Search

Paper waste sludge (PWS) is a waste produced in large quantities by the pulp and paper industry, and is usually disposed by landfilling. This study investigates the pyrolytic conversion of PWS as an alternative to its valorisation. Low and high ash PWSs (8.5 and 46.7 wt%) were subjected to fast pyrolysis conversion to maximise the bio-oil yield by optimising the reactor temperature and pellet size. Maximum bio-oil yields of 44.5 ± 1.7 daf, wt% at 400 °C, and 59.9 ± 4.1 daf, wt% at 340 °C, for an intermediate pellet size of 4.84 ± 0.15 mm, were attained from the conversion of the low and high PWS, respectively. The low optimal reactor temperatures, as well as the high bio-oil yields, make valorisation via fast pyrolysis conversion promising. A significant reduction in the O/C molar ratio of up to 35%, from the high ash PWS to its bio-oil product, led to a 65% increase of the higher heating value. A thermogravimetric study was implemented to investigate the pyrolytic mechanisms behind the increase in bio-oil yield with intermediate pellets sizes. It revealed that the observed increase in non-condensable gas yield, which corresponded to a decrease in the bio-oil yield, was due to the promotion of exothermic reactions for high heating rates using smaller pellet sizes. [ABSTRACT FROM AUTHOR]

• 72% − 80% of fibre was recovered from disposable coffee cups. • 2% and 3% consistency shredded cups required > 100 kWh/tonne to repulp with 3 refiner passes. • Pulp quality did not significantly diminish after repulping using a single-disk refiner. Over 64 billion paper-plastic laminate (PPL) coffee cups are consumed between the United States and Canada annually, the majority accumulating in landfills due to a hydrophobic plastic inner-lining. Recycling can mitigate environmental damage and provide economic value from repurposed products. We found that standard repulping methods were insufficient to separate fiber from plastic due to the low intensity of treatment. To increase process intensity, we mechanically refined shredded PPL coffee cups and Kraft eucalyptus sheets (control) at 2%, 3%, and 4% consistencies with three passes to determine the energy required to separate fibers from plastic and the effects on fiber quality. 2% and 3% consistency PPL cups measured under 40 kWh/tonne of input material for one refiner pass and ∼ 80 kWh/tonne for 4% consistency PPL cups. Recovered fiber fraction totaled 87.7%, 85.3%, and 80.5% of input mass of Kraft eucalyptus and 72.3%, 72.6%, and 79.6% of input mass of PPL cups at 2%, 3%, and 4% consistency, respectively. Fines content of PPL cups jumped from 8% pre-refining to ∼ 30% post-refining while Kraft eucalyptus fibers were unaffected, suggesting that breaking the plastic-fiber bonds results in fines generation. Mean fiber length of PPL cups slightly decreased with consistency and tensile strength improved. Freeness decreased with consistency only in PPL cup samples. These results demonstrate a low energy requirement to effectively separate fiber and plastics in PPL cups as well as minimal impact on fiber quality using existing refining technology, and provides an estimate of the financial costs of local recycling efforts. [ABSTRACT FROM AUTHOR]

Straw pulp in China, which is the world's largest producer of this material, suffers from water and energy shortages during its entire life cycle. However, limited systematic studies have focused on these issues, and decision makers need be provided with improvement methods for the environmental performance. Thus, an impact-oriented energy and carbon coupled water footprint analysis was conducted in this study based on ISO standards. Results showed that the impact of energy consumption and carbon emissions exceeded that of water footprint. Carcinogens, non-carcinogens, and freshwater ecotoxicity also played effective roles in improving the environmental performance. Optimizing key indirect processes, including chemicals production, steam preparation, electricity generation, wood pulping, and fertilizer recovery, dominated the reduction in environmental burdens. Direct freshwater consumption and wastewater disposal played additional effective roles in controlling water footprint. The water network was thus optimized by a water pinch analysis to decrease the freshwater consumption and pollutant emissions by maximum values of 91.5% and 99.7% after optimization, respectively. Meanwhile, carbon dioxide, methane, chromium, arsenic, mercury, titanium, copper, strontium, total nitrogen, total phosphorus, BOD 5 , and COD were the main pollutants. Overall, the environmental impact can be further reduced by diminishing coal power ratio in national energy structure, adopting recovered steam, and considering multistage regeneration water network to cope with different water use demands. • LCA-based energy and carbon coupled water footprint of straw pulp paper was applied. • Optimizing water network by water pinch method gained marked environmental benefit. • Electricity, steam, and chemicals exerted high impact among all inputs considered. • CO 2 , CH 4 , heavy metals, coal, and water were key contributors to footprint impact. • Improving national energy structure and adopting recovered steam were recommended. [ABSTRACT FROM AUTHOR]

An energy audit is a primary step toward improving energy efficiency at the facility level and ensuring a clean production. The pulp and paper sector is one of the most energy-intensive industries in Morocco. This article aimed at identifying energy conservation opportunities at a Small and Medium-sized paper industry. The audit results together with their financial viability are presented regarding the analysis of energy consumption and electrical quality issues. The paper introduces an action plan for a more efficient energy use of some specific applications such as furnaces and compressed-air installations as well. The recommended energy efficiency measures have the potential of saving about 347.85 MWh of electrical energy and 101.78 MWh of thermal energy corresponding to reductions of 11.48% and 2.22%, respectively. The total investments related to the application of the action plan is approximately 290.53 kMAD and the global payback period does not exceed one year. It was also shown that a total quantity of 283.39 t of CO 2 emissions can be saved annually. [ABSTRACT FROM AUTHOR]

India is developing fast in the lines of some of the greatest cities of the world. Graph from the last 20-25 years show that India has majorly borne a paradigm shift in development icons as such Its cities have surpassed even double to its initial infrastructure during this period. Most of these infrastructural icons have a lot to do with the IT industry boom in the country as such most of these cities (e.g. Delhi, Bombay, Bangalore, Hyderabad etc.) are further burdened with employable youth, who require transit accommodation in the same city as well. There are some other cities too who used to enjoy the tourist or the pilgrims’ inflow by virtue of some kind of religious, natural or heritage resource attached to it. But, as evident in History, India and the Indians are known to be cultural driven, Pilgrimage friendly people. As such, these Blessings to such cities are continuously turning out to be the sufferings in the light of the number of pilgrims/tourists (floating population) these cities bear on daily basis. Most of these cities lack the sustainable infrastructure to uphold these burdens and to meet the energy demands for the well-being of people and city. These infrastructural additions must contemplate the Energy demands of the built form, people and their activities. One of such vulnerable town due to Paradigm shift in its development priorities is KATRA town, which is continuously getting burdened with more and more buildings, people & loss of Rural Greens as such contemplation of energy requirements is the need of the hour. Katra town is world famous for the rich religious history attached to it as it forms the base town (Camp) of Trikuta Hills upon which (12 kms away from base town) the Holy Shrine of Goddess Maa Vaishno Devi is located. Every year millions of Pilgrims from around the globe visit the shrine & the Katra Town. The Katra town is the major contributor of J&K (Jammu & Kashmir State) economy & India at Large. Pertinently, its being projected as one of the smart cities of India in next few years in the lines of leading smart cities of the world. [ABSTRACT FROM AUTHOR]

The global cement industry produces over four billion tonnes annually. In recent years, the quest for increasing energy efficiency has led this industry to test and use “waste” materials as alternative fuels (AF). The objective of this study was to examine the use, as alternative fuel, of the shredded non-recycled plastics and paper residue (NRPP) of a materials recovery facility at the Balcones plant in San Antonio, Texas; this material has a Lower Heating Value (LHV) of about 17 MJ/kg and is called “engineered fuel” (EF). The results showed that EF consists of mostly paper fiber, a biogenic material, so its use helps to decrease CO 2 emissions from cement production. In the US, on an average about 4.3 MJ of thermal energy are used to dry, decompose, and sinter the carbonate minerals to produce one kg of “clinker” that is then ground to cement powder and mixed with other compounds. If the maximum amount of EF that can be used by the U.S. cement industry (83 million tonnes of cement per year) were to be separated at Material Recovery Facilities and used as alternative fuel in cement kilns, the diversion of non-recycled paper and plastics from landfills would amount to 17.7 million tonnes of EF. The general methodology used for the Life Cycle Assessment (LCA) is Eco-indicators 99 that uses the SimaPro database and four scenarios were assessed. The corresponding chemical structure of the EF was calculated and the associated emissions during combustion were determined. The laboratory analyses determined the average makeup of the sampled fuels consisted of 20% fossil based carbon and 80% biogenic. The use of EF in the cement industry reduces greenhouse gas emission by up to 3 tonnes of CO 2 per tonne of EF used in place of a high-quality coal. The study also found that use of EF in cement production has no adverse effect on the stack emissions of cement plants, nor on the quality of cement produced. The mercury concentration in the stack gas of U.S. cement kilns is well below the U.S. standard and the total dioxin emissions of all cement plants amount to only 0.05% of the dioxins emitted by all U.S. sources. Furthermore, the cement process incorporates the residual ash in the EF into the final clinker, thus resulting in both energy and materials recovery. [ABSTRACT FROM AUTHOR]

