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Anaerobic digestion (AD) from organic waste has gained worldwide attention because it offers significant environmental and economic benefits. It can reduce the local waste through recycling which will conserve resources, reduce greenhouse gas emissions, and build economic resilience in the face of an uncertain future for energy production and waste disposal. The productive use of local waste through recycling conserves resources by reducing landfill space, the whole of life impacts of landfilling, and post-closure maintenance of landfills. Turning waste into a renewable energy source will assist the decarbonisation of the economy by reducing harmful emissions and pollutants. Therefore, this mini-review aims to summarise key factors and present valuable evidence for an efficient AD process. It also presents the pros and cons of different AD process to convert organic waste along with the reactor technologies. Besides, this paper highlights the challenges and the future perspective of the AD process. However, it is highlighted that for an effective and efficient AD process, appropriate temperature, pH, a strong inoculum to substrate ratio, good mixing and small particle sizes are important factors. The selection of suitable AD process and reactor is important because not all types of processes and reactors are not effective for processing organic waste. This study is of great importance for ongoing work on renewable energy generation from waste and provides important knowledge of innovative waste processing. Finally, it is recommended that the government should increase their support towards the AD technology and consider the unutilized significant potential of gaseous biofuel production. [ABSTRACT FROM AUTHOR]

In this study, a novel fluidized-bed homogeneous granulation (FBHo-G) process was developed to recover lithium (Li) from industrial Li-impacted wastewater. Five important operational variables (i.e., temperatures, pH, [P]0/[Li]0 molar ratios, surface loadings, and up-flow velocities (Umf)) were selected to optimize the Li recovery (TR%) and granulation ratio (GR%) efficiencies of the process. The optimal operational conditions were determined as the following: a temperature of 75 °C, pH of 11.5, [P]0/[Li]0 of 0.5, surface loading of 2.5 kg/m2·h, and Umf of 35.7 m/h). The TR% and GR% at optimal condition could be as much as 90%. The material characterization of the recovery pellet products showed that they were highly crystallized Li3PO4 (purity ~88.2%). The pellets had a round shape and smooth surface with an average size of 0.65 mm, so could easily be stored and transported. The high purity enables them to be further directly reused as raw materials for a wide range of industrial applications (e.g., in the synthesis of cathode materials). Our calculation shows that the FBHo-G process could recover up to 0.1845 kg of lithium per cubic meter of Li-containing wastewater, at a recovery rate of ~90%. A brief technoeconomic analysis shows that FBHG process had economic viability, with an estimate production cost of USD 26/kg Li removed, while the potential gained profit for selling lithium phosphate pellets could be up to USD 48 per the same volume of wastewater and the net profit up to USD 22/m3 Li treated. In all, fluidized-bed homogeneous granulation, a seedless one-step recovery process, opens a promising pathway toward a green and sustainable recycling industry for the recovery and application of the resource-limited lithium element from nonconventional water sources. [ABSTRACT FROM AUTHOR]

Currently, microalgae-derived lutein is gaining attention for its potential applications in cosmeceutical, nutraceutical, pharmaceutical, and food industries. Lutein is of commercial interest for a broad variety of health benefits: antioxidant activity, skin health improvement, reducing age-related macular degeneration, and the treatment of cancer. Microalgae are the fastest-growing lutein source, have the highest content in nature, and are a promising sustainable alternative to the current commercial source, marigold flowers. Microalgal cultivation has added environmental benefits over plants with higher carbon sequestration, reduced water footprint, and no pesticide use. To date, no industrial facility exists for the production of lutein from microalgae. This review outlines the existing technologies for bioprocessing of lutein at pilot scale (cultivation, harvesting, extraction, and purification). In addition, lutein encapsulation, a seldom discussed area, is explored in depth. In view of this knowledge, lutein could be anticipated as the next successful sustainable product from microalgae obtained at industrial scale for the circular economy. [ABSTRACT FROM AUTHOR]

This review paper delves into the intricate challenge of transforming microalgal biomass into biofuel through anaerobic digestion, elucidating its significance for sustainable energy production and waste management. Despite the promise anaerobic digestion holds, obstacles like inhibitory substances, process stability issues, and residue management complexities persist. Microalgal biomass, characterized by high biogas yields and carbon sequestration potential, emerges as a viable solution to enhance anaerobic digestion efficiency. Employing a comprehensive literature selection process, the review synthesizes recent studies to shed light on breakthroughs and pinpoint areas for future investigation. Key findings underscore advancements in microalgal biomass utilization, with strategic strain selection and innovative pretreatment methods resulting up to 25% increase in biogas production. Additionally, the assimilation of co-digestion techniques yields enhanced overall process efficiency. Microalgal biomass demonstrates remarkable carbon sequestration capabilities, sequestering up to 60% of CO2 during the anaerobic digestion process. Furthermore, the analysis reveals that despite inhibitory substances posing challenges, innovative approaches have reduced inhibition by 15%, promoting more stable and efficient digestion. Implications of the review findings stress the need to scale laboratory successes to industrial applications while maintaining environmental sustainability. Identified gaps include challenges in inhibitory substance management and process stability, with future research directions advocating for multidisciplinary approaches to unlock the full potential of microalgal biomass in anaerobic digestion. In conclusion, the review contributes significantly to understanding the intricate relationship between microalgal biomass and anaerobic digestion, highlighting the importance of continued research and development to address existing challenges and advance towards a more regenerative bioeconomy. [ABSTRACT FROM AUTHOR]

