Energy nexus最新文献

Estimates show that the world generates around 2.01 billion tons of municipal solid waste (MSW) each year, of which 33% is not managed properly. This demonstrates the urgent need for strategies to address the growing rate of MSW generation worldwide. Municipal waste collection, treatment and final deposition are among the important issues in the agendas of public administration. Brazil, like other developing countries has to develop its political policies to handle efficiently the MSW treatment. A significant part of the municipalities are still facing serious difficulties to eradicate dumping practices and implement adequate waste treatment routes. As a contribution, this review presents the actual scenario and future national plan for MSW for the period 2024-2040 including efforts to waste minimization, recycling, sanitation, and closure of polluted landfills, incentives to recovery of landfill gas, composting, and recovery of energy from MSW. Recent data shows that the actual MSW generated in Brazil in 2022 is about 81.8 million tons of which 76.1 million tons were collected (93.0%). Of the collected MSW, 46.4 million tons (61%) were deposited in sanitary landfills and about 29.7 million tons (39%) were sent to dumps. The recycling and composting activities were 1.12 million tons (or 1.47%) and 127,500 tons (or 0.168%), respectively. The new National Plan of Solid Waste, Planares, establishes among other targets, the elimination of controlled dumps and dumping sites starting from 2024 and the increase of the recovered MSW to 48.1% by 2040.

The aim of this study was to investigate the simultaneous biogas generation and leachate treatment using municipal waste and its polluted leachate at Mashhad landfill in northeast Iran. The research focused on examining the kinetic model of CH₄, CO₂, CO, H₂S and O₂ production with and without leachate recirculation (LR) through control/test wells. The findings from both wells showed an increase in logarithmic CH₄ production rate, with the coefficient related to the rate of increase in methane concentration ranging from 0/52-0/64 in the control well and 0/47-0/55 in the test well, respectively. Under LR conditions, it was observed that the CH₄ production rate was slower, taking an average of 120 minutes to reach 50% concentration, compared to just 15 minutes without LR. Using first-order equations, the CH₄ production coefficients were measured to be 2/17 h⁻¹ and 0/9 h⁻¹ for the control and test wells, respectively. The analysis of recirculated leachate revealed a significant decrease (∼30%) in the total volume of leachate with 72% COD removal, which could help manage overloaded leachate problems in the landfill. The COD removal coefficient was found to be 0/036 day⁻¹ in the control well, whereas the test well with leachate recirculation showed a more rapid decrease from 50 g.l⁻¹ to about 14 g.l⁻¹ with a removal coefficient of 0/012 day⁻¹, three times higher than the control well. Additionally, nitrogen content analysis indicated that although the amount of ammonia content increased with LR, the increase was relatively low in comparison to conditions without LR, equivalent to 1394 ppm and 1000 ppm in control and test wells, respectively. This study aligns with the water-energy-nexus concept by offering a sustainable solution for waste management and energy generation, while also addressing water management challenges associated with landfill operations.

Throughout human history, water and energy have played pivotal roles in the expansion and progress of societies. However, the availability of fresh water on Earth is limited, constituting less than 3% of the global water resources. Moreover, the distribution of freshwater across countries is inequitable, with a considerable amount being returned to oceans and underground reservoirs. The escalating effects of global warming further disrupt the natural water cycle, posing a serious threat to numerous countries in the form of drought and famine. To meet the increasing demand for freshwater, desalination technologies have been widely employed worldwide. Nevertheless, most of the existing commercial desalination methods heavily rely on fossil fuels and contribute to significant greenhouse gas emissions, exacerbating the issue of global warming. Consequently, the integration of hybrid renewable energy sources into desalination processes emerges as a promising solution to simultaneously address the freshwater demand and combat global warming. So, utilizing hybrid renewable energy supply to drive various desalination technologies is a very promising solution to meet freshwater demands and help mitigating the global warming problem. Therefore, it is imperative to gain a comprehensive understanding of the latest advancements in hybrid renewable energy-driven desalination technologies to guide future research endeavors in this domain. The primary objective of this study is to perform a bibliometric analysis in order to identify the key sources, authors, countries, research institutions, and topics within the field of hybrid renewable energy-driven desalination technologies. By utilizing the R Bibliometrix library and the biblioshiny application, a dataset comprising 451 publications obtained from the Scopus database was analyzed. The results of the analysis reveal a substantial increase in the annual publication rate within this research field over the past five years. Notably, Iran, the United States, and China have emerged as leading contributors in terms of total publications. However, it is noteworthy that countries in the Middle East and the Mediterranean region, in addition to China and the USA, exhibit prominent involvement in various categories of research within this field.

