Low Sulfur Diesel Research Articles

Enhanced Performance and Emission Characteristics of Soybean Biodiesel using TiO2 Nanoparticles in CRDI Engines: A Comprehensive Analysis

Renewable and clean energy sources must replace conventional ones due to the dangerous effects of fossil fuel pollution. The impact of incorporating hydrogen and TiO2 nanoparticles into Soybean biodiesel and its CRDI engine performance was assessed in this study. For engine operations, a 10 L/min hydrogen flow and 75 ppm of the nanoparticle also used. Experiments comparing diesel engines running on clean diesel to those with a B15 biodiesel mix (75% diesel and 15% biodiesel) found that the latter had better performance, and combustion behaviour with the inclusion of both hydrogen gas and cenoxite oxide. Brake fuel consumption was 16.12% lower and brake thermal efficiency was 3.53% better than diesel at 80% loading condition. By incorporating nanoparticles and hydrogen into the biodiesel mixture, we were able to reduce CO emission by 30%, HC by 50%, and smoke by 42%. On the other hand, comparisons to diesel showed an 12.15% rise in NOx. A mix of hydrogen and TiO2 nanoparticles produced biodiesel with 9% greater in-cylinder pressure and 7% higher HRR. More power and efficiency from the engine are the outcomes of this blend's low ignition delay period under full load conditions. This experimental work has paved the path for diesel engines to run on biodiesel that is hydrogen-enriched and combined with nanoparticles.

The role of microwave radiation in extractive desulfurization of real diesel fuel for green environment: an experimental and computational investigation

The process of removing sulfur compounds and aromatic compounds to produce clean fuel is an important and effective contribution to the processes of mitigating and adapting to climate change. In contrast, it is necessary to find an innovative way to remove sulfur and carcinogenic aromatic compounds because clean, low-sulfur diesel is commonly used in all countries of the world at the present time. Therefore, in this work, we have studied the effect of the microwave radiation power and the irradiation time with the use of more than one type of organic solvent; methanol, acetonitrile and ethyl acetoacetate; as an extractant and solvent to feed ratio impact on the removal of sulfur and aromatic compounds of a real diesel fuel feed which has 450 ppm sulfur content and 16 wt% aromatic Content. The results showed that the best solvent used during this work was ethyl acetoacetate. According to the results, high sulfur removal (≈ 92%) was accomplished with microwave-assisted extractive desulfurization technique under the following ideal conditions: the irradiation time is 7 min, the solvent feed ratio is 3:1 and the microwave intensity is 180 W. To reveal the mechanism of microwave-assisted extractive desulfurization via different organic solvents, a theoretical study including structural examination and interaction energy analysis on the interaction between dibenzothiophene (DBT) or dimethyl dibenzothiophene (DMDBT) and the different organic solvents was also conducted.

Exploring realistic vehicle acceleration sounds through discomfort index analysis

Contemporary Japanese society's heavy reliance on automobiles is shifting from transportation to leisure, amidst rising environmental concerns over emissions. This has led to a pivot towards eco-friendly options, notably clean diesel vehicles (DVs) and electric vehicles (EVs), due to Europe's stringent regulations. DVs aim to lower harmful emissions, while EVs are favored for their minimal emissions and silent operation. However, EVs' lack of audible acceleration noise poses safety risks, as drivers may struggle to perceive speed changes. The study investigated how deviations in expected engine sounds impact perceived sound quality and vehicle performance assessment, focusing on DV and EV acceleration sounds. It explored the integration of certain sensations (rumbling, booming, humming) into EV sounds to enhance realism, assessing comfort levels among drivers with varying experience.

Enhancing Ultradeep Hydrodesulfurization of Coker Diesel through Adsorptive Predenitrogenation.

