Journal Description
Fuels
Fuels
is an international, peer-reviewed, open access journal on fuel science published quarterly online by MDPI. Institute for Chemical Processing of Coal (IChPW) is affiliated to Fuels and their members receive a discount on the article processing charges.
- Open Access—free to download, share, and reuse content. Authors receive recognition for their contribution when the paper is reused.
- Rapid Publication: manuscripts are peer-reviewed and a first decision provided to authors approximately 12.1 days after submission; acceptance to publication is undertaken in 7.2 days (median values for papers published in this journal in the second half of 2021).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
- Fuels is a companion journal of Energies.
Latest Articles
Nuclear Magnetic Resonance (NMR) Outputs Generation for Clastic Rocks Using Multi Regression Analysis, Examples from Offshore Western Australia
Fuels 2022, 3(2), 316-325; https://doi.org/10.3390/fuels3020019 - 17 May 2022
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A large database of nuclear magnetic resonance (NMR) logging data from clastic rocks of offshore oil and gas fields of Western Australia was used to assess the performance of multi regression analysis (MRA) to calculate NMR log outputs from conventional well logs. This
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A large database of nuclear magnetic resonance (NMR) logging data from clastic rocks of offshore oil and gas fields of Western Australia was used to assess the performance of multi regression analysis (MRA) to calculate NMR log outputs from conventional well logs. This short paper introduces a set of MRA equations for the calculation of the NMR log outputs using conventional well logs as inputs. This study shows that unlike machine learning methods the MRA approach fails to predict most of the NMR log outputs with acceptable accuracy but can provide Coates and SDR permeabilities with R2 of more than 0.75.
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Performance of Citric Acid as a Catalyst and Support Catalyst When Synthesized with NaOH and CaO in Transesterification of Biodiesel from Black Soldier Fly Larvae Fed on Kitchen Waste
Fuels 2022, 3(2), 295-315; https://doi.org/10.3390/fuels3020018 - 17 May 2022
Abstract
Current research and development to lower the production cost of biodiesel by utilizing feedstock derived from waste motivates the quest for developing catalysts with high performance in transesterification. This study investigates the performance of citric acid as a catalyst and support catalyst in
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Current research and development to lower the production cost of biodiesel by utilizing feedstock derived from waste motivates the quest for developing catalysts with high performance in transesterification. This study investigates the performance of citric acid as a catalyst and support catalyst in transesterification of oil from black soldier fly (Hermetia illucens) larvae fed on organic kitchen waste. Two catalysts were prepared by synthesizing citric acid with NaOH and CaO by a co-precipitation and an impregnation method, respectively. The design of the experiment adopted response surface methodology for the optimization of biodiesel productivity by varying: the percentage loading weight of citric acid, the impregnation temperature, the calcinating temperature and the calcinating time. The characteristic activity and reuse of the synthesized catalysts in transesterification reactions were investigated. The morphology, chemical composition and structure of the catalysts were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF) and X-ray diffraction (XRD). High citric acid loading on NaOH and a small amount of citric acid on CaO resulted in improved dispersion and refinement of the particle sizes. Increasing citric acid loading on NaOH improved the CaO and SiO2 composition of the modified catalyst resulting in higher biodiesel yield compared to the modified CaO catalyst. A maximum biodiesel yield of 93.08%, ±1.31, was obtained when NaOH was synthesized with a 130% weight of citric acid at 80 °C and calcinated at 600 °C for 240 min. Comparatively, a maximum biodiesel yield of 90.35%, ±1.99, was obtained when CaO was synthesized with a 3% weight of citric acid, impregnated at 140 °C and calcinated at 900 °C for 240 min. The two modified catalysts could be recycled four times while maintaining a biodiesel yield of more than 70%.
