Low Energy Input Research Articles

Kirigami Photopiezo Catalysts for Self-Sustainable Environment Remediation.

Photo(electro)-piezo catalysis has emerged as one of the most effective strategies for sustainable environmental remediation. While various (nano)materials have been investigated for enhancing the intrinsic properties related to the interfacial band structure, increasing the efficiency by integration of materials with rational design for stress-strain applications has not yet been considered. Herein, we introduce kirigami strain engineering to photopiezo catalysts for enhancing efficiency by increasing the magnitude of applied strain and density of bends. Macroscale stretching motion is converted into localized bending by a pliable kirigami structure using similar or even lower input energy, which can be easily modulated by natural waves. The kirigami structure leads to a significant enhancement (∼250%) in the degradation of dyes, and we discovered the significant contribution of the oxygen reduction pathway in the charge-transfer mechanism, which corresponds to the observed enhancement. The photopiezo catalytic effects of kirigami were further highlighted by the small water reservoir test, showing its feasibility in nature for self-sustainable environmental remediation that can be modulated using motions of winds, waves, and life vibrations.

Ionic-Liquid-Mediated Deconstruction of Polymers for Advanced Recycling and Upcycling.

Ionic liquids (ILs) are a promising medium to assist in the advanced (chemical and biological) recycling of polymers, owing to their tunable catalytic activity, tailorable chemical functionality, low vapor pressures, and thermal stability. These unique physicochemical properties, combined with ILs' capacity to solubilize plastics waste and biopolymers, offer routes to deconstruct polymers at reduced temperatures (and lower energy inputs) versus conventional bulk and solvent-based methods, while also minimizing unwanted side reactions. In this Viewpoint, we discuss the use of ILs as catalysts and mediators in advanced recycling, with an emphasis on chemical recycling, by examining the interplay between IL chemistry and deconstruction thermodynamics, deconstruction kinetics, IL recovery, and product recovery. We also consider several potential environmental benefits and concerns associated with employing ILs for advanced recycling over bulk- or solvent-mediated deconstruction techniques, such as reduced chemical escape by volatilization, decreased energy demands, toxicity, and environmental persistence. By analyzing IL-mediated polymer deconstruction across a breadth of macromolecular systems, we identify recent innovations, current challenges, and future opportunities in IL application toward circular polymer economies.

Enhancing energy efficiency and reducing carbon footprint in organic soybean production through no-tillage and rye cover crop integration

Organic agriculture has the potential to contribute to environmental conservation, although its impact varies depending on management practices. To investigate the effects of no-tillage (NT) combined with a rye (RY) cover crop on energy efficiency and carbon footprint (CF) in soybean production, a four-year experiment was conducted. Three tillage methods [moldboard plowing (MP), NT, and rotary tillage (RT)] and two cover crop treatments [fallow (FA) and RY] were compared. NT had 39.6% and 34.0% lower energy input compared with MP and RT, respectively, due to reduced fossil fuel consumption. However, NT also showed decreased soybean yield compared with MP and RT. Nonetheless, RY cover crop management mitigated yield reduction in the NT system, with the yield of NT-RY being 20.4% higher than that of NT-FA, although not significantly different. NT-RY exhibited the highest energy use efficiency, with high energy outputs from yield and low energy inputs. Moreover, NT-RY resulted in a 3.5% increase in soil organic carbon stock, offsetting total carbon dioxide (CO2) equivalent emissions, leading to the lowest CF (−1892.99 kg CO2 eq ha−1) and yield-scaled CF (−1.44 kg CO2 eq kg−1) among all treatments. Therefore, NT-RY management, with its high yield and energy efficiency and low CF, has the potential to be an environmentally friendly and sustainable cropping system for achieving cleaner agricultural practices in organic farming.

