Fossil Sources Research Articles

Prospects of electricity generation through the use of alternative sources such as waste tires processing products

The object of this study is a hybrid energy system that integrates the processes of recycling used tires with the use of alternative energy sources to design a sustainable and environmentally safe power generation system. The problem addressed in this study is to find effective methods for recycling waste tires for electricity generation, as traditional recycling methods are energy-intensive and lead to the loss of valuable resources. Three methods of tire processing have been considered: pyrolysis, thermal degradation, and mechanical grinding. The method of electricity generation using pyrolysis has demonstrated high environmental performance due to a significant reduction in greenhouse gas emissions and a high rate of renewable energy (80 %). According to the results of the study, the use of 5 MW pyrolysis furnaces in combination with 500 kW solar panels provides a reduction in dependence on fossil sources, reducing CO2 emissions to 50.0 kg/year. The method has high capital costs (NPC USD 4.2 million), but the cost of energy production (COE USD 0.18/kWh) makes this method competitive in the long run. Thermal degradation provides a balanced approach in terms of energy efficiency (75 %) and environmental performance. Although its CO2 emissions are higher than in pyrolysis, the method makes it possible to obtain additional products that could be used in other industries, thereby increasing economic efficiency. Mechanical shredding has the lowest average energy costs (USD 0.12/kWh) and the lowest CO2 emissions (30.0 kg/year), making it ideal for cost-conscious businesses. The study confirms the possibility of effective integration of renewable sources with tire recycling methods. The practical use of the research results is possible during the implementation of grant projects for the recycling of used tires, and in the work of relevant government structures for devising a policy for the disposal of used tires

Hourly electricity CO[formula omitted] intensity profiles based on the real operation of large-scale natural gas combined cycle cogeneration plants

The decarbonization of energy systems is a major challenge that requires complex cross-sectoral strategies that need to be supported by energy modeling. As many technologies rely on electricity, an accurate estimation of its CO2 intensity is of utmost importance for the reliability of modeling results. When electricity is generated from fossil sources, its CO2 intensity depends on several parameters. This research paper presents an hourly calculation of the CO2 intensity of power generation from natural gas combined cycles, based on real data from several years of operation of three plants. As these plants are also operated in combined heat and power mode, two alternative allocation methods are compared. The results confirm the variability of CO2 intensity based on the different operation strategies of the plants and the share of heat and electricity generated. The hourly analysis shows average values in the range of 230–250 gCO2/kWh in winter, rising to around 330–370 gCO2/kWh in summer. The real CO2 intensity profiles presented in this paper can be integrated into energy planning models to improve their ability to estimate the potential benefits of different decarbonization solutions by including the effect of the operational profiles over the day and the year.

Radiocarbon as a tracer of the fossil fraction of regional carbon monoxide emissions

Abstract Carbon monoxide (CO) is an atmospheric pollutant with a positive net warming effect on the climate. The magnitude of CO sources and the fraction of fossil vs biogenic sources are still uncertain and vary across emissions inventories. Measurements of radiocarbon (14C) in CO could potentially be used to investigate the sources of CO on a regional scale because fossil sources lack 14C and reduce the 14C/C ratio (Δ14C) of atmospheric CO more than biogenic sources. We use regional Lagrangian model simulations to investigate the utility of Δ14CO measurements for estimating the fossil fraction of CO emissions and evaluating bottom-up emissions estimates (United Kingdom Greenhouse Gas, UKGHG, and TNO Copernicus Atmosphere Monitoring Service, TNO) in London, UK. Due to the high Δ14CO in atmospheric CO from cosmogenic production, both fossil and biogenic CO emissions cause large reductions in Δ14CO regionally, with larger reductions for fossil than biogenic CO per ppb added. There is a strong seasonal variation in Δ14CO in background air and in the sensitivity of Δ14CO to fossil and biogenic emissions of CO. In the UK, the CO emissions estimate from TNO has a higher fraction from fossil fuels than UKGHG (72\% vs 67\%). This results in larger simulated decreases in Δ14C per ppb CO for TNO emissions. The simulated differences between UKGHG and TNO are likely to be easily detectable by current measurement precision, suggesting that Δ14CO measurements could be an effective tool to understand regional CO sources and assess bottom-up emissions estimates.

