In this growing age of clean energy and the use of power storage to circumvent the use of traditional fossil fuel technologies, batteries of greater capacity, storage, and power are increasingly ...becoming indispensable. New chemistries are being developed to increase the capacity of traditional lithium ion batteries and to develop batteries beyond Lithium ion. Promising high capacity cathodes and anodes are developed however their large-scale deployment is hindered due to safety concerns. In this review, we summarize recent progress of lithium ion batteries safety, highlight current challenges, and outline the most advanced safety features that may be incorporated to improve battery safety for both lithium ion and batteries beyond lithium ion. Of particular interest is the issue of thermal runaway mitigation by incorporation of novel nano-materials and advanced technologies.
Energy security has become a serious global issue and a lot of research is being carried out to look for economocially viable and environment-friendly alternatives. The only solution that appears to ...to meet the futuristic needs is the use of renewable energy. Although various forms of renewable energy are being currently used, the prospects of producing carbon-neutral biofuels from microalgae appears bright because of its unique features such as suitability of growing in open ponds required for production of a commodity product, high CO2-sequestering capability, ability to grow in wastewater/seawater/brackishwater and high lipid productivity. The major process constraint in the microalgal biofuel technology is the cost-effective and efficient extraction of lipids. The objective of this article is to provide a comprehensive review on various methods of lipid extraction from microalgae available till date, as well as to discuss their advantages and disadvantages. The article covers all areas of lipid extraction procedures including solvent extraction procedures, mechanical approaches and solvent-free procedures apart from some of the latest extraction technologies. A lot more research efforts are required in this area for successful implementation of this technology at a production scale.
The microalgal biotechnology industry is expanding rapidly and currently gaining attention due to multiple availabilities of high-value products such as pigments, carbohydrates, proteins, ...nutraceuticals, biopharmaceuticals, and unique oleaginous compounds fractionated by biomass biorefinery. Microalgae are efficient primary producers in the terrestrial and marine biotopes. They are major sources of global oxygen and are gaining topical prominence due to their concomitant role in the phycoremediation of wastewater effluents and biomass production. Despite their minuscule size, microalgae critically contribute to climate change mitigation through carbon fixation and play a major role in bioenergy applications. Furthermore, carotenoids and phycobiliproteins are the main accessory light-harvesting complexes in microalgae and cyanobacteria. The topical biomedical and pharmaceutical applications of microalgae include anticancer, antidiabetic, antiHIV, antimalarial, antimicrobial,
inter alia
. The endowment of unique indigenous microalgae and utilization of these biological resources must be harnessed by the biorefinery industry to exploit microalgal biomass opportunities. Therefore, this manuscript factually and critically explores the current status of the biorefinery approach, topical biomedical and pharmaceutical applications, biofuel applications, genetic manipulation of microalgae for enhancement of product yield, challenges and presents prospects, pros and cons, and outlook of the microalgal biotechnology industry.
Identification and mitigation of challenges associated with membrane distillation (MD) modeling are very crucial to the applicability of MD technology in the industry. Several research studies have ...been carried out on direct contact membrane distillation (DCMD) modeling because of its simplicity, while other MD configurations have gained little attention. Most studies conducted on MD modeling were achieved based on uniform membrane pore size and pore size distribution assumption. This study exploits the homogeneity of these assumptions to conduct a modeling review for temperature polarization (TP) and concentration polarization (CP), as they apply to MD configurations. TP and CP phenomena have been identified as two of the main challenges to advance MD modeling for further development of MD technology. Their impact are detailed in the heat and mass transfer mechanisms discussed. Thermal conductivity of common hydrophobic commercial membrane materials at different temperatures are presented in this study. The use of optimal operating flow rates, suitable membranes, and proper module design are recommended as viable solutions to reduce the effect of TP and CP on permeate flux decay.
Thermal runaway is one of the key failure reasons for the lithium-ion batteries. The potential of thermal runaway in applications increases when the industry starts to use high energy LiNixCoyMnzO2 ...cathode. The thermal runaway mechanism is still unclear, because the side reactions are complex. Heat generation during thermal runaway can be caused by the decomposition of individual cell components, or by interactive reactions between multiple components. This paper tries to comb the heat sources during thermal runaway using a novel method named the “Time Sequence Map” (TSM). The TSM tracks the heat sources according to the notion of thermodynamic systems. The thermodynamic system means a combination of materials that stay and react together, and generate heat independently without interruptions from other thermodynamic systems. With the help of the defined thermodynamic systems, researchers will be rescued from being trapped in the complex reactions, and the heat sources during thermal runaway can be clearly explained from bottom up. The thermal runaway results for two battery samples demonstrate the validity of the TSM. The TSM shows the heat sources including that: (1) fire, (2) internal short circuit, (3) oxidation-reduction reaction between the cathode and anode, etc. The contributions for the heat sources to the thermal runaway are further discussed. Conclusions come to: (1) the major heat source is the oxidation-reduction reaction; (2) the fire releases lots of heat, but most of the heat is not to heat the cell itself; (3) the internal short circuit is critical to trigger the oxidation-reduction reaction; (4) the internal short circuit is not the major heat source that heat the cell to 800°C or higher; (5) the oxidation-reduction reaction is triggered when the temperature reaches a critical temperature. The TSM helps depict the frontiers in the researches of battery thermal runaway. It suggests that we focus on: (1) the relationship between internal short circuit and thermal runaway; (2) the mechanism of the oxidation-reduction reaction between the cathode and anode; (3) the detailed reaction mechanisms for a specific thermodynamic system within the cell.
