Development of low-cost and high-efficiency solar modules based on perovskite solar cells for large-scale applications

Solar energy has emerged as a viable and competitive renewable resource due to its abundance and cost-effectiveness. To meet the global energy demands, there is a growing need for efficient devices with unique compositions. In this study, we designed and analyzed a perovskite solar cell (PSC) incorporating methylammonium tin iodide (CH3NH3SnI3) as the active optical absorber material, tin iodide (SnO2) as the electron transport layer (ETL), and copper thiocyanate (CuSCN) as the hole transport layer (HTL) using SCAPS-1D software for numerical investigations. Subsequently, the optimized outcomes were implemented in the PVSyst software package to derive the characteristics of a solar module based on the proposed novel solar cell composition. The objective of our research was to enhance the stability of solar cell for use in solar module. This was achieved by optimizing the thicknesses of the compositional layers which resulted in the enhancement of excess electron and hole mobilities and a reduction in defect densities, thereby leading to an improvement in the device performance. The optimization of excess electron and hole mobilities, as well as defect densities, was conducted to improve the device performance. SCAPS calculations indicated that the perovskite absorber layer (CH3NH3SnI3) may achieve the best possible performance with a maximum optimized thickness of 3.2 μm. The optimized thickness value for CuSCN-HTL and SnO2-ETL were found to be 0.07 μm and 0.05 μm respectively resulting in a maximum power conversion efficiency (PCE) of 23.57%. Variations in open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF %), and quantum efficiency (QE) associated with the optimized thickness values of all layers in the ITO/SnO2/CH3NH3SnI3/CuSCN/Mo composition were critically analyzed. The use of these input parameters resulted in power creation of 557.4 W for a module consisting of 72 cells with an annual performance ratio of 80.3%. These recent investigations are expected to be effective in the design and fabrication of eco-friendly and high-performance solar cells in terms of efficiency.

Methods for the Preparation of Silica and Its Nanoparticles from Different Natural Sources

Silica (SiO2), a component of the earth's crust, has been in use for many nanotechnological applications. This review presents one of the newest methods for safer, more affordable, and more ecologically friendly production of silica and its nanoparticles from the ashes of agricultural wastes. The production of SiO2 nanoparticles (SiO2NPs) from different agricultural wastes, including rice husk, rice straw, maize cobs, and bagasse, was systematically and critically discussed. The review also emphasizes current issues and possibilities linked with contemporary technology to raise awareness and stimulate scholars' insight. Furthermore, the processes involved in isolating silica from agricultural wastes were explored in this work.

Boundary of ecosystem services: Guiding future development and application of the ecosystem service concepts

Ecosystem Services (ESs) are either material or non-material benefits humans receive from ecosystems. Definitions, classifications, and typologies of ESs can vary to address different research and policy purposes. However, a boundary that distinguishes ESs from other ecosystem-related benefits (e.g., industrial products that consume raw materials, fossil fuels that used to be a part of ecosystems) is needed to avoid the risk of using ESs as an all-encompassing metaphor that captures any benefit. The boundary also maintains a common ground for communication and comparison of ESs across studies. To guide future development and application of the ES concepts, we suggest five criteria. ESs are (1) primary contributions of ecosystems, (2) flows assessed during a period or per time unit (not stock existing at a time point), (3) renewable (having the potential to be reproduced with a conceivable timeframe relevant to human use), (4) affected by biotic parts of ecosystems to occur. ESs include both biotic and some abiotic flows (e.g., water provisioning) but exclude abiotic flows (e.g., wind and solar energy) whose occurrence is unaffected by ecosystem functions, processes, or characteristics; and (5) inclusive to the benefits humans actually and potentially receive from ecosystems. These criteria link ESs with conservation of life-supporting and culturally important ecosystems, recognize use, option, and non-use values of ESs, and highlight ESs' sustainability.

The roles of renewable energy, globalization, population expansion and deliberative democracy on Sustainable Development in South Asia

South Asian region is extremely vulnerable to climate change which hampers its attainment of the sustainable development goals (SDGs). This study explores how sustainable development of South Asian nations is affected by the clean or renewable energy consumption, globalization, population growth and deliberative democracy. To tackle the effects of shocks within the cross-sectional units as well as to account for endogeneity, this study utilizes Common Correlated Effects Mean Group-Generalized Method of Moments (CCE-GMM) estimation technique proposed by Neal (2015). Common Correlated Effects Mean Group (CCE-MG) of Pesaran 2006 and Augmented Mean Group (AMG) by Eberhardt and Teal (2010) and Eberhardt and Bond (2009) techniques are also utilized as robustness checks. The empirical results reveal that the consumption of renewable or clean energy can significantly and positively affect sustainable development, implying that deploying clean energy technologies is helpful to achieve SDG agenda in South Asia. Population growth is found to be hampering sustainable development while deliberative democracy ensures this development. The impact of globalization on sustainable development was found to be negative yet insignificant. Bidirectional causal relationship was discovered between sustainable development and renewable energy, between population and sustainable development, between deliberative democracy and sustainable development and between deliberative democracy and globalization. Finally, the study provides policy directions to achieve sustainable development in South Asia via enhanced integration of renewable energy in the region's energy mix.