The petroleum refining industry places significant challenge in the production of ultralow-sulfur diesel (ULSD) from various middle distillates with high nitrogen concentration in an energy-efficient and cost-effective way to meet strict environmental regulations as coexisting nitrogen compounds significantly inhibit the ultradeep hydrodesulfurization (HDS). Among all of the approaches reported in the literature for this challenge, a combination of adsorptive denitrogenation (ADN) and HDS has attracted great attention. This study focuses on ultradeep HDS of coker diesel (CD) through a synergistic approach combining ADN over a carbon-based adsorbent and the current HDS process. The study found that the predenitrogenation significantly enhanced the HDS reactivity of CD and greatly reduced the start of run temperature for producing ULSD by even 20 °C, depending on the denitrogenation depth. It results in dominantly decreasing energy and H2 consumption in the HDS process, and increasing the lifetime of the catalyst. Furthermore, the predenitrogenation prior to HDS significantly improved the quality of the hydrodesulfurized product by decreasing aromatic content and density, increasing the cetane index, and improving the color and stability of the product as the HDS process for producing ULSD can be conducted at a much lower temperature. The study demonstrated the combination of ADN and HDS for producing ULSD from CD on a pilot unit scale, and the advantages and disadvantages of this combination were discussed in comparison with the conventional HDS process. In addition, it was found that there is a good linear relationship between the logarithm of the product sulfur concentration and the HDS reaction temperature, which can be used conveniently to predict the start-of-run temperature to achieve different sulfur levels.

Reduction of Emission and Fuel Consumptions based on Mingled Nano Additives in Biodiesel

Using the lipids identified as well as extra residual cooking oil, vegetable, and animal fats, bio-diesel a substitute for fuels derived from petroleum can be produced. Since the 1970s oil crisis, there has been a resurgence of interest in using biodiesel as a fossil fuel substitute due to the fuel's rapidly rising prices, availability uncertainties, and growing environmental and greenhouse gas (GHG) concerns.To produce biodiesel, glycerin and fat or vegetable oil are separated chemically through a process termed transesterification. Glycerin, a valuable byproduct that is typically sold to be used in soaps and other products, and methyl esters, the chemical term for biodiesel, are the two products left over from the process. The industrial term for diesel derived from petroleum, petro diesel, and biodiesel have similar viscosities. Due to the nearly zero sulfur content,it is recommended to be used as an additive in diesel oil formulations to improve the lubricity of pure ultra-low sulfur diesel (ULSD).The current work focuses heavily on reducing emissions and fuel consumption in automobiles. In addition to lowering pollutants and fuel consumption, the transition metal oxide (Copper oxide) additions in nanocrystalline particle form aid in molecular combustion. To create a stable Nano fluid, soap nut biodiesel is combined with metal oxide additive and ultrasonicated. For our experimental investigation, single cylinder, air cooled, constant speed Kirloskar engine is used. The reduction of hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide (NOx) emissions is investigated. The highest break power of the biodiesel employed in the study is 3.82 KW, greater than the typical diesel's 3.23 KW. The result shows improved engine efficiency, reduced emissions, and better brake thermal efficiency.

Cold idle vs hot idle: Gaseous and particulate emissions using a third-generation oxygenated biofuel

Engine idling is a significant contributor to vehicle emissions, however, it is often unaccounted for. Presented in this study is a comprehensive analysis of gaseous and particulate emissions during cold idle compared to hot idle operations. Fuels used in this study were B20 (20 %) and B10 (10 %) (%v/v) blends of di-octyl phthalate (a third-generation microalgae-based biofuel) and ultra-low sulphur diesel (B00), used as a reference fuel. Compared to cold idle operation, hydrocarbon (HC) emissions during hot idle showed marginal variation (±10 %) using blended fuels, and a significant increase (+55 %) using B00. Compared to cold idle operation, hot idle showed increased oxides of nitrogen (NOx) emissions, using all fuels (with a more significant increase shown using B00). During cold idle, particle concentrations (PNT) were 50–65 % higher using the blended fuels, compared to B00; however, during hot idle, the (PNT) using the blended fuels were one order of magnitude lower than B00. During cold idle operation, the average particle count mean diameter (CMD) in the Lower Aitken and Aitken modes was 5–10 % and 20–30 % higher using blended fuels, compared to B00, respectively. Higher CMD with the blended fuels during the cold idle operation caused a higher percentage increase in the particle mass (PMT), compared to B00. Sub-23 particles (<23 nm) were observed during cold and hot idle operations, using all fuels.

