Light Fuels Research Articles

CO2 Hydrogenation on Ru Single-Atom Catalyst Encapsulated in Silicalite: a DFT and Microkinetic Modeling Study.

The critical levels of CO2 emissions reached in the past decade have encouraged researchers into finding techniques to reduce the amount of anthropogenic CO2 expelled to the atmosphere. One possibility is to capture the produced CO2 from the source of emission or even from air (i.e., direct air capture) by porous materials (e.g., zeolites and MOFs). Among the different usages of captured CO2, its conversion into light fuels such as methane, methanol, and formic acid is essential for ensuring the long-awaited circular economy. In the last years, single-atom catalysts encapsulated in zeolites have been considered to this purpose since they exhibit a high selectivity and activity with the minimum expression of catalytic species. In this study, a detailed mechanism composed by 47 elementary reactions, 42 of them in both forward and reverse directions and 5 of them that correspond to the desorption of gas products just forwardly studied), has been proposed for catalytic CO2 hydrogenation over Ru SAC encapsulated in silicate (Ru1@S-1). Periodic density functional theory (DFT) calculations along with microkinetic modeling simulations at different temperatures and pressures were performed to evaluate the evolution of species over time. The analysis of the results shows that carbon monoxide is the main gas produced, followed by formic acid and formaldehyde. The rate analysis shows that CO(g) is formed mainly through direct dissociation of CO2 (i.e., redox mechanism), whereas COOH formation is assisted by OH. Moreover, the Campbell's degree of rate control analysis suggests that the determining steps for the formation of CO(g) and CH2O(g) gas species are their own desorption processes. The results obtained are in line with recent experimental and theoretical results showing that Ru1 SACs are highly selective to CO(g), whereas few atom clusters as Ru4 increase selectivity toward methane formation.

Extreme Learning Machine Combined With Whale Optimization Algorithm for Spectral Quantitative Analysis of Complex Samples

ABSTRACTExtreme learning machine (ELM) is combined with the discretized whale optimization algorithm (WOA) for spectral quantitative analysis of complex samples. In this method, the spectral variables selected by the discretized WOA were used to build the ELM model. Before establishing the model, the activation function and the number of hidden nodes in ELM as well as the transfer function of the discretized WOA are determined. Furthermore, the predictive performance of the full‐spectrum partial least squares (PLS), ELM, and WOA‐ELM models was compared with four complex sample datasets: blood, light gas oil and diesel fuels, ternary mixture, and corn samples using root mean square error of prediction (RMSEP) and correlation coefficient (R). The results show that the WOA‐ELM model has the best prediction accuracy compared to full‐spectrum PLS and ELM models. Therefore, the proposed method provides a novel approach for the quantitative analysis of complex samples.

Liquid-phase pulse discharge cracking of n-hexadecane: An efficient method for generating light and valuable fuels

The conversion of low-grade heavy oil into value-added chemicals has garnered significant attention. Plasma is a potentially cleaner, environmentally friendly, and faster method of cracking heavy oil. In this work, ethanol-assisted cracking of hexadecane, a model compound of heavy oil, to produce valuable light fuels such as syngas, C2 hydrocarbons, and gasoline was investigated under ambient conditions using liquid-phase pulsed-discharge plasma. The gas, liquid, and solid products formed by cracking were analyzed in detail. Single discharge energy and discharge time were the key influences on the cracking reaction. The increase in single discharge energy improved gas and light hydrocarbon yields and inhibited the production of heavy materials, with the maximum gas generation flow rate of 96.1 mL/min. Prolonging the discharge time did not significantly affect the light product selectivity (>97 %). The energy consumption of the reaction was also evaluated and showed a low level of energy consumption. At a single discharge energy of 2.28 mJ and a discharge of 15 min, it obtained 129.9 mg of light hydrocarbons, 13.6 % n-hexadecane conversion, 9.2 kWh/kg energy consumption for n-hexadecane conversion, and 4.0 kWh/m3 energy consumption for gas generation, and the mass balance of the product was determined.