Alkali fusion of bauxite refining residue (red mud-RM) to produce low carbon cements

This paper creates hydraulic binders using waste and a low energy input. Cements are produced with a bauxite refining residue (red mud-RM), blended with limestone and lime, and fused at temperatures from 600 to 1200 °C. The Saudi RM investigated has significant Al and Si but low Ca. Therefore, lime (CaO) and limestone (CaCO3) are used, as a source of calcium, to harvest cementing hydrates.When calcining RM alone, reactive aluminium phases begin to form at c.300 °C. However, at c.900 °C, they turn into crystalline corundum (Al2O3), a more stable and less reactive phase. It is hoped that the Ca provided by the lime/limestone will react with the Al in the RM during fusion, to form reactive silicates and aluminates rather than inert corundum. Both types of fusion produced calcium silicates and aluminates with cementing properties. However, lime fusion required higher temperature. Limestone fusion produces cementing phases at lower temperature than lime fusion, due to the lower decomposition temperature of CaCO3 when compared to CaO. High temperature is required to break down CaO (melting point = 2572 °C), whereas CaCO3 decomposes at 600 °C and disappears at 850 °C. Despite the top alkali fusion temperature being much lower than the CaO melting point, the results demonstrate that calcium was released from the lime and entered reactions forming calcium silicates and aluminates. This is probably due to the high alkali content of the RM acting as a flux and lowering the decomposition temperature of the CaO.

An efficient eco-friendly water depollution process based on electrodeposited birnessite thin films coupled to electrochemistry: Application to methylene blue degradation as phenothiazines model molecule

This paper describes successful use of nanostructured birnessite thin films as electrode to remediate aqueous solutions containing methylene blue, which can be a model molecule of phenothiazines largely used in industries. Such electrodeposited thin films, noted HB1, can spontaneously degrade dye, but the reactivity is limited by organic molecules sorption. The use as electrode improves largely efficiency for total discoloring in very soft conditions with very low energy inputs, even at high concentrations. The discolored solutions analyses by ion chromatography report the significant presence of non-toxic small organic compounds and inorganic ions confirming the degradation. Characterization of materials by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Raman spectroscopy confirm that no organic compound were adsorbed onto surface, with no modification of birnessite due to an efficient regeneration by electrochemistry in continuous. For better understanding reactions in real time, in situ measurements by UV–Visible spectroscopy were performed on solution confirming the real interest of coupling to electrochemistry. In complement, another type of sample with lower birnessite amount, noted HB4, was tested with success. These HB1 and HB4 samples used as electrodes present high degradation capacities towards methylene blue equal to 934 mg g−1 of HB1 and 2222 mg g−1 of HB4, without any modification of material. These results are very promising for future eco-friendly applications due to good efficiencies, very simple conditions, without toxic products and wastes, and with low energy needs, both for synthesis and depollution processes.

Microstructural Evolution, Mechanical Properties and Tribological Behavior of B4C-Reinforced Ti In Situ Composites Produced by Laser Powder Bed Fusion.

Based on the advantage of rapid net-shape fabrication, laser powder bed fusion (LPBF) is utilized to process B4C-reinforced Ti composites. The effect of volumetric energy density (VED) on the relative density, microstructural evolution, tensile properties and wear behaviors of B4C-reinforced Ti composites were systematically investigated. The LPBF-ed samples with high relative density (>99%) can be achieved, while the pores and un-melted powders can be observed in the sample owing to the low energy input (33 J/mm3). The additive particulates B4C were transformed into needle-like TiB whiskers with nano-scale while C dissolved in the Ti matrix. Fine-scale grains (<10 μm) with random crystallographic orientation can be achieved and the residual stress shows a downtrend as the VED increases. Through the analysis of the tensile and wear tests, the sample at 61 J/mm3 VED showed a good combination of strength and wear performance, with an ultimate tensile strength of 951 MPa and a wear rate of 3.91 × 10-4 mm3·N-1m-1. The microstructural evolution in VED changes and the corresponding underlying strengthening mechanisms of LPBF-ed Ti + B4C composites are conducted in detail.

Membranes with surficial spherical nanoarchitecture – Material importance in emulsion formulation by premix membrane emulsification

Premix membrane emulsification (PME), commonly utilized for the high-throughput manufacturing of sized-controlled emulsion droplets and microparticles with low energy inputs, was applied to the formulation of the emulsion with potential use in cosmetics. It was revealed that membrane material significantly impacts the quality and stability of the emulsion. Membrane materials with spherical (3D) architecture were generated by the chemical attachment of chitosan to the activated and silanized PVDF matrix. Hydrophobic (HB) and hydrophilic (HL) PVDF were used as starting materials. For the first time, hydrophilic PVDF was applied for such functionalization. The systematical study of wettability, surface charge, and physicochemistry was performed and referred to the quality and stability of the emulsion. It was found, that hybrid membranes HB-chitosan were the most effective, joining hydrophobic surface with hydrophilic domains. Owing to the unique structure, the mentioned material was the most promising, considering the transport features, stability, and physicochemical properties. Due to the production of highly stable emulsions their potential in the formulation of cosmetic products is pointed out. The collected results allow to fill the scientific gap identified in the literature on the lack of research focusing on the droplet break-up in PME and the correlation between membrane features and emulsion formulation effectiveness. Such correlation was deliberated and supported with the comprehensive experimental study.