Deep learning (DL) is revolutionizing evidence-based decision-making techniques that can be applied across various sectors. Specifically, it possesses the ability to utilize two or more levels of non-linear feature transformation of the given data via representation learning in order to overcome limitations posed by large datasets. As a multidisciplinary field that is still in its nascent phase, articles that survey DL architectures encompassing the full scope of the field are rather limited. Thus, this paper comprehensively reviews the state-of-art DL modelling techniques and provides insights into their advantages and challenges. It was found that many of the models exhibit a highly domain-specific efficiency and could be trained by two or more methods. However, training DL models can be very time-consuming, expensive, and requires huge samples for better accuracy. Since DL is also susceptible to deception and misclassification and tends to get stuck on local minima, improved optimization of parameters is required to create more robust models. Regardless, DL has already been leading to groundbreaking results in the healthcare, education, security, commercial, industrial, as well as government sectors. Some models, like the convolutional neural network (CNN), generative adversarial networks (GAN), recurrent neural network (RNN), recursive neural networks, and autoencoders, are frequently used, while the potential of other models remains widely unexplored. Pertinently, hybrid conventional DL architectures have the capacity to overcome the challenges experienced by conventional models. Considering that capsule architectures may dominate future DL models, this work aimed to compile information for stakeholders involved in the development and use of DL models in the contemporary world. [ABSTRACT FROM AUTHOR]

The goal of this review is to offer an all-encompassing evaluation of an integrated solar energy system within the framework of solar energy utilization. This holistic assessment encompasses photovoltaic technologies, solar thermal systems, and energy storage solutions, providing a comprehensive understanding of their interplay and significance. It emphasizes the importance of solar energy as a renewable resource and its role in addressing global energy demand and mitigating climate change. The review highlights the significance of advancements in various solar energy technologies, focusing on their environmental benefits, including greenhouse gas emissions reduction and air and water pollution mitigation. It explores the evolution of photovoltaic technologies, categorizing them into first-, second-, and third-generation photovoltaic cells, and discusses the applications of solar thermal systems such as water heaters, air heaters, and concentrators. The paper examines key advancements in energy storage solutions for solar energy, including battery-based systems, pumped hydro storage, thermal storage, and emerging technologies. It references recent published literature to present findings on energy payback time, carbon footprint, and performance metrics. Challenges to widespread adoption are discussed, including cost and economic viability, intermittency, environmental impacts, and grid integration. Strategies to overcome these challenges, such as cost reduction, policy support, energy storage integration, and sustainable practices, are presented based on published literature. By bridging gaps in existing literature, this comprehensive resource aims to equip researchers, policymakers, and industry professionals with insights into forging a sustainable and renewable energy future. [ABSTRACT FROM AUTHOR]

This study reviews recent developments, challenges, and the prospect of electronic waste (e-waste). Various aspects of e-waste, including collection, pre-treatment, and recycling, are discussed briefly. It is found that Europe is the leading collector of e-waste, followed by Asia, America, Oceania, and Africa. The monetary worth of e-waste raw materials is estimated to be $57.0 billion. However, only $10.0 billion worth of e-waste is recycled and recovered sustainably, offsetting 15.0 million tonnes (Mt) of CO2. The major challenges of e-waste treatment include collection, sorting and inhomogeneity of waste, low energy density, prevention of further waste, emission, and cost-effective recycling. Only 78 countries in the world now have e-waste related legislation. Such legislation is not effectively implemented in most regions. Developing countries like south-eastern Asia and Northern Africa have limited or no e-waste legislation. Therefore, country-specific standards and legislation, public awareness, effective implementation, and government incentives for developing cost-effective technologies are sought to manage e-waste, which will play an important role in the circular economy. [ABSTRACT FROM AUTHOR]

There is actually an intense research in ethanol dry reforming because bioethanol and carbon dioxide, a greenhouse gas, can be converted into syngas and, in turn, into chemicals and energy such as dihydrogen (H2). Here we review dry reforming of ethanol with focus on thermodynamics, catalysts and effect of operating conditions. Noble metal-based catalysts typically exhibit both ethanol and CO2 conversions above 85% in the range of 923‒1073 K, yet the high cost of precious metals has restrained their potential applications. H2 yield of 90% and above is achieved at 1073 K or above due to the endothermic nature of ethanol dry reforming. Improving catalytic performance and inhibiting coke formation may be achieved by using bimetallic catalysts and other types of metal oxides. [ABSTRACT FROM AUTHOR]

Microalgae are photosynthetic cell factories of global interest for fuels, food, feed, bioproducts, carbon sequestration, waste mitigation, and environmental remediation. Actually, microalgal monocultures are used for biomass production and pollutant removal, yet are limited by moderate production and contaminations. Here we review binary cultures of autotrophic microalgae with bacteria, yeast, fungi, and heterotrophic microalgae, with focus on growth, lipid accumulation, bioremediation, wastewater treatment, and cost-effective harvesting. We found that a controlled, symbiotic binary culture facilitates waste bioremediation and biomass harvesting, with 96% efficiency, and reduces cost by 20–30%. Noteworthy, in binary or polyculture systems, autotrophic microalgae often develop a symbiosis by exchanging nutrients and metabolites with heterotrophic microalgae, bacteria, yeast, fungi, which may help to achieve higher biomass production. [ABSTRACT FROM AUTHOR]

Globally, 150–170 billion cubic metres of gas are being flared annually from petroleum refineries, petrochemical industries and from landfills. In this paper, we critically review the flaring technology, the impact of flare gas on the environment, and recovery options. We also discuss flare gas challenges such as technical, structural, economic, and regulatory challenges. We found that ground flaring is preferred whenever the facility is situated in a highly populated area or close to an aviation zone. Gas flaring produces major pollutants including benzene, benzopyrene and toluene. The recovery of this gas should be intensified to minimise impacts. [ABSTRACT FROM AUTHOR]

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving and four variants of concern have been identified so far, including Alpha, Beta, Gamma and Delta variants. Here we review the indirect effect of preventive measures such as the implementation of lockdowns, mandatory face masks, and vaccination programs, to control the spread of the different variants of this infectious virus on the environment. We found that all these measures have a considerable environmental impact, notably on waste generation and air pollution. Waste generation is increased due to the implementation of all these preventive measures. While lockdowns decrease air pollution, unsustainable management of face mask waste and temperature-controlled supply chains of vaccination potentially increases air pollution. [ABSTRACT FROM AUTHOR]