Wood has always been an indispensable material in human society throughout history. Its efficient utilization is even more crucial today in achieving the Sustainable Development Goals (SDGs). However, its production, trade, use, and recycling are seldom systematically assessed, with Germany being an exception due to the extensive work conducted by the University of Hamburg and the Thünen Institute over the years. To provide a more precise account of wood use, this study employs oven-dry metric tonne as the reference unit to construct a static wood flow based on the material flow analysis and wood resource balance in Germany in 2020. The Sankey diagrams comprehensively visualize the flow and stock of wood in various sectors, including forests, sawmills, pulp mills, buildings, energy, and waste. Results showed that forest felling volume exceeded growth due to significant wood demand and export, while forest carbon sinks increased because more hardwood was retained in German forests. The building and construction sector was the largest consumer of primary wood products, accounting for 52.1 % of the total, followed by furniture (29.5 %) and packaging (14.0 %). All waste paper was used to produce recycled fiber pulp, whereas only 14 % of waste wood was employed in particle board production. The woody biomass energy, amounting to 142.4 TWh, provided approximately 4.4 % of Germany's primary energy consumption, with around half of it used in private households. In addition to apparent data, this study also uses resource allocation, carbon storage, and cascade potential as examples to demonstrate that wood flow is applicable for further in-depth analysis, supporting wood efficient utilization. It can even be applied to any country and period with sufficient data and conversion factors, but here, they also prevented this study from comprehensively describing past and future wood flows. [Display omitted] [ABSTRACT FROM AUTHOR]

Many proposals are being made for cleaner, more sustainable forms of energy production. Terrestrial solar photovoltaic farms (SPFs) could potentially deliver large quantities of energy to the grid, although these are limited to daytime use. The output from these SPFs could be enhanced, particularly around dawn and dusk, by the use of orbiting solar reflectors (OSRs) in near-polar orbit. These would reflect an image of the solar disk, or solar image (SI), onto the SPFs to augment their energy output. Pointing requirements are therefore to ensure that reflected sunlight is delivered to the terrestrial SPF, avoiding the losses incurred by an offset of the SI and the SPF itself. The SI would typically be of order 10 km for a reflector in a 1000 km orbit. Given the potentially large size of the reflectors, this presents a challenge for the attitude determination and control system (ADCS) to ensure that the maximum quantity of energy can be delivered to a SPF, typically requiring large control moment gyro actuators. In addition, there exist numerous sources of error in the ADCS which can cause further degradation in the quantity of energy delivered to the SPF. These errors can manifest in the resolution of the various sensors, flexible structural modes, manufacturing inaccuracies, and misalignments due to vibration during launch. This paper will investigate the effects of pointing error sources (PES) on the reflector ADCS and so on the quantity of energy delivered to the SPF. With the application of a PD controller with feedforward compensation, and the set of noise characteristics defined in this paper, numerical simulations will show the typical losses in energy delivered to SPFs of 0.015% when the model accounts for PES in onboard sensors, actuator uncertainty and flexible structural modes. • Orbiting solar reflectors. • Sensor and actuator noise modelling. • Establishing the energy delivery losses due to noise in OSRs and finding the minimum losses using PD controllers. [ABSTRACT FROM AUTHOR]

This study presents a bibliometric review focusing on the utilization of water electrolysis as a means of generating hydrogen as an energy carrier. The analysis includes research conducted over the past decade, covering from 2014 to 2023 (till August). Several key aspects are highlighted, including publication trends, the leading country in research output, journal rankings, and a citation analysis of papers related to water electrolysis. The findings reveal a notable increase in publication trends, with China emerging as the leading contributor in this research area. Furthermore, the International Journal of Hydrogen Energy is identified as the highest-ranked journal in terms of both publication number and citation impact. Additionally, the top ten most cited research articles and review papers are investigated to determine their influence within the field. To gain a deeper understanding of water electrolysis methods, the three primary approaches: alkaline water electrolysis (AWE), proton exchange membrane (PEM) electrolysis, and solid oxide electrolysis (SOE) is examined. The analysis emphasizes that PEM electrolysis is the most prevalent method for hydrogen generation, particularly when integrated with renewable energy sources such as solar and wind power due to its rapid response to electrical input fluctuation. Finally, the challenges and future directions of water electrolysis in hydrogen production are highlighted, including an exploration of economic and environmental considerations at large scale, offering insights into the path forward for advancing this technology sustainably. • A comprehensive bibliometric analysis of water electrolysis for hydrogen production. • Publication trends, journal rankings, and citation analysis are highlighted. • China is identified as the leading contributor in water electrolysis publications. • International Journal of Hydrogen Energy: the highest-ranked journal in this field. • Specific electrolysis methods, including AWE, PEM, and SOE are examined. [ABSTRACT FROM AUTHOR]

South Africa is an energy-intensive developing country in Africa and ranked as the 1st and 14th emitter of greenhouse gas (GHG) in Africa and the world, respectively. The abundance and availability of coal in South Africa make it the mainstay primary source of energy contributing 56% of national total GHG emissions. This paper focused on the duo of energy generation and emission associated with coal processing and utilization in South Africa, and the urgent need to advance coal processing technologies marked by high carbon footprints in consonance with the sustainable development goals. Different gasification techniques and their performances have been compiled and discussed. The economic, environmental impact, energetic, and exergetic characteristics of existing hydrogen production technologies for renewable and non-renewable energy sources have been examined along with hydrogen production from plasma gasification of coal. Hydrogen production via coal or coal/biomass plasma gasification technology (nuclear-, wind-, PV solar-, and concentrated solar power-driven) in addition to carbon capture technology for transforming the captured CO 2 into value-added products appears to be the most viable option to considerably reduce emissions and meet the energy demand of South Africa. This proposed technology can be pivotal to achieving a low-carbon economy (medium-term) and transition to hydrogen economy (long-term) as championed by the global sustainable development agenda. Conclusively, hydrogen (stored in different forms e.g., liquid hydrogen, ammonia, and organic hydride) seems to find more applications (in the space industry, transport, energy storage, defense industry, etc.) than coal owing to its immediate use in distribution/demand centers and remote areas. • Coal is the primary energy source of South Africa and key driver of national CO 2 emissions. • Traditional coal gasification technologies are marked by high CO 2 emissions. • Coal plasma gasification technology is a viable option for low-carbon energy economy. • Hydrogen production via coal or coal/biomass plasma gasification technology leads to zero-carbon economy. • This immensely supports the drive towards attaining the sustainable development goals. [ABSTRACT FROM AUTHOR]

The current paper deals with the development and analysis of an innovative multigeneration plant, which is powered by geothermal energy, and integrated with the transcritical Rankine cycle ( t C O 2 − R C), proton exchange membrane (PEM) electrolyzer, multi-effect desalination unit (MED), and ejector cooling system (ECS). The main objective of this research paper is to produce power, hydrogen, freshwater, and cooling in an environmentally benign way, by integrating the different subsystems. A comprehensive parametric analysis that is thermodynamic and economic and exergo-environmental impact assessment are addressed. For these parametric analyses, the variation of some important parameters that affect the system performance is examined and illustrated. According to the modeling findings, the net power and hydrogen production capacity of the modeled combined power plant is 982.4 kW and 0.0024 kgs−1, respectively. The cycle's overall energy efficiency is computed to be 40.04%, although its exergetic efficiency is 36.31%. When the irreversibility among the plant components is compared, the highest irreversibility occurred in the PEM water heater with 1508 kW, followed by heat exchangers 1 and 2. Given the economic results, the modeled plant's cost rate is calculated to be 200.2 $/hr. In the end, it can be recommended that this modeled plant is suitable that is from the point of perspective of the performance, economy, and exergo-environmental relations. • A novel multigeneration plant motivated by geothermal energy is proposed. • Modeling and analysis of a multigeneration plant for power, hydrogen, cooling, and freshwater production. • Energy, exergy, economic, and exergo-environmental index analyses are conducted. • Investigating the green and sustainable hydrogen generation method with PEM electrolyzer. • The overall energy and exergy efficiencies are 40.04% and 36.31%, respectively. [ABSTRACT FROM AUTHOR]

