Hasil untuk "Energy industries. Energy policy. Fuel trade"

Márton Kovács, Kaito Hirose, Koji Shimoyama et al.

A methodology is presented to develop compact, high-fidelity simplified reaction models for hydrocarbon combustion using virtual species and simplified reaction pathways, with rate parameters optimized via a genetic algorithm (GA). The method was applied to methane and natural gas combustion, targeting key combustion properties: ignition delay times (IDT) and laminar burning velocities (LBV). The approach combines a detailed H2/CO core with virtual reactions representing the main fuel oxidation pathways through fuel, fuel radical, and aldehyde virtual species. For natural gas, fuel components were lumped, and averaged thermodynamic properties were assigned to the virtual species. The optimization process produced simplified models with 14 species and 57 reactions, which could accurately reproduce the IDT and LBV simulation results of the AramcoMech 3.0 detailed model across a wide range of equivalence ratios and temperatures. The mean absolute deviations for all test conditions were 11.9% for IDT and 2.5% for LBV in methane, and 10.5% for IDT and 1.4% for LBV in natural gas simulations. The models could capture the tendency differences between methane/air and natural gas/air mixtures in ignition characteristics while preserving the similarities in flame propagation. The proposed method offers a practical alternative to conventional reduction techniques, enabling the generation of simple yet accurate reaction models suitable for CFD simulations in practical combustors with significantly reduced computational cost.

Thai-Ha Le, Youngho Chang, Donghyun Park

Zihe Wang, Yueqiao Sun, Hui Kong et al.

Abstract With the intensification of global climate change, carbon neutrality has become a crucial objective for achieving sustainable development, which critically requires systematic technological innovation and collaborative cooperation between technologies and countries. Through categorization and comprehensive technological assessments, a thorough examination of relevant technologies can furnish a framework to guide emission reduction efforts across various sectors. This review seeks to explore the methods by which various countries achieve carbon neutrality technology systems and pathways, with an in-depth study of the differences between the technological approaches and systems in China, the United States, and European countries. The construction of technology systems in several countries is reviewed, from the composition of the systems to the assessment of technologies that include indicators such as carbon reduction potential. Building upon an analysis of key technological pathways in renewable energy, carbon capture, utilization and storage, energy efficiency improvement, and hydrogen energy across different countries, a systematic evaluation is conducted from three key dimensions—policy formulation, resource endowment, and industrial foundation—to identify the similarities, differences, and driving factors in the construction of carbon neutrality technology systems among nations. Based on the previous work, we conducted a comparative analysis and summary of carbon neutrality pathways across various countries worldwide, systematically reviewing and evaluating carbon neutrality technologies in power generation, industry, transportation, and building sectors. Building upon these findings, the study offers recommendations for coupling diverse technological approaches and for international cooperation. By comparing international experiences and practices, this study provides operational references for countries in formulating technology planning and emission reduction strategies, and also provides an important basis for deepening global carbon neutral cooperation in the future.

M. Gandomzadeh, A.A. Yaghoubi, A. Hoorsun et al.

This review consolidates four decades of research (1983–2024) on dust mitigation for photovoltaic systems, categorizing strategies into four key areas: preventive measures, dust monitoring systems, active cleaning methods, and multi-criteria decision-making strategies for cleaning schedules. A systematic content analysis was employed to critically evaluate methodologies, findings, and emerging trends. Preventive measures, notably super-hydrophobic coatings, can reduce dust accumulation by up to 50 %. However, integrating monitoring systems remains complex. The review highlights the potential of hybrid cleaning methods combining manual, mechanical, electromechanical, and electrostatic approaches to balance their benefits and limitations for higher efficiency and practicality. It also emphasizes a shift from fixed-interval cleaning schedules to dynamic, AI-driven decisions based on real-time data, potentially reducing the levelized cost of energy by 8 % for large-scale photovoltaic plants and 4.3 % for smaller systems. Unmanned aerial vehicle-based cleaning methods are recognized as a promising future solution for large-scale photovoltaic systems. The review identifies critical research gaps and provides recommendations for advancing dust mitigation technologies and optimizing photovoltaic cleaning and maintenance strategies to minimize soiling effects. This comprehensive analysis aims to guide future research toward more sustainable and economically viable soil detection and mitigation systems as well as photovoltaic system management.

Jasper Okino, Zachary Siagi, Anil Kumar et al.