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(This article belongs to the Special Issue Waste to Fuels and Chemicals: Toward a Clean, Green, and Sustainable World)
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Effects of Injector Nozzle Number of Holes and Fuel Injection Pressures on the Diesel Engine Characteristics Operated with Waste Cooking Oil Biodiesel Blends
Fuels 2022, 3(2), 275-294; https://doi.org/10.3390/fuels3020017 - 11 May 2022
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This work covers the impact of varying injector nozzle hole numbers (INHNs) and fuel injection pressures (IPs) on fuel atomization, performance, and exhaust emission characteristics of a diesel engine. The primary goal of this research was to improve fuel characteristics. Increasing INHNs and
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This work covers the impact of varying injector nozzle hole numbers (INHNs) and fuel injection pressures (IPs) on fuel atomization, performance, and exhaust emission characteristics of a diesel engine. The primary goal of this research was to improve fuel characteristics. Increasing INHNs and fuel IPs have a substantial impact on the blended fuel viscosity and density, which leads to increased atomization and mixing rates, as well as combustion and engine efficiency. The fuel atomization was checked by varying the INHNs with an operating diesel fuel using the ANSYS Fluent spray simulation work. The experimental test was performed on the fuel blends of waste cooking oil (WCO)–diesel blends from 10 to 30% (with an increment of 10%) by evaluating the performance and emission parameters. The fuel IPs were altered on four, such as 190, 200 (default), 210, and 220 bar with a modification of INHN of 1 (default), 3, and 4), each 0.84, 0.33, and 0.25 mm in orifice size, respectively. The simulation result shows that the INHN-4 has better fuel atomization. Whereas the experimental test revealed that the increment in blending ratio of WCO was up to 30%, INHNs and fuel IPs enhanced the BSFC and BTE and reduced exhaust emissions. The results indicate that increasing the fuel IP up to 210 bar with a 4-hole INHN for B30 was the optimal combination for the overall enhancement of BSFC and BTE, as well as lower CO and HC emissions with a minor rise in NOx when compared to the baseline diesel.
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Open AccessArticle
Process Analysis and Design Considerations of a Low Carbon Methanol Synthesis Plant from Lignite/Waste Gasification
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, , , and
Fuels 2022, 3(2), 245-274; https://doi.org/10.3390/fuels3020016 - 01 May 2022
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This study presents design considerations and an evaluation of a full-scale process chain for methanol and advanced drop-in fuel production derived from lignite/solid recovered fuel (SRF) feedstock. The plant concept consists of a high-temperature Winkler (HTW) gasifier coupled with an air separation unit
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This study presents design considerations and an evaluation of a full-scale process chain for methanol and advanced drop-in fuel production derived from lignite/solid recovered fuel (SRF) feedstock. The plant concept consists of a high-temperature Winkler (HTW) gasifier coupled with an air separation unit (ASU), which provides a high-purity (99.55%) gasification oxidant agent. The concept includes the commercially proven acid gas removal (AGR) system based on cold methanol (e.g., Rectisol® process) for the removal of BTX and naphthalene components. With the involvement of Rectisol®, an almost pure CO2 off-gas stream is generated that can be further stored or utilized (CCS/CCU), and a smaller CO2 stream containing H2S is recovered and subsequently driven to the sulfur recovery unit (e.g., Claus process). One of the potential uses of methanol is considered, and a methanol upgrading unit is implemented. The overall integrated process model was developed in the commercial software Aspen PlusTM. Simulations for different feedstock ratios were investigated, ensuring the concept’s adaptability in each case without major changes. A number of parametric studies were performed concerning (a) the oxygen purity and (b) the reformer type, and a comparison against alternative methanol production routes was conducted. Simulations show that the proposed system is able to retain the cold gas efficiency (CGE) in the range of 79–81.1% and the energetic fuel efficiency (EFE) at around 51%. An efficient conversion of approximately 99.5% of the carbon that enters the gasifiers is accomplished, with around 45% of carbon being captured in the form of pure CO2. Finally, the metrics of EFE and total C for the conversion of methanol to liquid fuels were 40.7% and 32%, respectively, revealing that the proposed pathway is an effective alternative for methanol valorization.