Powering environmental sustainability through renewable energy and natural resources: a Dynamic ARDL simulation approach

The objective of this study is to examine the role of renewable energy consumption and natural resource rents along with control variables of globalization and economic growth on the environmental sustainability of Jordanian economy from 1985 to 2019. These variables have been selected based on theory and empirical literature. We apply a Dynamic Autoregressive Distributed Lag (D-ARDL) technique along with robustness checks of Fully modified OLS (FMOLS), Dynamic OLS (DOLS), and Canonical Cointegrating Regression (CCR) techniques in order to achieve the above goal. The result from the analysis confirms that the environmental Kuznets curve (EKC) is not valid for the Jordan in either long or short term. Our estimation results also confirm the highly significant and negative impact of renewable energy on CO2 emissions in both the long and short term. However, both natural resource rents and globalization are significant and positive in the long run, implying that these variables are detrimental to the environmental quality. The interaction analysis presents detrimental effect of globalization in terms of renewable energy while it shows beneficial effect of globalization in terms of natural resource for environmental quality. The frequency domain causality result shows causality at different frequencies across the variables. Based on the results, several policy directions are provided in order to achieve environmental sustainability in Jordan.

Biodiesel potential of Cucumeropsis mannii (white melon) seed oil: A neglected and underutilized resource in Nigeria

A major challenge in the biodiesel industry is the availability of high-quality vegetable oil feedstocks. Thus, there is a continuous search for quality biodiesel feedstock whose production will trigger economic impact on the agricultural sector, minimize land degradation and without significant disruption to the food chain. In this work, we extracted and analysed oil from neglected and underutilized Cucumeropsis mannii seeds for their potential in biodiesel production. The oil content of C. mannii seed was 40.8 ± 0.56%. GC-MS analysis of the oil revealed the presence of 47.0% saturated fatty (predominantly palmitic acid, stearic acid) and 53.0% of unsaturated fatty acids (predominantly oleic, linoleic and erucic acids). The physicochemical properties were determined and values were as follows: iodine value (111.07 ± 0.15 g/100 g), saponification value (192.03 ± 0.37 mg/kg of oil), peroxide value (2.60 ± 0.10 meq/kg), acid value (4.20 ± 0.02 mgKOH/g) free fatty acid (2.51 ± 0.02%), relative density (0.93 ± 0.02), the refractive index at 28 °C (1.46 ± 0.04) and viscosity at 30 °C (3.00 ± 0.10 mm²/s). The fuel properties namely, cloud point, pour point, flash point and caloric value were determined and the values were 3.03 ± 0.11 °C, 1.00 ± 0.10 °C, 279.04 ± 0.99 °C and 31.10 ± 0.11 MJ/kg, respectively. In addition, the protein content of the defatted seed was found to be 47.4 ± 0.61 g/100 g. The defatted protein-rich cakes can be upgraded as a food additive; thus the C. mannii seed oil can serve as biodiesel feedstock without altering the food chain. These characteristics demonstrate the potential of C. mannii oil as a high-quality feedstock for biodiesel production. We envisage that its utilization as biodiesel feedstock will improve the market value of these seeds, thus supporting the economic development of local farmers in rural areas.

Revisiting the environmental impact of renewable energy, non-renewable energy, remittances, and economic growth: CO2 emissions versus ecological footprint for top remittance-receiving countries

The study examined the impact of renewable energy, non-renewable energy, remittances, and economic growth on environmental degradation from the perspective of carbon dioxide emissions (CO₂) and ecological footprint for the top 50 remittance-receiving countries for 1991-2018. This study simulates the environmental future for attaining the targets of Sustainable Development Goal 7 (SDG7) using the latest datasets. This study is one of the few that empirically explores how various explanatory variables affect CO₂ and ecological footprint. The study employed the pool mean group autoregressive distributive lag (PMG-ARDL), fully modified ordinary least squares (FMOLS), and dynamic ordinary least squares (DOLS) techniques for the analysis. In the long-run, non-renewable energy and economic growth have a positive impact, whereas renewable energy and remittances have a negative impact on CO₂ and ecological footprint. The impact of non-renewable energy on CO₂ and ecological footprint is more significant than renewable energy in both the short- and long-run. Most of the variables have a bidirectional causality among each other. This highlights the need for a paradigm shift towards renewable energy in the top recipients specifically for developing countries.

Biodegradable thermoset poly(lactic acid) resin containing phosphorus: Flame retardancy, mechanical properties and its soil degradation behavior

With the growing environmental awareness, poly(lactic acid) (PLA) is regarded as one of the most promising varieties of bio-based polyesters owing to its environment-friendly and biodegradable advantages. However, poor thermal stability and flammability disadvantages limit the applications of PLA. Herein, a series of biodegradable intrinsic flame-retardant thermoset PLA resins (DMMP-M4sPLA) were designed. DMMP-M4sPLA resins exhibit excellent flame retardancy, achieving UL 94 V-0 rating and limiting oxygen index (LOI) of 28.1 %-31.7 %. Meanwhile, the cured DMMP-M4sPLA resins show a high glass transition temperature and tensile strength. In addition, the resins demonstrate full degradation with no harmful degradation products. This work provides an advanced design strategy to create bio-based and biodegraded resins with superior flame retardant and mechanical performance, holding great potentials in the fields of aviation interior, automotive, etc.