Toward sustainability for upcycling SoG-Si scrap by an immersion rotational segregation purification process

Recycling solar grade silicon (SoG-Si) scrap is critical for the sustainability of solar energy and fulfilling to close material loops in circular economics. A major challenge is to control trace impurities efficiently in short time for upgrading scrap to a level of SoG-Si. Here, a new immersion rotational separation purification (IRSP) process is developed to enhance trace impurities removal and the crystal growth from remelted metal by driving the rotating shear flow to improve the efficiency of solute and heat transfer. In a departure from conventional practice that forces extremely low solidification rate limited by the diffusion layer depth at approximately equilibrium solidification interface, here IRSP achieves the deep removal of impurities and the increase of solidification rate by the non-equilibrium rotating solidification interface. In the non-equilibrium solidification process caused by mold rotation, the rotating shear flow not only reduces the diffusion layer depth to improve impurity removal efficiency, but also increases the temperature gradient of the melt at the solidification front that is conducive to the increase of crystal growth rate. The new method is applicable to molten Si and the production of SoG-Si (99.9998%) has been demonstrated, which is able to improve the quality of recycled SoG-Si requiring a low energy input. It is expected that this process helps close high purity Si material loops, reduce resource consumption and the carbon footprint of the photovoltaic industry.

Predicting Auger Energy Consumption for Olive Orchards Using the Artificial Neural Networks

The present work aims to study the development and application of Radial Basis Function (RBF) networks for predicting auger energy consumption based on input energy. The study utilized RBF networks and explored the input energy with treatments 2 (Soil moisture content), 2 (Rotary speeds), 2 (Hole depths) and 4 (Replication) based on field operations. As indicated by the results, energy input differed between the treatments but was not significant. The highest input value in transaction soil moisture content was 14.75 %, rotary speeds of 235 rpm, and hole depths of 40 cm. In comparison, the lower input energy at transaction soil moisture content was 7.9%, rotary speeds of 235 rpm, and hole depths of 20 cm. Input energy in treatment (14.75 %, 235 rpm, and 40 cm) and treatment (7.9 %,235 rpm, and 20 cm) were 100.204 and 57.135 MJ. ha-1, respectively. The highest input energy shares were recorded for diesel fuel at all treatments. Furthermore, the RBF network with one hidden layer had good convergence. The output results showed 10 and five hidden neurons in a hidden layer with high accuracy for treatment (14.75 %, 235 rpm, and 40 cm) and treatment (7.9%, 235 rpm, and 20 cm). In the treatment (14.75 %, 235 rpm, and 40 cm), the MSE for the training and testing sets was 0.0001 % and 0.01 % for data points with Ordinary RBF (ORBF type). The performance of the 3-10-1 architecture was better than other architectures. Finally, this research concluded that the RBF network method can forecast the input energy and energy expenditures related to the types of treatments.

Cellulose Nanocrystal Preparation via Rapid Hydrolysis of Wood Cellulose Fibers Using Recyclable Molten Ferric Chloride Hexahydrate

