Energy nexus最新文献

The optimization and prediction of thermodynamic parameters including synergistic effects, and kinetic analysis in co-pyrolysis of banana peel (BP) and waste polystyrene (PS) plastic at different heating rates using ANN and AIC models has been performed. Thermogravimetric analysis was performed to determine the initial, maximum, and final degradation temperatures. The synergistic effect was studied using additive formula to determine the theoretical thermal behavior and compared with experimental TGA data. Kinetic parameters were determined by using the advanced isoconversional (AIC) model for estimation of activation energy (E_α), Criado master plot for reaction mechanism (f(α)), and compensation method for frequency factor (A_α). The analysis showed that the average activation energy values were 182.5, 140.6, and 161.8 kJ mol⁻¹ for PS, BP, and PS+BP, respectively. It also clearly shows positive synergy in co-pyrolysis of PS and BP by reducing 11.3 % activation energy compared to that of PS alone. The frequency factor was found to be 1.0 × 10¹⁴, 1.0 × 10¹⁵, and 1.0 × 10²³ s⁻¹ for PS, BP, and PS+BP, respectively. The reaction mechanism was identified as R3, D4, and D4+R3 for PS, BP, and PS+BP, respectively. Further, the obtained kinetic parameters were used to determine the thermodynamic parameters such as enthalpy (ΔH), Gibbs energy (ΔG), and Entropy (ΔS). Finally, ANN was designed to address the co-pyrolysis behavior subjected to various heating rates. Subsequently, the trained ANN model (5 × 4×4 × 4) was employed to forecast thermal degradation behavior. Impressively, the model yielded highly accurate results with a correlation coefficient R² > 0.998 in each case. The optimized model was further used to predict TGA data and activation energy for unknown mixtures of PS and BP. The suggested ANN model showed a great advantage in optimizing to avoid extensive experiments at various heating rates to achieve the goal.

The rise in the population and rapid industrialization has resulted in a rise in the global energy consumption. In order to minimize the load on the conventional energy sources, various studies are being conducted for the production of biofuels by hydrothermal operations. Unlike conventional processes of biofuel production, wet biomass can be directly utilised without drying in turn reducing the energy consumption. Feedstocks such as agricultural residue, forest residue, energy crops, algae, sludge, litter and food waste can be utilised for the production of biofuels. The operation intensities (temperature and pressure) can be varied from pressurized hot water to supercritical water. Hydrothermal operations depending on the operating parameters are further subcategorised into four types namely wet torrefaction (WT), hydrothermal carbonization (HTC), hydrothermal liquefaction (HTL) and hydrothermal gasification (HTG). Even though the operating conditions of wet torrefaction and hydrothermal carbonization lie in similar categories, the difference is clearly visible in the level of carbonization. Due to the wide range of operating temperature and pressure, mainly three different products are produced through hydrothermal operations. The temperature range for wet torrefaction can be limited between 150 and 220 °C, whereas the HTC process can be between 200 and 260 °C. At higher temperatures (260 – 370 °C) in hydrothermal liquefaction (HTL), increased isomerization, depolymerization and repolymerization of organic compounds within the biomass occurred, causing liquid product (bio-oil) to be formed as the major product. Hydrothermal gasification can be further subcategorised into three types: namely aqueous phase refining, near critical water gasification and supercritical water gasification (SCWG). This paper has reviewed different hydrothermal operations based on biofuel production from different biomass.

The water-energy-food (WEF) nexus is an interdisciplinary approach to address the transdisciplinary issues of developing a specific area with limited resources. We studied the potential of implementing the WEF model in the Rabia region located at Matrouh Governorate in Egypt on the Mediterranean Sea, to introduce sustainable management solutions for the limited resources in this area. The Rabia community lacks any source of water services and is not connected to the electric grid. It depends on existing wells that harvest rainwater for potable and non-potable purposes. The introduced WEF nexus scheme is based on the available resources in Rabia region to produce the required water for drinking, cultivation, and other purposes in addition to maximizing the productivity of water. It also provided renewable energy resources and food security in the area. The proposal also empowers women and provides job opportunities for the community, in addition to reducing carbon emissions to contribute to the efforts fighting climate change. This work will benefit policymakers, investors, and the local community to take tangible actions toward sustainable development in the region and other similar communities in arid coastal regions. The proposed scheme will save about 52 % of the required electricity and 54 % of the carbon emissions, through the use of renewable energy sources. It produces 2,096 t/yr of crops. It supports the achievement of many sustainable development goals and will promote the achievement of Egypt's National Vision 2030.