This paper delves into the increasingly complex domain of Optimal Power Flow (OPF) within modern power systems, enhanced by the integration of unpredictable renewable energy sources. The research originally integrates stochastic photovoltaic and wind energy sources, along with a suite of Flexible AC Transmission System (FACTS) components – including thyristor-controlled series compensators, static VAR compensators, and thyristor-controlled phase shifters. The primary objective is to solve the OPF problem by reducing generation costs while accommodating the variable nature of renewable energy sources and load demands. This study prioritizes the examination of both constant and fluctuating load requirements. The inherent variability of PV and wind energy, along with load demand, is captured through the modelling of probability density functions. This approach enables a more detailed optimization process, incorporating not just the cost of thermal energy generation but also the scheduling costs of renewable sources and associated penalty costs. Moreover, the study examines the strategic placement and sizing of FACTS components, an aspect essential in minimizing the overall cost of power production. Employing both single- and multi-objective optimization algorithms, the research addresses the OPF problem in a modified IEEE-30 bus system through various case studies. The application of the recently developed flow direction algorithm, including its multi-objective variant with an ε -based constraint-handling mechanism to OPF problem is the primary contributions of this work. The results, benchmarked against several advanced metaheuristic algorithms, reveal the proposed algorithm's superior performance. This comprehensive study not only underscores the potential of integrating renewable energy sources into the grid but also highlights the efficacy of intelligent optimization strategies in managing the complexities of modern power systems. • In a RESs integrated network, the OPF problem is assessed considering FACTS devices. • The placement and sizing of such devices are augmented, considering uncertainties. • Stochastic PV and wind power and uncertain load demand are included in OPF. • Formulation of multi-objective flow direction algorithm and constraint handling mechanism for the said problem. • Performance comparison among various well-known algorithms. [ABSTRACT FROM AUTHOR]

The necessity for sophisticated decision support in industrial manufacturing has been described manifoldly and simulation approaches as well as optimization methods are continuously developed. This can be especially promising when it comes to decision-making with multidimensional requirements of economic and ecological efficiency. However, due to the required expert knowledge, there is still a gap between theoretically applicable and industrially applied methods. The paper therefore presents results of two use cases as part of the European project ECOFACT where different approaches for the combination of simulation and (heuristic) optimization were applied with industry partners. An overview of recent works and systematic literature reviews of sustainable manufacturing and the approaches for combining simulation and optimization is given. Correspondingly, the investigated use cases of automobile paint shops refer to the reduction of environmental impacts by optimized heating processes and an improved batching process to minimize paint waste. In the first case, setup times for heating color pools and ovens were shifted to avoid load peaks in a calculation time of less than one minute. In the second use case batch size was increased by around 25%. [ABSTRACT FROM AUTHOR]

Hydrogen is a great energy carrier that has the potential to reduce pollution and greenhouse emissions if produced by renewables and clean energy systems. However, moving from dependence on fossil fuels to renewables without emissions is a giant and challenging leap. Therefore, nuclear energy is a well-established technology that can help cut emissions and produce the electricity required for hydrogen production. Electrolysis is a promising technology that uses electricity to produce hydrogen from water. This paper investigates the integration of a large-scale PEM electrolysis with the APR1400 nuclear power plant to produce hydrogen. The two subsystems are, firstly, separately modeled using energy and exergy concepts to conduct parametric analysis on each individually. These subsystems are then integrated into one system to evaluate the system performance, hydrogen production rate, and overall system efficiency. The integrated system is examined with different operation conditions. It is found that the overall thermal-to-hydrogen energy and exergy efficiencies of the integrated system are 22.9% and 53.52%, respectively, and the hydrogen production rate is 7.544 kg/s; this makes 651 t per day and 19.5 kt per month. • An APR1400 plant is integrated with a PEM electrolyzer for hydrogen production. • The thermodynamic performance of the integrated system is parametrically analyzed. • The integrated system can produce hydrogen at an optimum exergy efficiency of 53.5%. • The integrated system produces 651 t of H2/day at an energy efficiency of about 23%. [ABSTRACT FROM AUTHOR]

This paper concerns the design, development, and building of a unique electro-bio-membrane reactor for concurrent bioH 2 production, desalination, and energy production by microorganisms in a single reactor. The effects of varying biomass amounts (5–50 g) and inoculum amounts (250–1500 mL) on the bioH 2 production efficiency are also investigated. The lowest cumulative bioH 2 yield of 24.2 mL/g is obtained using a biomass amount of 5 g, while it is 44.7 mL/g at a biomass amount of 50 g. The highest H 2 production from water electrolysis is also found as 0.719 mL/min at improved conditions. Furthermore, the highest power and current density values are 2794.5 mW/m2 and 2786.1 mA/m2 at 1500 mL-inoculum, biomass amount of 30 g, initial pH of 5.5, and temperature of 37 °C in the dark fermentation (DF) cell. Moreover, the desalination efficiency increases from 41.6 to 65.8% with decreasing inoculum amounts from 1500 to 250 mL. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents a combined heating, power, and hydrogen system production by utilizing biogas energy. A novel methodology is proposed to identify thermodynamic cycle conditions and reform processes by using biogas as the energy source. Biogas steam and dry reforming methods are considered based on equilibrium data employing the EES program. It is found that biogas has two principal roles for combustion and reforming processes simultaneously. The thermal energy from the combustion of biogas causes its reforming and improves the efficiency of the system by 74%. The exergy efficiency, the overall exergy destruction, and hydrogen efficiency are calculated for various electric powers ranging from 5 to 40 MW. It is found that the combustion chamber has the maximum exergy destruction of about 51%. The parametric study of the system is performed to assess the optimum conditions for producing hydrogen. The optimal condition corresponds to CO 2 /CH 4 = 0.50–0.66, H 2 O/CH 4 = 2–3.6, and the reforming temperature range of 965–1036 K. The conversion of methane and carbon dioxide shows the reduction of the greenhouse gases. [Display omitted] • A combined heating, power, and hydrogen system production is proposed by utilizing biogas energy. • Biogas steam and dry reforming methods are considered. • The combustion of biogas improves the efficiency of the system by 74%. • The optimal condition corresponds to CO 2 /CH 4 = 0.50-0.66, H 2 O/CH 4 = 2-3.6, and the reforming temperature range of 965-1036 K. [ABSTRACT FROM AUTHOR]

Faced with the growing demand for energy worldwide, fossil fuels, like any other resource available in finite quantities, are in the process of disappearing since their production cannot increase indefinitely. On the other hand, Russia's war with Ukraine is driving up fossil fuel prices, which in turn is impacting price increases at several levels. Added to this is the need to limit global warming, which is largely due to CO2 emissions from the consumption of fossil fuels. Faced with all these constraints, it is essential that the world looks to other sources of energy and that Morocco, in particular, can limit its energy dependence on fossil fuel imports by ensuring an internal energy supply; the best solution appears to be the development of biofuel and in particular, biodiesel. Due to their high energy content and compatibility with gasoline supply infrastructure, biodiesel may be utilized in motor vehicles. To achieve the optimal utilization of biodiesel in internal combustion engines, it is first required to choose the best feedstock that will provide both increased engine performance and economic viability. In this perspective, this paper provides a summary of the climate and energy situation in the world and in Morocco in particular, and then addresses the interest of biodiesel and its production. [ABSTRACT FROM AUTHOR]

Green hydrogen, proposed as a sustainable alternative for conventional fuels, has gained utmost importance due to its reduced carbon footprint and potential application in maintaining balance between energy generation and demand. Utilization of hydrogen-based systems are challenged by cost effective storage methods. Bio-hydrogen storage technologies using cryogenic and adsorptive methods are discussed in this review paper, along with their operating conditions and storage capacities. An analysis of operational challenges and recent advancements in hydrogen storage techniques is presented. With a storage pressure of 70 MP, cryogenic hydrogen is almost twice as dense as compressed hydrogen. Technical challenges such as material cost and explosion risk can be addressed by hydrogen adsorption on activated carbon active sites. Maximum hydrogen storage capacity are reported by activated carbon obtained from Chitosan (6.77 wt%), Bamboo (6.6 wt%) and African palm shell (6.5 wt%) at 77 K and 4–20 Mpa. Further, nanotechnology approaches are presented in detail for increasing hydrogen storage capacity in pristine Si and Mg. The future perspectives in terms of technological, and economic aspects are discussed. • Detailed review on hydrogen storage methods is presented. • Role of cryogenics and adsorptive media are discussed. • The comparative performance of various methods is tabulated. • Existing research gap and future perspectives are analyzed. [ABSTRACT FROM AUTHOR]