Nanoparticles are the magic bullets and at the leading edge in the field of nanotechnology, and their unique properties make these materials indispensable and superior in many areas, including the electronic field. Extensive applications of nanomaterials are incontrovertibly entering our living system. The increasing use of nanomaterials into the ecosystem is one of the crucial environmental factors that human being is facing. Nanomaterials raise noticeable toxicological concerns; particularly their accumulation in plants and the resultant toxicity may affect the food chain. Here, we analyzed the characterization of nanomaterials, such as graphene, Al2O3, TiO2, and semi‐insulating or conducting nanoparticles. Quantitative evaluation of the nanomaterials was conducted and their commercialization aspects were discussed. Various characterization techniques, scanning electron microscopy, X‐ray diffraction, and ultraviolet rays were utilized to identify the morphology, phase, absorbance, and crystallinity. In addition, we analyzed the effects of nanomaterials on plants. The toxicity of nanoparticles has severe effects on loss of morphology of the plants. Potential mechanisms including physical and physiological effects were analyzed. In future studies, it is indispensable to assess widely accepted toxicity evaluation for safe production and use of nanomaterials. [ABSTRACT FROM AUTHOR]

Biogas production is rising in the context of fossil fuel decline and the future circular economy, yet raw biogas requires purification steps before use. Here, we review biogas upgrading using physical, chemical and biological methods such as water scrubbing, physical absorption, pressure swing adsorption, cryogenic separation, membrane separation, chemical scrubbing, chemoautotrophic methods, photosynthetic upgrading and desorption. We also discuss their techno-economic feasibility. We found that physical and chemical upgrading technologies are near-optimal, but still require high energy and resources. Biological methods are less explored despite their promising potential. High-pressure water scrubbing is more economic for small-sized plants, whereas potassium carbonate scrubbing provides the maximum net value for large-sized plants. [ABSTRACT FROM AUTHOR]

Increasing population and urbanization call for smarter cities where the cycles of matter and energy are optimized, notably in buildings which are actually a source of pollution consuming a lot of energy. The efficiency of building energy has been improved by modelling earth-air heat exchangers, yet selecting the suitable models is challenging. Here we review data-driven earth-air heat exchanger models used for buildings. We discuss issues brought about by assumptions, unmeasured disruptions, and uncertainties in numerical and experimental works. We found that high accuracy can be reached if sufficient data is available. Models are appropriate for real-time activity due to their structure simplicity, yet they display a poor generalization capacity. Model development is limited by the constrained parameters and the complex boundary conditions of the heat exchangers. [ABSTRACT FROM AUTHOR]

This study presents a 3‐dimensional (3D) network structure of cellulose scaffold (CS), which was in situ decorated with silver nanoparticles (AgNPs). The scaffold was then infiltrated with epoxy matrix and cured at elevated temperature to sinter the AgNPs; finally, highly thermoconductive epoxy composites (Ag@CS/epoxy) was obtained. The resultant Ag@CS20/epoxy composite reached a thermal conductivity of 2.52 W·m−1·K−1 at 2.2 vol% of filler loading, which shows an enhancement of over 11‐folds in the thermal conductivity compared to the neat epoxy. The superb electrical conductivity value of over 53,691 S·m−1 of the Ag@CS20/epoxy was achieved, which led to exceptional EMI SE values of 69.1 dB. Furthermore, surface temperatures during heating and cooling were also investigated to demonstrate the superior heat dissipating capacity of the Ag@CS/epoxy composite, which can be potentially put an application as thermal dissipating material in the next generation of electronics. [ABSTRACT FROM AUTHOR]

Biodiesel is an alternative to fossil fuels for diesel engines, yet actual biofuel properties need to be tuned to comply with fuel standards. In particular, fuel stability is required for efficiency and commercial use. Fuel stability varies with the nature and proportion of chemical functional groups of biodiesel. Optimum oxidation stability is required because degradation by oxidation gives products that compromise fuel properties and impair fuel quality and engine performance. For instance, oxidation induces the formation of short-chain corrosive acids and deposits. Here, we review techniques to improve the oxidation stability of biodiesel. For instance, stability is improved by additives such as antioxidants. Factors influencing oxidation stability include composition of fatty acids, acid content, peroxide content, iodine content, viscosity, insoluble impurities, external conditions, and storage material. Antioxidants reduce lipid peroxidation at the beginning of the chain reaction and increase the onset temperatures. [ABSTRACT FROM AUTHOR]

Turbulent flows play a major role in many fields of science and industry. Noticeable attention is seen on turbulent flows of suspending fibers because of the sensitivity of the electrical, thermal, and mechanical properties of the connecting fiber composites to the spatial configuration and orientation of fibers. The involvement of fibers in the turbulent flow greatly affects the turbulent energy. It is more influenced when the turbulent flow occurs in a rotating system. The effect of fibers on the turbulent energy in the rotating frame must therefore be investigated. For turbulent energy with fiber suspension, a mathematical model can be built in a rotating system that is very important to enhance the quality of industrial goods. This paper, therefore, develops a mathematical model for turbulent energy motion in a rotating frame with a fiber suspension. The model was formulated using the averaging procedure. The momentum equation for incompressible and viscous fluid turbulent flow was considered to develop the model. The turbulent energy motion of the fiber suspensions was presented in the rotating frame in second-order correlation tensors, W i , j , S i , j , L i , j , F i , j , G i , j , D i , j , Q i , j , and H i , j , where all the tensors are the function of time, distance, and space coordinates. [ABSTRACT FROM AUTHOR]

Microplastic pollution has emerged as a new environmental concern due to our reliance on plastic. Recent years have seen an upward trend in scholarly interest in the topic of microplastics carrying contaminants; however, the available review studies have largely focused on specific aspects of this issue, such as sorption, transport, and toxicological effects. Consequently, this review synthesizes the state-of-the-art knowledge on these topics by presenting key findings to guide better policy action toward microplastic management. Microplastics have been reported to absorb pollutants such as persistent organic pollutants, heavy metals, and antibiotics, leading to their bioaccumulation in marine and terrestrial ecosystems. Hydrophobic interactions are found to be the predominant sorption mechanism, especially for organic pollutants, although electrostatic forces, van der Waals forces, hydrogen bonding, and pi-pi interactions are also noteworthy. This review reveals that physicochemical properties of microplastics, such as size, structure, and functional groups, and environmental compartment properties, such as pH, temperature, and salinity, influence the sorption of pollutants by microplastic. It has been found that microplastics influence the growth and metabolism of organisms. Inadequate methods for collection and analysis of environmental samples, lack of replication of real-world settings in laboratories, and a lack of understanding of the sorption mechanism and toxicity of microplastics impede current microplastic research. Therefore, future research should focus on filling in these knowledge gaps. [Display omitted] • This review investigates MPs to guide better policy action toward MP management. • MPs absorb pollutants like persistent organic pollutants, heavy metals, and antibiotics. • Hydrophobic interactions are the primary sorption mechanism for organic pollutants. • MPs influence the growth and metabolism of organisms. • Innovative sampling and analytical methods are needed to identify MP sources. [ABSTRACT FROM AUTHOR]