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Open AccessArticle
Mutants with Enhanced Cellobiose-Fermenting Ability from Thermotolerant Kluyveromyces marxianus DMKU 3-1042, Which Are Beneficial for Fermentation with Cellulosic Biomass
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, , , and
Fuels 2022, 3(2), 232-244; https://doi.org/10.3390/fuels3020015 - 29 Apr 2022
Abstract
Several cellulose-hydrolysis enzymes are required for eco-friendly utilization of cellulose as renewable biomass, and it would therefore be beneficial if fermenting microbes can provide such enzymes without genetic engineering. Thermotolerant and multisugar-fermenting Kluyveromyces marxianus is one of the promising yeasts for high-temperature fermentation
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Several cellulose-hydrolysis enzymes are required for eco-friendly utilization of cellulose as renewable biomass, and it would therefore be beneficial if fermenting microbes can provide such enzymes without genetic engineering. Thermotolerant and multisugar-fermenting Kluyveromyces marxianus is one of the promising yeasts for high-temperature fermentation and has genes for putative oligosaccharide-degradation enzymes. Mutants obtained after multiple mutagenesis showed significantly higher activity than that of the parental strain for cellobiose fermentation. The efficient strains were found to have amino acid substitutions and frame-shift mutations in 26-28 genes including 3 genes for glucose transporters. These strains grown in a cellobiose medium showed higher β-glucosidase than that of the parental strain and greatly reduced glucose utilization. The introduction of KTH2 for a glucose transporter into one of the efficient mutants reduced the cellobiose fermentation activity of the mutant. The results suggest that release from glucose repression significantly promotes the uptake of cellobiose. Co-culture of one efficient strain and the parental strain allowed good fermentation of both glucose and cellobiose, suggesting that the efficient strains are useful for conversion of cellulosic biomass to ethanol.
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(This article belongs to the Special Issue Biomass Conversion to Biofuels)
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Comparison between Conventional and Non-Conventional Computer Methods to Define Antiknock Properties of Fuel Mixtures
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, , , , and
Fuels 2022, 3(2), 217-231; https://doi.org/10.3390/fuels3020014 - 13 Apr 2022
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Research Octane Number (RON) is one of the primary indicators for the determination of the resistance of gasoline fuels to autoignition. This parameter is usually determined with a test procedure involving a standardized engine that requires expensive hardware and time-consuming tests. In this
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Research Octane Number (RON) is one of the primary indicators for the determination of the resistance of gasoline fuels to autoignition. This parameter is usually determined with a test procedure involving a standardized engine that requires expensive hardware and time-consuming tests. In this work, a set of different methods with which to determine the RON of gasoline fuel surrogates is presented, considering only computer simulations, which allows to reduce both cost and time for the evaluation. A palette of 11 chemical species has been chosen as the basis for the surrogates’ database, which will be investigated in the work, allowing the representation of the complex chemical formulation of fuels in an easier way. A simplified zero-dimensional engine model of the standard variable compression ratio is used to provide pressure and temperature, then employed to calculate RON. This is done first by means of existing methods, and then by introducing new processes concerning a simplified chemical reactor built on kinetic schemes. Finally, these different methodologies are tested against a molar weighted sum of RONs of each chemical specie, allowing to have a criterion for comparison and evaluating their real prediction capabilities.
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Open AccessArticle
Spray Characteristics of Bioethanol-Blended Fuel under Various Temperature Conditions Using Laser Mie Scattering and Optical Illumination
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Fuels 2022, 3(2), 207-216; https://doi.org/10.3390/fuels3020013 - 02 Apr 2022
Abstract
Bioethanol has great potential to reduce emissions from transportation while improving energy security and developing the economy. Bioethanol has a higher octane-number and a higher enthalpy of vaporisation than gasoline (resulting in charge cooling)—properties that have been used to extend knocking limits. Therefore,
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Bioethanol has great potential to reduce emissions from transportation while improving energy security and developing the economy. Bioethanol has a higher octane-number and a higher enthalpy of vaporisation than gasoline (resulting in charge cooling)—properties that have been used to extend knocking limits. Therefore, bioethanol can be used to substitute gasoline in automotive engine applications. The characteristics of bioethanol spray, such as hydrous bioethanol fuel which consists of 93% bioethanol and 7% water, were investigated under various temperature conditions from sub-zero (−15 °C) to room temperature (17 °C) by means of high-speed direct photography and laser Mie scattering techniques without any seeding materials. The experimental results show that the spray patterns are not significantly changed. In the case of the sub-zero temperature condition, the spray tip penetration decreases while the spray angle keeps almost constant once the spray becomes fully developed. The results show that scaling of the spray tip penetration rate achieves a reasonable collapse of the experimental results. The normalised droplet diameter was also obtained and shows that larger droplets are formed at the sub-zero temperature condition.