Enhancing ammonia decomposition in ammonium hydroxide/diesel emulsion through hybrid nanocomposite and optimization for improved and greener combustion

In this study, a hybrid nanocomposite was synthesized and characterized to intensify ammonia decomposition in ammonium hydroxide (AH) emulsified diesel fuel. The optimal concentrations of AH and zinc oxide/carbon nanotube (ZnO/CNT) nanocomposite in diesel fuel were evaluated using response surface methodology for effectual and greener combustion. The range of AH concentration was varied from 10 % to 30 %, and ZnO/CNT nanocomposite concentration ranged from 50 ppm to 150 ppm in diesel fuel. Validation experiments were performed to confirm the optimized parameters’ competence compared to regular diesel fuel (RDF). Fourier Transform Infrared and X-ray Diffraction analyses verified successful ZnO/CNT nanocomposite synthesis with desired structural and chemical properties. Optimization results indicated that an 17.2 % volume concentration of AH and 82.3 ppm of ZnO/CNT nanocomposite in RDF yielded efficient combustion with reduced emissions. Validation results showed that the inclusion of 17 % AH in RDF decreased engine brake thermal efficiency (BTE) by 11.1 % and increased brake specific fuel consumption (BSFC), hydrocarbon (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) emissions by 11.3 %, 9.1 %, 9.9 %, and 3 %, respectively. Furthermore, the presence of the nanocomposite (82.3 ppm) enhanced BTE by 10.1 % and reduced BSFC, HC, CO, and NOx emissions by 6.9 %, 6.2 %, 6.9 %, and 5.9 %, respectively. The advancements in fuel additives, such as ZnO/CNT nanocomposites in AH emulsified diesel fuel, have the potential to create more fuel-efficient and cleaner diesel engines. These improvements can significantly contribute to sustainable energy solutions.

Effect of diglyme on diesel engine combustion and un/regulated emission

ABSTRACT The influence of diglyme on diesel engine combustion and emission, including regulated and unregulated emissions, was carried out at various engine modes, in which ultra-low sulfur diesel and diglyme were employed, and diesel-diglyme blends were designed containing specific mass oxygen content varied from 2% to 20% corresponding to 5% to 53% diglyme blended by volume. With the addition of diglyme, actual air/fuel ratio decreased in general, combustion initiated earlier by 5.3% to 14.6% at tested modes but weighted center postponed with short ignition delay and combustion duration, meanwhile maximum in-cylinder combustion temperature reduced by 3 to 30°C, which affected emissions significantly.Consequently, the optimized PM-NOx trade-off was obtained with particulate and NOx decreased simultaneously, but formaldehyde and acetaldehyde increased by the varation from 3% to 190% with the addition of diglyme. Sulfur dioxide emission was much lower with ultra-low sulfur diesel compared that with other fuels including conventional diesel, about one order of magnitude smaller, and diglyme could bring further reduction by maximum of 62.5%. In addition, the oxygen in diglyme promoted CO oxidation and NO2 conversion from NO, leading to an increased NO2/CO ratio by even to 375.9%.

Design of oscillatory helical baffled reactor and dual functional mesoporous catalyst for oxidative desulfurization of real diesel fuel