Beside the production of hydrogen, the transport is a key component to a successful development of a decarbonized global hydrogen economy. To answer the question, where the required amounts of hydrogen will be produced and along which routes and in which form they will be transported, a sector integrated global hydrogen transport system model needs to be established. This paper provides a flexible method and tool for geographical structuring of sector integrated energy transport systems. It enables the adaptability to existing energy system models and allow for flexible adjustment of the geographical scope. Combined with the integration of pipeline and ship transport it is a novelty, that enables the setup of energy transport systems to perform structured investigation of origin and transport in a future hydrogen economy. The model is validated by comparison with similar studies regarding the directions of hydrogen transport flows. • GIS based method to automate hydrogen transport system development. • Created an accessible and adaptable tool for implementing the method. • Integrated tool with existing energy model, allowing flexible spatial adjustment. • Ensured seamless handover between the tool and energy system modelling framework. [ABSTRACT FROM AUTHOR]

Multigenerational energy conversion plants are one of the most promising solutions for tackling environmental challenges and making efficient use of energy sources. In this regard, a newly designed multigeneration plant integrated with a methane-based Brayton cycle, a steam Rankine cycle, a supercritical CO 2 -based Brayton cycle, a multi-effect desalination process, a PEM unit, a domestic water heater process, and two thermoelectric generators is integrated, proposed and analyzed. The thermodynamic and environmental assessments of the developed paper are conducted and examined with energy and exergy efficiencies as well as CO 2 emission rate. Similarly, a parametric study is executed and reported, by the way, to define the impact of the various significant factors on the developed plant's efficiency. In the end, the CO 2 emission rate is determined and compared according to different energy conversion plants. In light of the analysis results, the net power, hydrogen, and freshwater production capacities of the reference study are calculated to be 1336 kW, 0.002004 kgs−1, and 0.954 kgs−1, respectively. Additionally, it is found that the developed study's energetic and exergetic performances are 55.76% and 52.17%. According to emission analysis results, the multigeneration system emits 272.2 k g / M W h less CO 2 emissions than the single energy conversion system. • A newly designed multigeneration plant is suggested. • Combination of a superciritical CO 2 based Brayton cycle is proposed. • Thermodynamic and environmental analysis of the multigeneration plant is conducted. • Freshwater, hydrogen, power and heating purposes are fulfilled. • The overall energy and exergy efficiencies are 55.76% and 52.17%, respectively. [ABSTRACT FROM AUTHOR]

The hybrid thermochemical copper-chlorine (Cu–Cl) cycle for water splitting, developed as a novel approach to produce green hydrogen, has gained greater attention. A series of close-loop reactions makes the process environmentally friendly. A newly developed hybrid six-step Cu–Cl cycle consists of thermochemical, electrochemical, and a unit operation of spray drying. The present paper analyzes the configuration of the six-step Cu–Cl cycle thermodynamically. Studies on many factors are carried out to determine the cycle's total energy and exergy efficiency. The modeling and simulation of the six-step process was done by Aspen Plus. The six-step cycle was found to have an energy and exergy efficiency of 38.94 % and 52.74 %, respectively. The effect on exergetic efficiency with ambient temperature and cycle temperature variation was also investigated. The enhancement in the effectiveness of six steps Cu–Cl cycle could be possible from the current study analysis using thermal recovery and minimizing exergy destructions. [Display omitted] • Thermodynamic evaluation of novel ICT-OEC copper-chlorine thermochemical cycle. • An investigation based on mass, energy, and exergy balances. • The energy and exergy efficiency of the overall system is 38.94 % and 52.74%, respectively. • The hydrogen production rate of the system is 0.002 kg/s. [ABSTRACT FROM AUTHOR]

The energy transition in many African countries involves the shift from firewood to charcoal and liquefied petroleum gas (LPG) as the primary domestic energy source. In Ghana, the demand for charcoal is on the rise, leading to diverse socio-economic and ecological outcomes in the Savannah woodland. Based on data produced through interviews, focus group discussions, observation, and a survey with 200 questionnaires administered, the paper examines the dynamics of charcoal livelihoods for energy and the ecological effects in the Savana woodland of Ghana. The article shows that charcoal production is critical to meeting household energy needs, supports the livelihood of different categories of people along the value chain and transforms local economies with unequal benefit streams to different actors. However, charcoal production results in loss of vegetation and ecological resilience with different levels of culpability on large migrant producers and small survivalist indigene producers. The paper shows that vegetation loss is highest in areas where indigenous charcoal producers continue to produce after the large-scale producers migrate when they exhaust matured trees. We recommend that stakeholders rethink governance strategies toward regulating the charcoal sector, considering its critical role in meeting domestic energy needs and supporting the livelihoods of many people. • Charcoal production is critical to meeting household energy needs • Charcoal supports livelihoods and transforms local economies with unequal benefit streams. • Charcoal production results in loss of vegetation and ecological resilience with different levels of culpability • Vegetation loss is highest in areas where indigenous charcoal producers continuously produce. [ABSTRACT FROM AUTHOR]

Hydropower has played an important role in Europe in recent decades, offering a unique combination of safe, low-cost, and clean power generation. Today, it is still one of the largest renewable energy sources (RES), accounting for about 35 % of RES electricity generation. However, grid stability is threatened by the increasing amount of undispatchable RES. Flexibility and dynamics such as energy storage and rapid response are urgently needed to achieve EU policy goals. In such a context, hydropower can play a key role, not only as a provider of regulated renewable energy but also due to its ability to balance a renewable energy system in the short term and the medium/long term by pumped storage technology. All these aspects underline the new role of hydropower, which aims to strengthen grid stability and power supply resilience and to enable higher penetration of volatile RES. In this context, the aim of this paper is to demonstrate the role of hydropower at the European level as well as the needs and opportunities of modernization to fully exploit its potential. In particular, this study provides, the assessment of the today flexibility offered by hydropower to the power system at the European level by leveraging a database of information collected through the participants to the working groups of the COST Action Pen@Hydropower which includes stakeholders in the hydropower sector of 34 European countries. The study confirms the key role of hydropower in future energy scenarios with 30 % of the flexibility demand at all time scales met by hydropower. Furthermore, the paper presents a review of the digitalization solutions and innovative technologies that support the growth of a new generation of sustainable hydropower together with the modernization opportunities for existing hydropower plants. The results of this work have practical implications for stakeholders in the hydropower sector and policymakers as it provides evidence at the European scale of the role of hydropower technology in balancing the power system and the need to have supportive frameworks and adequate markets to fully exploit the European hydropower potential to achieve the energy transition goals. [ABSTRACT FROM AUTHOR]

In the current period, there has been a prominent and gradual upswing in the application of Internet of Energy (IoE) sensors in smart cities. These sensors play a vital role across diverse aspects of the energy sector, ranging from producing energy to haggling with the complexities of the smart grid. The IoE sensors use fiber optics technology that increases the speed and bandwidth of data transfer in smart grid applications. Incorporating IoE sensors, including fiber optics, is paramount to rehabilitating extensive IoE sensor data into practical information to distribute energy based on prices, availability, and demand for smart homes and electric vehicles. However, from energy generation to consumption, many nodes are incorporated. Therefore, security is a crucial challenge to processing accurate IoE sensor data for energy generation and consumption in smart cities. This paper presents blockchain-enabled, energy-efficient IoE smart grid architecture for smart homes and electric vehicle applications. The proposed architecture suggests blockchain-energy-efficient IoE sensors data scheduling (BEDS) algorithm schemes that consist of blockchain, smart grid, and vehicle and smart home schemes. The paper considers grid data based on sensors for different applications. The proposed system integrates fiber optics, collecting and offloading sensors to the grid for execution. This study aims to process IoE sensor data based on blockchain with a minimum processing time of 29% and less power consumption of 41%. Simulation results show that BEDS has less processing time and energy consumption than existing proof-of-work and proof-of-stake blockchain methods in smart grid networks. • A smart-grid architecture for energy production in smart cities. • Blockchain energy data scheduling (BEDS) algorithm framework. • An energy-efficient blockchain-enabled IoE smart grid architecture. [ABSTRACT FROM AUTHOR]