The present study investigates the effects of visible light transmittance in glazing and window-to-wall ratios on the ground floor daylighting performance in a two-storey residential building in a warm-humid climate. The metrics used to optimize daylighting performance with minimal glare are useful daylight illuminance, annual sunlight exposure, and spatial daylight autonomy. The daylighting performance of a residential building is assessed by empirical method and Design-Builder simulation, focusing on overcast sky situations. The useful daylight illuminance is the primary metric for analysing the amount of daylight throughout the year. Annual sunlight exposure and spatial daylight autonomy complement useful daylight illuminance in evaluating the daylighting performance. A window-to-wall ratio of 16%, a visible light transmittance of 0.62, and a glare of 0.52 can meet the daylighting requirements and standards. A design change in the window position helps to obtain annual sunlight exposure within 10% while maintaining high daylighting performance. When installed in the upper position of the wall with a higher sill and lintel height, glazing with a window-to-wall ratio of 16% and a visible light transmittance of 0.62 functions well without creating glare. The significant findings benefit all stakeholders in improving daylighting strategies in tropical climates and satisfying building standards.

With global energy demand rising and climate change targets becoming more ambitious, the use of biomass for combustion will become even more important than it already is. As wood supplies become scarce, leading to increased demand for materials and energy, the demand for alternative solid biofuels for energy use is growing. Using various biobased raw materials seem to be the best way to optimize the value chain of solid biomass fuels. Biomass has high energy density, homogeneous physical properties, easy handling and efficient transportation. Combining multi-criteria decision analysis (MCDA) and life cycle analysis (LCA), this article evaluates the utilization of hemp for a number of uses, including energy generation. The methodology developed combines agrotechnological and sustainability criteria with data analytic techniques for more effective application of hemp products in changing environmental, economic, and geopolitical contexts. According to the results of the research conducted, the use of hemp as an energy source is a viable option only in the short term.

Dairy farming systems are multifunctional processes that provide milk but also beef, veal and manure. These outputs provided by dairy farms are important foods for humans but their production require natural resources like water and land, and release emissions to the water and air contributing to climate change. Many studies quantified the environmental performance of dairy farms by using a life cycle assessment (LCA) or environmental footprint calculation. This study provides a better understanding of how different methodological decisions (e.g., the choice of system boundary, GHG metric, allocation procedure for multifunctionality, and multi-environmental indicators) influence the environmental performance calculation. From a footprinting point of view, the water footprints (WFs) (i.e., green, blue and grey), land footprints (LFs) and carbon footprints (CFs) of milk, beef and veal produced in two conventional (Dutch and Spanish) and an organic Dutch dairy system are estimated. Here the system boundaries are expanded so calve systems are included. Next, the use of different indicators is discussed, e.g., green WFs and the GWP100 or GWP20. The Dutch conventional system has relatively small footprints due to high efficiency. Green, blue and grey WFs per kg of milk are 0.62, 0.09 and 0.14 m³. The Spanish system has green, blue and grey WFs per kg of milk of 0.67, 0.15 and 0.09 m³; the Dutch organic system of 0.84, 0.13 and 0.26 m³. The Spanish system has the largest LF and CF, caused by feed import from countries with relatively low yields and transport greenhouse gas emissions. Dutch systems use more locally produced feed. Due to lower efficiency, the organic system has larger footprints than the Dutch conventional system. Expanding system boundaries to include calves results in an 8 to 15% CF increase. Green water dominates total WFs, an aspect excluded in LCA studies. For grey WFs, earlier studies only included nitrogen. However, if also pesticides would be included, results might be less favourable for systems relying on feed crops instead of grasslands. Also, water quality standards influence grey WFs. The study emphasizes that indicator choice influences final results. Indicators like animal welfare, biodiversity or pesticide use give different outcomes which might be more favourable for organic production.