Manufacture of Solid Propellants Based on Renewable Succinic Acid Polyols

AbstractModern energy policies encourage the replacement of fossil fuels with a more sustainable type. Succinic acid is a promising renewable material that can react with ethylene glycol and 1,4‐butanediol in a two‐step polycondensation reaction to form hydroxylated polyesters. Copolymerization reactions were investigated to produce novel green binders for manufacture of solid propellants. The ester of the first step of polycondensation was used as a plasticizer in the propellant formulation. These products can be an alternative to binders of fossil sources, such as hydroxyl‐terminated polybutadiene (HTPB), frequently used as fuel of commercial propellants. Initially, analyses of Fourier transform infrared spectroscopy, nuclear magnetic resonance and gel permeation chromatography indicated the formation of polymeric products and adequate chain growth at reaction conditions. Then, the obtained copolymers were characterized by rheological analyses, which revealed that the processability of the copolymer materials was similar to that of the HTPB samples. Additionally, thermogravimetric analyses indicated that the copolymers presented good thermal stability below 200°C. Furthermore, differential scanning calorimetric (DSC) analyses indicated that the glass transition temperatures of the obtained copolymer samples ranged from −20 to −60°C, a suitable range for the intended use. Solid propellants were then prepared with solid loadings above 70 wt %, heat of combustion above 11,300 J g−1 and heat of explosion above 4,980 J g−1, which are compatible with values expected for solid propellants. Finally, oxygen balance calculations showed that the intrinsic oxygen content of the polyesters can allow the reduction of amounts of oxidizers in the final propellants.

The Illusion of a Green Transition in Slovenia by 2050

This study analyzes the possibilities of phasing out fossil and nuclear energy sources for Slovenia by 2050. Alternative carbon-free sources include renewable energy sources (RES) i.e. electricity, synthetic fuels and hydrogen from water electrolysis. The model is based on the use of currently mature low-carbon technologies and is adapted to Slovenia’s natural conditions. Photovoltaic panels (PV) and hydropower plants are used for the majority of renewable electricity generation. To bridge the winter period with minimal PV production, storage with a pumped storage power plant is planned. One of the assumptions of the national climate strategy has been incorporated into the model, which envisages zero growth in final energy consumption by 2050. The result of the paper is an assessment of what some of the basic characteristics of the Slovenian energy system would look like after the phase-out of fossil and nuclear energy sources. The estimated storage capacity required is 5.1 MWh/capita. Abandoning fossil fuels with the currently mature RES technologies is not realistically feasible for technical and economic reasons.

Environmental impact assessment of the production of biomethane from landfill biogas and its use as vehicle fuel

Biogas and biomethane are expected to play an increasing role in the short-term future of the energy market. It is imperative to identify alternative sources of these gases and minimize the utilization of those derived from fossil sources. One such source is biogas obtained from landfill gas, which can be subsequently upgraded to produce biomethane. This can then be used to replace the fossil natural gas for both energy generation and vehicle use. This paper employs the Life-Cycle Assessment methodology to analyze the environmental impact of the production of biomethane derived from landfill biogas. The objective was to identify the unit processes that have the greatest environmental impact. These processes were CO₂ removal, which contributed 84% to the impact category of 'global warming', and the second stage of biogas compression, which contributed 37% to the impact category of 'fossil resources scarcity'. Based on these results, we propose recommendations to reduce the environmental impact of both processes. Furthermore, an analysis was conducted on the use of biomethane as a vehicle fuel, which revealed that it has the potential to reduce the environmental impact of driving both light and heavy-duty vehicles in comparison with the use of diesel and petrol.

The Slow Pace of Green Transformation: Underlying Factors and Implications

Concerns about climate change are a hot topic in the current debate about a sustainable future, and despite more than 30 years of international conferences, including the Intergovernmental Panel on Climate Change (IPCC) and the United Nations Climate Change Conference (COP), the annual usage amount of fossil fuel-based energy sources has remained largely unchanged, and the green transition to a carbon-free energy system is progressing at a much slower pace than anticipated. This paper presents an original approach that consists in addressing the green transition’s dilemmas by analyzing the complex interplay of strongly interwoven forces hindering the rapid adoption of so-called green energy sources scrutinized from a three-fold perspective: socio-psychological; political–strategic and territorial; and technological. Moreover, these forces are ranked according to the magnitude of their impact on the anticipated transition to green, and it is estimated by logistic fit extrapolation that the total share of the contribution of low-carbon sources might reach a maximum of about 25% among all energy sources in 2050. A final original picture is presented, summarizing how all the involved forces are acting upon the expected transition as well as their consequences.