Microscopic investigation and local standard deviation analysis of liquid propane jets in supercritical environment

To improve the thermal efficiency of engines, the temperature and pressure in the combustion chamber are continually increased, potentially reaching the critical points of the fuels. Additionally, light fuels such as liquid ammonia and propane are utilized to reduce carbon emissions. The relatively low critical temperature of light fuels facilitates their transition into a supercritical state, which greatly change the jet characteristics. To gain a deeper understanding of the supercritical transition of fuels, jets of liquid propane are investigated through high-speed microscopic imaging technology, covering subcritical to supercritical environmental conditions. Liquid propane is injected through a transparent flat nozzle to observe the internal flow states within the nozzle. For image and data processing, local standard deviation (LSD) analysis and a Residual Network (ResNet-50) model are employed to identify the structures within the mixing region. Droplets counting and frequency domain analysis are also performed to reveal the features of supercritical transition. The findings highlight the importance of mask size in the jet feature extraction. Large mask highlights large scale structures including jet surface and mixing region structures, while small mask brings about full-scale feature including droplets and all other features. A criterion for mixing regime classification based on reduced temperature (Tr) and reduced pressure (Pr) is established directly from image data using the ResNet-50 model, where a condition of Tr1.6Pr0.4 ≥ 1.067 indicates a transcritical mixing regime. Both droplet counting and frequency domain analysis corroborate this mixing regime criterion. These insights enhance our understanding of supercritical transitions and are useful for simulation verifications.

Household Air Pollution Interventions to Improve Health in Low- and Middle-Income Countries: An Official American Thoracic Society Research Statement.

Background: An estimated 3 billion people, largely in low- and middle-income countries, rely on unclean fuels for cooking, heating, and lighting to meet household energy needs. The resulting exposure to household air pollution (HAP) is a leading cause of pneumonia, chronic lung disease, and other adverse health effects. In the last decade, randomized controlled trials of clean cooking interventions to reduce HAP have been conducted. We aim to provide guidance on how to interpret the findings of these trials and how they should inform policy makers and practitioners.Methods: We assembled a multidisciplinary working group of international researchers, public health practitioners, and policymakers with expertise in household air pollution from within academia, the American Thoracic Society, funders, nongovernmental organizations, and global organizations, including the World Bank and the World Health Organization. We performed a literature search, convened four sessions via web conference, and developed consensus conclusions and recommendations via the Delphi method.Results: The committee reached consensus on 14 conclusions and recommendations. Although some trials using cleaner-burning biomass stoves or cleaner-cooking fuels have reduced HAP exposure, the committee was divided (with 55% saying no and 45% saying yes) on whether the studied interventions improved measured health outcomes.Conclusions: HAP is associated with adverse health effects in observational studies. However, it remains unclear which household energy interventions reduce exposure, improve health, can be scaled, and are sustainable. Researchers should engage with policy makers and practitioners working to scale cleaner energy solutions to understand and address their information needs.

