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In the modern world, as the population rises and fossil fuel supplies decline, energy demands continue to rise. Moreover, the use of fossil fuels harms the ecology, contributing to pollution and global warming. In order to overcome these difficulties, several approaches are revealed, such as the utilization of biomass as a renewable source of energy. Studies revealed that biomass can be converted into bioenergy via several thermal conversion processes, like pyrolysis, gasification, and torrefaction. Pyrolysis is the most convenient process to obtain three different types of biofuels (biochar as a solid, bio-oil as a liquid, and syngas as a gas). The biofuels produced in this process are normally lower in quality and cannot be used directly as fuel because they contain many undesirable components. Catalytic pyrolysis is one of the best processes to upgrade the quality of biofuels. Several varieties of catalysts are used in the catalytic pyrolysis process (ex situ and in situ). Due to stable operating conditions, both catalytic and non-catalytic pyrolysis procedures produce biochar that has a consistent output. Meanwhile, the effects of catalysts in the catalytic pyrolysis process considerably enhance the quality and quantity of bio-oils and syngas. By removing the unwanted oxygenated and nitrogenous components, the bio-oils produced through the catalytic pyrolysis method have a higher calorific value, reduced viscosity, and improved stability. Many researchers have looked at ways to increase the rate of pyrolysis, whereas a few have focused on maximizing the effects of the factors in order to improve the efficiency of catalytic pyrolysis. This review addresses the impact of catalysts on the catalytic pyrolysis of biomass to enhance the quality of the bio-oils in great detail. Machine learning and techno-economic analysis were investigated, as well as the future potential of the catalytic pyrolysis method for the generation of bio-oil. [ABSTRACT FROM AUTHOR]

The demand for energy has increased tremendously around the whole world due to rapid urbanization and booming industrialization. Energy is the major key to achieving an improved social life, but energy production and utilization processes are the main contributors to environmental pollution and greenhouse gas emissions. Mitigation of the energy crisis and reduction in pollution (water and air) difficulties are the leading research topics nowadays. Carbonaceous materials offer some of the best solutions to minimize these problems in an easy and effective way. It is also advantageous that the sources of carbon-based materials are economical, the synthesis processes are comfortable, and the applications are environmentally friendly. Among carbonaceous materials, activated carbons, graphene, and carbon nanotubes have shown outstanding performance in mitigating the energy crisis and environmental pollution. These three carbonaceous materials exhibit unique adsorption properties for energy storage, water purification, and gas cleansing due to their outstanding electrical conductivity, large specific surface areas, and strong mechanical strength. This paper reviews the synthesis methods for activated carbons, carbon nanotubes, and graphene and their significant applications in energy storage, water treatment, and carbon dioxide gas capture to improve environmental sustainability. [ABSTRACT FROM AUTHOR]

Energy demands keep increasing in this modern world as the world population increases, which leads to a reduction in fossil fuels. To resolve these challenges, Pennisetum purpureum, an invasive grass in Brunei Darussalam, was examined as the feedstock for renewable energy through a catalytic pyrolysis process. The activated carbon was applied as the catalyst for a simple and economical solution. The catalytic pyrolysis was executed at 500 °C (the temperature for the highest biofuel yield) for both reactors to produce the highest amount of upgraded biofuels. The biochar produced from the non-catalytic and catalytic pyrolysis processes showed a consistent yield due to stable operating conditions, from which the activated carbon was generated and used as the catalyst in this work. A significant amount of improvement was found in the production of biofuels, especially bio-oil. It was found that for catalysts, the number of phenolic, alcohol, furans, and ketones was increased by reducing the amount of acidic, aldehyde, miscellaneous oxygenated, and nitrogenous composites in bio-oils. The highest amount of phenolic compounds was produced due to a number of functional groups (-C=O and -OH) in activated carbon. The regenerated activated carbons also showed promising outcomes as catalysts for upgrading the bio-oils. The overall performance of synthesized and regenerated activated carbon as a catalyst in catalytic pyrolysis was highly promising for improving the quality and stability of bio-oil. [ABSTRACT FROM AUTHOR]