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(This article belongs to the Special Issue Advanced Laser Diagnostics in Combustion)
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The Addition of Particles to an Alternative Jet Fuel
Fuels 2022, 3(2), 184-206; https://doi.org/10.3390/fuels3020012 - 22 Mar 2022
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The expansion of the research on nanoscale particles demonstrates several advantages in terms of stability and an increased surface area to volume ratio compared to micron-sized particles. Based on this, the present work explores the addition of aluminum particles in hydrotreated vegetable oil
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The expansion of the research on nanoscale particles demonstrates several advantages in terms of stability and an increased surface area to volume ratio compared to micron-sized particles. Based on this, the present work explores the addition of aluminum particles in hydrotreated vegetable oil (HVO), an alternative jet fuel. To evaluate the influence of particle sizes, nano and micron particles (40 nm and 5 μm) in a particle concentration of 0.5 wt.% were stably suspended in HVO. This study evaluates droplet combustion with an initial diameter of 250 μm in a drop tube furnace under different furnace temperatures (600, 800, 1000 °C). A high magnification lens coupled with a high-speed camera provides qualitative and quantitative data regarding droplet size evolution and micro-explosions. Pure HVO and Jet A-1 were also tested for comparison purposes. The results reveal that the addition of aluminum particles enhances the alternative jet fuel combustion. Furthermore, decreasing the particle size and increasing the furnace temperature enhances the burning rate compared to the pure HVO. Pure HVO presents a burning rate nearly to 1.75 mm2/s until t/D = 0.35 s/mm2 at T = 1000 °C. When nanoparticles are added to HVO in a particle concentration of 0.5 wt.%, an improvement of 24% in burning rate is noticed. Conventional jet fuel and pure HVO do not present any disruptive burning phenomena. However, when aluminum particles were added to HVO, micro-explosions were detected at the end of droplet lifetime, regardless of the particle size.
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(This article belongs to the Special Issue Advances in Propulsion and Energy Systems Utilising Alternative Fuels: Fuel Injection and Combustion Systems)
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Activation of CO2 on the Surfaces of Bare, Ti-Adsorbed and Ti-Doped C60
Fuels 2022, 3(1), 176-183; https://doi.org/10.3390/fuels3010011 - 19 Mar 2022
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There is a growing interest in finding a suitable catalyst for the adsorption and activation of CO2 molecules to minimize the effect of global warming. In this study, density functional theory-based simulations are employed to examine the adsorption and activation of a
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There is a growing interest in finding a suitable catalyst for the adsorption and activation of CO2 molecules to minimize the effect of global warming. In this study, density functional theory-based simulations are employed to examine the adsorption and activation of a CO2 molecule on the pure, Ti-supported and Ti-doped surfaces of C60. The adsorption on the pure surface is very week. Adsorption becomes significant on the Ti-supported C60 surface together with significant activation. Such strong adsorption is evidenced by the significant charge transfer between Ti and C60. The Ti-doped C60 surface adsorbs weakly, but the activation is not significant.
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Open AccessArticle
Torrefaction and Densification of Wood Sawdust for Bioenergy Applications
Fuels 2022, 3(1), 152-175; https://doi.org/10.3390/fuels3010010 - 07 Mar 2022
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In this study, wood sawdust as waste residue from wood processing mills was pretreated using torrefaction to improve fuel properties and densified to facilitate transportation. Sawdust was torrefied in a fixed bed reactor using inside temperatures (IT) of 230, 260 and 290 °C
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In this study, wood sawdust as waste residue from wood processing mills was pretreated using torrefaction to improve fuel properties and densified to facilitate transportation. Sawdust was torrefied in a fixed bed reactor using inside temperatures (IT) of 230, 260 and 290 °C for 15, 30 and 45 min, residence time. Due to the low calorific value of the treatments, the outside temperature (OT) of the fixed bed reactor was used instead for a fixed duration of 45 min, which resulted in an increase in energy value by 40% for the most severe conditions. The mechanical strength of the pellets was enhanced by adding 20% binder (steam-treated spruce sawdust) to biochar, which improved the pellet tensile strength by 50%. Liquid by-products from the torrefaction process contained furfural and acetic acid, which can be separated for commercial uses. Thermochemical analysis showed better fuel properties of OT torrefied samples such as high fixed carbon (52%), low volatiles (41%) and lower oxygen contents (27%) compared to IT torrefied samples (18, 77 and 43%, respectively). Low moisture uptake of torrefied pellets compared to raw pellets, along with other attributes such as renewability, make them competent substitutes to fossil-based energy carriers such as coal.
