protonic form.
TL;DR: In this paper, the authors proposed a method to quantify and link impacts associated with chemical-related product design decisions to actual limits for human and environmental health, and integrate this absolute perspective in chemical substitution practice.
Abstract: While many products become more sustainable, overall pressure from emissions and exposure to chemicals in products on human and environmental health increases, driven by worldwide growing chemical and product diversity and consumption. To benchmark environmental sustainability performance of new products and measure related progress, we need to move from eco-efficiency indicating relative improvements to eco-effectiveness linking chemical-related impacts to absolute sustainability limits, considering entire chemical and product life cycles. Efforts in chemical substitution and alternatives assessment to replace harmful chemicals with sustainable solutions are still in their infancy and lack applicability to product scales. Novel and innovative methods are required to understand the different life cycles, to quantify and link impacts associated with chemical-related product design decisions to actual limits for human and environmental health, and to integrate this absolute perspective in chemical substitution practice. With such methods at hand, it will be possible to develop products that are environmentally sustainable in absolute terms.
TL;DR: In this paper, the authors carried out a critical analysis upon the solvents proposed for CO2 capture and pursued technologies to make carbon capture, utilization, and storage a reality.
Abstract: The development of specific ‘green’ solvents with unique combination of properties and associated techniques for target applications, capable of minimizing the environmental impact from their use in chemical production or by developing sustainable and renewable energy and resources, has been gathering increasing attention over the last years. Emerging alternatives or undervalued self-claimed greener solvents, such as ionic liquids, amino acid–functionalized ionic liquids, ionic liquid–mixed solvents, and eutectic solvents, have been proposed as promising materials with unique properties not achievable by means of any other material. Nonetheless, in spite of all these greener compounds' outstanding properties and potential for acid gas separation, important limitations have hampered the development of separation units and processes capable of fulfilling industrial demands. This study intends to carry a critical analysis upon the solvents proposed for CO2 capture and the pursued technologies to make carbon capture, utilization, and storage a reality.
TL;DR: In this article, the authors argue that owing to inadequate infrastructure for e-waste management and non-enforcement of laws, multitudes of hazardous substances are released due to the crude way ewaste is recycled and could pose risks for humans and the environment.
Abstract: Electronic waste (e-waste) is generated in enormous amounts worldwide, and this has become a global environmental issue because of the way it is handled, especially in developing countries. Africa undoubtedly is the fastest growing economy than any other continent, and this has resulted in increase in the importation of electronic and electrical goods and in the implementation of information and communication technologies. However, owing to inadequate infrastructure for e-waste management and nonenforcement of laws, multitudes of hazardous substances are released due to the crude way e-waste is recycled and could pose risks for humans and the environment. On the other hand, a lot of opportunities abound if it is handled well. These include precious metal recovery for industry, employment opportunities and economic benefits to e-waste collectors, helping to clean the environment, refurbishment for sale of cheap electronic and electrical equipment, benefits of recovered metals over mineral mining, among others. E-waste management is an issue in Africa because of the increasing global production of electronic and electrical equipment, lack of clear action plans by African governments on the handling of e-waste, and the absence of infrastructure for appropriate e-waste management.
TL;DR: In this article, a review of recent trends in green and sustainable chemistry and their applicability for textile waste valorization is presented, which provides a comprehensive global perspective of the linear textile economy and investigates its possible transformation into a new circular textiles economy.
Abstract: This review presents recent trends in green and sustainable chemistry and their applicability for textile waste valorization It also provides a comprehensive global perspective of the linear textile economy and investigates its possible transformation into a new circular textiles economy Furthermore, bioconversions in a textile waste biorefinery to produce glucose syrup and polyester as examples of high value–added products are presented to showcase the realisation of circular textiles ambitions
TL;DR: In this paper, a Poly(ionic liquid)s (PILs) combine some unique properties of ILs with the properties of PILs to capture and convert CO2.
Abstract: Capture and conversion of CO2 are of great importance for environment-friendly and sustainable development of human society. Poly(ionic liquid)s (PILs) combine some unique properties of ILs with th ...
TL;DR: In this paper, the most recent state-of-the-art information on enzymatic CO2 reduction for the production of chemicals such as formic acid using oxidoreductase (single or multiple) enzymes as electrocatalysts in the Enzymatic electrosynthesis cell is presented.
Abstract: Enzymatic electrosynthesis offers a novel approach to the production of chemicals through CO2 sequestration. In this minireview, we present the most recent state-of-the-art information on enzymatic CO2 reduction for the production of chemicals such as formic acid using oxidoreductase (single or multiple) enzymes as electrocatalysts in the enzymatic electrosynthesis cell. Key challenges toward upscaling of this CO2 utilization approach are identified, and future research directions are discussed briefly.
TL;DR: In this article, a review succinctly describes the recent progresses in sonochemistry for the preparation of nanocatalysts as well as the use of ultrasound in organic reactions involving nano-car catalysts.