Life cycle assessment of electricity generation by tire pyrolysis oil

The disposal of used vehicle tires at the end of their life time, is a significant environmental concern. There is need for specific legislative framework, regulating their disposal, after these are replaced, however, there are several options for further processing. In the framework of circular economy, recovery methods and new applications for the material are available. This paper examines the life cycle environmental impacts of the pyrolysis of End of Life (EoL) tires and the use of the produced Tire Pyrolysis Oil (TPO) for generation, presenting a Life Cycle Assessment (LCA) for a 17.8 MW designed generation unit in Cyprus. The boundaries of the system under study start from the receipt of shredded used tyres, and include the pyrolysis process, the electricity generation and the management of by-products, pollutants and waste for a case study about a unit designed to operate in Cyprus. Two Functional Units (FU) are used, 1 Kg of TPO and 1 MWh of produced electricity. A detailed Life Cycle Inventory (LCI) is presented and moreover, by applying the CML 2001 impact characterization method, the magnitude of a number of characterization factors are calculated for both of them. These results are compared to the respective of Light Fuel Oil (LFO) and of Cyprus grid electricity as alternatives. While, the TPO found to have lower environmental impact than LFO for all the impact categories, the production of electricity at the unit cause higher potential of depletion of abiotic resources – elements and marine aquatic ecotoxicity potential than the grid electricity. Specifically, the first, for 1 MWh produced in the unit under study, is 0.00026 kg antimony eq. and the second 171666.4 kg 1,4-dichlorobenzene eq., while for 1 MWh of Cyprus grid electricity they are 0.00013 kg antimony eq. and 136095.2 kg 1,4-dichlorobenzene eq., respectively. A contribution analysis, for these two impact categories is presented, showing that the use of urea and the production of solid waste to the unit contributes the most to both plus the exhaust gases to the second, therefore specific suggestions to minimize the contribution are formulated, available to be exploited for similar units. Moreover, concluding that the TPO use for generation could be an advantageous environmental option, recommendations for its strategic adoption are also made.

Thermodynamic Reactivity Study during Deflagration of Light Alcohol Fuel-Air Mixtures with Water

In this paper, a thermodynamic and reactivity study of light alcohol fuels was performed, based on experimental and numerical results. We also tested the influence of water addition on fundamental properties of the combustion reactivity dynamics in closed vessels, like the maximum explosion pressure, maximum rate of pressure rise and the explosion delay time of alcohol–air mixtures. The substances that we investigated were as follows: methanol, ethanol, n-propanol and iso-propanol. All experiments were conducted at initial conditions of 323.15 K and 1 bar in a 20 dm3 closed testing vessel. We investigated the reactivity and thermodynamic properties during the combustion of liquid fuel–air mixtures with equivalence ratios between 0.3 and 0.7 as well as some admixtures with water, to observe water mitigation effects. All light alcohol samples were prepared at the same initial conditions on a volumetric basis by mixing the pure components. The volumetric water content of the admixtures varied from 10 to 60 vol%. The aim of water addition was to investigate the influence of thermodynamic properties of light alcohols and to discover to which extent a water addition may accomplish mitigation of combustion dynamics and thermodynamic reactivity.

Self‐Degradable Photoactive Micromotors for Inactivation of Resistant Bacteria

AbstractPathogenic bacteria pose a significant threat to human health, and their removal from food and water supplies is crucial in preventing the spread of waterborne and foodborne diseases. Recently, silver‐based photocatalytic micromotors have emerged as promising candidates for inactivating pathogenic microbes due to their high antibacterial activity. In this study, the synthesis of photoactive Ag3PO4 micromotors with a well‐defined tetrapod‐like structure (TAMs) is presented using a simple precipitation method. These TAMs autonomously move and release Ag ions/nanoparticles (NPs) through a photodegradation process when exposed to light, which enhances their antimicrobial activity against Gram‐negative (Escherichia coli) and Gram‐positive (Staphylococcus aureus) bacterial strains. Interestingly, different motion modes are observed under different manipulated light wavelengths and fuels. Furthermore, the self‐degradation of TAMs is accelerated in the presence of negatively charged bacteria, which results in higher removal rates of both bacteria, E. Coli and S. aureus. The findings introduce a new concept of self‐degradable micromotors based on photocatalytic components, which hold great potential for their use in antimicrobial applications. This work offers significant implications for materials chemistry, especially in designing and developing the next generation of light‐driven antimicrobial agents.