Nexus between environmental vulnerability and agricultural productivity in BRICS: what are the roles of renewable energy, environmental policy stringency, and technology?

This study aims to examine the effect of carbon dioxide emission and air pollution on agricultural productivity while accounting for the effect of renewable energy use, ICT, technological innovation, environmental policy stringency, and democracy for Brazil, Russia, India, China, and South Africa (BRICS) during the period 1990-2019. Several econometric procedures including mean group estimates are employed. The result suggests that both carbon dioxide emission and air pollution negatively affect the productivity of the agricultural sector. The effects of renewable energy, ICT, technological innovation, and democracy are found to be increasing agricultural productivity. Environmental policy stringency coefficient confirms the porter hypothesis. The result from the causality test suggests that bidirectional causality exists between CO2, PM2.5, renewable energy, technological innovation, ICT, and agricultural productivity. Finally, the study provides several policy suggestions for the governments of the BRICS economies in order to increase agricultural productivity while tackling the environmental vulnerability.

Whole cell of pure Clostridium butyricum CBT-1 from anaerobic bioreactor effectively hydrolyzes agro-food waste into biohydrogen

Recycling organic waste and converting them into renewable energy are a promising route for environment protection and effective biochemical reactions suitable for industrial hydrogen synthesis. This study targeted to isolate a pure anaerobic culture with potential to hydrolyze different biomass and production of biohydrogen. For this, a sample of full-scale anaerobic digester, fed with a multicomponent solid, was inoculated on Reinforced Clostridial Medium (RCM) in strict anaerobic conditions. An anaerobic Clostridium butyricum CBT-1 strain was isolated, identified from morphological and 16S rRNA sequence. The CBT-1 culture expressed amylase, cellulase and peroxidases activities. The strain exhibited visual decolorization of both Azure B and crystal violet dyes. In batch fermentation experiment, the CBT-1 produced highest of 3.06, 2.67 and 2.46 mol/mol H₂ yield from glucose, starch and cellulose respectively, whereas, the CBT-1 showed low 0.43 mol H₂/mol of substrate from untreated rice straw due to lignin in compact structure and comparatively high H₂ yield of 1.91 and 2.01 mol H₂/mol of substrate rice straw hydrolysate and kitchen food waste (KFWS) respectively. The cumulative volumetric yield of H₂ was 358.15, 300.8 and 294.5NmL/gSub from glucose, starch and cellulose respectively. Similarly, the cumulative H₂ volume was 76.7, 184.4, 237.2 NmL/gVS from untreated rice straw, rice straw hydrolysate and kitchen food waste. This study emphasizes the prospects to find similar robust anaerobic culture for hydrolyzing complex biomass. Such strains could be used as standard co-inoculum for biohydrogen obtaining and as the biocatalyst for commercial scale applications.

Climate change analysis in energy-mix with non-carbon emission energy incorporated with pandemic society

The climate energy-mix is analyzed in the aspects of the pandemic as well as global warming where the nuclear and renewable energies are considered the cleaner powers. These factors of the pandemic, global warming, and energy-mix are able to be related to each other in the analysis. The simulations are performed by the modeling which has the quantifications of energy-mix study as mitigations, pandemic, and global-warming. Carbon neutrality is connected to global warming via energy-mix and mitigations. In the case of mitigations, energy-mix case oscillated much higher than the non-energy-mix case. In the case of global warming, the relative impact value is higher in the non-energy-mix case. So, global warming is mitigated when the energy-mix is performed. In figure, the 9.875th year has the biggest difference between the two cases when the energy-mix has the highest effect on the global warming aspect. After this pandemic, the leverage of carbon neutrality could be made.

Sustainable development of renewable energy integrated power sector: Trends, environmental impacts, and recent challenges

The continuous growth in overall energy demand and the related environmental impacts play a significant role in the large sustainable and green global energy transition. Moreover, the electrical power sector is a major source of carbon dioxide emissions. Therefore, renewable energy (RE) integration into the power grid has attracted significant economic, environmental, and technical attention in recent years. However, RE can also harm the environment, even though it is deemed less harmful than fossil fuel-based power. It may also cause technical, operational, and social issues. This, in return, more consideration and appropriate precautions should be taken. Given the recent sharp increase in RE utilization and its progressing impact on the world energy sector, evaluating its effect on the environment and sustainable development is limitedly explored and must be investigated. This study aims to discuss the role of RE integration in sustainable development. It provides an up-to-date review of the most recent global trend of various RE integrations into the power sector. The role and impact of this high integration level on the environment and the adverse effects of each RE source are discussed in detail. The recent challenges, including technical and operational challenges (i.e., voltage stability, frequency stability, and power quality), integration policy and standards challenges, RE environmental concerns, resource selection and location, and social challenges towards a sustainable electricity future and grid decarbonization, are comprehensively reviewed, discussed, and analyzed. A review of the literature was conducted from 2010 to 2021. Around 712 articles were classified during this process, and 177 papers were filtered for critical review. The literature analysis showed that RE integration has increased dramatically and has many benefits; however, more attention should be paid to mitigate its harmful impacts and recent challenges appeared. The new challenges resulting from the increasing generation of RE and linking it to the electric grid were listed to allow for future studies to find the appropriate solutions towards green and sustainable energy. Finally, towards a sustainable power system, the paper concludes with recommendations for future research directions.

