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Biodiesel is an alternative source of fuel for various automotive applications. Because of the increasing demand for energy and the scarcity of fossil fuels, researchers have turned their attention to biodiesel production from various sources in recent years. The production of biofuels from organic materials and waste components allows for the use of these waste resources in transporting resources and people over long distances. As a result, developing sustainable measures for this aspect of life is critical, as knowledge of appropriate fuel sources, corresponding emissions, and health impacts will benefit the environment and public health assessment, which is currently lacking in the literature. This study investigates biodiesel’s composition and production process, in addition to biodiesel emissions and their associated health effects. Based on the existing literature, a detailed analysis of biodiesel production from vegetable oil crops and emissions was undertaken. This study also considered vegetable oil sources, such as food crops, which can have a substantial impact on the environment if suitable growing procedures are not followed. Incorporating biodegradable fuels as renewable and sustainable solutions decreases pollution to the environment. The effects of biodiesel exhaust gas and particulates on human health were also examined. According to epidemiologic studies, those who have been exposed to diesel exhaust have a 1.2–1.5 times higher risk of developing lung cancer than those who have not. In addition, for every 24 parts per billion increase in NO2 concentration, symptom prevalence increases 2.7-fold. Research also suggests that plain biodiesel combustion emissions are more damaging than petroleum diesel fuel combustion emissions. A comprehensive analysis of biodiesel production, emissions, and health implications would advance this field’s understanding.

Abstract Microalgae originating from wastewater has been exhibiting particularly promising results in terms of biohydrogen production and wastewater treatment. This paper aims to review the factors affecting production, pretreatment techniques to improve synthesis, advanced technologies utilized for enhancing biohydrogen production, and techno-economic feasibility evaluation of the processes at a commercial scale. Microalgae possess metabolic components to synthesize biohydrogen using photobiological and fermentative processes but must undergo pretreatment for efficient biohydrogen production. The efficiency of these processes is influenced by factors such as the microalgae species, light intensity, cell density, pH, temperature, substrates, and the type of bioreactors. Moreover, many limitations, such as oxygen sensitivity, altered thylakoid constitution, low photon conversion efficiency, light capture disruption, and the evolution of harmful by-products hinder the sustainability of biohydrogen production processes. High operational and maintenance costs serve as the major bottleneck in the scaling up of the process as an industrial technology. Therefore, future research needs to be directed towards increasing optimization of the processes by reducing energy and resource demand, recycling metabolic wastes and process components, genetically engineered microalgae to adopt more efficient routes, and conducting pilot studies for commercialization.

Abstract Microalgal biomass has been proved to be a sustainable source for biofuels including bio-oil, biodiesel, bioethanol, biomethane, etc. One of the collateral benefits of integrating the use of microalgal technologies in the industry is microalgae’s ability to capture carbon dioxide during the application and biomass production process and consequently reducing carbon dioxide emissions. Although microalgae are a feasible source of biofuel, industrial microalgae applications face energy and cost challenges. To overcome these challenges, researchers have been interested in applying the bio-refinery approach to extract the important components encapsulated in microalgae. This review discusses the key steps of microalgae-based biorefinery including cultivation and harvesting, cell disruption, biofuel and value-added compound extraction along with the detailed technologies associated with each step of biorefinery. This review found that suitable microalgae species are selected based on their carbohydrate, lipid and protein contents and selecting the suitable species are crucial for high-quality biofuel and value-added products production. Microalgae species contain carbohydrates, proteins and lipids in the range of 8% to 69.7%, 5% to 74% and 7% to 65% respectively which proved their ability to be used as a source of value-added commodities in multiple industries including agriculture, animal husbandry, medicine, culinary, and cosmetics. This review suggests that lipid and value-added products from microalgae can be made more economically viable by integrating upstream and downstream processes. Therefore, a systematically integrated genome sequencing and process-scale engineering approach for improving the extraction of lipids and co-products is critical in the development of future microalgal biorefineries.

Abstract Globally, the research on battery technology in electric vehicle applications is advancing tremendously to address the carbon emissions and global warming issues. The effectiveness of electric vehicles depends on the accurate assessment of key parameters as well as proper functionality and diagnosis of the battery storage system. However, poor monitoring and safety strategies of the battery storage system can lead to critical issues such as battery overcharging, over-discharging, overheating, cell unbalancing, thermal runaway, and fire hazards. To address these concerns, an effective battery management system plays a crucial role in enhancing battery performance including precise monitoring, charging-discharging control, heat management, battery safety, and protection. The goal of this paper is to deliver a comprehensive review of different intelligent approaches and control schemes of the battery management system in electric vehicle applications. In line with that, the review evaluates the intelligent algorithms in battery state estimation concerning their features, structure, configuration, accuracy, advantages, and disadvantages. Moreover, the review explores the various controllers in battery heating, cooling, equalization, and protection highlighting categories, characteristics, targets, achievements, benefits, and shortcomings. The key issues and challenges in terms of computation complexity, execution problems along with various internal and external factors are identified. Finally, future opportunities and directions are delivered to design an efficient intelligent algorithm and controller toward the development of an advanced battery management system for future sustainable electric vehicle applications.