The next great innovation in Unmanned Aerial Vehicles (UAV) technology is smart UAVs, which aim to provide new possibilities in numerous applications. There is an increasing usage of UAVs in various fields of civil applications including live tracking, wireless connectivity, distribution of goods, remote sensing, protection and surveillance, precision agriculture, and review of civil infrastructure. UAVs or drones have a tremen- dous potential to provide smart farming with various productive solutions. Internet of Things (IoT) technologies together with UAVs are anticipated to transform agriculture, allowing decision- making in days rather than weeks, offering substantial cost savings and yield increases. These technologies are employed in a number of different ways, from monitoring crop status and amount of moisture in soil in real time to using drones to help with activities such as the application of pesticide spray. Nonethe- less, the employment of such IoT and smart networking technol- ogy, exposes the smart farming ecosystem to cyber security risks and vulnerabilities. This survey gives a detailed understanding of UAV applications in Precision Agriculture (PA). In this survey, we demonstrate a comprehensive analysis on security and privacy in a smart farming scenario. In this complex and dispersed cyber- physical environment, we describe how Blockchain technology along with 5 G in UAVs communication network can dissipate the security issues of the network. The survey addresses possible scenarios for cyber threats and the advancement in the fields of machine learning and artificial intelligence that can boost cybersecurity. At last, the survey outlines open research issues and future directions in the field of cybersecurity in UAVs and PA.

There is a substantial need for removing the contaminants from aqueous waste stream using affordable, stable, and active adsorbents, such as heteroatom-doped carbonaceous materials. Heteroatom such as N-doped carbonaceous materials greatly improve the performance of carbon materials by enhancing their conductivity, basicity, oxidation stability, catalytic activity and adsorption capacity. In this study, hemp fibers (HFs) and N-aminoguanidine were utilized as carbon and nitrogen precursors to synthesize N-functionalized mesoporous carbon materials (N-HFCs) via simultaneous activation and carbonization with ZnCl₂. Higher BET surface area with a distinctive mesoporous structure and the covalent bond between N and C was developed in the prepared carbon, making N-HFCs suitable for adsorbing naphthenic acids (2-naphthoic acid and benzoic acid) from aqueous waste streams. Developed covalent bond helps to prevent the leaching of carbonaceous materials during adsorption study. The results showed that N-HFC-2 (ZnCl₂: N-HFs ratio = 2:1) exhibited a higher removal efficiency of naphthenic acids (2-naphthoic acid and benzoic acid) compared to nonfunctionalized porous carbon (HFC). Adsorption of 2-naphthoic acid and benzoic acid on the adsorbents followed the typical monolayer type of Langmuir adsorption model. The maximum adsorption capacity of HFC after 48 h was evaluated as 70 and 27 mg/g for 2-naphthoic acid and benzoic acid. Likewise, the maximum adsorption capacity of N-HFC-2 for 2-naphthoic acid and benzoic acid was found to be 71 and 33 mg/g. In the adsorption kinetic experiment, adsorption of 2-naphthoic acid and benzoic acid reached equilibrium within 1 h using both the adsorbents (N-HFC-2 and HFC). Adsorption kinetics were analyzed using pseudo-first-order and pseudo-second-order kinetic models and were found to follow a pseudo-second-order kinetic model. Although changing pH from 4.4 to 8.5 did not have any significant effect on the removal efficiency of 2-napthoic acid using HFC and N-HFC-2, the removal efficiency of benzoic acid was decreased from 94 to 60 % using HFC and increased from 98 to 100 % using N-HFC-2. Comparative evaluations demonstrated that the mesoporous carbonaceous materials derived from HFs are an attractive adsorbent for removal of such contaminants from contaminated aqueous streams.

Perovskite solar cells (PSCs) are a type of solar cell that has an ABX₃ structure and have found applications in photoluminescence, sensors and actuators, ferroelectric and piezoelectric devices, semiconductors, and supercapacitors. Despite being cheaper and easier to fabricate than the silicon-based solar cells, their use has been hampered by the accompanying surface defects leading to thermal and moisture instability and reduced photovoltaic performances. Bidentate ligands have been reported to improve the photovoltaic properties of perovskites by increasing the short-circuit current density (J_sc), the open-circuit voltage (V_oc), the fill factor (FF), the power conversion efficiency (PCE), and the hysteresis. Passivation of some PSCs has led to certified efficiencies of 26.4% and 33.7% in a single and heterojunction materials, respectively. In addition to the improved photovoltaic performances, bidentate ligand-derived perovskites have been reported to improve operational stability wherein the perovskite retained above 99% of its earliest power conversion efficiency even after 5000 h of constant heating at 80 °C, humidity of 60%, or illumination of 3.0 W. Beside passivation using bidentate ligands, the use of impurities for doping and interface optimization has also been linked to improved perovskite performance. However, with doping, there is an introduction of more uncoordinated metal ions at the perovskite surface during surface optimization. The nicotinimidamide, N,N-diethyldithiocarbamate and the isobutylhydrazine were the most outstanding bidentate ligands used for the passivation of perovskite, showing power conversion efficiency of 25.30, 24.52, and 24.25% respectively. We also observed that the replacement of MA in MAPbI₃ (methylammonium lead iodide) perovskite reported by Mas-Montoya with FA, giving FAPbI₃ (formamidinium lead iodide) perovskite reported by Liu's, group, led to improvement in the efficiency from 16.20 to 24.52% using N,N-diethyldithiocarbamate for passivation. This review x-rayed the role of bidentate ligands in the surface passivation of perovskite solar cells leading to improved stability and photovoltaic performances.