CO2 behavior amidst the COVID-19 pandemic in the United Kingdom: The role of renewable and non-renewable energy development

The spread of the COVID-19 pandemic since the end of 2019 has forced an unprecedented lockdown worldwide, and environmental quality was significantly affected by the pandemic and its induced lockdown. The objective of this study is to examine the role of renewable energy, non-renewable energy and COVID-19 case on CO₂ emission in the context of United Kingdom. Several non-linear techniques such as Fourier ADL cointegration test, Non-Linear ARDL, Markov switching regression, and Breitung and Candelon (BC) causality test are employed to attain this objective. The result reveals that there is long run cointegration among the variables in this study. The results demonstrate that positive (negative) shift in renewable energy development decrease (increase) CO₂ emissions while positive (negative) shocks in fossil fuel energy increase CO₂ emissions. Moreover, negative (positive) variation in COVID case leads to a decrease (increase) in CO₂ emissions. Moreover, an uni-directional causal impact was found to run from all the variables - renewable energy, fossil fuel, and COVID-19 case to CO₂ emissions. Finally, several policy recommendations are provided.

The role of technological innovation and diffusion, energy consumption and financial development in affecting ecological footprint in BRICS: an empirical analysis

Economic activities, technological innovation and diffusion, energy consumption and financial development have been significant in BRICS countries over the last three decades. Corresponding to it, BRICS have been facing substantial environmental deterioration. The growth of such factors needs a comprehensive analysis. Hence, this paper examines the impact of technological innovation and diffusion, renewable and non-renewable energy consumption and financial development on ecological footprint under the Kuznets framework in BRICS countries over the time from 1990 to 2018. To confirm the long- and short-run relationship, we apply the second-generation and heterogeneity panel techniques. Where, to measure the impact of technological innovation and diffusion, energy consumption and financial development and other control variable on ecological footprint we use Westerlund Co-integration and pooled mean group (PMG) model for this interest. The results reveal that technological diffusion and non-renewable energy consumption deteriorate environmental quality in the long run. In contrast, renewable energy and technological innovation improve environmental sustainability/quality significantly. Further, results also confirm the existence of the EKC hypothesis. The study suggests that the government should encourage technological innovation and renewable energy consumption to improve environmental quality and achieve the sustainable development goal (SDG).

Waste-Derived Fuels and Renewable Chemicals for Bioeconomy Promotion: A Sustainable Approach

Bio-based fuels and chemicals through the biorefinery approach has gained significant interest as an alternative platform for the petroleum-derived processes as these biobased processes are noticed to have positive environmental and societal impacts. Decades of research was involved in understanding the diversity of microorganisms in different habitats that could synthesize various secondary metabolites that have functional potential as fuels, chemicals, nutraceuticals, food ingredients, and many more. Later, due to the substrate-related process economics, the diverse low-value, high-carbon feedstocks like lignocellulosic biomass, industrial byproducts, and waste streams were investigated to have greater potential. Among them, municipal solid wastes can be used as the source of substrates for the production of commercially viable gaseous and liquid fuels, as well as short-chain fattyacids and carboxylic acids. In this work, technologies and processes demanding the production of value-added products were explained in detail to understand and inculcate the value of municipal solid wastes and the economy, and it can provide to the biorefinery aspect.

Synthesis of reusable and renewable microporous organic networks for the removal of halogenated contaminants

Microporous organic networks (MONs) have shown great potential in the removal of environmental contaminants. However, all studies have focused on the design and construction of novel and efficient adsorbents, and the recycling and reuse of adsorbates were disregarded. In this study, we report a feasible approach to synthesize renewable and reusable MONs by using target halogenated contaminants such as tetrabromobisphenol A (TBBPA), 2,3-dichlorophenol (2,3-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) as starting monomers. TBBPA, 2,3-DCP, and 2,4,6-TCP acted as hazardous contaminants and starting monomers for MONs, leading to the recycling of both adsorbents and adsorbates. The obtained TBBPA-MON, 2,3-DCP-MON, and 2,4,6-TCP-MON not only offered good reusability and large adsorption capacity for their elimination but also provided good adsorption for other phenolic contaminants relying on multiple interactions. Density functional theory calculation indicated the dominant role of π-π and hydrophobic interactions and the secondary role of hydrogen bonding interactions during the adsorption process. The used TBBPA-MON could be reused and the eluted TBBPA could be recycled and renewed for the construction of fresh MONs. This study provided a feasible approach to design and synthesize renewable MONs for environmental contaminants.

Electrical Reverse Shift: Sustainable CO2 Valorization for Industrial Scale

Utilization of CO 2 is a requirement for a sustainable production of carbon-based chemicals. Reverse water-gas-shift (RWGS) can valorize CO 2 by reaction with hydrogen to produce a synthesis gas compatible with existing industrial infrastructure. Fully electrified reverse water-gas-shift (eRWGS™) was achieved using integrated ohmic heating and a nickel type catalyst at industrially relevant conditions. Using a feed of H 2 :CO 2 in a ratio of 2.25 at 10 barg, utilizing high temperature operation at 1050°C allowed for production of a synthesis gas with a H 2 /CO ratio of 2.0 and no detectable methane, ideal for production of sustainable fuel by e.g. the Fischer-Tropsch synthesis. Facilitating RWGS through CH 4 as intermediate was found superior to the selective RWGS route, due to higher activity and suppression of carbon formation. The eRWGS™ catalyst is found to provide a preferential emissions free route for production of synthesis gas for any relevant H 2 /CO ratio, enabling production of sustainable carbon-based chemicals from CO 2 and renewable electricity with high hydrogen and carbon efficiency.