The study presents a novel integrated three-compartment electrochemical continuous electrodeionization reactor that was constructed in a laboratory environment. In order to extract large amounts of carbon dioxide from naturally occurring oceanwater in the form of bicarbonate and carbonate, it develops a innovative electrolytic cation exchange process. At the same time, it produces hydrogen gas for possible hydrocarbon synthesis. The study employs the Box-Behnken experimental design approach implemented through the Design Expert software to investigate and optimize the performance of electrochemical hydrogen extraction from Ocean water from an integrated reactor. The integrated electrochemical continuous-type electrodeionization reactor comprises two cation-permeable membranes that operate as boundaries between three compartments: a central compartment and electrode compartments that house the cathode and anode, each of which may reverse polarity. These membranes are made of gel polystyrene cross-linked with divinylbenzene, which has acidic properties that allow cation transport while inhibiting anions. The integrated reactor's electrode chambers are enclosed in plexiglass end plates and contain distinct Plexiglass electrode compartments. These compartments have mesh and solid steel anode and cathode electrodes, with an electrode active area of 176.71 cm2. The influence of various factors, such as voltage and electrolyte amount, on the production of hydrogen synthesis is examined. The study results demonstrate a maximum hydrogen production rate of 2.2 mg/min and a hydrogen production efficiency of 7.82%. The lab testing was carried out using experimental equipment to determine viability. The tests included 35-min runs that measured hydrogen generation under various parameters, such as applied voltage, electrolyte concentration, and pH levels. The ocean salt solutions of 0.5M, 1M, and 2M were initially prepared and evaluated for hydrogen generation. Each concentration is assessed at a voltage range of 4–15V, with matching solution pH values ranging from 2 to 7. Optimization studies were conducted to enhance the hydrogen production rate. The results indicate that hydrogen production rises proportionally with applied voltage and electrolyte concentration but falls with pH growth. Within the Design Expert software, the statistical methods for response surface analysis and optimization are utilized accordingly. • The paper develops an integrated three-compartment system for hydrogen production. • The paper investigates the system overall efficiencies for assessment. • It discusses how varying voltage and concentration affects hydrogen production. [ABSTRACT FROM AUTHOR]

As one of fundamental problems in robotics, coverage path planning (CPP) requires the robot path to cover the entire workspace which has been employed in several essential applications such as cleaning robots, land mine detector, lawnmowers and automated harvesters. Unlike most of existing studies considering the CPP problem under a unrealistic assumption of infinity energy, this paper takes the battery limitation of robots into account. This poses a significant challenge for enabling an efficient coverage path while satisfying the limited energy constraint, even in a priori known environment. Handling this challenge, we propose a BWave Framework that guides the robot to move following an improved Boustrophedon-like motion and a special area prioritization and especially, to return a charging station effectively before an exhausted energy. To that end, a weighted map is applied for recognizing the special areas, namely trap regions, and governing the robot to enter these fields in priority. Moreover, a return matrix, which forms the shortest-path tree from the charging station, is pre-computed to not only validate the energy requirement, but also speed up the calculation process of return and advance paths during the robot's operation. We then evaluate BWave Framework extensively in various scenarios in both generated and real-life indoor maps datasets. The results show that compared to typical baseline methods, BWave Framework achieves the CPP solution at a significantly accelerated running time, namely 51.5 to 72.8 times lower for generated maps, and 44.8 to 255 times for real maps, while reducing the total path length by 2.4%–17.6% and by 2.9%–18.5%, respectively. Moreover, the proposed method also outperforms the baselines in terms of overlap rate, number of returns and accounts for a lower number of deadlocks. • This paper tackles coverage path planning with energy constraints. • It introduces BWave, a novel framework for complete coverage. • BWave has two phases: environment knowledge extracting and complete coverage. • BWave is evaluated in various scenarios and compared with state-of-the-art methods. • BWave performs well in environments with many trap areas. [ABSTRACT FROM AUTHOR]

• Evaluation: steam sterilisation combined with gasification of Australian hospital waste is technically feasible. • Literature review reveals that compositional breakdown of Australian hospital waste is lacking. • Detailed breakdown of Australian hospital waste publicly reported for first time; plastic accounted for ∼75 % of waste. • Treatment can divert ∼96 % of hospital waste mass from landfill, transport & associated emissions reduced by ∼92 %. • National adoption of gasification may divert ∼200,000t of hospital waste from landfill annually. This paper reports on an alternate approach to hospital waste management by technically evaluating onsite steam sterilisation coupled with gasification to treat general and clinical waste. A literature review revealed a dearth of information on compositional breakdown of Australian hospital waste which may limit the application of more circular waste management practices. Three Australian hospital waste profiles were assessed; general and clinical wastes contributed on average 84.8 % and 6.9 % by weight respectively. Australian hospital general waste composition, reported here for the first time, was categorised into its major components with plastic and paper & cardboard representing 74.5 % and 13.4 % respectively. Technical assessment combining waste composition with theoretical values revealed that Australian hospital waste was well suited to processing through gasification and provided significant benefits. Environmental benefits included 95.9 % reduction in landfilling and associated emissions from landfill, transport and incineration, improved landfill lifespan and recycling. National hospital waste production was estimated at 230,717 tonnes per annum for 2019/2020. [Display omitted] [ABSTRACT FROM AUTHOR]

• Based on GTAP 10 database, RED-ALC China and China Global Investment Tracker database, we use the CGE model to simulate the influences of Chinese multinationals' investment on Latin American and Caribbean (LAC) economies. • Chinese investment and the booming economy are the engines for LAC development. • Chinese ODI contributes to GDP growth, and trade balance improvement in LAC. • The industries with resource endowments in LAC have expanded largely and squeezed out the production of manufactures. Under the 'Belt and Road' initiative, China has expanded its footprint in Latin America and Caribbean (LAC) and contributed to LAC FDI stock, as well as, gross fixed capital formation and GDP. Based on the firm-level Chinese investment data and GTAP database, this paper uses the computable general equilibrium model to estimate the influences of Chinese direct investment on LAC economies. Chinese ODI and the booming economy are the engines for LAC development, according to its contribution to GDP, and trade balance improvement. The rest of LAC economies, China and US benefit indirectly from Chinese investment as well. Each country gives its full play to its comparative advantages. However, it is cautious that the industries with resource endowments in LAC have expanded largely and squeezed out the production of manufactures, which makes LAC economies more dependent on the growth of Chinese economy. [ABSTRACT FROM AUTHOR]

The UK government aims to transition its modern natural gas infrastructure towards Hydrogen by 2035. Since hydrogen is a much lighter gas than methane, it is important to understand the change in parameters when transporting it. While most modern work in this topic looks at the transport of hydrogen-methane mixtures, this work focuses on pure hydrogen transport. The aim of this paper is to highlight the change in gas distribution parameters when natural gas is replaced by hydrogen in the existing infrastructure. This study uses analytical models and computational models to compare the flow of hydrogen and methane in a pipe based on pressure loss. The Darcy-Weisbach and Colebrook-White equations were used for the analytical models, and the k- ε model was used for the computational approach. The variables considered in the comparison were the pipe material (X52 Steel and MDPE) and pipe diameters (0.01m–1m). It was observed that hydrogen had to be transported 250–270% the velocity of methane to replicate flow for a fixed length of pipe. Furthermore, it was noted that MDPE pipes has 2–31% lower pressure losses compared to X52 steel for all diameters when transporting hydrogen at a high velocity. Lastly, it was noted that the analytical model and computational model were in agreement with 1–5% error in their findings. [Display omitted] • Hydrogen is expected to replace methane by 2035 for domestic heating applications. • Analytical and computational models were used to compare flow of hydrogen and methane. • Hydrogen velocity must be up to 2.7 times faster than methane to replicate flow. • MDPE pipes showed lower pressure losses than steel pipes due to reduced roughness. [ABSTRACT FROM AUTHOR]

The energy of a graph is defined as the sum of absolute values of all eigenvalues of its adjacency matrix. For a nonempty graph G , S. Akbari, A. Alazemi, M. Andelić and M.A. Hosseinzadeh proposed a conjecture: The energy of the line graph of G is at least | E (G) | + Δ (G) − 3 , where E (G) is the edge set of G and Δ (G) is the maximum degree of G. In this paper, we give a proof confirming the conjecture, and present a lower bound and an upper bound for the energy of line graphs of regular graphs. [ABSTRACT FROM AUTHOR]