Attractiveness of clean energy stocks in Europe

The Ukrainian conflict has put in evidence the need to understand if oil and gas shocks increase the attractiveness of clean energy investments in Europe. If that is the case, clean energy investments are both the solution to the end of the month problem in Europe and to the end of the world problem due to climate change. Using monthly data for the period 2008–2021, we pinpoint supply and demand shocks in the oil and gas markets affecting Europe and investigate their effects on clean energy stock returns using a structural VAR model. We complete the analysis by studying the connection of these shocks with geopolitical risk. Our findings show that, clean energy stocks are positively impacted by a negative shock in the gas supply to Europe but are not significantly affected by a negative shock in global oil supply. Moreover, clean energy stocks are positively influenced both by oil-specific and gas-specific demand shocks. Finally, the favorable impact of economic demand shocks on clean energy returns lasts more in the oil price model than in the gas price model. Regarding geopolitical risk, we find a strong connectedness, particularly with shocks in the European gas market. These findings imply that, in Europe, clean energy is indeed a substitute to oil and gas in times of crisis. We are then likely to observe an increase in clean energy returns as prices of fossil sources spike.

Comparative analysis of the combustion and emission characteristics of biojet and conventional Jet A‐1 fuel: a review

AbstractConventional jet fuels derived from fossil sources contribute to greenhouse gas emissions and air pollution, leading to climate change. Recent studies have shown that biobased jet fuels from different feedstocks offer a more sustainable alternative to conventional fuels as they are derived from renewable biomass, reducing greenhouse gas emissions. The major feedstocks reviewed are jatropha curcas, camelina, karanja oil, waste cooking oil, and municipal solid waste. They offer diverse benefits for sustainable aviation fuel development. As a comparative analysis, this review examined jet fuel characteristics based on their physicochemical properties, namely energy content, viscosity, calorific value, cetane number, and freezing and flash points. The objective was to understand the influence of the properties on performance evaluation, environmental impact, and combustion characteristics. The properties of biojet fuels are compared with their fossil counterparts to validate their suitability as renewable alternatives and their benefits in terms of emissions reduction and engine performance. Biojet fuels perform better in terms of lower sulfur content, lower soot content, and a lower freezing point, their aromatic content, and their high cetane number. This study enhances the understanding of biojet fuels and their quality, and supports the development of sustainable fuel options. Overall, adherence to the American Society for Testing and Materials (ASTM) D7566‐18 standard is crucial for the acceptance and integration of biojet fuels into the aviation sector. Future research should explore feedstocks such as wood biomass, wastepaper, and agricultural residues for biojet fuels. It should also investigate the combustion and emission characteristics of biosourced aviation fuel at higher blending ratios (>50% by volume) with fossil Jet A‐1.

Chemical Transformation of Biomass-Derived Furan Compounds into Polyols

Polyols such as 1,5-pentadiol, 1,6-hexanediol, and 1,2,6-hexanetriol are crucial chemicals, traditionally derived from non-renewable fossil sources. In the pursuit of sustainable development, exploring renewable and environmentally benign routes for their production becomes imperative. Furfural and 5-hydroxymethylfurfural are C5 and C6 biomass-derived platform molecules, which have potential in the synthesis of various polyols through hydrogenation and hydrogenolysis reactions. Currently, there is an extensive body of literature exploring the transformation of biomass-derived furan compounds. However, a comprehensive review of the transformation of furan compounds to polyols is lacking. We summarized the literature from recent years about the ring-opening reaction involved in converting furan compounds to polyols. This article reviews the research progress on the transformation of furfural, furfuryl alcohol, and 2-methylfuran to 1,2-pentadiol, 1,4-pentadiol, 1,5-pentadiol, and 1,2,5-pentanetriol, as well as the transformation of 5-hydroxymethylfurfural to 1,2-hexanediol, 1,6-hexanediol, and 1,2,6-hexanetriol. The effects of the supported Pd, Pt, Ru, Ni, Cu, Co, and bimetallic catalysts are discussed through examining the synergistic effects of the catalysts and the effects of metal sites, acidic/basic sites, hydrogen spillover, etc. Reaction parameters like temperature, hydrogen pressure, and solvent are considered. The ring opening catalytic reaction of furan rings is summarized, and the catalytic mechanisms of single-metal and bimetallic catalysts and their catalytic processes and reaction conditions are discussed and summarized. It is believed that this review will act as a key reference and inspiration for researchers in this field.