An evaluation of the causal effect between air pollution and renewable electricity production in Sweden: Accounting for the effects of COVID-19

The COVID-19 pandemic has made a significant disruption in the renewable industry, and the effects will last longer. In this context, understanding how and which specific renewable power got affected due to this crisis is of crucial importance. This study examines the nexus between COVID-19 and Sweden's renewable electricity production from three sources of energy such as nuclear, solar, and wind, where the data ranges from January 1, 2019, to February 17, 2021. Since this study compares the period before and during the pandemic event, the study uses Air Quality Index as a measure of COVID-19 induced event and thus study the linkage between air quality and electricity production from three types of renewable energy. To analyse the above issue, several advanced techniques such as Wavelet Power Spectrum, Wavelet Coherence, Partial and Multiple Wavelet Coherence have been applied. The findings from the Wavelet Coherence approach demonstrate that COVID-19 has disrupted the linkage between wind energy generation and air quality, while the disruption in the case of solar and nuclear electricity generation has been minimal. Moreover, solar energy generation and air pollution both negatively affect each other, implying the need to generate solar power as well as reduce the level of air pollution in Sweden. In light of the above findings, the study discusses possible policy actions the country can take to fulfil its renewable development goals.

Hybrid multi-criteria decision-making approach to select appropriate biomass resources for biofuel production

Biofuel generation from local biomass resources can significantly contribute to greenhouse gas mitigation and cleaner energy production. In this regard, a hybrid Multi-Criteria Decision-Making (MCDM) approach was employed to prioritize appropriate biomass resources for biofuel production. Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), Additive Ratio Assessment (ARAS), and Weighted Aggregates Sum Product Assessment (WASPAS) were the employed MCDM approaches. Subsequently, ranking aggregation methods, i.e., Borda, Copeland, and Rank Mean, were applied to integrate the rankings obtained from the MCDM approaches. Guilan province of Iran was selected as a case study based on its promising potential for biofuel production from first-, second-, and third-generation biofuel resources. Initially, through an in-depth review of the literature and the use of academic professors' expert opinions, ten criteria were selected as the evaluation indices of the study: 1) creating technical side jobs, 2) preserving non-renewable energy resources, 3) relative advantage of biofuel production, 4) complexity of biofuel production process, 5) cost of the biomass conversion process, 6) biomass reusability, 7) cost of biomass supply, 8) environmental impacts of biomass accumulation, 9) adaptability of the biofuel production process to the size of biomass production units and the attitude and knowledge of the producers, and 10) energy self-sufficiency of the biomass producer. Moreover, the 11 investigated potential sources of biofuel production were rice, peanut, livestock and poultry wastes, rice waste, peanut waste, tea residues and its processing wastes, olive residues and its processing wastes, livestock and poultry slaughter and farm-raised fish wastes, municipal solid waste and sewage, forest and wood farming wastes, algae and Azolla. The results indicated that "municipal solid wastes and sewage", "forest and wood farming wastes" and "livestock and poultry wastes" from the second-generation biofuels were identified as the most important biomass resources in the studied area.

Open source all-iron battery 2.0

In this work we present significant improvements to the open-source all-iron battery. We show higher power density and simpler fabrication. We also show a more reproducible procedure for preparing the electrolytes. The results are a highly rechargeable electrochemical cell based on iron, chloride, sulfate, and potassium ions in water at near-neutral pH. The cell is stable for thousands of cycles. It displays modest energy density consistent with the previous all-iron battery. The current is improved by a factor of 10 to a practical level of 500 mA/L and is able to deliver a maximal power of 250 mW/L. While this is modest performance compared to commercial rechargeable batteries, its low cost, simple synthesis, and safe manufacturing may make it suitable for storing renewable energy.

Potential applications of polycarbohydrates, lignin, proteins, polyacids, and other renewable materials for the formulation of green elastomers

Renewable resources including polycarbohydrates, lignin, proteins, and polyacids are the intrinsically valuable class of materials that are naturally available in great quantities. Their utilization as green additives and reinforcing bio-fillers, in substitution of environmentally perilous petroleum-based fillers, for developing high-performance green rubber blends and composites is presently a highly tempting option. Blending of these renewable materials with elastomers is not straight-forward and research needs to exploit the high functionality of carbohydrates and other natural materials as proper physicochemical interactions are essential. Correlating and understanding the structural properties of lignin, carbohydrates, polyacids, and other biopolymers, before their incorporation in elastomers, is a potential approach towards the development of green elastomers for value-added applications. Promising properties i.e., biodegradability, biocompatibility, morphological characteristics, high mechanical properties, thermal stability, sustainability, and various other characteristics along with recent advancements in the development of green elastomers are reviewed in this paper. Structures, viability, interactions, properties, and use of most common natural polycarbohydrates (chitosan and starch), lignin, and proteins (collagen and gelatin) for elastomer modification are extensively reviewed. Challenges in commercialization, applications, and future perspectives of green elastomers are also discussed. Sustainability analysis of green elastomers is accomplished to elaborate their cost-effectiveness and environmental friendliness.