The last 20 years has seen rapid expansion of sustainable energy deployment in the European Union (EU) and the United States (U.S.) that is driving the demand for trained professionals. An engineering degree with coursework in sustainable energy systems is a desirable initial qualification. However, engineering students should also appreciate the societal and environmental impacts of the sustainable energy transition. Furthermore, since the sustainable energy transition is a global endeavor, an international perspective is needed. The sustainable energy engineering course described in this paper taught students the scientific and engineering principles underlying the major types of emerging sustainable energy technologies from a chemical engineering perspective. The technical content served as context for comparing renewable energy deployment in the EU country of Austria with the U.S. The broader impacts (societal and environmental) of renewable energy deployment were then illustrated through student presentations. Survey results showed that students gained understanding of the engineering fundamentals underlying these renewable energy systems and challenges of their deployment in Austria and the U.S. Therefore, a unique outcome of this course was that students gained an international perspective on the expansion of sustainable energy systems needed to secure a low-carbon energy future. • New approach for developing and teaching a sustainable energy engineering course. • Topics sequenced through Technology-Resources-Deployment-Broader Impact subtopics. • Renewable energy technologies taught from a chemical engineering perspective. • International perspectives by comparing US and Austria renewable energy deployment. • Broader (societal, environmental) impact discussions through student presentations. [ABSTRACT FROM AUTHOR]

With advances in AI (Artificial Intelligence) and the surge of Big Data, Deep learning (DL) has a remarkable impact on businesses in various domains including finance, marketing, healthcare, manufacturing, and agriculture. From sales prediction to detection and monitoring customer behaviors, its use in business analytics is proven to help grow and improve business functions. However, execution of DL can instigate high cost during both model training and deployment. Time and energy are two essential cost factors of DL computation as they imply not only monetary but also environmental consequences. Moreover, different DL architecture incurs different costs. Selecting the best model to train and deploy is hence important to the business. Most existing work focuses on building a DL model that obtains the highest accuracy or similar measures to evaluate quality of data analytics. In this paper, we argue that in practice, such performance criteria may not be adequate, for example, the most accurate model may not be the most cost-effective. This paper studies a practical approach that includes energy consumption during training and deploying the trained DL in deciding what DL model should be deployed. The paper describes how energy consumption can be estimated and illustrates the approach for cost analysis of DL application on the smart agriculture business where plant disease classification model is trained and deployed. Lessons learned from the study is included. In summary, our contributions are: (1) an approach to analyze cost of using DL model in terms of time, accuracy and energy consumption to support model selection, and (2) application of the approach on plant disease classification in smart agriculture business. [ABSTRACT FROM AUTHOR]

Drones or unmanned aerial vehicles (UAVs) are increasingly deployed for disaster relief, from aiding in drug or supply delivery to search and rescue victims. For a large-scale mission, the more drones are used, the more difficult they are to control and manage in a timely manner. Automated control is one of the central techniques used in knowledge-based drone management systems to enhance the quality and efficiency of the disaster relief mission. Although many drone management systems have been developed, automatic control of these systems remains a difficult problem. Many approaches have "human in the loop" that trades the degree of autonomy with the efficiency and perhaps accuracy. Our goal is not to fully automate the system but to reduce user interactions where intelligible (e.g., selecting appropriate drones/actions based on prioritized needs) by means of significant advances in control mechanisms. This paper presents a knowledge-based framework for intelligent drone management by explicitly representing control knowledge for use in selecting appropriate task-specific actions. The paper describes how control decisions are derived using domain knowledge relevant to drones and disaster relief. By employing a blackboard control architecture, our framework provides adaptability for dynamic control behaviors and flexibility to handle unanticipated situations during the drone mission activities. The paper illustrates the use of the framework on specific scenarios. [ABSTRACT FROM AUTHOR]

Electric ships are becoming a promising way in shipping decarbonization. Nevertheless, the promotion of electric ships encounters obstacles related to indirect emissions, energy and costs. This paper proposes the Shipping Emission-Energy-Economic Impact Assessment Model (SE3IAM) to assess the decarbonization potential of electric ships. China is selected for the case study. This paper also analyzes the impact of climate policies and other factors on CO 2 emissions. Results indicate that as the market share of electric ships gradually reaches 1%, 20%, and 35% by 2050, accompanied by advancements in other technological aspects, the total emissions to 2050 are estimated to be around 2, 1.5, and 1 billion tons, respectively. There is a positive correlation between energy demand and decarbonization costs with the level of economic development. Technological progress can alleviate pressures on energy and costs. It is recommended to advance decarbonization at a fundamental level by enhancing energy efficiency and fostering electrification. [ABSTRACT FROM AUTHOR]

As the most consumed edible oil worldwide, palm oil consumption boosting results in more planting and more oil palm by-products (5 times more than palm oil production). In order to meet environmental sustainability, various oil palm by-products in the form of residual lignocellulosic biomass are available for exploitation from palm oil mills. Although their disposal might pose some undesirable environmental impacts, economical applications of these untapped by-products, oil palm fiber in particular, into useful alternatives have been progressively developed over the past decades: pulp and paper, animal feed, renewable energy, automobile, agricultural and architectural substitutes, water treatment media, polymer and composite, to name a few. This review addresses various innovative valorization of oil palm fiber, their versatile application status and potential projection as a sustainable alternative. A proposed scheme to fill in the knowledge gaps identified and provide future direction is put forth for consideration. • Examines progress and rate of oil palm fiber utilisation under improper disposal issue. • Various innovative valorization and potential projection as a sustainable alternative. • The top three sectors in 2022 is revealed via bibliometric analysis of the literature. • The research findings of dominant sectors can serve as a guide for future study. [ABSTRACT FROM AUTHOR]

When customers purchase goods provided by public utilities, such as telecommunications, water, gas or electricity, the predominant payment system is pay-later billing. This paper tests the effectiveness of a pay-as-you-go system and the importance of payment timing in reducing consumption. I conduct a lab experiment which mimics an energy consumption choice and randomizes the timing of when consumption costs are paid: Either immediately ('pay-as-you-go') or one-week after consumption ('pay-later'). Results show that pay-as-you-go billing significantly decreases energy consumption. Yet the decrease in consumption comes at the cost of needing more work time to complete a fixed number of real-effort tasks. As the design controls for a number of contaminating effects, present-focused discounting of the future energy bill under the pay-later system is the likely explanation for the change in behavior. [ABSTRACT FROM AUTHOR]

This paper presents a one-dimensional and semi-empirical model of a high-temperature PEM fuel cell (HT-PEMFC) to determine the performance characteristics through energy, exergy, and ecological analysis. The proposed model is compared with different experimental studies and supported by a few statistical approaches to prove its accuracy. As a result, the minimum and maximum R2 values are determined to be 99.67% and 99.97%, respectively. In addition, the performance of the fuel cell is investigated under varying leakage current densities and doping levels. Accordingly, increasing the leak current density decreases the power density, net output voltage, energy efficiency, and exergy efficiency by 5.77%, 5.88%, 5.44%, and 5.48%, respectively, whereas increasing the doping level boosts these parameters by 23.07%, 11.76%, 30.25%, and 32.52%, respectively. In addition, increasing the leak density decreases all ecological functions. In contrast, raising the doping level increases the ecological parameters considerably and reduces the improvement potential. • A novel one-dimensional and semi-empirical model of the HT-PEMFC was adopted. • The proposed model was compared and verified with different experimental studies. • Performance assessment was conducted via energy, exergy, and ecological analyses. • Increasing the doping level from 6.2% to 30% enhances exergy efficiency by 32.52%. • The doping level is more effective on the performance than the leak current density. [ABSTRACT FROM AUTHOR]

The present review paper aims to shed lights on the concept of fully green energy system which includes both the source of energy and the storage system. The objective is to propose an energy label "Green to Green" (G2G) that identifies systems involving simultaneously green source and green storage, as an efficient solution to achieve a significant reduction in the dangerous level of pollution that most countries have reached today. Green sources include mainly renewable energy systems such as solar, wind, geothermal and wave energy systems. In its turns green storage includes pumped hydroelectric, flywheel, hydrogen and compressed air. Moreover, and as a case investigation on G2G concept, the paper reviews the main solar-hydrogen coupling systems, that are categorized within four categories parabolic trough-hydrogen, solar tower-hydrogen, photovoltaic-hydrogen and solar chimney-hydrogen. • Green to Green (G2G) is presented as a label to promote pollution-free systems. • Green storage includes Hydrogen, flywheel, compressed air and pumped hydro. • As a case study on (G2G) concept, the paper highlights solar – hydrogen coupling. [ABSTRACT FROM AUTHOR]