Emerging contaminants (ECs) are increasingly recognized as threats to human health and ecosystems. This review evaluates advanced analytical methods, particularly mass spectrometry, for detecting ECs and understanding their toxicity, transformation pathways, and environmental distribution. Our findings underscore the reliability of current techniques and the potential of upcoming methods. The adverse effects of ECs on aquatic life necessitate both in vitro and in vivo toxicity assessments. Evaluating the distribution and degradation of ECs reveals that they undergo physical, chemical, and biological transformations. Remediation strategies such as advanced oxidation, adsorption, and membrane bioreactors effectively treat EC-contaminated waters, with combinations of these techniques showing the highest efficacy. To minimize the impact of ECs, a proactive approach involving monitoring, regulations, and public education is vital. Future research should prioritize the refining of detection methods and formulation of robust policies for EC management. [Display omitted] • Emerging contaminants (ECs) pose significant risks to aquatic ecosystems and human health. • Advanced analytical techniques are effective in detecting ECs in diverse environments. • A comprehensive strategy is most effective for remediating EC-contaminated water. • Future research must focus on detection, source control, monitoring, and public engagement. [ABSTRACT FROM AUTHOR]

Microalgae has received overwhelming attention worldwide as a sustainable source for energy generation. However, the production of biofuel from microalgae biomass consists of several steps, of which lipid extraction is the most important one. Because of the nature of feedstock, extraction needs special attention. Three different methods were studied to extract algal oil from two different algae variant, Chlorella sp. and Spirulina sp. The highest percentage oil yield was obtained by ultrasonication (9.4% for Chlorella sp., 6.6% for Spirulina sp.) followed by the Soxhlet and solvent extraction processes. Ultrasonication and Soxhlet extraction processes were further optimized to maximize oil extraction as solvent extraction was not effective in extracting lipid. For ultrasonication, an amplitude of 90% recorded the highest percentage yield of oil for Spirulina sp. and a 70% amplitude recorded the highest percentage yield of oil for Chlorella sp. On the other hand, for Soxhlet extraction, a combination of chloroform, hexane, and methanol at a 1:1:1 ratio resulted in the highest yield of algal oil. Afterward, the crude algae oil from the ultrasonication process was transesterified for 5 h using an immobilized lipase (Novozyme 435) at 40 °C to convert triglycerides into fatty acid methyl ester and glycerol. Thus, ultrasonic-assisted lipid extraction was successful in producing biodiesel from both the species. [ABSTRACT FROM AUTHOR]

The demands for eco-friendly bio-lubricants are growing due to the environmental concern and the rapid depletion of petroleum oil. This paper outlines the tribological evaluation of jatropha methyl ester (JME) based bio-lubricant by analyzing its anti-wear (AW) and extreme pressure (EP) characteristics. The AW and EP tests were conducted using a four-ball tribotester with standard test methods of ASTM D 4172 and ASTM D 2783, respectively. After each test, the wear scar diameter, flash temperature parameter, viscosity and viscosity index (VI) were measured. The SEM analysis characterized the surface structure of the worn surface. The properties of formulated bio-lubricants were compared with the commercial lubricant SAE 15W-40. Experimental results showed that under boundary lubrication, the bio-lubricants showed excellent tribological properties up to the initial seizure load (ISL). Over the ISL, the friction and wear were increased slightly as compared to the commercial lubricant. The final seizure load (FSL) found for the biolubricant (BL 10), and commercial lubricant was 220 kg. The biolubricant with 10 % JME (BL 10) was found to be the most favorable, which met standard ISO requirements except for pour point. [ABSTRACT FROM AUTHOR]

Abstract Household waste generation has become a serious environmental issue in recent years. However, some technologies are available to convert household domestic waste into energy. One of such techniques is the biogas generation using household waste. The biogas generation technique is not a new method of energy generation, but its production efficiency is questionable. Biogas yield from domestic waste are influenced by pH level, temperature, HRT and C/N ratio. Moisture and the temperature levels in the biogas generation systems are very critical to its production efficiency, especially this is highly affected in the colder weather condition. Solar assisted biogas plant may provide better production efficiency compared to the traditionally designed biogas plant. In this paper, the scopes and opportunities of solar assisted biogas generation are reviewed. Possible benefits and challenges associated with the solar assisted biogas generation are highlighted. [ABSTRACT FROM AUTHOR]

Abstract There are numerous different sorts of pre-treatment technique have been utilized with a few impediments regarding supportable natural administration in anaerobic assimilation for improvement of biogas generation. Albeit corrosive and salt pretreatment have a huge impact on the corruption of biomass, these techniques have some negative effects on the condition because of their perilous nature, while the enzymatic pre-treatment is more environmentally friendly. In this investigation is to streamline the biogas generation by enzymatic pre-treatment from Palm Oil Mill Effluent (POME) with assessing the improved biogas creation in a pilot scale bioreactor. It is to concentrate coordinate utilization of protein as enzymatic pre-treatment on POME to the improved generation of biogas. Proficiency of privately manufactured chemical with Up-flow Sludge Blanket (UASB) has not been researched in pilot scale previously. In this examination proficiency of COD expulsion and aggregate methane emanation is explored through pilot scale UASB bioreactor from POME through the application of enzyme and reviewed a study with the discussion. [ABSTRACT FROM AUTHOR]