This study explored the catalytic upgrading of heavy distillate (HD) from plastic industries into diesel-like fuel using kaolin as a catalyst. A modified brick electric furnace was employed as a heating source for batch reactor and a central composite design response surface methodology utilized for experimentation during both thermal and catalytic pyrolysis. The results showed that kaolin significantly enhanced oil yields, achieving 73.28 wt % at 400 °C with 5 % catalyst loading and 150 min reaction time, and 70.13 wt % at 400 °C with 15 % catalyst loading and 150 min reaction time whereas, thermal pyrolysis yielded 63.63 wt % at 400 °C and 18.88 wt % at 350 °C. The catalytic process modified the functional groups, increasing paraffin and olefin yields, and shifting the carbon range towards diesel-like organics (C6-C23). The resulting diesel-like products exhibited improved properties, with distinct differences observed between those produced with and without kaolin catalyst. Without catalyst, the products had a density of 779 kg/m³, viscosity of 2.63 cSt, and calorific value of 46.62 MJ/kg and that obtained with kaolin catalyst had a density of 788 kg/m³, viscosity of 2.88 cSt, and calorific value of 47.23 MJ/kg, comparable to commercial diesel. Elemental analysis revealed increased carbon content from 77.21 wt % in HD to 83.24 wt % without catalyst and 84.83 wt % with catalyst, accompanied by decreased hydrogen, nitrogen, sulfur, and oxygen contents. The study demonstrates the potential of kaolin-catalyzed pyrolysis for converting heavy distillate into valuable diesel-like fuel. Further research on process optimization, desulfurization, and dehalogenation is recommended to improve the diesel fuel quality. Hence, this study contributes to the development of sustainable waste management and renewable energy solutions.

Raja Owais, Sheikh Javed Iqbal

Abstract Network operators with significant solar photovoltaic (PV) penetration are having difficulty maintaining grid frequency and voltage within acceptable bounds due to the progressive displacement of synchronous machines. Utility‐scale solar PV plants have a huge potential for participation in frequency and voltage regulation since they are linked to the grid through power electronic interfaces with flexible, decoupled control of active and reactive power. A comprehensive control strategy for a utility‐scale solar PV plant is proposed to simultaneously participate in frequency and voltage control without the aid of any energy storage. The frequency response is accomplished by maintaining some active power reserves that enable the PV plant to participate in both over‐ and under‐frequency events. The active power of the PV plant is modulated by operating the PV as a virtual synchronous generator (VSG). Unlike the classic notion of VSG, an intelligent fuzzy‐based technique is employed to adapt the gains of the VSG controller for improved control performance. Additionally, an adaptive droop‐based voltage control mechanism is proposed to control the reactive power reference for the PV plant. The gain of the droop controller is adapted to the varying maximum reactive power capacity of the PV plant. This ensures that the PV system's unused reactive power capability is fully utilised. Through simulation studies, the efficiency of the proposed frequency and voltage control mechanisms is validated under a range of realistic circumstances. The findings show that the suggested control approach can efficiently leverage the PV plants' capacity to handle both frequency and voltage events.

Philip Kofi Adom

I assessed energy efficiency performance and investigated transition tendencies for economies at different development levels. I found that energy efficiency performance is tied to the level of economic development, with developed economies exhibiting higher performance than developing economies. Furthermore, developed economies are more likely than developing countries to transition out of a low energy-efficient (LEE) state. Consequently, achieving higher energy efficiency (HEE) status is expected to be highly sustainable in the short-, medium-, and long-term for developed countries. However, for similar achievements, I found moderate sustainability in the medium-to long-term for upper-middle-income countries and higher unsustainability in the medium-to long-term for lower-middle-income countries. Addressing the gap in the global energy efficiency system requires a ‘big push’ investment in energy efficiency, particularly in developing countries, in addition to implementing a broad policy overhaul aimed at eliminating or reducing market barriers and inefficiencies in energy efficiency.

Tianle Liu, Yixin Hu, Yufei Wang et al.

National parks are rare natural resources that provide refuges for wildlife, harmonious ecology, and leisure activities. These protected areas, which include a variety of ecosystems, habitats for wildlife, and geological wonders, have been set aside to preserve and highlight the beauty of the natural world. Under the goals of carbon neutrality of all countries in the world, it is urgently need to pay attention to the relationship between climate change and protected natural resources. This study uses the Xianju pilot national park as an example to identify key activities that increase carbon absorptions and reduce carbon emissions, calculate the carbon sink of national park construction, and discuss whether tourism industry can achieve low carbon or even negative emissions based on the analysis of low-carbon measures of national parks. Using the Mento-Carlo method, we find that the total carbon sink in Xianju National Park is around 70832–97930 tons CO2, which accounts for about 10 % of Xianju County's total carbon emissions. This illustrates that the development of tourism has indeed brought benefits to the low carbon development of Xianju National Park. From the perspective of stakeholders, this paper also summarizes the stakeholders, relevant actions and policy tools for Xianju National Park to carry out low-carbon tourism. Finally, compared with the development experience of national parks in France and the United States, this paper gives policy suggestions on low-carbon development of Xianju National Park, and proposes to mobilize stakeholders to participate in low-carbon tourism and low-carbon governance.