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(This article belongs to the Special Issue Feature Papers in Fuels)
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Numerical Investigation of Dual Fuel Combustion on a Compression Ignition Engine Fueled with Hydrogen/Natural Gas Blends
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, , , and
Fuels 2022, 3(1), 132-151; https://doi.org/10.3390/fuels3010009 - 01 Mar 2022
Cited by 1
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The present work aims to assess the influence of the composition of blends of hydrogen (H2) and Natural Gas (NG) on Dual Fuel (DF) combustion characteristics, including gaseous emissions. The 3D-CFD study is carried out by means of a customized version
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The present work aims to assess the influence of the composition of blends of hydrogen (H2) and Natural Gas (NG) on Dual Fuel (DF) combustion characteristics, including gaseous emissions. The 3D-CFD study is carried out by means of a customized version of the KIVA-3V code. An automotive 2.8 L, 4-cylinder turbocharged diesel engine was previously modified in order to operate in DF NG–diesel mode, and tested at the dynamometer bench. After validation against experimental results, the numerical model is applied to perform a set of combustion simulations at 3000 rpm–BMEP = 8 bar, in DF H2/NG-diesel mode. Different H2–NG blends are considered: as the H2 mole fraction varies from 0 vol% to 50 vol%, the fuel energy within the premixed charge is kept constant. The influence of the diesel Start Of Injection (SOI) is also investigated. Simulation results demonstrate that H2 enrichment accelerates the combustion process and promotes its completion, strongly decreasing UHC and CO emissions. Evidently, CO2 specific emissions are also reduced (up to about 20%, at 50 vol% of H2). The main drawbacks of the faster combustion include an increase of in-cylinder peak pressure and pressure rate rise, and of NOx emissions. However, the study demonstrates that the optimization of diesel SOI can eliminate all aforementioned shortcomings.
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Ultrasonication Assisted Catalytic Transesterification of Ceiba Pentandra (Kapok) Oil Derived Biodiesel Using Immobilized Iron Nanoparticles
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, , , , , , and
Fuels 2022, 3(1), 113-131; https://doi.org/10.3390/fuels3010008 - 22 Feb 2022
Abstract
The embedded immobilized enzymes (Rhizopus-oryzae) on the magnetic nanoparticles (Fe3O4-NPs) is a new application for the sustainable production of high-quality biodiesel. In this study, biodiesel is derived from Kapok oil via ultrasonication (US)-assisted catalytic transesterification method. A
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The embedded immobilized enzymes (Rhizopus-oryzae) on the magnetic nanoparticles (Fe3O4-NPs) is a new application for the sustainable production of high-quality biodiesel. In this study, biodiesel is derived from Kapok oil via ultrasonication (US)-assisted catalytic transesterification method. A novel attempt is made to prepare magnetic nanoparticles embedded by an immobilized enzyme to solve the problem of enzyme denaturation. This innovative method resulted in optimum biodiesel conversion of 89 ± 1.17% under reactant molar ratio (methanol: oil) of 6:1, catalyst loading 10 wt% with a reaction time of 4 h at 60 °C. The kinetic and thermal study reveals that conversion of Kapok oil to biodiesel follows a pseudo first-order reaction kinetic with a lower ΔE of 30.79 kJ mol−1. The ΔH was found to be 28.06 kJ mol−1 with a corresponding ΔS of −237.12 J mol−1 K−1 for Fatty Acid Methyl Ester formation. The ΔG was calculated to be from 102.28 to 109.40 kJ mol−1 for temperature from 313 K to 343 K. The positive value of ΔH and ΔG is an indication of endothermic and non-spontaneous reaction. A negative ΔS indicates the reactant in the transition state possesses a higher degree of ordered geometry than in its ground state. The immobilized catalysts provided great advantages towards product separation and efficient biodiesel production. Highlights: 1. Effective catalytic transesterification assisted by the ultrasonication method was used for bi-odiesel production. 2. Magnetite nanoparticles synthesized by the co-precipitation method were used as heteroge-neous catalysts. 3. An immobilized enzyme (Rhizopus-oryzae) was embedded in the heterogeneous catalyst, as it is reusable and cost-effective. 4. The maximum biodiesel yield obtained from Kapok oil was 93 ± 1.04% by catalytic trans-esterification reactions.