Am I really willing to use my electric vehicle sustainably? A study on the charging preferences of electric vehicle users

As, in most countries, electricity cannot be efficiently and practically stored at a systemic level, charging EVs during peak hours implies that additional energy has to be generated (relying almost exclusively on fossil sources) to cover the additional demand during that time window. This article reports the results of an SP-study, in which EV-owners were confronted with the option of charging their EVs at home (for a fixed known price) or at a publicly accessible charging station with charging price variability (as well as other features of EV charging). The results of the behavioral experiment show that EV-users exhibit a high willingness to accept alternative compensations for not charging EVs during peak-hours and that small monetary incentives as well as shorter access times, a guaranteed charging place, or fast charging could all efficiently promote a shift in the charging patterns toward a more sustainable behavior.

Evaluation of two acrylic acid production processes from renewable crude glycerol: Rigorous process design, techno-economic evaluation, and life cycle assessment

This study aims to propose and evaluate two acrylic acid (AA) production processes that utilize bio-based crude glycerol as a feedstock. Scheme 1 employs acrolein as an intermediate, while Scheme 2 utilizes allyl alcohol as an intermediate. For process intensification, Scheme 1 employs a one-pot reactor configuration that couples the glycerol dehydration and oxidation reactions and uses an additional reactor to suppress the formation of side products. Scheme 2 implements a membrane that helps prevent the multiple azeotropic distillation between water and other substances. Furthermore, both processes were systematically optimized based on varying levels of information available in the process (i.e., three objectives for Scheme 1, single objective for Scheme 2). From a techno-economic evaluation, Scheme 2 (2.136 USD/kg) slightly outperforms Scheme 1 (2.514 USD/kg) in terms of the minimum required selling price (MRSP). Both values are significantly higher than the market price (1.24–1.32 USD/kg) based on the conventional process that uses propene as a feedstock. Subsequently, a cradle-to-gate life cycle assessment was conducted to compare these processes across five impact categories (i.e., global warming potential, fossil source scarcity, human non-carcinogenic toxicity, water consumption, and terrestrial acidification). We have observed that Scheme 1 can be more sustainable than Scheme 2 and the conventional process if the issue associated with the acrolein left in the wastewater can be addressed. In contrast, Scheme 2 is far from environmentally friendly even compared to the conventional process, primarily because of the use of formic acid as a co-reactant.

Evaluation of waste composition for biochar production as a sustainable waste management approach

Background: To meet human life needs, fuel energy is obtained from fossil sources, such as coal, found in the Earth's crust. However, non-renewable energy sources in the Earth's crust will eventually run out. One alternative fuel is the production of biobriquettes from various types of waste. Methods: Using a literature review method, this study aims to determine which waste is most suitable for use in the production of biobriquettes. The samples taken are journals sourced from Google Scholar ranging from 2017 to 2022 that align with the discussion topic. Findings: Among various raw materials, the best waste for biobriquette production is found to be a mixture of dacron waste and corn cob, with a moisture content of 3.45% and a carbon value of 7986.45 cal/g. Conclusion: The results of the above study indicate that the production of biobriquettes from dakron waste and corn cobs is the best option because it yields the highest calorific value and the lowest moisture content, in accordance with SNI 01/6235/2000. Novelty/Originality of this article: This study presents a novel approach by identifying a specific combination of dacron waste and corn cob for biobriquette production, showcasing its superior calorific value and low moisture content, thus contributing to sustainable energy solutions and waste management practices.

Future Prospects of MeOH and EtOH Blending in Gasoline: A Comparative Study on Fossil, Biomass, and Renewable Energy Sources Considering Economic and Environmental Factors