Synthesis, characterization, and application of N-CNT/1-(2-Hydroxyethyl)-3-methylimidazolium dicyanamide as a green nanocatalyst for the sulfur removal from light oils

Adsorptive desulfurization of light fuels is sustainable due to its ambient operation and reusability of exhausted adsorbents. In this study, 1-(2-hydroxyethyl)-3-methylimidazolium dicyanamide [HEMIM][DCA] IL was synthesized and utilized to modify N-doped carbon nanotubes (CNTs) to produce N-CNT/[HEMIM][DCA] as a green hybrid adsorbent. The adsorbent was characterized using XRD, FE-SEM, FTIR, BET, and TGA. It was indicated that the N-CNT treatment with [HEMIM][DCA] IL resulted in decreased crystallinity with the cubic and rod-shaped morphology and harsh surfaces and curved edges. The absence of shifts or variations in FTIR peaks of starting materials and N-CNT/[HEMIM][DCA] suggested that neither component was affected by chemical interactions. The adsorption capacity of N-CNT and N-CNT/[HEMIM][DCA] was 54.3 mg/g and for 83.6 mg/g for 50 ppm BT, respectively. Saturated with BT, the adsorbent's performance was decreased at high BT concentrations. The adsorption isotherms provided an understanding of interactions of BT with sorbent surface which follows the Langmuir model for N-CNT/[HEMIM][DCA] and N-CNT. The kinetics of BT adsorption on N-CNT/[HEMIM][DCA] was fitted with second-order kinetic model with the decreased adsorption ratio over time due to pore saturation. 25 % reduction of the adsorption capacity was obtained after two recycling cycles of the adsorbent (62.5 mg/g). N-CNT/[HEMIM][DCA] showed good recyclability and potential as a promising BT adsorbent.

CO2 enhanced continuous microwave pyrolysis of low-density polyethylene to produce high-quality products: Energy recovery balance and intrinsic mechanism exploration

The utilization of microwave pyrolysis technology and CO2 dry reforming to recover high-quality products from waste plastics has become a research hotspot. In this work, light fuels were recovered by CO2-enhanced continuous microwave pyrolysis (CMP) of low-density polyethylene (LDPE). The balanced relationship between CO2 utilization and energy recovery was investigated, and the intrinsic pyrolysis mechanism was analyzed. Increasing the pyrolysis temperatures and CO2 concentrations helped to increase the pyrolysis gas yield and the syngas content, which were 96.44 wt% and 65.61 vol%, respectively. CO2 enhanced the CMP degree of LDPE and reacted with intermediates to form oxygen-containing intermediates to produce high-quality products and release CO, thereby regulating the syngas content and H2/CO ratio (0.62–3.99). Although an increase in CO2 concentration enhanced CO2 utilization efficiency, it reduced energy recovery efficiency by increasing energy consumption. The efficiencies of CO2 utilization and energy recovery could reach 81.69% and 75.29% at pyrolysis conditions of 650 °C-75 vol% CO2 and 650 °C-25 vol% CO2, respectively. Appropriate CO2 concentration (25 vol%) was the key to synergistically improving product quality, resource utilization, and energy recovery. This work evaluated the potential of CO2-enhanced CMP to produce high-quality products and provided novel insights for improving the resource utilization efficiency of waste plastics and CO2.

A review on indoor air pollution from lightning sources in developing countries—The pollutants, the prevention and the latest technologies for control

Currently, developing nations around the world rely heavily on the use of biomass and fossil fuels for cooking, lighting, and warmth due to a lack of access to clean fuels and constant electricity supply. Unfortunately, the use of these materials has the side effect of emitting of harmful pollutants into the air. Constant exposure to some of these emissions has led to the death of millions of people around the world, with women and children disproportionately affected due to greater amounts of time spent indoors. The work focused on indoor air pollution from lightning sources in developing countries and the negative impacts of cases of ill-health and mortality. The techniques adopted for the research comprised extensive and intensive review of literature on lightning sources. Resources used encompassed internet materials, current reports and recent publications by researchers of note. The findings show that there are associated pollutants, the prevention and the latest technologies for control the pollutants. It was concluded that the dearth of research in lighting sources as sources of indoor air pollution is needed to be addressed by researchers. Also, policy implications to improve electricity deficits should be embarked upon by governments to discourage the use of fossils and biomass for lighting indoors.