Enhancing real diesel fuel properties by expelling pollutants using a new design has received considerable interest in the present day. This work investigates the conversion of sulfur compounds via oxidation reaction with peracetic acid as an oxidant. For this purpose, a dual functional mesoporous catalyst was synthesized via loading active metal (iron oxide) nanoparticles over mesopore γ-alumina-anatase titanium oxide prepared via the impregnation procedure (IWI) and precipitation methods, respectively. The novel design of the mesoporous catalyst represents the dual functional catalyst in the oxidative desulfurization process (ODS). The mesoporous catalyst that was formulated underwent a comprehensive analysis using various characterization techniques such as physical adsorption-desorption under N2, X-ray diffraction-XRD, Fourier transforms infrared spectroscopy-FTIR, Field Emission Scanning Electron Microscopy-FESEM, Energy dispersive X-ray analyzer-EDX, and thermogravimetric analysis-TGA. A newly designed laboratory pilot plant for an oscillatory helical baffled reactor (OHBR) was developed and utilized for the ODS process to evaluate the performance of the synthesized mesopore catalyst. The investigated rapid conversion for sulfur removal was found to be 98.42 % under ambient operating conditions such as oscillation of frequency 2 Hz, oscillation of amplitude 8 mm, temperature of oxidation 80°C, and residence time of 9 min. It is clearly observed that the new design of OHBR and mesoporous catalyst highly affected sulfur removal, resulting in a clean diesel.

Kinetics for the highly selective hybrid and cleaner diesel production by hydro-co-processing of a Jatropha curcas L. oil and gas oil blend using a supported Ni-W/Al-SBA-15 sulfided catalyst

ABSTRACT This work reports the kinetics for the hydro-co-processing of a Jatropha curcas L. oil and gas oil mixture using a sulfided NiO(5.5%)-WO3(25%)/Al(0.05)-SBA-15 catalyst at 360–420°C, 6 MPa of initial H2 pressure, and 4 h of reaction time. It was found that more than 47% of a diesel-like fraction could be obtained due to the HDO of the vegetable oil, and the HDS and HCK of the sulfured and heavier compounds in the gas oil within the mixture. HDO was the most favored reaction, followed by HDS and HCK due to HDO rates were two times higher than those for HDS, demonstrating that oxygen removal was influenced by H2S production during HDS. Accordingly, 96% of the oxygen compounds and 24% of the sulfured compounds were removed during hydro-co-processing. Finally, the intrinsic properties (acidity and metallic character) influenced HCK reactions due to 52.9% of the heavier fraction in the reaction mixture was readily hydroconverted into lighter hydrocarbons. Hence, lighter, cleaner and hybrid fuels can be obtained by hydro-co-processing technologies with the sulfided NiO(5.5%)-WO3(25%)/Al(0.05)-SBA-15 catalyst at reaction temperatures below 400°C to avoid thermal cracking.

Engine & vehicle modeling for fuel assessment under local driving conditions

Automotive biofuels offer a promising alternative to traditional fossil fuels. Accurate evaluation of combustion and emissions in IC engines and vehicles is crucial. This research aimed at developing and validating an engine and vehicle simulation methodology to assess the fuel effect on vehicle consumption and emissions considering different driving cycles and the road slope (barely evaluated for fuels widely used in emerging markets). Two blends were tested: 20 % biodiesel (B20) and 20 % hydrotreated vegetable oil (HVO20) with Ultra-Low-Sulfur Diesel (ULSD). A light-duty diesel vehicle model was developed in GTSuite®, using emission maps from a calibrated steady-state engine model. Good agreement with experiments was found. Road slope in local DC significantly increased fuel consumption and CO, CO2, NOx, and PN emissions, reducing HC. Compared to ULSD, B20 reduced PN and HC by 27–35 % and 12–22.5 %, respectively. HVO20 had a smaller effect on PN but reduced HC emissions by up to 19.5 %. Neither blend significantly affected CO and CO2. B20 slightly increased NOx and fuel consumption, while HVO20 had no significant impact on these.

Impact of multi-walled carbon nanotubes (MWCNTs) on hybrid biodiesel blends for cleaner combustion in CI engines