Blockchain technology has been proposed to achieve sustainable development through various solutions, such as carbon credit trading, energy systems and supply chain management. While existing literature has not covered this topic in a structured fashion, this paper provides insights to policymakers on how blockchain can deliver sustainable development. This study conducted a systematic literature review on the role of blockchain technologies in assisting policymakers in achieving ESG and environmental sustainability goals. The paper performs a detailed PRISMA SLR analysis of 10,188 technical and policy papers sourced from Scopus and IEEE databases to ensure high-quality inputs and breadth of coverage across relevant sources. In addition, the study reviews the relevant regulatory environment related to ESG, including SDGs, IPCC, COP 27, ESMA, ISSB, SEC, GRI, TCFD, ESRS, IFRS S1 and S2 and CRSD. Most papers do not outline a structured approach to applying blockchain in the emerging regulatory environment. Our paper outlines recommendations to policymakers wishing to ensure that the blockchain research community and solutions proposed are usefully directed to enable the world to achieve its net zero goals. • Blockchain energy measurements are currently heterogenous, unable to be compared and provide varying results. • The blockchain and cryptocurrency industry could learn much from how the ICT industry approaches environmental measurement. • Emerging regulations for CRSD and others mean increasing demands to measure energy consumption efficiently. • Policymakers can drive the industry to ensure blockchain delivers sustainable development instead of unintended consequences. • Paper provides a systematic literature review of 6545 papers on blockchain and sustainability to guide policymakers in this space. [ABSTRACT FROM AUTHOR]

• Existing technologies like smart grid (SG) and smart meters play a significant role in meeting the everlasting demand of energy consumption, supply, and generation for Peer-to-Peer (P2P) energy trading between different distributed prosumers. Whereas blockchain when used with P2P energy trading plays a major role in cost and security for trading by eliminating any involvement of outsiders and third parties. However, existing works related to the blockchain with P2P energy trading are engaged in increasing the cost related to resource allocation, latency, computational processing, and large network setup. • Moreover, in current existing techniques, peer nodes can send 25-200 transactions per second. By expanding the number of peer nodes, the network traffic volume can also be enhanced. This resulted in a significant reduction in network throughput. The network latency will increase as the number of peer nodes grows. • The objective of this paper is to design and develop a 3-tier architecture, an analytical model, and a hybrid algorithm for network analysis in a blockchain-based P2P energy trading system using reinforcement learning (RL) and feed-forward neural network (FFNN) techniques. In this model, we will examine the various parameters and tradeoffs which affect the delay, throughput, and security in P2P energy trading. This will lead to profitable P2P energy trading between different distributed prosumers. Existing technology like smart grid (SG) and smart meters play a significant role in meeting the everlasting demand of energy consumption, supply, and generation for peer-to-peer (P2P) energy trading between different distributed prosumers. Whereas blockchain when used with P2P energy trading plays a major role in cost and security by eliminating any involvement of outsiders and third parties. However, existing works related to the blockchain with P2P energy trading are engaged in increasing the cost related to resource allocation, latency, computational processing, and large network setup. The objective of this paper is to design and develop a three-tier architecture, an analytical model, and a hybrid algorithm for network analysis in a blockchain-based P2P energy trading system using reinforcement learning (RL) and feed forward neural network (FFNN) techniques. In this model, we will examine the various parameters and tradeoffs which affect the delay, throughput, and security in P2P energy trading. This will lead to profitable P2P energy trading between different distributed prosumers. By analyzing the simulation results of the proposed model and algorithm by benchmarking with the existing state-of-the-art techniques it's clear that the proposed algorithm shows marked improvement over network latency generated results. The simulation of the model is conducted using the iFogSim simulator, Ganache with Ethereum platform, Truffle, Python editor tool, and ATOM IDE with solidity. [ABSTRACT FROM AUTHOR]

• This study reports a novel approach for hydrogen production and measurement of coated 3D-printed electrodes for hydrogen evolution reaction in alkaline water electrolysis. • The initial hydrogen rate is reported to be 2.48 × 10-9 kg/s and 2.37 × 10-9 kg/s respectively for nickel-copper non-conductive PLA-conductive nickel paint electrodes and nickel-copper-coated conductive PLA. • The approaches investigated provide the potential for optimizing the electrodes for electrolysis, offering a promising avenue for design improvements. This paper introduces a unique approach for hydrogen production and measurement of coated 3D-printed electrodes for hydrogen evolution reaction in alkaline water electrolysis. The method investigated in this study involve using non-conductive and conductive polylactic acids (PLAs) followed by various coating techniques to fabricate cathodes for alkaline water electrolysis. During the electrodeposition process, nickel and nickel alloys, including nickel-copper, nickel-iron and nickel-molybdenum, are investigated as coating materials. This paper also provides valuable data on hydrogen production and the respective cathode energy and exergy efficiencies. The study finds that the hydrogen production rate is the highest at the start and declines over time. The hydrogen rate for the first 15 min is reported to be 2.48 × 10-10 kg/s and 1.38 × 10-10 kg/s after 30 min for nickel-copper coated electrode where non-conductive PLA is used along with conductive paints. In comparison, the hydrogen rate for the electrode with nickel-copper coated directly on the conductive PLA is 2.37 × 10-10 kg/s for the first 15 min and 1.35 × 10-10 kg/s after 30 min. Interestingly, the coated conductive PLA electrodes are shown to be more efficient despite slightly lower hydrogen production rates. Moreover, the unique approaches employed in this paper are expected to provide a potential cost-effective approach for improving the performance of the electrodes for electrolysis which can lead to the development of more efficient hydrogen production for industrial applications. [ABSTRACT FROM AUTHOR]

Spontaneous combustion often occurs when carbonaceous materials are stored for a long time. Up to now, domestic and foreign scholars have done a lot of research on the spontaneous combustion mechanism of coal and biomass fuel, monitoring methods and prevention measures, and achieved fruitful results. It is worth noting that coal and biomass are not the same type of energy, but the internal mechanism and external performance of spontaneous combustion of the two are very similar, and both involve complex physical and chemical reactions. At present, very fruitful results have been achieved in coal spontaneous combustion monitoring and fire prevention in mine, but the spontaneous combustion research around coal storage silos and biomass silos is insufficient, and the spontaneous combustion monitoring and fire prevention technology for them is relatively backward. Therefore, by summarizing and comparing the relevant work in recent years, this paper aims to sort out the similarities and differences of the occurrence mechanism, monitoring methods and prevention measures of the two, explore the technologies and theories that can learn from each other, promote the progress of the two in the study of spontaneous combustion mechanism, and promote the development of more advanced spontaneous combustion monitoring and fire prevention technology. And the application in the mine-out area, coal storage silo, biomass silo and other scenarios, to provide theoretical and technical references for the future safe storage of coal and biomass. • This paper first draws out the similarities and differences between coal and biomass in terms of spontaneous combustion mechanism, monitoring and prevention through case analysis. In order to promote their integration and reference in theory and technology. • Through the comparison of biomass and coal spontaneous combustion studies, this paper puts forward some feasible new ideas in spontaneous combustion monitoring and fire prevention. • This is of great innovative significance for spontaneous combustion monitoring and prevention of coal and biomass under silo conditions. [ABSTRACT FROM AUTHOR]

To achieve carbon neutrality, China must grasp the intricate factors driving coal market, as it addresses coal consumption and reduces the carbon footprint. While previous studies have identified certain factors, they have largely overlooked the impact of the overall industry sector on the coal market. In this paper, a hybrid causal machine learning model was proposed that combine with least absolute shrinkage and selection operator (LASSO), multiple linear regression (MLR), peter and clark momentary conditional independence (PCMCI) and interpretable machine learning. The approach employed a complex network perspective to identify 10 key factors in China's coal market from three dimensions: industrial sector, foreign trade and energy market. The hierarchical pattern of these factors is classified into two levels: direct factors, primarily encompassing crude oil futures, exchange rates and architectural decoration, and intermediary factors, mainly including the chemical industry and building material. Interestingly, this paper reaffirms the roles of crude oil futures and exchange rates in the coal market, as identified in prior studies. Additionally, it uncovers new influential factors primarily driven by the chemical industry and architectural decoration, previously unexplored. Furthermore, this paper found a significant contemporaneous relationship between crude oil futures and coal price index (0.151) as well as coal consumption (0.102), and the strong relationship between coal consumption and the Indonesian Rupiah to Chinese Yuan exchange rate (0.063) was also confirmed. Among the emerging dominant factors, the coal price index and the chemical industry (0.145), along with coal consumption and building materials (0.250), also exhibit a strong contemporaneous relationship. These findings highlight the importance of considering the entire industry sector while analyzing the coal market and promoting a cleaner transformation of the industry in China, and the paradigm presented not only applicable to the coal market, but can be extended to other industries. [Display omitted] • Better grasping key factors in China's coal market critical to carbon neutrality. • A comprehensive study encompassing industrial sector, foreign trade and energy market. • A novel hybrid machine learning models and industry-wide features are introduced. • Identification and categorization of direct and intermediary factors. • Findings offer a new paradigm for decision-making, driving cleaner production reforms. [ABSTRACT FROM AUTHOR]