Industrial furnaces play a significant role in industrial energy consumption and production. Minimizing losses from these furnaces can contribute to industrial sustainability. Exergy being an optimization tool can reduce energy loss and emission from furnaces and contribute to environmental sustainability. Currently, no exergy-based sustainability analysis has been adopted in the literature. In this analysis, a reheater furnace that is fired by natural gas is analyzed in terms of energy and exergy utilization. To address the sustainability of the furnace, several exergy-based sustainability parameters have been used. The overall energy efficiency of the furnace is 93.40%, while exergy efficiency is only 27.37%. From sustainability analysis, it is found that 72.63% of the fuel is diminished from the furnace, and it contributes to a lower sustainability index of 1.38. Higher exergy losses from this furnace positively affect the environment, which is validated from the higher value of the environmental destruction coefficient, the environmental destruction index, and the lower value of the environmental benign index. The value of the environmental destruction coefficient is 3.65, and the value of the environmental benign index is 0.38. Recovering waste energy and optimizing auxiliary equipment will increase the value of sustainability parameters.

Biodiesel is a fuel that has numerous benefits over traditional petrodiesel. The transesterification process is the most popular method for biodiesel production from various sources, categorized as first, second and third generation biodiesel depending on the source. The transesterification process is subject to a variety of factors that can be taken into account to improve biodiesel yield. One of the factors is catalyst type and concentration, which plays a significant role in the transesterification of biodiesel sources. At present, chemical and biological catalysts are being investigated and each catalyst has its advantages and disadvantages. Recently, nanocatalysts have drawn researchers' attention to the efficient production of biodiesel. This article discusses recent work on the role of several nanocatalysts in the transesterification reaction of various sources in the development of biodiesel. A large number of literature from highly rated journals in scientific indexes is reviewed, including the most recent publications. Most of the authors reported that nanocatalysts show an important influence regarding activity and selectivity. This study highlights that in contrast to conventional catalysts, the highly variable surface area of nanostructure materials favours interaction between catalysts and substrates that efficiently boost the performance of products. Finally, this analysis provides useful information to researchers in developing and processing cost-effective biodiesel.

Air pollution caused by vehicle emissions has raised serious public health concerns. Vehicle emissions generally depend on many factors, such as the nature of the vehicle, driving style, traffic conditions, emission control technologies, and operational conditions. Concerns about the certification cycles used by various regulatory authorities are growing due to the difference in emission during certification procedure and Real Driving Emissions (RDE). Under laboratory conditions, certification tests are performed in a ‘chassis dynamometer’ for light-duty vehicles (LDVs) and an ‘engine dynamometer’ for heavy-duty vehicles (HDVs). As a result, the test drive cycles used to measure the automotive emissions do not correctly reflect the vehicle’s real-world driving pattern. Consequently, the RDE regulation is being phased in to reduce the disparity between type approval and vehicle’s real-world emissions. According to this review, different variables such as traffic signals, driving dynamics, congestions, altitude, ambient temperature, and so on have a major influence on actual driving pollution. Aside from that, cold-start and hot-start have been shown to have an effect on on-road pollution. Contrary to common opinion, new technology such as start-stop systems boost automotive emissions rather than decreasing them owing to unfavourable conditions from the point of view of exhaust emissions and exhaust after-treatment systems. In addition, the driving dynamics are not represented in the current laboratory-based test procedures. As a result, it is critical to establish an on-road testing protocol to obtain a true representation of vehicular emissions and reduce emissions to a standard level. The incorporation of RDE clauses into certification procedures would have a positive impact on global air quality.

Banana stem is being considered as the second largest waste biomass in Malaysia. Therefore, the environmental challenge of managing this huge amount of biomass as well as converting the feedstock into value-added products has spurred the demand for diversified applications to be implemented as a realistic approach. In this study, banana stem waste was experimented for bioethanol generation via hydrolysis and fermentation methods with the presence of Saccharomyces cerevisiae (yeast) subsequently. Along with the experimental analysis, a realistic pilot scale application of electricity generation from the bioethanol has been designed by HOMER software to demonstrate techno-economic and environmental impact. During sulfuric acid and enzymatic hydrolysis, the highest glucose yield was 5.614 and 40.61 g/L, respectively. During fermentation, the maximum and minimum glucose yield was 62.23 g/L at 12 h and 0.69 g/L at 72 h, respectively. Subsequently, 99.8% pure bioethanol was recovered by a distillation process. Plant modeling simulated operating costs 65,980 US$/y, net production cost 869347 US$ and electricity cost 0.392 US$/kWh. The CO2 emission from bioethanol was 97,161 kg/y and SO2 emission was 513 kg/y which is much lower than diesel emission. The overall bioethanol production from banana stem and application of electricity generation presented the approach economically favorable and environmentally benign.