LCA Analysis Decarbonisation Potential of Aluminium Primary Production by Applying Hydrogen and CCUS Technologies

The energy intensity and high emissions of extractive industries bring a major need for decarbonisation actions. In 2021, extraction and primary processing of metals and minerals were responsible for 4.5 Gt of equivalent CO2. The aluminium industry specifically accounted for total emissions of 1.1 Gt CO2 eq. per year. Reaching the European milestone of zero emissions by 2050, requires a 3% annual reduction. To achieve this, the industry has searched for innovative solutions, considering the treatment of emitted CO2 with techniques such as Carbon Capture Utilisation and Storage (CCUS), or the prevention of CO2 formation on the first place by utilising alternative fuels such as hydrogen (H2). This study aims to comprehensively compare the overall environmental performance of different strategies for addressing not only greenhouse gas (GHG) emission reduction potential, but also emissions to air in general, as well as freshwater and terrestrial ecotoxicity, which are commonly overlooked. Specifically, a Life Cycle Assessment (LCA) is conducted, analysing four scenarios for primary Al production, utilising (1) a combination of fossil fuels, specifically Natural Gas (NG), Light Fuel Oil (LFO) and Heavy Fuel Oil (HFO) (conventional approach); (2) carbon capture and geological storage; (3) Carbon Capture and Utilisation (CCU) for methanol (MeOH) production and (4) green H2, replacing NG. The results show that green H2 replacing NG is the most environmentally beneficial option, accounting for a 10.76% reduction in Global Warming Potential (GWP) and 1.26% in Photochemical Ozone Formation (POF), while all other impact categories were lower compared to CCUS. The results offer a comprehensive overview to support decision-makers in comparing the overall environmental impact and the emission reduction potential of the different solutions.

Potential of Integrating Solar Energy into Systems of Thermal Power Generation, Cooling-Refrigeration, Hydrogen Production, and Carbon Capture

Abstract Global warming due to the accumulation of CO2 in the atmosphere has directed global attention toward the adaptation of renewable energies and the use of renewable energy resources, like solar energy. Solar energy utilization could contribute to clean energy production, which is continuously needed due to increased population and industrialization. Recent increasing anxieties over energy sustainability and the preservation of the falling global ecosystem have renewed the expedition for extra efficient and economical processes for the utilization of renewable energy. Various approaches have been developed for the effective utilization of solar energy in different fields, which are highlighted in this work. In power generation, solar energy is utilized in preheating the air upstream of the combustion chamber in gas turbines and in waste heat recovery for combined-cogeneration cycles. It can also be used in Rankine cycles of thermal power plants utilizing low critical temperature gases such as CO2. In cooling and refrigeration systems, solar energy is utilized in reboilers, absorption, and mechanical cooling systems. Solar energy can also be utilized to produce clean fuels such as H2 production either from water splitting or from light and heavy fuels via fuel reforming and membrane separation. In addition, solar systems can be integrated to carbon capture applications in each of its three technologies of precombustion, oxyfuel combustion, and post-combustion. Integration of solar energy in these processes is reviewed comprehensively in this work. Thus, the solar energy in power generation, cooling-refrigeration, hydrogen production-storage, and carbon capture technologies are analyzed and evaluated.

Numerical Analysis of Fuels Type Effect on Combustion and Emissions of Turbo-Charged Direct Injection Engine

One of the most important sources of contaminant emissions, especially in urban areas, is the car. Certain types of fuels are considered very beneficial in reducing emissions. The objective of this work is to study the effects of different types of fuels on the combustion and flow characteristics through the modeling of a direct injection turbocharged diesel engine. In this study, the simulation of combustion and pollutant emission evolution of an engine alimented with five fuels (C14H30, C16H34, C8H18, C5H12, and C2H5OH) was performed with CONVERGE CFD software. The results obtained confirm that the diesel engine is more powerful than an engine powered by light fuels such as gasoline. Injection of C16H34 and C14H30 resulted in higher pressure, temperature, and heat rate than C8H18 (15.17% and 12.8% for pressure, 25.12% and 24.4% for temperature, and 54.54% and 31.81% for heat rate compared to C8H18). For polluting gases, if the engine is powered by heavy fuel oil, there are fewer unburned hydrocarbons and carbon monoxide, on the other hand, more soot and NOx, compared to C8H18. For the gaseous pollutants, the injection of the C14H30 generates more NOx and soot but less HC and CO (58.3%, 49.23%, 51.61%, and 2% respectively compared to C8H18). On the other hand, injection of C2H5OH generates a lower NOx and soot emissions level if compared to diesel (reduced levels by 75% and 95% respectively compared to diesel).