Has COVID-19 lockdown impacted on aged care energy use and demand?

In late March to April 2020 residential aged care facilities (RAC) in Australia were under COVID-19 lockdown. This paper explores whether the resultant restrictions on entry and exit and elimination of site group activities within RACs impacted on the total electricity use, peak demand and electrical load profiles. Six RACs in four different climate zones are analysed, comparing historical electricity load and demand profiles with the lockdown period. The facilities in warm regions showed largest reductions in energy use and peak demands. There was a peak demand timing shift in temperate regions and hot regions' changes were negligible for energy use or peak demands. This study revealed the limitations of using aggregate data as the key performance indicator (KPI) - energy use per bed. Also, KPIs in relation to cooling degree days (or total cooling and heating degree days) have been examined and are not recommended for temperate regions or temperate seasons. The potential CO₂ emission reduction from onsite renewable generation is quantified. Further research is to investigate energy use changes at circuit levels under lockdowns, and develop more nuanced KPIs that include the rate of energy use and the timing of that use.

Platinum and zinc oxide modified carbon nitride electrode as non-enzymatic highly selective and reusable electrochemical diabetic sensor in human blood

Development of non-enzymatic glucose sensor is essential to reduce the cost of diabetes regular monitoring. Here, graphitic carbon nitride (g-C₃N₄) is modified with platinum and zinc oxide for non-enzymatic electrochemical glucose sensing in physiological conditions for the first time in the literature. The interactions between Pt, g-C₃N₄ and the ZnO are studied using different physicochemical characterization techniques. The Electrochemical glucose sensing at the ZnO-Pt-gC₃N₄ occurs at low applied potential of +0.20 V (vs. Ag/AgCl) with high sensitivity 3.34 μA/mM/cm² and fast response (5 s) time. This sensor exhibited a wide linear range 0.25-110 mM with lower limit of detection of 0.1 µM. The architectured sensor was evaluated in human blood, serum and urine samples. The sensor is 4 time reusable in whole blood without activity deterioration. This reusable surface helps to reduce the cost of strip.

Towards sustainable biodiesel and chemical production: Multifunctional use of heterogeneous catalyst from littered Tectona grandis leaves

Waste biomass derived heterogeneous catalyst is an excellent alternative to chemically synthesized catalysts. In this work, calcined Tectona grandis leaves were proposed as an eco-friendly, renewable and low cost heterogeneous base catalyst. The prepared catalyst was examined by FTIR, XRD, XPS, SEM, EDX, TEM, TGA, BET and Hammett indicator test. The catalyst has an appealing nature towards various chemical transformations due to its basic surface sites provided by alkali and alkaline earth metals. The efficiency of the catalyst was successfully investigated by its application in biodiesel production. The products were confirmed by ¹H and ¹³C NMR. 100% FAME conversion was attained using a catalyst loading of 2.5 wt% under optimized reaction parameters. The catalyst was further explored for Knoevenagel condensation reaction, in which it showed its effectiveness and recyclability towards the formation of benzylidenemalononitrile derivatives of aryl aldehydes. Thus, it is a potential 'green catalyst' derived from waste biomass without any addition of chemicals that can replace the industrial base catalysts used for biodiesel production and Knoevenagel reaction and makes the protocol environmentally benign.

The effect of medium and light wavelength towards Stichococcus bacillaris fatty acid production and composition

Introduction of novel species will highlight technical feasibility of microalgae-based biofuels for commercial applications. This paper reports the effect of culture medium and light wavelength on biomass and fatty acid production of S. bacillaris which holds some advantages as short life cycle, easy cultivation, high lipid content, diversity of fatty acids and stability under harsh environmental conditions. The results displayed that, soil extract (SE) greatly enhance growth rate of cultures. Maximum biomass and lipid productivity were achieved in TAP medium as 81 mg/L·day, 19.44 mg/L·day; respectively. Light wavelength didn't significantly change growth kinetics but played a critical role on chlorophyll-a accumulation. C14:0, C16:0 and C18:0 fatty acids were abundant which are suitable for biodiesel conversion. Interestingly, blue and red light increased longer chain fatty acids content. These results indicated that; S. bacillaris holds potential for further development of biodiesel production and feasibility of algal biodiesel for fundamental and applied sciences.

The Role of Sorghum in Renewables and Biofuels

Sorghum bicolor (L.) Moench is an important annual C₄ cereal crop with unique properties-it can be used in almost all renewable schemes being proposed for renewable fuels and green technologies. In the United States, the grain is currently used as a feedstock in the grain-ethanol process, while in China, the Philippines, and India, sweet sorghums are used in a sugar-to-ethanol process. High-tonnage biomass sorghums are being investigated for their potential use in both cellulosic and lignocellulosic renewables. Other countries have been exploring sorghum's use as a renewable building material and as a potential source of high-value C molecules for the creation of renewable oils and other important industrial chemicals. Sorghum can become a major player in the renewable feedstock industry because of its potential for high-yield production under limited water and inputs, strong research capacities, a well-established seed industry, and a robust history of research on production and cultural practices. The following review highlights various research activities in support of renewables using sorghum as a primary feedstock.