This study investigates the influence of multi-walled carbon nanotubes (MWCNTs) and hybrid biodiesel blends on the performance, combustion, and emission characteristics of a compression ignition engine. The hybrid biodiesel comprises waste frying oil methyl ester (WFOME), sesame oil methyl ester (SOME), and ultra-low sulfur diesel (ULSD) blended at 20 %:80 % by volume (B20). MWCNTs were added into B20 at 25 ppm and 50 ppm concentrations (B20-25MWCNT and B20-50MWCNT). Experimental analysis was conducted under varying engine loads and injection pressures, complemented by CFD simulations. Results demonstrate that the addition of MWCNTs significantly enhances B20 blend performance, with B20-50MWCNT exhibiting a 25 % increase in brake thermal efficiency and a 17 % reduction in brake specific fuel consumption compared to neat B20. Additionally, the incorporation of MWCNTs resulted in notable reductions in harmful emissions. NOx emissions for the B20 + 50MWCNT blend were reduced by up to 36 % compared to diesel and 43 % compared to B20. Smoke opacity and particulate emissions also showed significant decreases, highlighting the cleaner combustion facilitated by the presence of MWCNTs. The CFD simulations provided detailed insights into the combustion process, validating the experimental findings and elucidating the mechanisms behind the observed improvements. The enhanced fuel atomization, better fuel-air mixing, and catalytic properties of MWCNTs were identified as key factors contributing to the superior performance and reduced emissions.

Shock tube and comprehensive kinetic modeling study of ammonia/diethyl ether (DEE) mixtures

Ammonia (NH3) is a promising alternative clean fuel due to its carbon-free and high hydrogen content, along with the well-established infrastructure for storage and distribution. To overcome the issue of the low reactivity of NH3, a feasible strategy is co-burning ammonia with highly reactive fuels. Diethyl ether (DEE) is considered a promising alternative and biomass-oxygenated clean diesel substitute. Therefore, the NH3/DEE blend is also a promising carbon neutral alternative fuel. In this work, we measured the ignition delay times (IDTs) of NH3/DEE mixtures with DEE fractions (XDEE) of 0.05, 0.10, 0.30, and 1.00 at equivalence ratios of 0.5, 1.0, and 2.0, pressures of 1.75 and 10 bar, and temperature ranges from 1102 K to 1673 K in a shock tube. The DEE-NH3 model was proposed in this work, which included the DEE sub-model, NH3 sub-model, and some new cross-reactions between N-containing species and C-containing species. The DEE sub-model from Shrestha et al. (Fuel Communications, 2022) was modified in this work, NH3 sub-model was from our previous work (Reaction Chemistry & Engineering, 2023). The DEE-NH3 model was extensively validated by the IDTs, laminar flame speeds (LFSs), and species profiles (SPs) of NH3/DEE mixtures as well as pure DEE and NH3. The comparison of the prediction performance between the DEE-NH3 model and the Shrestha model was conducted for the ignition, flame propagation, and NH3 consumption. The effects of the cross-reactions on the NH3/DEE ignition and combustion were studied in detail.

Ultrasound-assisted extractive-catalytic removal of micro-organic pollutants in liquid hydrocarbon fuels using highly active ZnO nanoparticles supported zinc-substituted phosphotungstate

To produce ultra-low sulfur diesel (ULSD), it is necessary to remove compounds such as 2-methylthiophene and 3-methylthiophene that cannot be isolated by conventional industrial methods. This paper presents, a phosphotungstate catalyst improved with zinc atoms placed on the surface of super active zinc oxide nanoparticles and is able to switch between two phases using a hydrophobic ionic liquid (transfer agent). Here, is a description of the synthesis of the α-keggin type hybrid nanocatalyst and its application for the removal of 2- methylthiophene and 3-methylthiophene. The nanocatalyst was subjected to various characterization techniques, including Fourier Transform Infrared Spectrometer (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) Surface Area Analysis, Barrett-Joyner-Halenda (BJH) pore size and volume analysis and Energy-dispersive X-ray analysis(EDAX). The optimized conditions for the ultrasound-assisted extractive-catalytic oxidative desulfurization (UA-ECODS) process were determined using a statistical design, specifically the Box-Behnken design (BBD), which was proposed as a plan for designing experiments and studying the behavior of the parameters. The optimal conditions, which encompass four parameters, namely ultrasonic time, reactor temperature, amount of nanocatalyst, and oxidant concentration, are archived as 14.43 min, 40.52 °C, 86.27 mg catalyst, and 24 % H2O2 Respectively. The results indicated that the removal efficiency was higher for 2- methylthiophene than 3-methylthiophene. The paper concludes that the UA-ECODS method utilizing the synthesized nanocatalyst is a promising and effective approach for desulfurizing of liquid hydrocarbon fuels.