Highlights: What are the main findings? FTIR analysis showed multiple surface functional groups, e.g., R-OH, OH, -C=O, -COOH, etc., on the biochar surface. FESEM confirmed the randomized and porous tunnel-like structures of biochar. The BET specific surface area was 19.90 ± 1.20 m2/g. Kinetics and isotherm analysis showed alignment with pseudo-second-order kinetic and Langmuir Isotherm models. What is the implication of the main finding? ~85% removal and 166.30 mg/g sorption capacity were obtained. The possible interaction of MB and BGS-derived biochar can be characterized by elec-trostatic attraction, H-bond and π–π conjugation. Biochar prepared from different bio-sources serves as a feasible solution for the decontamination of dye-contaminated wastewater. In this study, biochar was synthesized from a sustainable source, i.e., local fruit waste, Burmese grape seeds (BGSs). The seeds were collected from a local market, washed, pre-teated and finally converted into biochar by pyrolysis in a N2 furnace. The removal efficiency of the synthesized biochar was evaluated towards a cationic industrial azo dye, methylene blue (MB). The phosphoric acid (H3PO4) and potassium hydroxide (KOH) pretreated BGS were pyrolized at 500 °C for 3 h in a N2 furnace at a heating rate of 10 °C/min. The spectroscopic analysis confirmed the presence of multiple surface functional groups, e.g., R-OH, OH, -C=O, -COOH, etc. The surface of the biochar was randomized with porous tunnel-like structures. The specific surface area and pore volume obtained from BET analysis were 19.90 ± 1.20 m2/g and 5.85 cm3/g. The MB concentration (mg/L), contact duration (min) and pH were varied to assess the MB sorption phenomena. The optimum pH was found to be 8. During the first 20 min of contact time, adsorption was rapid and equilibrium was reached after 75 min. The adsorption was best described by pseudo-first-order kinetics with a good fit (R2 = 0.99). The maximum removal percentage was ~85%, and per gram of BGS can adsorb 166.30 mg of MB, which supports the Langmuir adsorption isotherm model. The obtained results were compared with the reported literature, and BGS showed its excellent candidacy to be industrially utilized in the tertiary stage of wastewater treatment plants. [ABSTRACT FROM AUTHOR]

Energy consumption is rising dramatically at the price of depleting fossil fuel supplies and rising greenhouse gas emissions. To resolve this crisis, barley waste, which is hazardous for the environment and landfill, was studied through thermochemical characterization and pyrolysis to use it as a feedstock as a source of renewable energy. According to proximate analysis, the concentrations of ash, volatile matter, fixed carbon, and moisture were 5.43%, 73.41%, 18.15%, and 3.01%, consecutively. The ultimate analysis revealed that the composition included an acceptable H/C, O/C, and (N+O)/C atomic ratio, with the carbon, hydrogen, nitrogen, sulfur, and oxygen amounts being 46.04%, 6.84%, 3.895%, and 0.91%, respectively. The higher and lower heating values of 20.06 MJ/kg and 18.44 MJ/kg correspondingly demonstrate the appropriateness and promise for the generation of biofuel effectively. The results of the morphological study of biomass are promising for renewable energy sources. Using Fourier transform infrared spectroscopy, the main link between carbon, hydrogen, and oxygen was discovered, which is also important for bioenergy production. The maximum degradation rate was found by thermogravimetric analysis and derivative thermogravimetry to be 4.27% per minute for pyrolysis conditions at a temperature of 366 °C and 5.41% per minute for combustion conditions at a temperature of 298 °C. The maximum yields of biochar (38.57%), bio-oil (36.79%), and syngas (40.14%) in the pyrolysis procedure were obtained at 400, 500, and 600 °C, respectively. With the basic characterization and pyrolysis yields of the raw materials, it can be concluded that barley waste can be a valuable source of renewable energy. Further analysis of the pyrolyzed products is recommended to apply in the specific energy fields. [ABSTRACT FROM AUTHOR]

Battery electric vehicles (BEVs) have started to play a significant role in the transport sector and automotive industries. The broader market penetration of BEVs has still not been achieved due to significant barriers associated with initial costs and short driving ranges. The purchase price and a limited driving range are barriers that are inevitably associated with battery technology. Therefore, the growing demand for BEVs has expedited new innovative approaches to improve battery capacity and performance and to reduce battery costs. Considerable advancements have been employed to meet the challenges. However, there are still many challenges to make BEVs affordable and convenient for users. In this review, the main aims are to identify and address challenges by considering the prospects of BEVs in the future market and to explore the technological and financial difficulties of low energy density of battery materials, fast charging rate, battery lifetime, and cost-effectiveness, associated with effectively implementing and adopting BEVs. Moreover, potential suggestions are proposed for researchers, manufacturers, users, and government policy planners. Finally, a concrete conclusion is drawn by disseminating a vision about the future adoption of BEVs. This review of technologies, challenges, prospects, and potential solutions associated with BEVs could provide a base for effective strategic policy and could help policymakers to frame strategies for adapting and achieving targets. This review could help to achieve sustainable BEV transport and to adopt next-generation green vehicles. [ABSTRACT FROM AUTHOR]