Pollutants from fish feeding recycled for microalgae production as sustainable, renewable and valuable products

Trash fish feeding of cage fish can result in marine pollution. Whole and chopped trash fish can leach pollutants such as ammonia, phosphate and protein into surrounding waters. Reduction of pollution can be achieved by recycling the wastewater generated from trash fish feeding for cultivation of microalgae. Microalgae are potent candidates for the production of renewable and sustainable products such as feed and food, health and pharmaceutical, cosmeceutical, industrial products, and biofuel. Two microalgae, Chlorella saccharophila and Nannochloropsis sp., have the potential to produce high amounts of polyunsaturated fatty acids. Furthermore, high oil content ranging from 10.7 to 13.6% is found in Chlorella saccharophila and up to 9.3% for Nannochloropsis sp. Moreover, these microalgae can also be utilized as a biofuel to give a mean calorific value of 5364 Cal/g which is higher than that of wood for Chlorella saccharophila and 6132 Cal/g which is equivalent to that of coal for Nannochloropsis sp. An alternative biofuel derived from microalgae is feasible due to the fact that they do not compete for arable land for cultivation and land crops for feed and food. This study discusses the synergistic coupling of microalgae mass production with wastewater treatment and carbon sequestration potential for mitigation of environmental impacts and a technically viable alternative energy resource. Additionally, the de-oiled biomass byproduct after oil extraction or its whole biomass can be converted into sustainable and renewal industrial products such as bioplastic, biopaint, bioasphalt, and biobuilding components.

Engineering Yarrowia lipolytica for the production of cyclopropanated fatty acids

Traditional synthesis of biodiesel competes with food sources and has limitations with storage, particularly due to limited oxidative stability. Microbial synthesis of lipids provides a platform to produce renewable fuel with improved properties from various renewable carbon sources. Specifically, biodiesel properties can be improved through the introduction of a cyclopropane ring in place of a double bond. In this study, we demonstrate the production of C19 cyclopropanated fatty acids in the oleaginous yeast Yarrowia lipolytica through the heterologous expression of the Escherichia coli cyclopropane fatty acid synthase. Ultimately, we establish a strain capable of 3.03 ± 0.26 g/L C19 cyclopropanated fatty acid production in bioreactor fermentation where this functionalized lipid comprises over 32% of the total lipid pool. This study provides a demonstration of the flexibility of lipid metabolism in Y. lipolytica to produce specialized fatty acids.

Use of wastewater treatment plant biogas for the operation of Solid Oxide Fuel Cells (SOFCs)

Solid Oxide Fuel Cells (SOFCs) perform well on light hydrocarbon fuels, and the use of biogas derived from the anaerobic digestion (AD) of municipal wastewater sludges could provide an opportunity for the CH₄ produced to be used as a renewable fuel. Greenhouse gas (GHG), NO_x, SO_x, and hydrocarbon pollutant emissions would also be reduced. In this study, SOFCs were operated on AD derived biogas. Initially, different H₂ dilutions were tested (N₂, Ar, CO₂) to examine the performance of tubular SOFCs. With inert gases as diluents, a decrease in cell performance was observed, however, the use of CO₂ led to a higher decrease in performance as it promoted the reverse water-gas shift (WGS) reaction, reducing the H₂ partial pressure in the gas mixture. A model was developed to predict system efficiency and GHG emissions. A higher electrical system efficiency was noted for a steam:carbon ratio of 2 compared to 1 due to the increased H₂ partial pressure in the reformate resulting from higher H₂O concentration. Reductions in GHG emissions were estimated at 2400 tonnes CO₂, 60 kg CH₄ and 18 kg N₂O. SOFCs were also tested using a simulated biogas reformate mixture (66.7% H₂, 16.1% CO, 16.5% CO₂, 0.7% N₂, humidified to 2.3 or 20 mol% H₂O). Higher humidification yielded better performance as the WGS reaction produced more H₂ with additional H₂O. It was concluded that AD-derived biogas, when cleaned to remove H₂S, Si compounds, halides and other contaminants, could be reformed to provide a clean, renewable fuel for SOFCs.

Impact of lignin structure on oil production via hydroprocessing with a copper-doped porous metal oxide catalyst

A copper-catalyzed depolymerization strategy was employed to investigate the impact of lignin structure on the distribution of hydroprocessing products. Specifically, lignin was extracted from beech wood and miscanthus grass. The extracted lignins, as well as a commercial lignin (P1000), were then fractionated using ethyl acetate to provide three different portions for each source of lignin [total of 9 fractions]. Each fraction was structurally characterized and treated with a copper-doped porous metal oxide (Cu-PMO) catalyst under 4MPa H₂ and at 180°C for 12h. The reaction conditions provided notable yields of oil for each fraction of lignin. Analysis of the oils indicated phenolic monomers of commercial interest. The structure of these monomers and the yield of monomer-containing oil was dependent on the origin of the lignin. Our results indicate that hydroprocessing with a Cu-PMO catalyst can selectively provide monomers of commercial interest by careful choice of lignin starting material.