Alcohol-blended gasoline is recognized as an effective strategy for reducing carbon emissions during combustion and enhancing fuel performance. However, the carbon footprint associated with its production process in refineries deserves equal attention. This study introduces a refinery modeling framework to evaluate the long-term economic and environmental performance of utilizing alcohols derived from fossil, biomass, and carbon capture sources in gasoline blending processes. The proposed framework integrates Extreme Learning Machine-based models for gasoline octane blending, linear programming for optimization, carbon footprint tracking, and future trends in feedstock costs and carbon taxes. The results indicate that gasoline blended with coal-based alcohol currently exhibits the best economic performance, though its carbon footprint ranges from 818.54 to 2072.89 kgCO2/t. Gasoline blended with biomass-based alcohol leads to a slight reduction in benefits and an increase in the carbon footprint. Blending gasoline with CCUM (CO2 capture and utilization to methanol) results in the lowest economic performance, with a gross margin of 8.91 CNY/toil at a 30% blending ratio, but achieves a significant 62.4% reduction in the carbon footprint. In long-term scenarios, the additional costs brought by increased carbon taxes result in negative economic performance for coal-based alcohol blending after 2040. However, cost reductions driven by technological maturity lead to biomass-based alcohol and CCUM blending gradually showing economic advantages. Furthermore, owing to the negative carbon emissions characteristic of CCUM, the blending route with CCUM achieves a gross margin of 440.60 CNY/toil and a gasoline carbon footprint of 282.28 kgCO2/t at a 20% blending ratio by 2050, making it the best route in terms of economic and environmental performance.

Comparative Study of Anion Exchange Membranes for Application in Advanced AEM Water Electrolysers

The chemical nature of hydrogen combined with its capability to be an energy carrier for energy conversion devices with zero- emission and its higher energy density than any other commercial fossil fuel-based energy source, make it unique [1]. The International Renewable Energy Agency has identified three of the most viable technologies for producing hydrogen in large volume, namely: alkaline water electrolyzers (AWEs), proton exchange membrane water electrolyzers (PEMWEs), and anion exchange membrane water electrolyzers (AEMWEs) [2]. Among the three types of electrochemical devices the AEMWEs are the newest and most promising, because they (i) have the same slim design of the PEMWEs, (ii) can operate at high current densities, and (iii) can use non-precious catalysts [3]. The durability and efficiency of the AEMWEs systems are significantly influenced by the anion exchange membranes (AEMs), which are currently under development. In addition, the used catalysts, as well as the methods for fabrication of the membrane electrode assemblies (MEAs) also impact substantially the electrolyzer’s performance. Catalyst-coated substrate (CCS) is one of the methods for fabrication of MEAs [4], while the other used method is known as catalyst coated membranes (CCMs). The Reactive Spray Deposition Technology (RSDT) is an innovative flame-assisted method that can be used for fabrication MEAs from both types [5].In this work, CCS are fabricated by the ultrasonic spray deposition method and 5 MEAs are assembled with various AEM membranes. This approach involves the application of Platinum Group Metal (PGM) catalysts, Pt/C and as cathode and anode catalyst layers, onto a Gas Diffusion Layer (C-GDL) and a porous transport layer (Ti-PTL). As fabricated CCSs are assembled with the three state-of-the-art commercially available AEMs, namely: FAA-3, Sustainion X-37, and TM1, and their performance is evaluated. In addition, CCSs with ultra-low PGM loadings in their catalyst layers are fabricated with the RSDT method and better performance in comparison to the baseline MEAs with high PGM loadings, is achieved. This comparative study provides valuable insights into the strengths and weaknesses of each membrane type for application in AEM water electrolysers. Reference: [1] M. G. Rasul, M. A. Hazrat, M. A. Sattar, M. I. Jahirul, and M. J. Shearer, “The future of hydrogen: Challenges on production, storage and applications,” Energy Conversion and Management, vol. 272, p. 116326, Nov. 2022, doi: 10.1016/j.enconman.2022.116326.[2] D. Yang et al., “Patent analysis on green hydrogen technology for future promising technologies,” International Journal of Hydrogen Energy, vol. 48, no. 83, pp. 32241–32260, Oct. 2023, doi: 10.1016/j.ijhydene.2023.04.317.[3] D. S. Falcão, “Green Hydrogen Production by Anion Exchange Membrane Water Electrolysis: Status and Future Perspectives,” Energies, vol. 16, no. 2, p. 943, Jan. 2023, doi: 10.3390/en16020943.[4] J. E. Park et al., “High-performance anion-exchange membrane water electrolysis,” Electrochimica Acta, vol. 295, pp. 99–106, Feb. 2019, doi: 10.1016/j.electacta.2018.10.143.[5] Z. Zeng, J. Xing, L. Bonville, D. R. Dekel, R. Maric, and S. Bliznakov, “Advanced nickel-based catalysts for the hydrogen oxidation reaction in alkaline media synthesized by reactive spray deposition technology: Study of the effect of particle size,” International Journal of Hydrogen Energy, p. S0360319923013721, Apr. 2023, doi: 10.1016/j.ijhydene.2023.03.249.