Microplastics' dangers and the absence of effective regulation technologies have risen to prominence as a worldwide issue in recent years. South Asian countries, such as Bangladesh, are among the most threatened nations to face the drastic consequence of releasing microplastics into the aquatic environment. The research on managing and degrading microplastics is ongoing, however, sustainable techniques have not yet been found. To create a green and efficient microplastic management plan, we have compiled all the information on the existing removal and degradation techniques for microplastics and provided an overview of all the noteworthy methods that can be implemented in Bangladesh. In the portrayed biotic and abiotic techniques, coagulation and photocatalysis were found to be most efficient in removing microplastics (as high as 99%) in different studies. The concept of microplastic is new to the researchers of Bangladesh, therefore, the characteristics, occurrence, fate, and threats are briefly discussed in this paper. Sampling, extraction, and identification methods of microplastic in freshwater and sediment samples are also thoroughly specified. The sources of microplastic pollution in Bangladesh and possible strategies that can be implemented to minimize additional microplastic discharge into aquatic environments are discussed. Although Bangladesh was the very first country to ban polythene, the failure of the implementation of rules and regulations and a lack of management strategy made Bangladesh the 10th worst country in managing plastic waste. This work is a wake-up call for other researchers to conduct an in-depth investigation to improve microplastic degrading technologies and develop a sustainable strategy to end microplastic pollution in Bangladesh. [ABSTRACT FROM AUTHOR]

Clothing, one of the basic needs, demands the growth of textile industries worldwide, resulting in higher consumption and pollution of water. Consequently, it requires extensive treatment of textile effluent for environmental protection as well as reuse purposes. Primary treatment, secondary treatment, and tertiary treatment are the three major phases of textile wastewater treatment. Secondary treatment under aerobic and anaerobic circumstances is carried out to decrease BOD, COD, phenol, residual oil, and color, whereas primary treatment is utilized to remove suspended particles, oil, grease, and gritty materials. However, biological treatment is not fully capable of treating water according to discharge/reuse standards. Hence, tertiary treatment is used to remove final contaminants from the wastewater. Adsorption is regarded as one of the most feasible processes for dye and metal removal in consideration of cost and variation in the adsorbent. Though membrane filtration is an efficient process, the cost of operation limits its application. It's unfortunate that there isn't a universally applicable treatment solution for textile effluents. Therefore, the only flexible strategy is to combine several therapy modalities. Treatment of complicated, high-strength textile wastewater depending on pollutant load will be more successful if physical, chemical, and biological approaches are used in tandem. Enforcement of stringent environmental regulation policies, increasing costs and demand for freshwater, and the rising costs and difficulties associated with wastewater disposal are accelerating efforts toward achieving ZLD. Additionally, research into methods for extracting useful materials from wastewater has blossomed in recent years. As such, the purpose of this analysis is to give a holistic overview of textile wastewater treatment systems, with a focus on zero liquid discharge (ZLD) and efficient resource recovery, both of which may hasten the transition to more sustainable water management. [ABSTRACT FROM AUTHOR]