This paper presents the development of a fuzzy control implemented in a domestic refrigerator in which the thermal load (food) is included as an input variable and a novel aspect of the control. The fuzzy control regulates the speed of the fan attached to the evaporator and the airflow to the fresh food compartment of the refrigerator according to a set of rules that incorporate the amount of thermal load and the temperature conditions of the compartments. The fuzzy control was evaluated in an empty refrigerator (without food) and with three thermal load conditions. Thus, resulting in a fuzzy control capable of maintaining thermal conditions similar to those obtained with the factory ON/OFF refrigerator controller. In addition, the total energy consumption is reduced by 1.7% when the refrigerator is empty and by a maximum of 9.53% in the presence of a low thermal load. Finally, the coefficient of performance shows increases in all the cases studied with the implementation of the fuzzy control. [ABSTRACT FROM AUTHOR]

Due to leachate contamination in groundwater and also soil, global concerns about improper waste management are today raising. On the other hand, with the emergence of the circular economy, increasing the recycling rate, reducing the landfilling rate, and producing by-products such as energy and compost from waste have become particularly important. In this regard in this paper, a chain consisting of a collector, a municipality, a compost plant, and a power plant is considered in a municipality-led Stackelberg game under government intervention. Indeed, the government supports citizens, the compost plant, and the power plant with subsidies to control the prices economically and sets penalties for greenhouse gas (GHG) emissions and leachate infiltration. The collector collects waste through two competitive channels: one from the city's trash bins and the other through buying recyclable waste from citizens, whereas each channel has its collection function. The municipality makes environmental efforts such as increasing people's awareness and investing in technology level to separate and treat leachate. The municipality also receives a fee from the collector for allowing the collection of recyclable waste. On the other hand, the compost and power plants produce compost and energy from waste and price their product based on the level of environmental efforts such as leachate treatment and GHG control, respectively. A real example has been finally implemented for the Tehran Waste Management Organization and the sensitivity analysis is presented. The results have shown that the source separation rate 72.36 % and the recycling rate 69.62 % of the ordinary waste channel are the highest and the landfilling rate 4.09 % is the lowest in the best government policy, which is environmental efforts compared to other policies; Moreover, the profit of the members is the maximum in this policy. [Display omitted] • Investigating the waste SC by game theory approach under government intervention. • Considering a collector, a municipality, a compost plant, and a power plant. • Proposing collection functions depend on level of environmental effort and price. • Subsidizing the purchase of recyclable waste from the citizens by government. • Pricing of by-product of waste supply chain (electricity and compost). [ABSTRACT FROM AUTHOR]

International trade volumes have grown due to acceleration of marine transportation of goods between continents. However, there is a concomitant increase in fossil fuel consumption and adverse environmental impact. This paper presents a new design of marine engines comprising of gas Brayton cycle, solid oxide fuel cell, and two organic Rankine cycles to replace two-stroke internal combustion engines. Hydrogen, methane, dimethyl ether, ethanol, and methanol are potentially selected as green fuels. In addition, liquified natural gas is used for cooling processes. This integrated hybridized marine engine is thermodynamically analyzed using the Aspen Plus software to assess its performance energetically and exergetically. It is found that the engine's total power is boosted by 33% to an average of 15758 kW with average energetic and exergetic efficiencies of 38% and 46%, respectively. The maximum power is fulfilled using all sustainable fuel blends to reach 16087 kW with a maximum carbon emission reduction of 83% and minimum specific fuel consumption. The proposed engine has better performance and less environmental impact, which is a more convenient choice than traditional engines. [Display omitted] • Five alternative fuels are chosen with different concentrations. • Integrated hybrid marine engine produces a total power of 16087 kW by 33% increase. • Engine runs at a 38% energy efficiency and 46% exergetic efficiency. • Alternative fuels can reduce carbon emissions by more than 80%. • New engine fuel consumption is reduced by more than 55%. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new arrangement of a single flash geothermal power plant with a transcritical carbon dioxide recovery cycle is presented. • Energy analysis and exergy have been performed for both BASIC and recovery performance modes. • The results show that the proposed system in the recovery mode with a net power of 401.40 kW, energy efficiency of 53.6%, and exergy efficiency of 46.32% has been calculated. • Compared to the basic operating mode, the total output values of energy, energy efficiency and exergy efficiency show an increase of 149.9 kW, 2.39% and 12.12%, respectively. The use of new energy sources, such as geothermal energy, is rapidly expanding worldwide, and it is a viable alternative to fossil fuels. This paper proposes a geothermal power generation system (combined single flash geothermal cycle with transcritical carbon dioxide recovery cycle). To improve system performance, a recuperator is used to recover some of the heat loss. The proposed system simulation is performed in EES software and then validated by previous research. The proposed system is analyzed from the perspective of energy and exergy. The effects of the proposed system separator pressure, carbon dioxide turbine inlet pressure and carbon dioxide condenser outlet temperature on energy efficiency, exergy efficiency and system net power output have been investigated. Findings show that the proposed system in recovery mode has a net power output of 401.40 kW, energy efficiency of 53.6 percent, and exergy efficiency of 46.32 percent, which are significantly higher than the basic mode's values of 149.9 kW, 2.39 percent, and 12.12 percent, respectively. [ABSTRACT FROM AUTHOR]

The high interfacial resistance between V 2 O 5 cathode materials and conductive agents (molten salt and super carbon) is one of the biggest issues that hinder the development of high specific energy thermal batteries. Designing fast Li+ and e– transport channels in cathode electrodes is considered as an effect method to improve electrochemical performance. Hence, a high-temperature ultrafast welding is proposed to reduce V 2 O 5 /conductive agents interfacial resistance by reconstructing the transmission channels of Li+ and e– in this paper. The experimental studies reveal the optimum ultrafast welding of 700 °C for 10 s, eliminating gap resistance of cathode electrodes induced by the melt of solid molten salt and rebuilding the more plentiful Li+ and e– transport channels, further reducing the contact resistance and gap resistance. Therefore, the electrodes deliver a high specific capacity of 270.69 mAh g−1 and a high specific energy of 610.60 Wh kg−1 at 0.1 A cm−2 and 500 °C with a cut-off voltage of 1.6 V. The high-temperature ultrafast welding provides guidance to build Li+ and e– transport channels of other cathode materials in thermal batteries. [ABSTRACT FROM AUTHOR]

Biomass is the most widely used renewable energy source which is highly appreciated due to its high availability and non-intermittent nature. Considering problems such as reduction of fossil fuels, global warming, and emission of greenhouse gases, lack of attention to the existing situation may cause irreversible damage to the future of the planet. In addition to using renewable energy sources, improving the efficiency of systems will also be helpful. Polygeneration systems play an important role in increasing efficiency and reducing pollution. So, the use of biomass in polygeneration systems seems to be a great approach for sustainable development. Recent studies on biomass-based polygeneration systems have focused on how to use biomass and integrate diverse subsystems to achieve the best performance from energy and exergy viewpoints. The present paper reviews biomass-based systems, and the parameters affecting the performance of these systems. The literature review shows that the high exergy destruction rate in the gasifiers is the most frequent problem among recent articles. In addition, despite the advantages of anaerobic digestion process, the number of studies conducted on the use of this method for biomass conversion is small. In the end, results, limitations, and future outlooks of these systems are discussed. [ABSTRACT FROM AUTHOR]

• Energy and climate papers that link models and socio-technical transitions theories or theoretical frameworks are reviewed. • Three aims are identified: Solutions to energy and climate challenges , increasing realism , and interdisciplinary learning. • Most studies demonstrate substantial benefits of interdisciplinary learning. • Few studies demonstrate concrete findings on how to meet climate and energy targets or to improve realism of models. • We suggest redirecting such integrative research to provide more practical outcomes to meet energy and climate targets. In the last decade, a new strand of energy and climate research emerged that links quantitative models and socio-technical transitions theories or frameworks. Linking the two enables capturing the co-evolution of society, technology, the economy and the environment. We systematically review this literature (N = 44) and describe the papers' trends, scope, temporal and spatial foci, and methodological strategies. The reviewed literature aspires to find solutions to the energy and climate challenges, to increase realism in models and theories, and to enable interdisciplinary learning between the two scholarly communities. The outcomes in this literature show benefits of interdisciplinary learning between modellers and transitions theorists. However, the literature rarely identified practical insights for energy and climate solutions or for improving realism in models and theories. We conclude by suggesting that integrative research should be continued, but redirected to provide more practical outcomes to meet energy and climate targets. [ABSTRACT FROM AUTHOR]