New Rislone DEF crystal clean diesel DEF and SCR emissions system cleaner

New Rislone DEF crystal clean diesel DEF and SCR emissions system cleaner

REACTOR SECTION PRESSURE CONTROL AT DIESEL HYDROTREATING UNIT

Diesel Hydrotreating Units (DHUs) are essential components within petroleum refineries, playing a critical role in the production of clean and high-quality diesel fuel. This abstract provides a comprehensive overview of the mechanisms, necessity, and operational significance of DHUs in the refining process. Firstly, the abstract discusses the fundamental principles underlying the operation of DHUs. The catalytic hydrotreating process is elucidated, highlighting the role of hydrogenation reactions in the removal of sulfur, nitrogen, and aromatic compounds from diesel feedstocks. The synergy between catalysts and hydrogen gas in promoting desulfurization, denitrification, and hydrodenitrogenation reactions is examined, emphasizing the pivotal role of DHUs in enhancing the environmental and performance attributes of diesel fuel. Furthermore, the abstract addresses the imperative need for Diesel Hydrotreating Units. The detrimental impacts of sulfur-containing compounds, such as sulfur oxides (SOx), on air quality and human health are discussed, underscoring the regulatory mandates aimed at reducing sulfur emissions from diesel fuel. DHUs emerge as indispensable tools for compliance with stringent environmental regulations, ensuring the production of low-sulfur diesel fuel that meets or exceeds regulatory standards. Moreover, the abstract emphasizes the operational significance of DHUs within petroleum refineries. Through the integration of advanced reactor designs, catalyst technologies, and process optimization strategies, DHUs enable refineries to achieve efficient desulfurization and meet production targets while minimizing energy consumption and operational costs. The adaptability of DHUs to varying feedstock compositions and processing conditions further underscores their versatility and importance in the refining industry. In conclusion, this abstract provides a comprehensive overview of Diesel Hydrotreating Units, elucidating their mechanisms, necessity, and operational significance in the production of clean and high-quality diesel fuel. By facilitating the removal of sulfur and other impurities from diesel feedstocks. Keywords: Diesel Hydrotreatment Unit, Control Systems, Petrochemical Industry, Efficiency, Safety.

Odors Detection and Recognition Based on Intelligent E-Nose

Electronic noses have become more common as a result of developments in sensor technology, machine learning (ML), and Artificial Intelligence (AI). At the moment, the majority of e-nose research is conducted in laboratories; access from other locations is not possible with e-nose. Very few real-time smell detection applications, including tiny drones equipped with commercial gas sensors or biosensors made of insect antennas, have been created. The scope of this work is to design an intelligent E-Nose for odors detection. Smell Inspector developer kit has been used to get measurements. The Smell Inspector consists of sensors for temperature and humidity in addition to four smell iX16 chips. The Smell Inspector creates digital fragrance fingerprints using a variety of separate gas detectors. The approach for object recognition and classification using artificial intelligence techniques is presented in this paper. These techniques include Machine Learning (ML), clustering, and regression algorithms. Using the K-Nearest Neighbor (KNN) algorithm, the experimental results' array sensors were able to recognize; clean air, onion, garlic, coffee, spices, lemon, vinegar, gasoline, petrol, diesel, and perfumes with 78% accuracy rate.