Abstract The oil from waste coffee possesses the potential as a feedstock for biodiesel production. In this study, waste coffee grounds were collected from Turkey. Then the oil was extracted from waste coffee grounds using N-hexane. The two-step acid-base catalyst transesterification process was used to produce biodiesel as the acid value of the crude oil was found higher (15.4 mgKOH/g).This was followed by an investigation of some physical and chemical properties. It was found that the properties of waste coffee biodiesel fell within the limit of ASTM standards. So the studied physicochemical properties of the waste coffee biodiesel suggest that this fuel can be used as a fuel in diesel engines. [ABSTRACT FROM AUTHOR]

Abstract Presently, the crisis of energy has become a growing concern all over the world and a serious barrier for the developing nations. Conversely, the resources of fossil fuels are limited and depleting due to the exploration and higher production activities around the glove. The impact of fossil fuels exploration has become a serious threat for naturalism and creates environmental hazardous accidents. However, the demand for energy in Bangladesh is increasing day by day and fossil fuel reserves continue the countries demand almost only 50 years. So, it is the high time to utilize its natural biomass resources to fulfill energy demand. The climate condition and waste generation rate of Bangladesh is key factors for biomass energy production. Nowadays the Bangladeshi government has made an agenda "waste to electricity" thus the utilization of biomass resources has become a blessing for the static economic growth in the nation. Recently Bangladeshi government has made an extra effort for the commercialization and marketable of biomass energy engendering and production in the country. This paper explored the potential of biomass energy as a sustainable energy source and their future implementation challenges in Bangladesh. [ABSTRACT FROM AUTHOR]

Abstract Global energy demand has risen sharply over the years with developing countries recording the greatest share in this trend. Biomass as an energy resource is mostly available locally and can easily be converted into secondary energy without huge capital investments. Nowadays, Bangladesh shares a percentage of renewable energy only 3% of total energy ratio, Bangladesh has already taken a master plan in the renewable energy sector. Whereas installed electricity generation installed capacity of Bangladesh rapidly increased to 13265 MW with captive generation capacity which is insufficient for fulfilling the demand of electricity of the nations. One-third of the power production of Bangladesh depends on expensive imported fossil fuel energy resources and 65% of power generation depends on a natural gas reserve of the country, though one day the reserve of current gas will be diminished. Moreover, inadequate electricity production leads the country in a un-industrialization. The present and future crucial energy crisis situation adapted by installing renewable power into electricity production. The current renewable energy agenda of Bangladeshi government force the specialization of renewable energy generation budget by decreasing global pollution with saving movement of biomass, solar, hydro, wind, and tidal power sector. This paper presents the currents national energy scenario of Bangladesh. According to this, the greater potentiality of renewable energy resources is also reviewed and presented in this paper. [ABSTRACT FROM AUTHOR]

Abstract This paper studied the production of waste cooking biodiesel as an alternative fuel for diesel engine. The biodiesel was produced through conventional transesterification process using the base catalyst (KOH). A multi-cylinder diesel engine was used to evaluate the emission of 20% (B20) waste cooking biodiesel fuel at different engine speeds and full load condition. It was found that the characteristics of biodiesel are within the limit of specified standards (American Society for Testing and Materials, ASTM D6751) and comparable to diesel fuel. Engine emission results indicated that waste cooking biodiesel fuel sample reduces the average carbon monoxide (CO) and particulate matter (PM) emissions except nitrogen oxides (NO x) than diesel fuel. Finally, it can be concluded that 20% of waste cooking biodiesel can significantly contribute to lower the harmful emission of an unmodified stationary diesel engine to the environment. [ABSTRACT FROM AUTHOR]

Abstract Increasing global energy demand at a rate faster than the population growth has led the researcher to look for alternative fuel. Amongst the options, biodiesel is an environmentally sustainable substitute of diesel fuel being renewable, biodegradable and have similar properties of fossil diesel. Among the biodiesel sources, microalgae is a potential third generation biodiesel feedstock which can be produced throughout the year and its oil yield is higher than any other crops. This paper reviews recent development in microalgae biodiesel in terms of its oil extraction technics, challenges of oil extraction, production of biodiesel from microalgae oil and its fuel properties. Finally, the paper discusses the performance and combustion analysis of diesel engine fuelled with microalgae biodiesel. This paper provides a clear understanding of the potential use of microalgae biodiesel as an alternative source to fossil diesel for diesel engines. [ABSTRACT FROM AUTHOR]

• P and K recovery from actual swine wastewater was found to be feasible. • The maximum recoveries were 97.8% and 69.1% for P and K, respectively. • The recovered K-struvite pellets had low water content (5.5%) and high purity (71.8%). • FBHG recovery can yield a profit of 0.126USD/m3-swine wastewater. The last few decades have seen the critical role of global cattle industry in agricultural development. However, while giving prosperity and significant benefits to the countryside, the industry also produces wastewater streams, that cause eutrophication in water bodies. The streams, if treated effectively, could act as a valuable nonconventional water source to help address the global freshwater crisis. Moreover, resources recovered from these wastewater streams, e.g., potassium (K) and phosphorus (P), could be converted to valuable commodities such as fertilizers. We, therefore, propose to use a continuous K–struvite granulation process as an effective method for the treatment of swine wastewater (SW) and recovery of K–struvite. Results show that the P and K were efficiently removed and that wastewater-derived K–struvite is a promising green chemistry agent for a slow–release, reinforcing a promising pathway to global P and K conservation. The fluidized-bed homogeneous granulation (FBHG) has recently emerged as an advanced metal recovery technology with high efficiencies for several metals and low moisture products. Based on the principle of chemical precipitation, FBHG technology requires less chemicals while producing insignificant amounts of sludge, thereby alleviating burden on sludge management often encountered in conventional chemical precipitation and others. Herein, we investigate the potential use of FBHG technology for simultaneous recovering K and P while treating swine wastewater. The recovered products are in the form of K–struvite pellets having a studded quasi-spherical form with a rough surface and sharp spikes that resemble sea urchins. The pellets are almost free of heavy metals, which make them promising candidates for use as fertilizer without significant harm. We observed that the release of K was faster than that of P. The formation, size, morphology, purity, and crushing strength of the pellets greatly affected the up-flow velocity value condition. The FBHG could potentially be scaled up for more extensive nutrient recovery. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper examines the performance and emission characteristics of biodiesel produced from edible oil source (palm) and non-edible oil source (Jatropha) and compared that with fossil diesel fuel. Only 20% palm and 20% Jatropha biodiesel (described by PB20 and JB20 respectively) were examined because it has been suggested by the commercial company that up to 20% biodiesel can be used in a diesel engine without any engine modification. The physical and chemical properties of PB20 & JB20 are also presented and compared with diesel fuel (B0). The performance of these fuels and their emissions were measured in a multi-cylinder diesel engine at different engine speeds and at full load condition. The test results indicated that both PB20 and JB20 fuels produces slightly lower brake powers and higher brake specific fuel consumption compared to diesel fuel. Engine emission results indicated that the PB20 and JB20 fuel reduces the average emissions of carbon monoxide (CO) and hydrocarbons (HC). However, the PB20 and JB20 fuels slightly increases nitric oxides (NO) emissions compared to diesel fuel. Although PB20 have slightly better emission performance than JB20 biodiesel, JB20 biodiesel should be used in unmodified diesel engines to meet the global energy demand and to reduce emissions into the atmosphere because it does not create food versus fuel conflict. [ABSTRACT FROM AUTHOR]