Carbon-Dots (C-Dots) have drawn much attention in recent years owing to their remarkable properties such as high biocompatibility, low toxicity, nano-scale size, and ease of modification with good ...tuneable photoluminescence performance. These unique properties have led C-Dots to become a promising platform for bioimaging, metal ion sensing and an antibacterial agent. C-Dots can be prepared using the top-down and bottom-up approaches, in which the latter method is commonly used for large scale and low-cost synthesis. C-Dots can be synthesized using sustainable raw materials or green biomass since it is environmentally friendly, in-expensive and most importantly, promotes the minimization of waste production. However, using biomass waste to produce high-quality C-Dots is still a matter of concern waiting for resolution, and this will be the main focus of this review. Fundamental understanding of C-Dots such as structure analysis, physical and chemical properties of C-Dots, various synthesis methodology and type of raw materials used are also discussed and correlated comprehensively. Additionally, factors affecting the bandgap of the C-Dots and the strategies to overcome these shortcomings are also covered. Moreover, formation mechanism of C-Dots focusing on the hydrothermal method, option and challenges to scale up the C-Dots production are explored. It is expected that the great potential of producing C-Dots from agricultural waste a key benefit in view of their versatility in a wide range of applications.
This paper presents the energy security, energy poverty, and mediating role of environmental tax policy. The environmental tax policy affects energy consumption and energy poverty. The research ...applied multiple, comprehensive, and relevant sets of indicators to measure energy security, energy poverty, and environmental consideration of energy poverty through environmental tax. The study used a mathematical composite indicator and an econometric estimation to conduct an empirical estimation. The study used annual data from 1990 to 2018 and concluded that long-run associations between energy security, energy poverty, and environmental tax have been characterized by the linear and asymmetric association to specify hidden cointegration behavior among the trilemma. The results show how policymakers have clouded the decision to implement appropriate energy security to mitigate energy poverty in Vietnam through environmental tax.Results show that from 2001 to 2016 in Vietnam, energy security was low and energy poverty was high, but after 2016, it can be seen that there is a dramatic change in energy security and energy poverty. The year 2018 shows the highest energy security index score (0.92) and the lowest energy poverty index score (0.12). Since 2017, Vietnam’s rural electrification plan has provided electricity to 100% of Vietnam’s population. The plan provides electricity access to 82 million people who traditionally have no grid access.
Increasing pressure on farming systems due to rapid urbanization and population growth has severely affected soil health and fertility. The need to meet the growing food demands has also led to ...unsustainable farming practices with the intensive application of chemical fertilizers and pesticides, resulting in significant greenhouse gas emissions. Biochar, a multifunctional carbon material, is being actively explored globally for simultaneously addressing the concerns related to improving soil fertility and mitigating climate change. Reviews on biochar, however, mainly confined to lab-scale studies analyze biochar production and its characteristics, its effects on soil fertility, and carbon sequestration. The present review addresses this gap by focusing on biochar field trials to enhance the current understanding of its actual impact on the field, w.r.t. agriculture and climate change. The review presents an overview of the effects of biochar application as observed in field studies on soil health (soil’s physical, chemical, and biological properties), crop productivity, and its potential role in carbon sequestration. General trends from this review indicate that biochar application provides higher benefits in soil properties and crop yield in degraded tropical soils vis-a-vis the temperate regions. The results also reveal diverse observations in soil health properties and crop yields with biochar amendment as different studies consider different crops, biochar feedstocks, and local climatic and soil conditions. Furthermore, it has been observed that the effects of biochar application in lab-scale studies with controlled environments are not always distinctly witnessed in corresponding field-based studies and the effects are not always synchronous across different regions. Hence, there is a need for more data, especially from well-designed long-term field trials, to converge and validate the results on the effectiveness of biochar on diverse soil types and agro-climatic zones to improve crop productivity and mitigate climate change.
The non-renewable nature of fossil energy and the environmental pollution caused by its use, such as haze, make it very urgent to develop clean and efficient renewable energy. By using microalgae ...biomass as an alternative raw material energy sources like biohydrogen, methane can be produced through fermentation and photosynthesis. Unlike solar energy, which has the disadvantages of low energy density, instability and difficulty in storage, biohydrogen and biogas are one of the novel ideal energy sources at present. The utilization of microalgae has various attractive prospects in their production due to its cost-effectiveness, renewable biomass and ease of scaling-up technology. This paper discusses the latest microalgae biomass biohydrogen and biogas production technology including integrated biorefinery systems, co-production or mixed production techniques and puts forward the key problems to be solved in the development of microalgae biohydrogen production technology.
A commercial wave energy system will typically consist of many interacting wave energy converters installed in a park. The performance of the park depends on many parameters such as array layout and ...number of devices, and may be evaluated based on different measures such as energy absorption, electricity quality, or cost of the produced electricity. As wave energy is currently at the stage where several large-scale installations are being planned, optimizing the park performance is an active research area, with many important contributions in the past few years. Here, this research is reviewed, with a focus on identifying the current state of the art, analyzing how realistic, reliable, and relevant the methods and the results are, and outlining directions for future research.
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