Pyrolytic carbon black (CBp) is a solid by-product of tyre pyrolysis that contains various contaminants from the tyre additives. These contaminants limit the use of CBp as a carbon source for energy storage applications such as supercapacitors. This study aims to improve the physicochemical, morphological, and electrochemical properties of CBp by applying different chemical treatments and activation methods. The chemical treatments include acid (HCl), base (NaOH), acid-base (HCl/NaOH), and desulphurization (NaOH in xylene) processes to remove impurities such as sulphur, zinc, and silicon. The treated CBp samples are then activated by KOH impregnation technique to increase the surface area and porosity. The characterizations of the treated CBp samples are performed using Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDX), X-ray Diffraction (XRD), and Brunner Emmett Teller (BET). The electrochemical performance of the treated CBp samples are evaluated using galvanostatic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results show that the chemical treatments significantly reduce the impurity levels and enhance the electrochemical performance of CBp. The desulphurized CBp sample exhibits the highest specific capacitance of 218 F/g among the treated CBp samples. The findings of this study suggest that CBp can be effectively utilized as a potential carbon source for supercapacitor electrodes by applying suitable chemical treatments and activation methods. This will create a circular economy to valorize CBp.

Methylene blue (MB) is a model dye used in many adsorption studies, and it is chemisorbed on activated carbon (AC) adsorbent. The adsorption of an adsorbate by a natural adsorbent is a phenomenon where kinetics is often complex despite the necessity of having reliable information on such reactions which is much needed to predict the efficiency of industrial processes of which rate of adsorption plays an integral part. Such information is, at times, not available under different experimental conditions, limiting desired applications. The research reported herein was thus performed to investigate rate of adsorption of MB onto coconut shell activated carbon by fitting experimental data to kinetics and diffusion models. According to the regression analysis of linearized pseudo-order models applied for various experimental conditions, the pseudo first order (PFO) model is found to be best suited to describe the kinetics of the MB-AC system having rate constants in the range 0.0799 – 0.2437 min⁻¹ under different experimental conditions at the ambient temperature. The rate constants determined through the PFO model at different solution temperatures are indicative of chemisorption of MB on AC surface. Application of the Webber and Morris intra-particle diffusion (IPD) model, which accounts for the boundary layer effect on mass transfer, indicates that adsorption kinetics may be controlled by both film diffusion and intra-particle diffusion sequentially, and that the thickness of the boundary layer on the AC surface, which is a measure of the intercept of the linearized Webber and Morris IPD model, is sensitive to experimental conditions. Consequently, experimental parameters would be able to control the adsorption behaviour of the MB-AC system, which can be investigated by monitoring the magnitude of the initial adsorption factor.

In this work, we conduct acidified aqueous glycerol pre-treatment (AAG) on rice husks (RH) and utilize the response surface methodology (RSM) to assess the impact of pre-treatment parameters. The primary objective of this research is to optimize the parameters to maximize the cellulose content within RH. The parameters under consideration encompassed temperature (ranging from 80 to 110 °C), retention time (spanning 15 to 45 min), and biomass loading (varying from 5 to 10 wt. %). To achieve this optimization, we perform the Box-Behnken Design (BBD) within the framework of RSM. Additionally, we scrutinize the interactive effects of these parameters on cellulose content. Our findings unveiled a remarkable increase in cellulose content, escalating from 40 % in untreated RH to an impressive 75 % in pre-treated RH under the optimized conditions of 110 °C for 45 min with a 5.0 wt. % biomass loading. To further evaluate the effectiveness of the pre-treatment process, we conduct scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses, shedding light on alterations in surface morphology and crystallinity of RH. This investigation yields valuable insights, presenting novel opportunities for the efficient conversion of readily available rice husks into high-value products, such as biofuels and composites.

Economic utilization of waste in the generation of value-added products is the primary prerequisite of a circular economy. Agro-waste is one waste that is enormous on one hand and is rich in nutrients and bioproducts on the other hand. Microbial fermentation is an easy technology that can work following the nature of the waste substrate. Development of such a process is very much possible however it faces the initial challenge of diversity in substrates, microorganisms, enzymes, and bioproducts. It would be thus ideal to make an axis of one waste to one value-added product and then optimize around this axis. Here we explore the potential of a widely industrially used enzyme α-amylase as one terminal of the axis. The other axis would be starch-rich agro-waste like cereal waste. The connection between these two axis terminals would be an α-amylase producing microorganism. A lot of products e.g. nutraceuticals, biofuels, other enzymes, fertilizers, nanoparticles, etc. are possible around this axis. This review explores the suitability of α-amylase to serve as such an axis. We discuss the agro-waste that has the potential for α-amylase production, the industrial applicability of α-amylase, microorganisms known and bioengineered to produce α-amylase, and the optimization of this production process.