Study on small molecular organic compounds pyrolysed from rubber seed oil and its sodium soap

Rubber seed oil (RSO) and its sodium soap were pyrolysed in a batch reactor to obtain low molar mass organic substances. The pyrolitic oil of RSO was redistilled and the distillates were characterized by GC-MS and FTIR. Density, acid value, saponification value and ester values were also measured according to the ASTM standard methods. A similar analysis was done for samples taken out at different time intervals from the reaction mixture. Industrially important low molar mass alkanes, alkenes, aromatics, cyclic compounds and carboxylic acids were identified in the pyrolysis process of rubber seed oil. However, pyrolysis of the sodium soap of rubber seed oil gave a mixture of hydrocarbons in the range of C14-C17 and hence it has more applications as a fuel.

Graphitic biochar as a cathode electrocatalyst support for microbial fuel cells

Graphitic biochar (BC) was generated using high temperature gasification and alkaline post-treatment (BCw) of wood-based biomass. The BCw was evaluated as a manganese oxide electrocatalytic support (MnO/BCw) and microbial fuel cell (MFC) air cathode. Nano-structured MnO2 crystals were successfully immobilized on biomass-based graphitic sheets and characterized using physical, chemical, and electrochemical analyses. Cyclic voltammetry of MnO/BCw/Nafion inks showed electrochemical features typical of β-MnO2 with a current density of 0.9 mA cm(-2). BC showed satisfactory maximum power densities of 146.7 mW m(-2) (BCw) and 187.8 W m(-2) (MnO/BCw), compared with Vulcan Carbon (VC) (156.8 mW m(-2)) and manganese oxide VC composites (MnO/VC) (606.1 mW m(-2)). These materials were also tested as oxygen reduction reaction (ORR) catalysts for single chamber MFCs inoculated with anaerobic sludge. Our results demonstrate that BC can serve as an effective, low cost, and scalable material for MFC application.

Super water-absorbing new material from chitosan, EDTA and urea

A new, super water-absorbing, material is synthesized by the reaction between chitosan, EDTA and urea and named as CHEDUR. CHEDUR is probably formed through the crosslinking of chitosan molecules (CH) with the EDTA-urea (EDUR) adduct that is formed during the reaction. CHEDUR as well as the other products formed in control reactions are characterized extensively. CHEDUR exhibits a very high water uptake capacity when compared with chitosan, chitosan-EDTA adduct, as well as a commercial diaper material. A systematic study was done to find the optimum composition as well as reaction conditions for maximum water absorbing capacity. CHEDUR can play a vital role in applications that demand the rapid absorption and slow release of water such as agriculture, as a three in one new material for the slow release of urea, water and other metal ions that can be attached through the EDTA component. The other potential advantage of CHEDUR is that it can be expected to degrade in soil based on its chitosan backbone. The new material with rapid and high water uptake could also find potential applications as biodegradable active ingredient of the diaper material.

Efficient conversion of solar energy to biomass and electricity

The Earth receives around 1000 W.m(-2) of power from the Sun and only a fraction of this light energy is able to be converted to biomass (chemical energy) via the process of photosynthesis. Out of all photosynthetic organisms, microalgae, due to their fast growth rates and their ability to grow on non-arable land using saline water, have been identified as potential source of raw material for chemical energy production. Electrical energy can also be produced from this same solar resource via the use of photovoltaic modules. In this work we propose a novel method of combining both of these energy production processes to make full utilisation of the solar spectrum and increase the productivity of light-limited microalgae systems. These two methods of energy production would appear to compete for use of the same energy resource (sunlight) to produce either chemical or electrical energy. However, some groups of microalgae (i.e. Chlorophyta) only require the blue and red portions of the spectrum whereas photovoltaic devices can absorb strongly over the full range of visible light. This suggests that a combination of the two energy production systems would allow for a full utilization of the solar spectrum allowing both the production of chemical and electrical energy from the one facility making efficient use of available land and solar energy. In this work we propose to introduce a filter above the algae culture to modify the spectrum of light received by the algae and redirect parts of the spectrum to generate electricity. The electrical energy generated by this approach can then be directed to running ancillary systems or producing extra illumination for the growth of microalgae. We have modelled an approach whereby the productivity of light-limited microalgae systems can be improved by at least 4% through using an LED array to increase the total amount of illumination on the microalgae culture.

Conversion of lignocellulosic biomass to green fuel oil over sodium based catalysts

Upgrading of biomass pyrolysis vapors over 20 wt.% Na2CO3/γ-Al2O3 catalyst was studied in a lab-scale fix-bed reactor at 500°C. Characterization of the catalyst using SEM and XRD has shown that sodium carbonate is well-dispersed on the support γ-Al2O3. TGA and (23)Na MAS NMR suggested the formation of new hydrated sodium phase, which is likely responsible for the high activity of the catalyst. Catalytic oil has much lower oxygen content (12.3 wt.%) compared to non-catalytic oil (42.1 wt.%). This comes together with a tremendous increase in the energy density (37 compared to 19 MJ kg(-1)). Decarboxylation of carboxylic acids was favoured on the catalyst, resulting to an oil almost neutral (TAN=3.8mg KOH/g oil and pH=6.5). However, the mentioned decarboxylation resulted in the formation of carbonyls, which correlates to low stability of the oil. Catalytic pyrolysis results in a bio-oil which resembles a fossil fuel oil in its properties.