Boosting methanolysis of polycarbonate (PC) for bisphenol A recovery from end-of-life PC and PC/ABS blend

Poly(bisphenol A carbonate) (PC) is an essential polymer from fossil sources. Currently, PC lacks any economically viable recycling strategy, which leads to a loss of valuable resources, and the accumulation of PC in the environment can have a negative impact on human health due to the leaching of toxic Bisphenol A (BPA). BPA recovery from PC wastes is a prerequisite to meet the demand for sustainable resource utilization and address environmental concerns. Hence, this work demonstrates the efficient BPA recovery from PC wastes via methanolysis at high PC loading (47 wt%) in the presence of a low amount of sodium hydroxide (NaOH, ≤0.05 wt%) at moderate temperatures (125 °C – 175 °C). Selected conditions prevented unwanted decomposition of BPA and ensured a mild alkaline product requiring simple purification steps to recover BPA. The environmental impact factor (ξ) of these processes was shown to be quite low compared to the ones represented in the literature. When these processes were used to recover BPA from real wastes: 93 ± 1.5 % of pure BPA was recovered from end-of-life PC roof panels (EOL-PC) after 30 min at 175 °C with 0.004 wt% of NaOH. On the other hand, direct recovery of BPA from the EOL-PC/acrylonitrile butadiene styrene (EOL-PC/ABS) blend was hindered by additive contamination and proceeded at a slower reaction rate due to the presence of ABS. However, subjecting EOL-PC/ABS to a decolorization-depolymerization method ensured ∼94 ± 2.5 % BPA yield.

PRODUCTION OF BIODIESEL FROM MICROALGAE CULTIVATED WITH VINASSE

Purpose: The objective of this work was to carry out the cultivation of the microalgae Chlorella sorokiniana with diluted vinasse, verifying its potential for remediation of nutrients and increase of its lipid fraction, to produce biodiesel according to the current regulation. Theoretical Framework: The quest to reduce fossil fuels, which are responsible for negative environmental impacts, has boosted the demand for biofuels in recent years. Biodiesel has been gaining prominence as a promising alternative to replace petroleum derivatives since it can be produced from various raw materials, such as microalgae. Design/Methodology/Approach: Different vinasse dilutions were studied for the cultivation of Chlorella sorokiniana CTT 7727, being 5, 10 and 15% (v v-1) and N:P:K (20:5:20) 1% (v v-1) medium as a comparative standard. Biodiesel was produced by direct transesterification and analyzed by gas chromatography coupled to a flame ionization detector, enabling the identification and quantification of the fatty acid profile. Findings: The results obtained indicated that vinasse 10% (v v-1) proved to be promising for application as a culture medium for this microalgae species, as it guaranteed a good cell growth rate, high biomass productivity and lipid yield. Considering the biodiesel produced, it fits the regulatory standards analyzed by the National Agency of Petroleum, Natural Gas and Biofuels (ANP). Research, Practical & Social Implications: The research demonstrates the feasibility of cultivating the microalga Chlorella sorokiniana with diluted vinasse, highlighting the 10% concentration as promising for optimizing cell growth and lipid yield. The results ensure compliance with ANP regulations for biodiesel production, indicating immediate and sustainable applicability on an industrial scale. Socially, it contributes to the pursuit of biofuels, reducing dependence on fossil sources and promoting more sustainable practices in the bioenergy industry. Originality/Value: The study's originality lies in the unique combination of Chlorella sorokiniana CTT 7727, diluted vinasse, and biodiesel production in accordance with ANP regulations. It stands out for identifying the optimal vinasse concentration (10%) for cultivation, presenting an economical and effective approach. The strategic value is in the use of an alternative raw material cultivated with an industrial residue, promoting the diversification of the energy matrix and mitigating environmental impacts associated with conventional fuels.