Cellulose nanocrystals (CNCs) are clean and sustainable materials that have drawn significant attention in academia and industry because of their unique physicochemical properties. However, realizing economical and environmentally friendly production of CNCs remains a challenge. In this study, we proposed an innovative strategy to fabricate CNCs, which involves the acid hydrolysis pretreatment of wood cellulose fibers using innocuous and recyclable ferric chloride hexahydrate (FeCl3·6H2O). During the molten FeCl3·6H2O treatment, the degree of polymerization (DP) of the cellulose fibers sharply decreased, along with the transformation of cellulose I to cellulose II crystallites. Molten FeCl3·6H2O quickly hydrolyzed cellulose fibers within 5 min at 80 °C, inducing a rapid decrease in the DP from 922 to 196, and the water-insoluble solid (WIS) retention reached 80.1%. CNCs were successfully produced from the mechanical disintegration of the WIS with a low energy input. Hence, the yield of CNCs is consistent with that of the WIS. Interestingly, the CNCs exhibited typical cellulose II crystallites, which were significantly different from those of the cellulose feedstock (cellulose I). Detailed characterization revealed that the CNCs had tunable number-averaged heights of 10.4–26.9 nm and high thermal stability (a maximal weight loss temperature of 327 °C). Most notably, FeCl3·6H2O was easily recycled from the hydrolysate after hydrolysis, with a high recovery of 94.0–94.5 wt %, using simple concentration and crystallization technologies. Thus, this study proposes a novel production technology for CNCs that is both economical and eco-friendly, providing new ideas for clean and large-scale production of CNCs.

Hydrometallurgical recovery of silver and gold from waste printed circuit boards and treatment of the wastewater in a biofilm reactor: An integrated pilot application

A hydrometallurgical process for the recovery of gold and silver from waste printed circuit boards (PCBs) was experimentally verified and tested at pilot scale. The process comprises four sequential leaching stages; the first two based on HCl, correspond to base metals (e.g. Sn, Cu) removal, while the third is based on HNO3 for Ag leaching and the final on aqua regia for Au leaching. After base metals leaching, the solid residue, enriched in silver and gold about 5 times, contained silver almost quantitively as insoluble AgCl and significant losses (Ag loss <8%) were avoided. The necessary reduction of Ag in the solid phase was achieved with a solution of 0.5 M N2H4 and 3 M NaOH, at 80 °C and S/L ratio 10%. Leaching of silver by 4 M HNO3 was followed by its recovery from nitrate solution by 0.08 Μ N2H4 at ambient temperature with an efficiency of 83%. Gold was leached by aqua regia and quantitively recovered by 0.13 M N2H4 at ambient temperature. Wastewater resulting from the process, rich in nitrate (5 g/L) and chloride (50 g/L), was treated by an effective and novel biological denitrification system tolerating metals at ppm level, to comply with zero nitrate and residual metals discharge guidelines. The overall process requires low reagents and energy input and has zero discharge for liquid effluents. The scheme is appropriate to be applied at local small to medium industrial units, complying with decentralized circular economy principles for metal recovery from electronic waste.

Fast formation of a black inner α‐Al2O3 layer doped with CuO on Al–Cu–Li alloy by soft sparking PEO process

AbstractForming high‐temperature α‐Al2O3 phase under soft sparking is an intriguing phenomenon in plasma electrolytic oxidation (PEO) of Al alloys, which contradicts the low energy input of the process. In this study, α‐Al2O3 doped with black CuO is formed beneath an amorphous white outer layer on Al–Cu–Li alloy by PEO in a dilute silicate electrolyte under soft sparking. In comparison, reddish coatings with dominating γ‐Al2O3 are formed under the conventional plasma discharges, although blackish inner layer with α‐Al2O3 can also be exposed by heavily polishing the samples. In order to know the underlying mechanism, temperatures at the coating surface and the underlying substrate have been monitored by a thermocouple under the conventional and soft sparking PEO regimes, respectively. Interestingly, high temperatures are detected in the case of soft sparking rather than PEO with strong discharges. The formation of CuO, quartz, and cristobalite within the soft sparking coating also supports the existence of high temperature. Hence, the formation of α‐Al2O3 under soft sparking can be resolved to the conventional thermal activation mechanism, without the need of seeking other plausible explanations. Thermal condition evaluation for soft sparking PEO suggests that values of the effective thermal conductivity during PEO process for the outer layer and the barrier layer at the coating/substrate interface might be lower than ∼0.05 and ∼0.0017 W m−1 K−1, respectively. It is believed that the amorphous structure of the outer and barrier layers effectively blocks the heat dissipation, facilitating the formation of a highly wear‐resistant inner layer with α‐Al2O3, CuO, and the other high‐temperature species under soft sparking.

Graphene Nanopores Enhance Water Evaporation from Salt Solutions: Exploring the Effects of Ions and Concentration.