Wanglin Ma, Puneet Vatsa, Hongyun Zheng

Umar Numan, Benjiang Ma, Muhammad Aslam et al.

The largest contributor to environmental deterioration, the carbon footprint, arises from excessive fossil fuel consumption. Meanwhile, international experts note that despite the positive dynamics in the issue of making commitments to carbon-zero targets, most companies around the globe do not have a clear plan or strategy to achieve environment-based targets. This study addresses sustainable development goals (SDGs) concerning clean energy usage, sustainability, and the environment. Hence, this study investigates the impacts of the economic complexity index (ECI), energy productivity (EPD), renewable energy electricity generation (REEG), and environment-based patents on ecological footprints (ECFP) to attain a carbon-zero environment and SDGs for forty-five exporting countries from 1990 to 2020. An extensive exploration into the connection amongst the explored variables shows that the rises in ECI, EPD, and REEG help subside ECFP in the short-term and long-term estimations. Besides, the results show a bidirectional and unidirectional causality from ECFP to REEG and EPD, respectively. The key practical policies of this work are building modernized tax systems with progressive tax policies, better tax collection, private SDGs financing with incentives regulations, promising project planning on green technologies, and accessibility of grants from global organizations and private sectors to invest in SDGs and a carbon-zero environment target.

Mihai Mutascu

Sampo Soimakallio, Hannes Böttcher, Jari Niemi et al.

Abstract Fossil‐based emissions can be avoided by using wood in place of non‐renewable raw materials as energy and materials. However, wood harvest influences forest carbon stocks. Increased harvest may reduce the overall climate benefit of wood use significantly, but is widely overlooked. We reviewed selected simulation studies and compared differences in forest carbon and amount of wood harvested between harvest scenarios of different intensities for three different time perspectives: short‐ (1–30 years), mid‐ (31–70 years), and long‐term (71–100 years). Out of more than 450 reviewed studies 45 provided adequate data. Our results show that increased harvest reduces carbon stocks over 100 years in temperate and boreal forests by about 1.6 (stdev 0.9) tC per tC harvested (referred to as carbon balance indicator (CBI)). CBI proved to be robust when outliers explicitly influenced by factors other than changes in the harvest rate, such as fertilization or increase in forest area, were removed. The carbon impacts tend to be greatest in the mid‐term, but no significant difference in was found for average values between short and long time‐horizons. CBI can be interpreted as carbon opportunity costs of wood harvest in forests. Our results indicate that even after 100 years, CBI is significant compared to the typical GHG credits expected in the technosphere by avoiding fossil emissions in substitution and increasing carbon stocks in harvested wood products. Our estimates provide typical values that can directly be included in GHG balances of products or assessments of mitigation policies and measures related to wood use. However, more systematic scenarios with transparent information on influencing factors for forest carbon stocks are required to provide better constrained estimates for specific forest types.

Achiraya Chaichaloempreecha, Puttipong Chunark, Tatsuya Hanaoka et al.

Abstract Background The Paris Agreement aims at minimizing threats of climate change by keeping global temperature rise well below 2 degrees Celsius above the pre-industrial level and to pursue efforts to limit the rise to 1.5 degrees Celsius. The Representative Concentration Pathways (RCPs) are developed to investigate GHG emission pathways. RCP2.6 focuses on limiting the global temperature rise to less than 2 degrees Celsius. This paper assesses the impacts of carbon price and CCS on energy and GHG emissions in Thailand. The no carbon price (T0) and the carbon price pathways are compared. In addition, the net-zero emissions and year are discussed. Results The decarbonized energy system with low-carbon power generation and increased electricity usage in the final energy consumption is the main pillar of GHG mitigation. Imposing carbon prices; increasing solar, wind, and biomass electricity generation; energy efficiency improvements in power generation; and energy savings in the industry and the building sectors, will be the key options for clean power generation in the carbon prices (CT) scenarios. Renewable electricity, coal and natural gas, coupled with CCS and bio-energy with CCS (BECCS) will be utilized significantly to curb GHG emissions. The increase of renewable energy and the electrification of end-use plays a key role in reducing GHG emissions. Fuel switching from diesel to biodiesel, energy efficiency improvement and electric pick-ups and trucks will help reducing GHG emissions in the transport sector. Conclusions There are three major policy implications to meet Thailand’s 2 degrees Celsius target. First, carbon prices will be the mechanism to accelerate the transformation in the energy sector. Wind and solar electricity will be key pillars of clean electricity in 2050. Policy-makers should update the renewable electricity plans to meet Thailand’s 2 degrees Celsius target in 2050. Second, coal- and gas-fired plants, and BECCS will become important options in reducing CO2 emissions. The policy-makers should investigate the application of CCS in the power sector and the storage location. Third, a major transformation in the transport sector is critically needed. Liquid biofuel and electrification in pick-ups, sedans, and trucks will help reduce GHG emissions.