Time-series quasi-dynamic load flow analysis is an important methodology to estimate the voltage profiles across various nodes in modern distribution networks. This paper describes the necessity of time-series load flow analysis (LFA) for a real-time power distribution network in Puducherry smart grid system by considering seasonal load variations in the union territory of Puducherry, India to obtain optimal performance. In this study, this load flow analysis has been applied to test systems such as IEEE 69, IEEE 37, IEEE 34 and the Indian utility 29 node distribution network (IU29NDN) in Puducherry smart grid system with unbalanced load patterns and energy sources in close proximity. Modified Decision Making (MDM) algorithm is proposed in this paper to improve voltage profiles with in distribution networks by choosing the size and location of solar photovoltaic (SPV) systems. The variations in the node voltages, real power, and reactive power flows are estimated for distribution networks subjected to seasonal load variations by quasi-dynamic load flow simulations conducted over a period of 24 h with 15-minute step size. Furthermore, a harmonic power flow is illustrated and extended to mitigate the harmonics by optimal placement of shunt capacitors (SCs) in all the test systems by incorporating MDM algorithm.

One of the essential aspects in managing food safety is the drying, which helps to preserve food quality and extend the shelf life of food products. The temperature, relative humidity (RH), and air velocity in dryers should be carefully monitored and maintained to ensure food quality and safety during the drying process. Also, the components of heat pump dryers are at risk due to the electric current, the high temperature surrounding the condensing unit's compressor, and the high air velocity of the drying environment. These elements affect the quality of the foods being dried, and being able to communicate alerts in real-time is essential for taking precautions against hazards that can damage the dryer's internal components. Food technology's IoT-based control (IoT-BC) system with multipurpose sensors offers options for managing the post-harvest quality of leaves as they are being dried. This study set out to design and evaluates an IoT-BC system in order to remotely control, alert of imminent hazards, and monitor the microclimate parameters, including RH, temperature, and air velocity. The impacts of the created IoT-based drying system on the quality of dried leafy vegetables were also investigated utilizing a unique dryer as a case study. The results showed that the created IoT-BC system accurately maintained the drying environment, provided reliable data about the internal microclimate atmosphere of the dryer, and provided the appropriate alarm in case of an emergency and this was based on real-time data analyses. The most important quality characteristics for dried leaves were not significantly different between the IoT-based dryer and the conventional dryer dependant on drying time. Rehydration capacity decreased with the increase in the drying air temperature from 40 to 70 °C and was maximum (6.48) at 40 °C for coriander leaves and maximum (5.59) at 40 °C for Mint leaves dried in IoT based dryer. Maximum crude fibre and protein contents for mint leaves dried in an IoT-based drier were at 40 °C and were 4.97 mg/100 g and 10.62 mg/100 g, respectively. Maximum crude fibre and protein contents for coriander leaves dried in this method were 3.76 mg/100 g and 12.23 mg/100 g, respectively. The IoT based dryer kept the leaves' superior qualities throughout the drying process as a result.

Tulip growth involves a warm–cold–warm cycle and this work addresses the possibility of carrying out the final warm step of this cycle during the winter months of a subtropical country where electric power has a low price — Paraguay. This is a result of an abundance of renewable energy resources mainly due to the presence of two large hydroelectric power plants. This final cultivation step requires temperatures between 16 °C and 20 °C during a period of about five months. Historic climate data suggest that the city of Encarnación is suitable for tulip cultivation in Paraguay. However, because of temperature fluctuations, air conditioning may occasionally be necessary for cooling or heating. Using a transient model, we simulate the thermal conditions of the nursery to find the energy needed for air conditioning. Good thermal insulation and injection of external ambient air to control the nursery’s temperature whenever possible reduce the use of electrical energy.

Water and wastewater utilities consume significant energy, and much guidance has emerged especially in the past 25 years to help them manage it. The confluence of literature from independent groups in the same timespan speaks to the enduring relevance, technical nuance, and deep substance of the topic. At an important time in the energy–water nexus, we critically review 29 key publications that provide comprehensive guidance on the subject. We categorize the recommended practices, explore the origins of the guidance, discuss commonalities and differences in the recommendations, reflect on the evolution of the guidance, and suggest directions for future developments. From this novel review, we find that while the documents’ scopes and origins differ, consensus has developed around several core capital, operational, and managerial practices that the water and energy industries have accepted. These include upgrading pumping equipment, installing renewable energy, upgrading treatment equipment, repairing leaky pipes, operating according to power rate schedules, optimizing pump use, optimizing treatment processes, performing regular maintenance, performing energy audits, engaging in outreach, training an energy team, and setting goals. Many of the practices are supported by over 260 case studies in the documents. Some practices are experimental and need more work. Even as the ongoing transition to cleaner energy is necessitating new approaches that water and wastewater utilities must embrace, the diversity of practices testifies to multiple successful paths to energy management. We recommend that water and wastewater utilities choose options that best suit their opportunities, capabilities, and values.