With increased water stress, the development of clean water technologies is an active area of research. Evaporation-based solutions offer the advantage of low energy consumption, and recently a 10-30 fold enhancement in water evaporation flux has been observed through Å-scale graphene nanopores (Lee, W.-C., et al., ACS Nano 2022, 16(9), 15382). Herein, using molecular dynamics simulations, we examine the suitability of Å-scale graphene nanopores in enhancing water evaporation from salt solutions (LiCl, NaCl, and KCl). Cation-π interactions between ions and the surface of nanoporous graphene are found to significantly influence ion populations in the nanopore vicinity, leading to varied water evaporation fluxes from different salt solutions. The highest water evaporation flux was observed for KCl solutions, followed by NaCl and LiCl solutions, with the differences reducing at lower concentrations. Relative to the bare liquid-vapor interface, 4.54 Å nanopores exhibit the highest evaporation flux enhancements ranging from 7 to 11, with an enhancement of 10.8 obtained for 0.6 M NaCl solution, which closely resembles seawater compositions. Functionalized nanopores induce short-lived water-water hydrogen bonds and reduce surface tension at the liquid-vapor interface, thereby lowering the free energy barrier for water evaporation with a negligible effect on the ion hydration dynamics. These findings can aid in developing green technologies for desalination and separation processes with low thermal energy input.

Removal of micropollutants and ecotoxicity during combined biological activated carbon and ozone (BO3) treatment

Ozonation is a viable option to improve the removal of micropollutants (MPs) in wastewater treatment plants (WWTPs). Nevertheless, the application of ozonation is hindered by its high energy requirements and by the uncertainties regarding the formation of toxic transformation products in the process. Energy requirements of ozonation can be reduced with a pre-ozone treatment, such as a biological activated carbon (BAC) filter, that removes part of the effluent organic matter before ozonation. This study investigated a combination of BAC filtration followed by ozonation (the BO3 process) to remove MPs at low ozone doses and low energy input, and focused on the formation of toxic organic and inorganic products during ozonation. Effluent from a WWTP was collected, spiked with MPs (approximately 1 µg/L) and treated with the BO3 process. Different flowrates (0.25–4 L/h) and specific ozone doses (0.2–0.6 g O3/g TOC) were tested and MPs, ecotoxicity and bromate were analyzed. For ecotoxicity assessment, three in vivo (daphnia, algae and bacteria) and six in vitro CALUX assays (Era, GR, PAH, P53, PR, andNrf2 CALUX) were used.Results show that the combination of BAC filtration and ozonation has higher MP removal and higher ecotoxicity removal than only BAC filtration and only ozonation. The in vivo assays show a low ecotoxicity in the initial WWTP effluent samples and no clear trend with increasing ozone doses, while most of the in vitro assays show a decrease in ecotoxicity with increasing ozone dose. This suggests that for the tested bioassays, feed water and ozone doses, the overall ecotoxicity of the formed transformation products during ozonation was lower than the overall ecotoxicity of the parent compounds. In the experiments with bromide spiking, relevant formation of bromate was observed above specific ozone doses of approximately 0.4 O3/g TOC and more bromate was formed for the samples with BAC pre-treatment. This indirectly indicates the effectivity of the pre-treatment in removing organic matter and making ozone more available to react with other compounds (such as MPs, but also bromide), but also underlines the importance of controlling the ozone dose to be below the threshold to avoid formation of bromate. It was concluded that treatment of the tested WWTP effluent in the BO3 process at a specific ozone dose of 0.2 g O3/g TOC, results in high MP removal at limited energy input while no increase in ecotoxicity, nor formation of bromate was observed under this condition. This indicates that the hybrid BO3 process can be implemented to remove MPs and improve the ecological quality of this WWTP effluent with a lower energy demand than conventional MP removal processes such as standalone ozonation.

Field performance of switchgrass plants engineered for reduced recalcitrance.