Highlights: The work analyzes the impact of chitosan and ZnO modification on surface and sorption characteristics of Moringa oleifera biochar. Moreover, statistical analysis was used to validate the experimental data. What are the main findings? Chitosan modification enhanced the surface functional groups of raw M. oleifera biochar. The highest and lowest BET surface areas were found for BZ and BC, respectively. Chitosan-modified biochar showed a 75% increment in % removal of methylene blue compared to raw biochar. ZnO modification decreased the performance of biochar by 16%. Kinetics and Isotherm analysis of Chitosan-modified biochar align with statistical analysis. The adequate precision ratio was 52.80 and lack of fit p-value was 0.0018. Industrial effluents contaminated with different types of organic dyes have become a major concern to environmentalists due to the carcinogenic nature of the dyes, which are harmful to human and aquatic life. In recent years, the treatment of contaminated effluents by natural resources has been proposed as the most sustainable solution for this problem. In this work, Moringa oleifera (M. oleifera) seed-derived biochar composites, e.g., Biochar-Chitosan (BC), Biochar-ZnO (BZ), and Chitosan-ZnO (CZ) were produced and characterized. The synthesized materials were then utilized to adsorb a cationic dye, methylene blue. Spectroscopic analysis of the biochar-based composites revealed that the modification of biochar by chitosan and ZnO introduced different functional and active groups in the biochar surface. Pore development in the structure of biochar nanocomposites was visible in surface morphological images. The derived biochar was fully amorphous and increased crystallinity by the ZnO modification. The obtained surface area varied from 0.90 ± 0.00 to 14.48 ± 1.13 m2 g−1 for prepared sorbents, where BZ corresponds to the highest and BC corresponds to the lowest surface area, respectively. The basic pH (9) was the most favorable condition for sorption. The sorption reached equilibrium at 90 min. Isotherm revealed the favorability of the Langmuir model over the Freundlich and Temkin models. The highest sorption capacity (~170 mg/g) was found for BC. The BC and BZ showed a 75% increase and 16% decrease in removal due to the chitosan and ZnO modification, respectively. Response surface methodology (RSM) optimization for BC showed similar results to the analytical experiments. The characterization and experimental results prefigure the chemical functionalities as the critical parameter over the surface area for the adsorption process. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) management has become a major concern for developing countries. The physical and chemical aspects of MSW management and infrastructure need to be analyzed critically to solve the existing socio-economic problem. Currently, MSW production is 2.01 billion tonnes/yr. In developing countries, improper management of MSW poses serious environmental and public health risks. Depending on the socio-economic framework of a country, several MSW management procedures have been established, including landfilling, thermal treatment, and chemical treatment. Most of the MSW produced in underdeveloped and developing countries such as Bangladesh, India, and Pakistan is dumped into open landfills, severely affecting the environment. Waste-to-Energy (WTE) projects based on thermal treatments, e.g., incineration, pyrolysis, and gasification, can be feasible alternatives to conventional technologies. This research has explored a comprehensive method to evaluate MSW characteristics and management strategies from a global and Bangladesh perspective. The benefits, challenges, economic analysis, and comparison of MSW-based WTE projects have been analyzed concisely. Implementing the WTE project in developing countries can reduce unsupervised landfill and greenhouse gas (GHG) emissions. Alternative solutions and innovations have been discussed to overcome the high capital costs and infrastructural deficiencies. By 2050, Bangladesh can establish a total revenue (electricity sales and carbon credit revenue) of USD 751 million per year in Dhaka and Chittagong only. The landfill gas (LFG) recovery, waste recycling. and pyrolysis for energy production, syngas generation, and metal recovery are possible future directions of MSW management. The MSW management scenario in developing countries can be upgraded by improving waste treatment policies and working with government, academicians, and environmentalists together. [ABSTRACT FROM AUTHOR]

Highlights: Expansion of chlor-alkali industries in Bangladesh has been stopped because of a lack of Cl2 demand. Yearly PVC piping and fitting material demand is increasing in Bangladesh at a rate of about 20%. Integration of chlor-alkali and PVC industries is a feasible solution for the sustainable development of caustic industry. The hypothesized PVC plant can consume byproduct Cl2 of 78,000 MT/y from chlor-alkali plants. The byproduct H2 can be utilized to produce H2O2, power, and operating fuel cell-based vehicles. The chlor-alkali industries produce caustic soda (NaOH), chlorine (Cl2), and hydrogen (H2) as primary products. In 2021, the global chlor-alkali market was valued at $63.2 billion. The article evaluates the global aspects of chlor-alkali industries and prospects for Bangladesh. The current production capacity of NaOH from the chlor-alkali industries in Bangladesh is around 282,150 metric tons/year (MT/y). The by-products, chlorine (Cl2) of 250,470 MT/y and hydrogen (H2) of 7055 MT/y, are produced domestically. The local demand of Cl2 is 68,779 MT/y. However, there are no systematic utilizations of the residual Cl2 and vented H2, which threatens the sustainability of the chlor-alkali industries. The article prefigures that a 150,000 MT/y PVC plant can utilize 45.2 % of residual Cl2 of chlor-alkali plants, which would be an economical and environmental milestone for Bangladesh. The residual Cl2 can earn revenue of 908 million USD/y, which can be utilized to import ethylene. For the sustainable utilization of vented H2, production of H2O2, fuel cell electric vehicle (FCEV) and H2 fuel-cell-based power plant are the feasible solutions. Thus, for the long-term growth of the chlor-alkali industry in Bangladesh and other developing countries, systematic utilization of Cl2 and H2 is the only feasible solution. [ABSTRACT FROM AUTHOR]