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(This article belongs to the Special Issue Energy Crops for Biofuel Production)
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Study of Spray Behaviors to Correlate with Engine Performance and Emissions of a Diesel Engine Using Canola-Based Biodiesel
Fuels 2022, 3(1), 87-112; https://doi.org/10.3390/fuels3010007 - 10 Feb 2022
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The use of renewable biodiesel fuel in diesel engines can reduce the demand for depleting fossil fuels and reduce harmful emissions to the environment. In this research, an engine simulation is conducted using ANSYS Forte software, which allows for visualization of the spray
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The use of renewable biodiesel fuel in diesel engines can reduce the demand for depleting fossil fuels and reduce harmful emissions to the environment. In this research, an engine simulation is conducted using ANSYS Forte software, which allows for visualization of the spray inside the combustion chamber. The results show that biodiesel has higher liquid and vapor penetration lengths, higher droplet mass and diameter, and a longer breakup length. Molecular images of fuel molecules show that the temperature of biodiesel molecules is 141 °C lower than diesel molecules at 709 degree crank angle (°CA). These characteristics result in an extended evaporation time for biodiesel, consequently leading to poorer performance. Additionally, increased penetration length can lead to carbon deposits inside the combustion chamber. Therefore, such inefficiencies of biodiesel spray properties lead to lower combustive performance than diesel. In terms of performance, on average, biodiesel produces 16.9% lower power and 19.9% higher brake specific fuel consumption. On average, the emissions of CO, CO2, and HC of biodiesel are 17.8%, 3.41%, and 23.5% lower and NOx is 14.39% higher than the corresponding values obtained for pure diesel, respectively. In-cylinder combustion analyses show that the peak pressure of biodiesel is 0.5 MPa lower, the peak cycle temperature is 36 °C lower, the ignition delay is 4 °CA longer, the peak heat release rate is 16.5 J/deg. higher, and the combustion duration is 5.96 °CA longer compared to diesel combustion.
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Acknowledgment to Reviewers of Fuels in 2021
Fuels 2022, 3(1), 85-86; https://doi.org/10.3390/fuels3010006 - 29 Jan 2022
Abstract
Rigorous peer-reviews are the basis of high-quality academic publishing [...]
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Characterization Techniques Coupled with Mathematical Tools for Deepening Asphaltene Structure
Fuels 2022, 3(1), 75-84; https://doi.org/10.3390/fuels3010005 - 27 Jan 2022
Abstract
Asphaltenes are the heavy fraction of fossil fuels, whose characterization remains a very difficult and challenging issue due to the still-persisting uncertainties about their structure and/or composition and molecular weight. Asphaltene components are highly condensed aromatic molecules having some heteroatoms and aliphatic functionalities.
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Asphaltenes are the heavy fraction of fossil fuels, whose characterization remains a very difficult and challenging issue due to the still-persisting uncertainties about their structure and/or composition and molecular weight. Asphaltene components are highly condensed aromatic molecules having some heteroatoms and aliphatic functionalities. Their molecular weights distribution spans in a wide range, from hundreds to millions of mass units, depending on the diagnostic used, which is mainly due to the occurrence of self-aggregation. In the present work, mass spectrometry along with size exclusion chromatography and X-ray diffraction analysis have been applied to asphaltenes for giving some further insights into their molecular weight distribution and structural characteristics. Relatively small polycyclic aromatic hydrocarbons (PAHs) with a significant degree of aliphaticity were individuated by applying fast Fourier transform (FFT) and double bond equivalent (DBE) number analysis to the mass spectra. X-ray diffraction (XRD) confirmed some aliphaticity, showing peaks specific of aliphatic functionalities. Size exclusion chromatography indicated higher molecular weight, probably due to the aliphatic substituents. Mass spectrometry at high laser power enabled observing a downward shift of molecular masses corresponding to the loss of about 10 carbon atoms, suggesting the occurrence of aryl-linked core structures assumed to feature asphaltenes along with island and archipelago structures.