Switchgrass (Panicum virgatum L.) is a promising perennial bioenergy crop that achieves high yields with relatively low nutrient and energy inputs. Modification of cell wall composition for reduced recalcitrance can lower the costs of deconstructing biomass to fermentable sugars and other intermediates. We have engineered overexpression of OsAT10, encoding a rice BAHD acyltransferase and QsuB, encoding dehydroshikimate dehydratase from Corynebacterium glutamicum, to enhance saccharification efficiency in switchgrass. These engineering strategies demonstrated low lignin content, low ferulic acid esters, and increased saccharification yield during greenhouse studies in switchgrass and other plant species. In this work, transgenic switchgrass plants overexpressing either OsAT10 or QsuB were tested in the field in Davis, California, USA for three growing seasons. No significant differences in the content of lignin and cell wall-bound p-coumaric acid or ferulic acid were detected in transgenic OsAT10 lines compared with the untransformed Alamo control variety. However, the transgenic overexpressing QsuB lines had increased biomass yield and slightly increased biomass saccharification properties compared to the control plants. This work demonstrates good performance of engineered plants in the field, and also shows that the cell wall changes in the greenhouse were not replicated in the field, emphasizing the need to validate engineered plants under relevant field conditions.

Algae-based green AgNPs, AuNPs, and FeNPs as potential nanoremediators

Abstract This review addresses green algae-based gold (Au), iron (Fe), and silver (Ag) nanoparticles (NPs) as eco-friendly nanomaterials to deal with biological, organic, and inorganic environmental contaminants. Among nanotechnological tools that can fully degrade, adsorb, and/or convert pollutants into less harmful structures, AgNPs, AuNPs, and FeNPs deserve highlight for their efficiency and low cost. However, green protocols are preferable to produce them in an eco-friendly manner. Although phycosynthesis is still in its infancy, algae present various advantages as green raw materials to NPs’ synthesis; fast growth rate, low-energy input requirement, low costs, easy and eco-friendly cultivation, and high tolerance to metals are examples. To allow their large-scale application, however, challenges regarding obtaining sufficient biomaterial with good reproducibility, designing protocols to achieve desirable features on NPs, and recovering the biocompatible nanomaterial after use still need attention. Perspectives for the field involve surpassing these limitations, broadening knowledge on synthesis mechanisms, protocols, and new species useful to offer, in the future, commercial eco-friendly, and low-cost phycosynthesized AuNPs, AgNPs, and FeNPs to nanoremediation. The potential of these NPs to deal with environmental contaminants, their advantageous characteristics and biocompatibility, the main limitations associated with their large-scale application, and future prospects for the field will receive attention.

Rapid method for determination of biogas composition by gas chromatography coupled to a thermal conductivity detector (GC-TCD)

ABSTRACT The search for alternative fuel sources to replace non-renewable energy is a highly relevant topic in current research studies. Both biomethane and biohydrogen can be obtained from several anaerobic biological processes, which have some advantages over traditional energy supply chains, especially due to the ability to use various wastes and/or wastewaters as feedstock for the biogas production, which is considered a renewable fuel. These features combined with low energy inputs support the potential of these processes to play a key role in replacing fossil energy sources in the coming decades, as well as helping to avoid climate changes. Thus, it is essential to accurately determine the composition of the biogas generated in different biological processes, regardless of the application: from lab-scale studies to industrial plants. In this work, a gas chromatography set consisting of a Shimadzu/TCD GC-2030 equipped with a Supelco Carboxen 1010PLOT column was used to determine hydrogen (H2), nitrogen (N2), methane (CH4) and dioxide carbon (CO2) by a low-cost manual injection procedure”. Two analytical curves (low and high ranges) were obtained for each target, which enables analysing biogas containing low and high concentrations of the targets. The validation parameters evaluated, namely, [i] linearity, working range, linear working range and sensitivity; [ii] limit of detection (LOD); [iii] limit of quantification (LOQ); and [iv] precision, expressed through repeatability and intermediate precision attested the reliability of the method for numerous applications.

Metal-Organic Bichromophore Lowers the Upconversion Excitation Power Threshold and Promotes UV Photoreactions.