Long term trends in source apportioned particle number concentrations in Rochester NY

During the past two decades, efforts have been made to further reduce particulate air pollution across New York State through various Federal and State policy implementations. Air quality has also been affected by economic drivers like the 2007–2009 recession and changing costs for different approaches to electricity generation. Prior work has focused on particulate matter with aerodynamic diameter ≤2.5 μm. However, there is also interest in the effects of ultrafine particles on health and the environment and analyses of changes in particle number concentrations (PNCs) are also of interest to assess the impacts of changing emissions. Particle number size distributions have been measured since 2005. Prior apportionments have been limited to seasonal analyses over a limited number of years because of software limitations. Thus, it has not been possible to perform trend analyses on the source-specific PNCs. Recent development have now permitted the analysis of larger data sets using Positive Matrix Factorization (PMF) including its diagnostics. Thus, this study separated and analyzed the hourly averaged size distributions from 2005 to 2019 into two data sets; October to March and April to September. Six factors were resolved for both data sets with sources identified as nucleation, traffic 1, traffic 2, fresh secondary inorganic aerosol (SIA), aged SIA, and O3-rich aerosol. The resulting source-specific PNCs were combined to provide continuous data sets and analyzed for trends. The trends were then examined with respect to the implementation of regulations and the timing of economic drivers. Nucleation was strongly reduced by the requirement of ultralow (<15 ppm) sulfur on-road diesel fuel in 2006. Secondary inorganic particles and O3-rich PNCs show strong summer peaks. Aged SIA was constant and then declined substantially in 2015 but rose in 2019. Traffic 1 and 2 have steadily declined bur rose in 2019.

Chemometric Analysis Combined with GC × GC-FID and ESI HR-MS to Evaluate Ultralow-Sulfur Diesel Stability.

Diesel has been the most employed fuel in highway and nonhighway transportation systems. Many studies over the past years have attempted to classify diesel as a stable or unstable composition since this fuel can still degrade during storage or thermal oxidative processes. Products generated because of such degradation are the reason for the formation of soluble gums and insoluble organic particulates, which in turn cause a negative influence on engine performance. This work reports a detailed composition of nonpolar and polar compounds in many ultralow-sulfur diesel (ULSD) samples by comprehensive two-dimensional gas chromatography with a flame ionization detector (GC × GC-FID) and electrospray ionization high-resolution mass spectrometry (ESI HR-MS). In addition, chemometric approaches were applied for ULSD storage stability investigation. GC × GC-FID experiments achieved the nonpolar chemical characterization for the ULSD samples, including all main hydrocarbon classes: paraffins, mono- and dinaphthenics and olefins, and aromatics. The GC × GC-FID data combined with principal component analysis (PCA) described that the separation of the samples' concerning storage stability was mainly due to the contents of mono- and diaromatic compounds in the unstable ULSD samples. Moreover, PCA was also applied to the ESI (±) data set, and the results highlight the presence of compounds belonging to O class (natural antioxidants), which decrease the rate of oxygen consumption in the fuel, characterizing it as stable composition. The basic nitrogen compounds are mostly present in the stable ULSD samples indicating that they did not affect the stability of the fuel. On the other hand, the HC classes presented pronounced abundance among unstable ULSD samples suggesting that the fuel degradation may go through the oxidation of hydrocarbons and the formation of Ox compounds as byproducts. Furthermore, MS/MS experiments point to the formation of CcHhNnOo-like precursor species, which can react with each other and lead to the formation of gums and insoluble sediments in the fuel. In summary, the results express the potential of using the GC × GC-FID and ESI (±) Orbitrap MS techniques as valuable tools for diesel stability evaluations.

Investigating the Possibility of Using Renewable Energies in Livestock Units in Iran (A Case Study: Fereydounshahr)

Fereydounshahr experiences growing electricity shortfalls and an overreliance on polluting diesel generators. This analysis models renewable hybrid systems to electrify a local dairy operation using HOMER Pro 3.11 software. Despite higher upfront costs, adding just 5% solar photovoltaics maintained low net present costs while increasing clean energy penetration versus diesel generators alone. Furthermore, a combined diesel-solar-wind system reduced carbon dioxide and nitrogen oxide emissions by over 1%. Although diesel generators had the shortest payback period at 48 years, the capital recovery factor for a diesel–solar combination reached 62 years. Thus, tailored hybrid renewable systems could provide an affordable, low-emissions electricity solution for the Fereydounshahr livestock facility. With suitable wind and solar resources, the right policy incentives could also unlock substantial local renewable capacity to meet rising demand and mitigate dependence on imported, climate-harming fossil fuels.