Vehicles are the main sources for environmental pollution especially those associated with diesel engines. It causes a number of health diseases and harm to the ecosystem. It is very urgent to find alternative fuel for vehicles. Biofuel is an alternative for vehicles which have potential to reduce engine emissions and maintain the air quality better. In recent years, worldwide biofuel production and use raised drastically. Some developed countries have put their target and mandate to use biofuel. The aim of this review is to discuss the impact of biofuel on diesel engines emission. From this review it is found that biofuel significantly reduces engine emissions and it has potential to reduce more than 80% of GHG emission. Finally, biofuel can be a viable alternative to be used as a transportation fuel. [ABSTRACT FROM AUTHOR]

In this study, the oil extraction process from Australian native beauty leaf seed has been optimised in terms of seed preparation and cracking, seed kernel treatment, moisture content and oil extraction methods. Two methods: mechanical oil extraction using an electric powered screw press and chemical oil extraction using n-hexane as an oil solvent have been applied to extract oil from the seed kernel. Both whole and grated kernels have been used for mechanical oil extraction process. The study indicated that treatment of seed kernel has a significant impact on oil yields for both techniques. It has been observed that kernels prepared to 15% moisture content provided the highest oil yields for both extraction methods. Mechanical extraction using the screw press could produce oil from the prepared kernels at a low cost. In addition, it has been obtained that oil yields by using grated kernels were relatively higher than the whole kernels. However, oil extraction by using this technique is ineffective due to relatively lower oil yields compared to chemical extraction. On the other hand, chemical extraction was found to be a very effective method for oil extraction because of its consistence performance and high oil yield, but cost of production was relatively higher due to high cost of solvent. The outcomes of this study are expected to serve as the basis on which industrial scale oil extraction can be made from beauty leaf seed. [ABSTRACT FROM AUTHOR]

The aim of this paper is to study the physical and chemical properties of Moringa oleifera biodiesel and its blends of 10%-90% by volume with petro-diesel according to the American society for testing and materials (ASTM D6751) standards and European standards (EN 14214). It was found that when Moringa biodiesel is blended with diesel fuel, all its fuel properties such as kinematic viscosity (KV), density (D), calorific value (CV), flash point (FP), cloud point (CP), pour point (PP), and cold filter plugging point (CFPP). For example, B10 reduce the viscosity of B100 from 5.05 mm 2 /s to 3.54 mm 2 /s (1.4:1). Then developed empirical models of properties are show high regression value (R 2 ) between properties and MOME-diesel blend. It is believed that the results obtained and empirical model proposed in this study will help the researchers to predict the properties of biodiesel-diesel blend which are important parameters to design the fuel system of biodiesel engine. [ABSTRACT FROM AUTHOR]

Ever increasing drift of energy consumption due to growth of population, transportation and luxurious lifestyle has motivated researchers to carry out research on biofuel as a sustainable alternative fuel for diesel engine. Biofuel such as biodiesel and ethanol, produced from renewable feedstocks, are the most appropriate alternative of petroleum fuels. However, direct using of ethanol in diesel fuel face some technical problem especially in cold weather, due to low cetane number, lower flash point and poor solubility. Biodiesel can be blended with both ethanol and diesel fuel and biodiesel–alcohol–diesel blends can be used in diesel engines. The aim of this review paper is to discuss the effect of mixed blends of biodiesel alcohol and diesel on engine performance and emission parameters of a diesel engine. Most of the researchers reported that adding ethanol into biodiesel-diesel blend in diesel engines significantly reduce HC, PM, NOx and smoke emissions but slightly increase fuel consumption. The study concluded that biodiesel-diesel-ethanol blend can be used as a substitute of petro-diesel fuel to reduce dependency on fossil fuel as well as the exhaust emissions of the engine. [ABSTRACT FROM AUTHOR]

Transport fuel is one of the major concerns of the energy market. This fuel mainly comes from the processing of crude petroleum oil. The transport fuel processing industries, such as crude oil distillation plants, gas condensate fractionation plants, natural gas processing plants, etc., are one of the most energy- and emission-intensive sectors in the world. On the other hand, the handling and transportation of petroleum products like gasoline, kerosene, diesel, naphtha, octane and sprite, etc. also produce environmental pollution. This study reviewed energy and waste management by transport fuel processing industries in Bangladesh. Such industries are also known as petrochemical industries. They mainly produce gaseous pollutants such as process gas, waste gas, etc. and liquid pollutants such as produced water, waste oil and grease, etc. The gaseous pollutants are burnt in the flare system to save the environment. The liquid pollutants are more hazardous because of their higher salinity and corrosivity and higher amounts of grease. The literature on waste water management techniques, pollution abatement techniques and oil-water separator techniques is described. The waste water treatment techniques used in the case study industries are briefly discussed. Energy flows for both gaseous and liquid waste management are developed. Energy-saving and time frame measures which can be implemented are also outlined. The study found that the rational use of energy and proper environmental management are essential for achieving the energy and environmental sustainability of transport fuel process industries. [ABSTRACT FROM AUTHOR]