Toward a physics-based model of power coefficient in horizontal-axis wind turbine

Global energy is in a major shift from energy using fossil sources to renewable energy using more sustainable energy sources. The wind is the clean and inexhaustible one of renewable energy resources that is available in most parts of the world. In order for wind power generation to meet more ambitious targets around the world, it is necessary to understand all the physics behind process of wind generation. The most interesting of this process is the power coefficient which involves the real characteristics of the wind turbine as a function of the generated power. Up to now, the power coefficient does not yet have a general form but are fitted as mathematical functions from manufacturer data measured from popular wind turbines in the world. In this paper, we develop an analytical physics-based method to estimate the power coefficient general for various wind generation systems of horizontal-axis wind turbines (HAWT). Instead of 12 parameters in semi-experimental exponential formula , our power coefficient uses only 5 parameters with their physical meanings. By varying these five parameters we also obtain the power coefficients fitted from experimental data.

Application of novel dual-ligand co metal-organic framework/graphene oxide for electrocatalytic oxidative degradation of bisphenol A in marine wastewater

The adjustment of the electron distribution of 2D metal-organic frameworks (2D-MOFs), as a hot anode candidate for electrocatalytic oxidation, is crucial for its application. In this work, a new electron distribution was achieved with dual-ligand connection and graphene oxide (GO) loading and the complex of dual-ligand 2D-MOF/GO (Co-IH/GO) exhibit faster electron transfer efficiency (Rct = 62.5) and more active sites (ID/IG = 1.01). Co-IH/GO demonstrated excellent electrocatalytic performance and achieved 100 % electrocatalytic degradation of bisphenol A (BPA) within 10 min. In addition, superior properties of stability, temperature tolerance, and pH tolerance were achieved, after 5 cycles of degradation, the catalyst was able to maintain 100 % degradation efficiency, Capable of maintaining good degradation performance over a temperature range of 25 °C–45 °C and a wide pH range of pH = 5–11. Both experimental and electron paramagnetic resonance analysis results indicated that 1O2 acted as the dominant active substrate. With the involvement of Cl− in marine wastewater, activated chlorine was also generated during the reaction, which contributed to fast BPA degradation. Furthermore, the established dual-ligand 2D-MOF/GO electrocatalytic system exhibited superior activity for the degradation of dyes and complex microflora, while the solar-driven degradation experiment shed light on the independence of fossil and stationary sources of energy.

The water-insoluble organic carbon in PM2.5 of typical Chinese urban areas: light-absorbing properties, potential sources, radiative forcing effects, and a possible light-absorbing continuum

Abstract. Water-insoluble organic carbon (WIOC) constitutes a substantial portion of organic carbon (OC) and contributes significantly to light absorption by brown carbon (BrC), playing pivotal roles in climate forcing. China is a hotspot region with high levels of OC and BrC, but information regarding the sources and light-absorbing properties of WIOC on a national scale remains scarce. Here, we investigated the light-absorbing properties and sources of WIOC in 10 representative urban cities in China. On average, WIOC made up 33.4 ± 7.66 % and 40.5 ± 9.73 % of concentrations and light absorption at 365 nm (Abs365) of extractable OC (EX-OC), which includes relatively hydrophobic OC (WIOC and humic-like substances, HULIS-C) and hydrophilic OC (non-humic-like substances, non-HULIS-C). The mass absorption efficiency of WIOC at 365 nm (MAE365) was (1.59 ± 0.55 m2 (g C)−1) comparable to that of HULIS (1.54 ± 0.57 m2 (g C)−1) but significantly higher than non-HULIS (0.71 ± 0.28 m2 (g C)−1), indicating that hydrophobic OC possesses a stronger light-absorbing capacity than hydrophilic OC. Biomass burning (31.0 %) and coal combustion (31.1 %) were the dominant sources of WIOC, with coal combustion sources exhibiting the strongest light-absorbing capacity. Moreover, employing the simple forcing efficiency (SFE300–700 nm) method, we observed that WIOC exhibited the highest SFE300–700 nm (6.57 ± 5.37 W g−1) among the EX-OC fractions. The radiative forcing of EX-OC was predominantly contributed by hydrophobic OC (WIOC – 39.4 ± 15.5 % and HULIS – 39.5 ± 12.1 %). Considering the aromaticity, sources, and atmospheric processes of different carbonaceous components, we propose a light-absorbing carbonaceous continuum, revealing that components enriched with fossil sources tend to possess stronger light-absorbing capacity, higher aromatic levels, increased molecular weights, and greater recalcitrance in the atmosphere. Reducing fossil fuel emissions emerges as an effective means of mitigating both gaseous (CO2) and particulate light-absorbing carbonaceous warming components.