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(This article belongs to the Special Issue Valorization of Biogenic and Not Biogenic Residuals/Byproducts from Thermochemical Processes: Diagnostic, Product Characterization, and Emissions Control)
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Synthesis of Surrogate Blends Corresponding to Petroleum Middle Distillates, Oxidative and Extractive Desulfurization Using Imidazole Ionic Liquids
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and
Fuels 2022, 3(1), 44-74; https://doi.org/10.3390/fuels3010004 - 25 Jan 2022
Abstract
Surrogate fuels are composed of a few pure components, mixed together in order to imitate a real fuel’s characteristics regarding its combustion and emission. In this study, four surrogate feeds were synthesized, corresponding to petroleum middle distillates. The desulfurization of the surrogate blends
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Surrogate fuels are composed of a few pure components, mixed together in order to imitate a real fuel’s characteristics regarding its combustion and emission. In this study, four surrogate feeds were synthesized, corresponding to petroleum middle distillates. The desulfurization of the surrogate blends was performed using the hydrogen peroxide–acetic acid oxidative system. Consequently, extractive desulfurization was carried out using imidazolium-based ionic liquids, namely 1-butyl-3-methylimidazolium bromide [BMIM][Br] and 1-butyl-3-methylimidazolium hydrogen sulfate [BMIM][HSO4], in a multiple extraction cycle procedure. Both ionic liquids were synthesized and characterized with spectroscopic techniques. The influence of the extraction temperature process was studied. In each extraction cycle, the sulfur concentration and the physical properties of the surrogate extraction products were estimated. The used ionic liquids were regenerated with a reasonably effective method. The synthesized and recycled ionic liquids showed high desulfurization efficiency, while [BMIM][Br] prevailed. Additionally, extractive desulfurization in oxidized surrogate LCO using ionic liquids is comparable with that using acetonitrile, since it has an advantage in terms of mass yield.
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(This article belongs to the Special Issue Feature Papers in Fuels)
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CO Oxidation Capabilities of La- and Nd-Based Perovskites
Fuels 2022, 3(1), 31-43; https://doi.org/10.3390/fuels3010003 - 05 Jan 2022
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Catalytic tests to assess the performance of mixed perovskite-type oxides (La0.9Ca0.1FeO3-δ, La0.6Ca0.4FeO3-δ, Nd0.9Ca0.1FeO3-δ, Nd0.6Ca0.4FeO3-δ, Nd0.6Ca0.4Fe
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Catalytic tests to assess the performance of mixed perovskite-type oxides (La0.9Ca0.1FeO3-δ, La0.6Ca0.4FeO3-δ, Nd0.9Ca0.1FeO3-δ, Nd0.6Ca0.4FeO3-δ, Nd0.6Ca0.4Fe0.9Co0.1O3-δ, Nd0.6Ca0.4Fe0.97Ni0.03O3-δ, and LSF) with respect to CO oxidation are presented as well as characterization of the materials by XRD and SEM. Perovskites are a highly versatile class of materials due to their flexible composition and their ability to incorporate dopants easily. CO oxidation is a widely used “probe reaction” for heterogeneous catalysts. In this study, it is demonstrated how tuning the composition of the catalyst material (choice of A-site cation, A-site and B-site doping) greatly influences the activity. Changing the A-site cation to Nd3+ or increasing the concentration of Ca2+ as A-site dopant improves the performance of the catalyst. Additional B-site doping (e.g., Co) affects the performance as well—in the case of Co-doping by shifting ignition temperature to lower temperatures. Thus, perovskites offer an interesting approach to intelligent catalyst design and tuning the specific properties towards desired applications.