Abstract: This review succinctly describes the recent progresses in sonochemistry for the preparation of nanocatalysts as well as the use of ultrasound in organic reactions involving nanocatalysts. The main recent uses of power ultrasound in these fields reported here allow to determine some interesting trends and perspectives for this research, but also highlight some needs to innovate.
TL;DR: In this article, advances in the past two years on amine-modified silica for CO2 capture are summarized, and their preparation and performances are discussed, as well as their performance.
Abstract: Escalating CO2 emission into the atmosphere is causing great concern about the global climate change. CO2 capture and storage (CCS) technology is considered the most effective option to alleviate this issue in the short term. Among the various adsorbent materials for CCS, amine-modified silica has been widely studied. In this short review, advances in the past two years on amine-modified silica for CO2 capture are summarized, and their preparation and performances are discussed.
TL;DR: The role of sensor technology and portable miniaturized systems has been considered to be paid special attention to the portable sample treatment systems based on microwave and ultrasound technologies and the use of image processing systems.
Abstract: Recent advances in portability of analytical equipment have been considered to enlighten the advantages offered by portable instrumentation on greening the analytical methods. Their use drastically reduces sampling, sample stockage, and transport, thus avoiding environmental side effects and risks, also improving decision-making. The fact that portable instrumentation is, in general, less expensive than bench instruments and apparatuses makes also available the analytical tools for extended sectors of the population, thus making accessible the advantages derived from analytical methods. The role of sensor technology and portable miniaturized systems has been considered to be paid special attention to the portable sample treatment systems based on microwave and ultrasound technologies and the use of image processing systems.
TL;DR: This article aims to describe the new trends in the release of pharmaceuticals in the environment, with several approaches being previously described.
Abstract: The presence of human pharmaceutical products in the environment is a source of concern for both the environment and public health. Numerous options exist to reduce the release of pharmaceuticals, with several approaches being previously described. This article aims to describe the new trends.
TL;DR: In this short review, the green potential of solvents from biomass is analysed and the toxicity of these chemicals has been studied, and information has been analysed according to the type of endpoint studied.
Abstract: In this short review, the green potential of solvents from biomass is analysed. A selection of the chemicals under study has been made, and the information brought together has been examined according to different types of properties. To explore the volatile organic compound character, the environmental fate and potential applications and several key physicochemical properties such as hydrophobicity, vapour pressure or solubility have been gathered and evaluated. Furthermore, the (eco)toxicological information of solvents from biomass has also been analysed. Information about the effect of these types of solvents in several organisms in the environment has been collected. Similarly, the toxicity of these chemicals has also been studied, and information has been analysed according to the type of endpoint studied.
TL;DR: In this article, a mini-review succinctly describes the recent progresses in selective heterogeneous photocatalysis for the preparation of high value organics from lignocellulose-based waste as well as the perspective use of its fundamentals to develop a new concept of solar bio-refineries highlighting the challenges for the future and some needs to innovate.
Abstract: This mini-review succinctly describes the recent progresses in selective heterogeneous photocatalysis for the preparation of high value organics from lignocellulose-based waste as well as the perspective use of its fundamentals to develop a new concept of solar bio-refineries highlighting the challenges for the future and some needs to innovate The main recent uses of heterogeneous photocatalysis in the field of green synthesis procedures for making key value organics starting from a suitable depolymerization of lignocellulose trough a downstream processing is giving a lot of hope to develop the concept of a bio-refinery based on solar photocatalysis
TL;DR: In this article, the authors present recent progress on employing ionic porous organic polymers for the CO2 capture and subsequent conversion and present a short review on the use of these materials for CO2 mitigation.
Abstract: The predominant greenhouse gas CO2 is the major contributor to the global warming. Very recently, ionic porous organic polymers have been taken as a kind of promising candidate material for addressing the CO2 capture and conversion issue. Compared to most neutral porous materials, ionic porous organic polymers exhibit excellent CO2 capture capacity and the ability to convert into cyclic carbonates via reaction with epoxides, owing to the existence of ionic sites in the porous structure. In addition, the counterions can be readily exchanged for tuning the uptake capacity and catalytic performance, which is another advantage for design and synthesis of ionic porous organic polymers. In this short review, we will present recent progress on employing ionic porous organic polymers for the CO2 capture and subsequent conversion.
TL;DR: In this article, the authors provide an outline of lignocellulosic biomass upgrading processes using ZSM-5 zeolites in their acidic form and exchanged with transition metals.
Abstract: The use of zeolite catalysts for biomass valorization has increasingly contributed to the development of more efficient and sustainable processes in recent times. ZSM-5 zeolites, in special, have displayed great potential as catalysts in such reactions owing to their promising features e.g. the tridimensional medium size pore system and the wide Si/Al ratio. Considering these facts, in this review we provide an outline of lignocellulosic biomass upgrading processes using ZSM-5 zeolites in their acidic form and exchanged with transition metals; we will cover not only the direct conversion of lignocellulosic biomass, but also the upgrading of its derivatives.