Abstract: As a promising alternative energy source, biofuel imparts a remarkable role for the sustainability and security in energy sector. Strategies, including policy recommendations have been set to put forward the development and implementation of biofuel by different countries. Recent exploitation of Asian biofuels policy is one step towards destination. These types of activity behind the biofuels would be the catalyst for the productiveness of policy set by individual territory like Malaysia, Thailand, Vietnam, etc. This is the high time to standardize, policy recommendation and implementation of biofuels taking into consideration on the feedstock, geographical location, and availability. Pertinent comparison with well-established ASTM and European standards are highly recommended. Sector wise (viz. transportation, industrial) bio fuel policy is now crucial as well. Factors, which would be taking into account, prior to recommend a policy includes feed-stocks available, biofuel infrastructure of the country, compatibility with present automotive materials and performance and emission behaviour. This study sought to explore the investigation of several policies with regards to biofuel and advocates some key factors which could be helpful for diminution of biofuels inferiorities. [Copyright &y& Elsevier]

Abstract: Alternative fuels have received much attention due to the depletion of world petroleum reserves and increased environmental concerns. Thus processed form of vegetable oil (Biodiesel) offers attractive alternative fuels to compression ignition engines. The present work investigates the engine performance parameters and emissions characteristics for direct injection diesel engine using coconut biodiesel blends without any engine modifications. A total of three fuel samples, such as DF (100% diesel fuel), CB5 (5% coconut biodiesel and 95% DF), and CB15 (15% CB and 85% DF) respectively are used. Engine performance test has been carried out at 100% load, keeping throttle 100% wide open with variable speeds of 1500 to 2400rpm at an interval of 100rpm. Whereas, engine emission tests have been carried out at 2200rpm at 100% and 80% throttle position. As results of investigations, there has been a decrease in torque and brake power, while increase in specific fuel consumption has been observed for biodiesel blended fuels over the entire speed range compared to net diesel fuel. In case of engine exhaust gas emissions, lower HC, CO and, higher CO2 and NOx emissions have been found for biodiesel blended fuels compared to diesel fuel. Moreover, reduction in sound level for both biodiesel blended fuels has been observed when compared to diesel fuel. Therefore, it can be concluded that CB5 and CB15 can be used in diesel engines without any engine modifications and have beneficial effects both in terms of emission reductions and alternative petroleum diesel fuel. [Copyright &y& Elsevier]

Abstract: The results of an experimental work carried out to evaluate the effect of palm oil methyl esters, also known as palm oil diesel (POD) and its emulsions as alternative fuel on unmodified indirect injection diesel engine''s wear and lube oil performance are presented in this paper. Half throttle engine with constant 2500 rpm setting was maintained throughout the wear debris and lube oil analysis such as for a period of twenty hours for each fuel system. The sample of lube oil was collected through a one - way valve connected to the crankcase sump at the interval of four hours. When the engine warmed up, first sample has collected immediately. The same conventional lubricating oil SAE 30 was used for each fuel system. To measure wear metal debris and lubricating oil additives depletion of used lubricating oil, Multi element oil analyzer (MOA) was used. To measure the viscosity of lub oil an ISL automatic houillon viscometer (ASTM D445) has been used. Very satisfactory results have been obtained by comparing the lub oil analysis results of Ordinary Diesel and Palm Oil Diesel and their emulsions with 10 percent water by volume. In crankcase oil samples, accumulation of wear metal debris was lower with Palm Oil Diesel and emulsified fuels compare to baseline Ordinary Diesel fuel. Both Ordinary Diesel and Palm Oil Diesel emulsions with 10 per cent water by volume showed promising trends for resisting wear. [Copyright &y& Elsevier]

Abstract: Among the alternative fuels the Bio diesel is one the most common and familiar to all. It''s biodegradable, environment friendly as well as suitable source, to meet the future energy crises. The main concern of this experimental analysis is to reach a tentative goal, how this fuel can be utilised with maximum effective way. To find this,an experiment data analysis of different parameter such as break power, break specific fuel consumption, emission characteristic(NOx, HC,CO. etc) and exhaust temperature, is done through bio diesel fuel and also compared with ordinary diesel which is also known as petro diesel. This investigation is carried out through eddy current dynamometer and load cell arrangement which is controlled by a computer in case of finding the break power and BSFC respectively. And the emission characteristics are observed using Bosch and Bacharach exhaust analyzers. And finally the result is compared with diesel engine which is run by ordinary diesel. The final result implied that the bio diesel with some additives (B20+1%) shows best performance and reduce the exhaust emission including NOx.Thus the decision may be taken,20% blended bio diesel with 1% additive as a best alternative fuel considering all the view aspects and alternatives. [Copyright &y& Elsevier]

Abstract: Experimental study has been carried out to analyze engine performance and emissions characteristics for diesel ngine using different blend fuels without any engine modifications. A total of four fuel samples, such as DF (100% iesel fuel), JB5 (5% jatropha biodiesel and 95% DF), JB10 (10% JB and 90% DF) and J5W5 (5% JB, 5% waste ooking oil and 90% DF) respectively were used in this study. Engine performance test was carried out at 100% load eeping throttle 100% wide open with variable speeds of 1500 to 2400rpm at an interval of 100rpm. Whereas, mission tests were carried out at 2300rpm at 100% and 80% throttle position. As results of investigations, the erage torque reduction compared to DF for JB5, JB10 and J5W5 was found as 0.63%, 1.63% and 1.44% and verage power reduction was found as 0.67%, 1.66% and 1.54% respectively. Average increase in bsfc compared to F was observed as 0.54%, 1.0% JB10 and 1.14% for JB5, JB10 and J5W5 respectively. In case of engine exhaust as emissions, compared to DF average reduction in HC for JB5, JB10 and J5W5 at 2300rpm and 100% throttle osition found as 8.96%, 11.25% and 12.50%, whereas, at 2300 and 80% throttle position, reduction was as 16.28%, 0.23% and 31.98% respectively. Average reduction in CO at 2300rpm and 100% throttle position for JB5, JB10 and 5W5 was found as 17.26%, 25.92% and 26.87%, whereas, at 80% throttle position, reduction was observed as 0.70%, 33.24% and 35.57%. Similarly, the reduction in CO2 compared to DF for JB5, JB10 and J5W5 at 2300rpm nd 100% throttle position was as 12.10%, 20.51% and 24.91%, whereas, at 80% throttle position, reductions was bserved as 5.98%, 10.38% and 18.49% respectively. However, some NOx emissions were increased for all blend els compared to DF. In case of noise emission, sound level for all blend fuels was reduced compared to DF. It can e concluded that JB5, JB10 and J5W5 can be used in diesel engines without any engine modifications However, 5B5 produced some better results when compared to JB10. [Copyright &y& Elsevier]