Sensitized triplet-triplet annihilation upconversion is a promising strategy to use visible light for chemical reactions requiring the energy input of UV photons. This strategy avoids unsafe ultraviolet light sources and can mitigate photo-damage and provide access to reactions, for which filter effects hamper direct UV excitation. Here, we report a new approach to make blue-to-UV upconversion more amenable to photochemical applications. The tethering of a naphthalene unit to a cyclometalated iridium(III) complex yields a bichromophore with a high triplet energy (2.68 eV) and a naphthalene-based triplet reservoir featuring a lifetime of 72.1 μs, roughly a factor of 20 longer than the photoactive excited state of the parent iridium(III) complex. In combination with three different annihilators, consistently lower thresholds for the blue-to-UV upconversion to crossover from a quadratic into a linear excitation power dependence regime were observed with the bichromophore compared to the parent iridium(III) complex. The upconversion system composed of the bichromophore and the 2,5-diphenyloxazole annihilator is sufficiently robust under long-term blue irradiation to continuously provide a high-energy singlet-excited state that can drive chemical reactions normally requiring UV light. Both photoredox and energy transfer catalyses were feasible using this concept, including the reductive N-O bond cleavage of Weinreb amides, a C-C coupling reaction based on reductive aryl debromination, and two Paternò-Büchi [2 + 2] cycloaddition reactions. Our work seems relevant in the context of developing new strategies for driving energetically demanding photochemistry with low-energy input light.

Cold-Adapted Proteases: An Efficient and Energy-Saving Biocatalyst.

The modern biotechnology industry has a demand for macromolecules that can function in extreme environments. One example is cold-adapted proteases, possessing advantages such as maintaining high catalytic efficiency at low temperature and low energy input during production and inactivation. Meanwhile, cold-adapted proteases are characterised by sustainability, environmental protection, and energy conservation; therefore, they hold significant economic and ecological value regarding resource utilisation and the global biogeochemical cycle. Recently, the development and application of cold-adapted proteases have gained gaining increasing attention; however, their applications potential has not yet been fully developed, which has seriously restricted the promotion and application of cold-adapted proteases in the industry. This article introduces the source, related enzymology characteristics, cold resistance mechanism, and the structure-function relationship of cold-adapted proteases in detail. This is in addition to discussing related biotechnologies to improve stability, emphasise application potential in clinical medical research, and the constraints of the further developing of cold-adapted proteases. This article provides a reference for future research and the development of cold-adapted proteases.

Assessment of Energy–Economy and Environmental Performance of Perennial Crops in Terms of Biogas Production

Biogas production plays an important role in the clean energy economy and is reducing the problems of the energy crisis. The main objective of the current study is to analyze environmental performance by using perennial energy crops in the agricultural sector. Perennial energy crops are neutral for carbon and can be used for electricity and heating, which may mitigate climate change as well. The purpose of this work was to investigate and compare the energy–economy effectiveness and environmental performance of the suitability of four perennial crops for biogas production. Environmental performance was analyzed using the method of the life cycle assessment. To identify the most environmentally sustainable perennial crops for biogas production, a comparative analysis was conducted on four different crops: Lucerne, Miscanthus, Switchgrass, and Reed canary grass. The results of the analysis showed that Lucerne and Miscanthus, during the first–sixth years period, have lower indirect energy input (from 15.2 to 3.2 GJ/ha and 15.6 to 3.2 GJ/ha) than Switchgrass (from 20.9 to 3.2 GJ/ha) and Reed canary grass (from 16.7 to 3.2 GJ/ha). However, the highest direct energy input was determined by Lucerne (from 15.7 to 1.6 GJ/ha), and Miscanthus (from 11.9 to 0.9 GJ/ha) compared to Switchgrass (from 7.4 to 1.8 GJ/ha) and Reed canary grass (from 8.1 to 1.6 GJ/ha). Additionally, the lowest result of the direct economy and indirect economy costs was determined by Lucerne (from 3.9 to 3.7 kEUR/ha (direct) and 9.9 to 2.1 kEUR/ha (indirect)) and by Miscanthus (from 2.4 to 4.9 kEUR/ha (direct) and 11.8 to 1.9 kEUR/ha (indirect)) compared to Switchgrass (5.9 to 5.7 kEUR/ha (direct) and 17.5 to 2.1 kEUR/ha (indirect)), and reed canary grass (from 5.3 to 4.9 kEUR/ha (direct) and 13.7 to 1.9 kEUR/ha (indirect), respectively. The assessment of environmental performance revealed that Reed canary grass and Miscanthus had a more pronounced impact on Acidification. In contrast, Lucerne and Switchgrass had a more significant impact on Eutrophication indicators. The crop cultivation of four perennial crops impacted the environment in various significant ways. Despite the varying environmental impacts of the four perennial crops, the analysis revealed that all of them have the potential to increase biogas production.