Precise Control of Dissipative Self-assembly by Light and Electricity.

Nature-inspired synthetic dissipative self-assemblies have attracted much attention recently. However, it remains a major challenge to achieve precise control over dissipative supramolecular assembly structures and functions of self-contained systems. Here we combine light and electricity as two clean, and spatiotemporally addressable fuels to provide precise control over the morphology for dissipative self-assembly of a perylene bisimide glycine (PBIg) building block in a self-contained solution. In this design, electrochemical oxidation provides the positive fuel to activate PBIg self-assembly while photoreduction supplies the negative fuel to deactivate the system for disassembly. Through programming the two counteracting fuels, we demonstrated the control of PBIg self-assembly into a variety of assembly morphologies in a self-contained system. In addition, by exerting light and electrical dual fuels simultaneously, we could create an active homeostasis exhibiting dynamic instability, leading to morphological change to asymmetric assemblies with curvatures. Such precise control over self-assembly of self-contained systems may find future applications in programming complex active materials as well as formulating pharmaceutical reagents with desired morphologies.

Accelerated dissolution of doped UO2-based model systems as analogues for modern spent nuclear fuel under repository conditions

Systematic single-effect dissolution studies were carried out on the dissolution behaviour of pure and Cr- or Nd-doped UO2 reference pellets as model materials for spent nuclear fuel with varying doping levels, densities, and grain sizes as well as of industrially produced Cr- and Cr/Nd-doped UO2 pellets. The results were obtained from accelerated static batch dissolution experiments performed under strictly controlled conditions using H2O2 as simulant for radiolytic oxidants formed due to the alpha-irradiation of water. The results indicate that the addition of Cr and the consequential modification of the fuel matrix does not lead to a significant change of the dissolution behaviour of these model materials compared to pure UO2 reference materials. Contrarily, the dissolution rates of Nd-doped pellets are significantly lower than those of pure and Cr-doped pellets. These results provide additional insights into the influence of doping on the dissolution behaviour of modern spent light water reactor fuels under the post-closure conditions expected in a deep geological repository.Graphical abstract

Detailed Speciation of Semi-Volatile and Intermediate-Volatility Organic Compounds (S/IVOCs) in Marine Fuel Oils Using GC × GC-MS.

Ship emissions contribute substantial air pollutants when at berth. However, the complexity and diversity of the marine fuels utilized hinder our understanding and mapping of the characteristics of ship emissions. Herein, we applied GC × GC-MS to analyze the components of marine fuel oils. Owing to the high separation capacity of GC × GC-MS, 11 classes of organic compounds, including b-alkanes, alkenes, and cyclo-alkanes, which can hardly be resolved by traditional one-dimensional GC-MS, were detected. Significant differences are observed between light (-10# and 0#) and heavy (120# and 180#) fuels. Notably, -10# and 0# diesel fuels are more abundant in b-alkanes (44~49%), while in 120# and 180#, heavy fuels b-alkanes only account for 8%. Significant enhancement of naphthalene proportions is observed in heavy fuels (20%) compared to diesel fuels (2~3%). Hopanes are detected in all marine fuels and are especially abundant in heavy marine fuels. The volatility bins, one-dimensional volatility-based set (VBS), and two-dimensional VBS (volatility-polarity distributions) of marine fuel oils are investigated. Although IVOCs still take dominance (62-66%), the proportion of SVOCs in heavy marine fuels is largely enhanced, accounting for ~30% compared to 6~12% in diesel fuels. Furthermore, the SVOC/IVOC ratio could be applied to distinguish light and heavy marine fuel oils. The SVOC/IVOC ratios for -10# diesel fuel, 0# diesel fuel, 120# heavy marine fuel, and 180# heavy marine fuel are 0.085 ± 0.046, 0.168 ± 0.159, 0.504, and 0.439 ± 0.021, respectively. Our work provides detailed information on marine fuel compositions and could be further implemented in estimating organic emissions and secondary organic aerosol (SOA) formation from marine fuel storage and evaporation processes.