Darian N. Smercina, Sarah E. Evans, Maren L. Friesen et al.

Abstract Free‐living nitrogen fixation (FLNF) represents an important terrestrial N source and is gaining interest for its potential to contribute plant available N to bioenergy cropping systems. Switchgrass, a cellulosic bioenergy crop, may be particularly reliant on FLNF when grown on low N systems, like marginal lands. However, the potential contributions of FLNF to switchgrass as well as the controls on this process are not well understood. In this study, we evaluated drivers of FLNF rates and N‐fixing microbial (diazotrophic) community composition in field‐grown switchgrass systems over two growing seasons with high temporal sampling. We found that climate variables are strong drivers of FLNF rates in switchgrass systems, compared to other environmental and biological factors including soil nutrients and diazotrophic community composition. Increased soil moisture availability generally promoted FLNF rates, but extreme rainfall events were detrimental. These climate‐related responses suggest a potential for loss of FLNF‐derived N contributions under projected climate shifts. We found a significant, but weak correlation between diazotrophic community composition and FLNF rates. We also observed a significant shift in the diazotrophic community composition between 2017 and 2018 and similarly measured a significant difference in FLNF rates between growing seasons. Lastly, we found that seasonal FLNF N contributions, based on measurement with high temporal resolution, has the potential to meet up to 80% of switchgrass N demands suggesting that FLNF measurements extrapolated from fewer time points or locations may underestimate these potential N contributions.

Marija Lazarevikj, Viktor Iliev, Valentino Stojkovski

Nestacionarno strujanje fluidа i pојаvа hidrauličnog udаrа u svојim spеcifičnоstimа uklјučuјu uslоvе оkružеnjа u kојеm sе оdviја strujanje fluida. Rаznоlikоst mаtеriјаlа zа izgrаdnju cеvоvоdа (čеlik, pоliеtilеn ili drugi mаtеriјаl) dеfinišе uslоvе zа rаzvој hidrauličnog udаrа. Prеdmеt istrаživаnjа u оvоm rаdu su pаrаlеlno vezani cevovodi izrađeni od rаzličitih mаtеriјаlа i mеđusоbni uticај u uslоvimа nestacionarnog strujanja fluidа. Izvršеnо je numeričko istrаživаnjе nа dugim (pravim) cеvоvоdimа. Kоrišćеn је sоftvеrski pаkеt АFТ-Impulsе kојi је vеć tеstirаn upоrеdnim еkspеrimеntаlnо izmеrеnim vrеdnоstimа. Моdеl zа аnаlizu rаzmаtrа paralelno vezane cеvоvоdе оd čеlikа i pоliеtilеnа. Rеzultаti simulаciоnih uslоvа dаti su krоz upоrеdnе diјаgrаmе, gdе sе intеrаktivni uticај јаsnо i nеdvоsmislеnо оtkrivа. Uslоvi еksplоаtаciје i intеrаktivni uticај dаti su u kоmеntаru i zаklјučku оvоg rаdа

Seyed Mohammad Fahimifard

According to apposite and ambiguous opinions about the effects of foreign direct investment and innovation on environmental performance in developing countries, in this research despite the environmental Kuznets curve (EKC) hypothesis, pollution haven hypothesis (PHH), and rebound effects hypothesis (REH) in D8 countries (Iran, Turkey, Malaysia, Indonesia, Egypt, Pakistan, Bangladesh, and Nigeria) were studied. For this purpose, the required data was gathered from World Bank during the years 2000-2018. Also, the fully modified ordinary least squares (FMLOS) model and STATA software were applied for analyzing data. Results of variables description indicated that during the studied period, Iran has the lowest average amount of FDI to GDP, the lowest average amount of per capita GDP growth, the highest average of the proportion of fossil energies to total energy consumption, and the highest average of the proportion of per capita CO2 emission. In addition, the results of the specification of the econometrics model showed that there is a U inverse relationship between GDP and CO2 in D8 countries. Therefore, the EKC hypothesis is approved for studied countries. Also, foreign direct investment has a positive significant effect (in 10%) on CO2 emission. Hence, the PHH hypothesis is approved for studied countries. Finally, innovation has a negative significant effect (in 5%) on CO2 emission. Hence, the REH hypothesis didn’t approve for studied countries.

Nurit Gal, Irena Milstein, Asher Tishler et al.

Rossella Bardazzi, Maria Grazia Pazienza

Boqiang Lin, Chuanwang Sun

Ana Gonzalez Hernandez, Simone Cooper-Searle, Alexandra C.H. Skelton et al.