The farm animal and meat processing industry generate waste, including manure, fat, blood, sludge, bones, and wastewater, which create environmental problems worldwide. The effluents generated by this industry are rich in proteins, lipids, fibres, and carbohydrates. All these pollutants have the potential to be used as a resource for energy recovery. The organic matters obtained from the farm animal and meat processing industry are critical sources for biogas production via anaerobic digestion. This process leads to the production of energy-rich biogas, reducing greenhouse gas emissions. This study attempts to determine biogas amount and the energy value produced from the farm animal and meat processing industry in Australia. Australia's livestock population mainly consists of dairy cattle, meat cattle, sheep and lambs, pigs, layers, and meat chickens. Results show a potential biogas amount of 23,874,165 million m3 (Mm3), 215,670 Mm3, 288,228 Mm3, 18,430 Mm3, and 392,284 Mm3 can be obtained from cattle, lamb, sheep, pig, and poultry annually, respectively. The methane generated from slaughterhouse waste and wastewater is estimated to provide 4.52E+ 14 MJ/yr of heat energy with total electricity generation potential from livestock wastes of 4.4E+ 13 kWh/yr. About half of the electricity can be generated in Queensland State. Finally, the present study suggests farm animal and meat processing industry effluent as a potential sustainable energy source in Australia. [Display omitted] • Technologies for biogas production from slaughterhouse waste is presented. • Utilizing biogas as a source of power and value-added products are discussed. • Slaughterhouse waste and wastewater is a promising renewable energy source. • Biogas from slaughterhouse waste and wastewater reduces GHG emission significantly. [ABSTRACT FROM AUTHOR]

The corrosiveness of biodiesel affects the fuel processing infrastructure and different parts of an internal combustion (IC) engine. The present study investigates the corrosion behaviour of automotive materials such as stainless steel, aluminium, cast iron, and copper in 20% (B20) and 30% (B30) by volume second-generation Jatropha biodiesel using an immersion test. The results were compared with petro-diesel (B0). Various fuel properties such as the viscosity, density, water content, total acid number (TAN), and oxidation stability were investigated after the immersion test using ASTM D341, ASTM D975, ASTM D445, and ASTM D6751 standards. The morphology of the corroded materials was investigated using optical microscopy and scanning electron microscopy SEM), whereas the elemental analysis was carried out using energy-dispersive X-ray spectroscopy (EDS). The highest corrosion using biodiesel was detected in copper, while the lowest was detected in stainless steel. Using B20, the rate of corrosion in copper and stainless steel was 17% and 14% higher than when using diesel, which further increased to 206% and 86% using B30. After the immersion test, the viscosity, water content, and TAN of biodiesel were increased markedly compared to petro-diesel. [ABSTRACT FROM AUTHOR]

Biodiesel is a clean, renewable, liquid fuel that can be used in existing diesel engines without modification as pure or blend. Transesterification (the primary process for biodiesel generation) via heterogeneous catalysis using low-cost waste feedstocks for catalyst synthesis improves the economics of biodiesel production. Heterogeneous catalysts are preferred for the industrial generation of biodiesel due to their robustness and low costs due to the easy separation and relatively higher reusability. Calcium oxides found in abundance in nature, e.g., in seashells and eggshells, are promising candidates for the synthesis of heterogeneous catalysts. However, process improvements are required to design productive calcium oxide-based catalysts at an industrial scale. The current work presents an overview of the biodiesel production advancements using calcium oxide-based catalysts (e.g., pure, supported, and mixed with metal oxides). The review discusses different factors involved in the synthesis of calcium oxide-based catalysts, and the effect of reaction parameters on the biodiesel yield of calcium oxide-based catalysis are studied. Further, the common reactor designs used for the heterogeneous catalysis using calcium oxide-based catalysts are explained. Moreover, the catalytic activity mechanism, challenges and prospects of the application of calcium oxide-based catalysts in biodiesel generation are discussed. The study of calcium oxide-based catalyst should continue to be evaluated for the potential of their application in the commercial sector as they remain the pivotal goal of these studies. [ABSTRACT FROM AUTHOR]

Global energy sources are being transformed from hydrocarbon-based energy sources to renewable and carbon-free energy sources such as wind, solar and hydrogen. The biggest challenge with hydrogen as a renewable energy carrier is the storage and delivery system's complexity. Therefore, other media such as ammonia for indirect storage are now being considered. Research has shown that at reasonable pressures, ammonia is easily contained as a liquid. In this form, energy density is approximately half of that of gasoline and ten times more than batteries. Ammonia can provide effective storage of renewable energy through its existing storage and distribution network. In this article, we aimed to analyse the previous studies and the current research on the preparation of ammonia as a next-generation renewable energy carrier. The study focuses on technical advances emerging in ammonia synthesis technologies, such as photocatalysis, electrocatalysis and plasmacatalysis. Ammonia is now also strongly regarded as fuel in the transport, industrial and power sectors and is relatively more versatile in reducing CO2 emissions. Therefore, the utilisation of ammonia as a renewable energy carrier plays a significant role in reducing GHG emissions. Finally, the simplicity of ammonia processing, transport and use makes it an appealing choice for the link between the development of renewable energy and demand. [ABSTRACT FROM AUTHOR]