The impacts of cash transfers on household energy choices

AbstractThere are sizeable energy access deficits in the developing world. Leveraging panel data from the experimental impact evaluations of three unconditional cash transfer programs in Malawi and Zambia, we investigate how ultra‐poor households in rural areas adapt their energy portfolios when experiencing exogenous increases in income. Households make several changes to the primary fuel sources that they use on a regular basis after receiving 3 to 4 years of transfers—moving from fires to torches for lighting purposes and reducing collected firewood use for cooking purposes. In general, households are more likely to make income‐induced adjustments to lighting fuels than to cooking fuels. While facilitating some movement away from firewood (arguably the most inferior energy source), the unconditional cash transfers rarely enable households to completely abandon this fuel. This is understandable given the range of pressing needs facing the beneficiary households—such as food security, the enhancement of which is the primary purpose of the transfer programs. Although recipient households are able to meet a greater share of their energy needs with relatively improved fuels (such as charcoal/coal in Zambia) and obtain assets for generating solar power, the observed impacts are unlikely to be large enough to lead to meaningful health impacts (such as lower respiratory disease via reductions in indoor air pollution). However, the cash transfers appear to enhance well‐being in other ways through the energy use channel—for example, by reducing the time households spend foraging for fuel resources.

Performance of a single cylinder direct injection 4-stroke diesel engine under effect of using diesel and naphtha blends

The demand for diesel fuel in the transport industry is expected to rise due to greenhouse gas laws and global economic expansion, necessitating the search for alternative sources. If light distillate fuels can match diesel fuel's efficiency and cleanliness at a more affordable cost, they could potentially enter the market. This study assessed a 1-cylinder, 4-stroke diesel engine's performance using various blends of diesel and heavy naphtha: D100, D97.5N2.5, D95N5, D92.5N7.5, and D90N10. Tests were conducted at 3000 rpm and variable loads, revealing that the maximum permissible naphtha content in D100 is 10%. Higher naphtha proportions led to misfire and instability under heavy loads. 100% diesel demonstrated the lowest brake-specific fuel consumption and higher thermal efficiency, while 90% diesel + 10% naphtha showed the highest fuel consumption and lower thermal efficiency.

Measurement of the fission yield of 136Cs in the 239Pu(nth,f) reaction

A recent experimental campaign performed at the LOHENGRIN spectrometer at ILL aimed at measuring the independent fission yield of 136Cs in the 239Pu(nth,f) reaction. This nuclide can have an important contribution to the total dose rate coming from spent light water reactor UOX and MOX fuels. Moreover, its impact is of first order on the uncertainty of the total dose rate calculated in specific areas of Nuclear Power Plants within accidental conditions. One of the most important sources of uncertainty is its independent fission yield. Therefore, a new measurement of its independent yield along with a rigorous uncertainty analysis was performed. Due to its low independent yield, a new measurement technique has been applied. Ions recoiling from neutron-irradiated 239Pu target were collected by implantation into an Al foil placed inside a vacuum chamber. This foil was then transferred to a low γ-ray background setup located at nearby laboratory (LPSC). The procedure was then repeated for different LOHENGRIN settings. Compared to the JEFF-3.1.1 library, a decrease of the fission yield of 136Cs with a reduced uncertainty is obtained.