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Investigation of the Performance and Emission Characteristics of Diesel Engine Fueled with Biogas-Diesel Dual Fuel
Fuels 2022, 3(1), 15-30; https://doi.org/10.3390/fuels3010002 - 05 Jan 2022
Abstract
Due to the popularity of diesel engines, utilization of fossil fuel has increased. However, fossil fuel resources are depleting and their prices are increasing day by day. Additionally, the emissions from the burning of petroleum-derived fuel is harming the global environment. This work
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Due to the popularity of diesel engines, utilization of fossil fuel has increased. However, fossil fuel resources are depleting and their prices are increasing day by day. Additionally, the emissions from the burning of petroleum-derived fuel is harming the global environment. This work covers the performance and emission parameters of a biogas-diesel dual-fuel mode diesel engine and compared them to baseline diesel. The experiment was conducted on a single-cylinder and four-stroke DI diesel engine with a maximum power output of 2.2 kW by varying engine load at a constant speed of 1500 RPM. The diesel was injected as factory setup, whereas biogas mixes with air and then delivered to the combustion chamber through intake manifold at various flow rates of 2, 4, and 6 L/min. At 2 L/min flow rate of biogas, the results were found to have better performance and lower emission, than that of the other flow; with an average reduction in BTE, HC, and NOx by 11.19, 0.52, and 19.91%, respectively, and an average increment in BSFC, CO, and CO2 by 11.81, 1.05, and 12.8%, respectively, as compared to diesel. The diesel replacement ratio was varied from 19.56 to 7.61% at zero engine load and 80% engine load with biogas energy share of 39.6 and 16.59%, respectively.
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(This article belongs to the Special Issue Alternative Fuels for Internal Combustion (IC) Engines)
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Assessing NO2-Hydrocarbon Interactions during Combustion of NO2/Alkane/Ar Mixtures in a Shock Tube Using CO Time Histories
Fuels 2022, 3(1), 1-14; https://doi.org/10.3390/fuels3010001 - 04 Jan 2022
Abstract
Modern gas turbines use combustion chemistry during the design phase to optimize their efficiency and reduce emissions of regulated pollutants such as NOx. The detailed understanding of the interactions during NOx and natural gas during combustion is therefore necessary for this optimization step.
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Modern gas turbines use combustion chemistry during the design phase to optimize their efficiency and reduce emissions of regulated pollutants such as NOx. The detailed understanding of the interactions during NOx and natural gas during combustion is therefore necessary for this optimization step. To better assess such interactions, NO2 was used as a sole oxidant during the oxidation of CH4 and C2H6 (the main components of natural gas) in a shock tube. The evolution of the CO mole fraction was followed by laser-absorption spectroscopy from dilute mixtures at around 1.2 atm. The experimental CO profiles were compared to several modern detailed kinetics mechanisms from the literature: models tuned to characterize NOx-hydrocarbons interactions, base-chemistry models (C0–C4) that contain a NOx sub-mechanism, and a nitromethane model. The comparison between the models and the experimental profiles showed that most modern NOx-hydrocarbon detailed kinetics mechanisms are not very accurate, while the base chemistry models were lacking accuracy overall as well. The nitromethane model and one hydrocarbon/NOx model were in relatively good agreement with the data over the entire range of conditions investigated, although there is still room for improvement. The numerical analysis of the results showed that while the models considered predict the same reaction pathways from the fuels to CO, they can be very inconsistent in the selection of the reaction rate coefficients. This variation is especially true for ethane, for which a larger disagreement with the data was generally observed.
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Open AccessEditor’s ChoiceReview
Organic Waste Gasification: A Selective Review
Fuels 2021, 2(4), 556-650; https://doi.org/10.3390/fuels2040033 - 07 Dec 2021
Cited by 2
Abstract
This review considers the selective studies on environmentally friendly, combustion-free, allothermal, atmospheric-pressure, noncatalytic, direct H2O/CO2 gasification of organic feedstocks like biomass, sewage sludge wastes (SSW) and municipal solid wastes (MSW) to demonstrate the pros and cons of the approaches and
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This review considers the selective studies on environmentally friendly, combustion-free, allothermal, atmospheric-pressure, noncatalytic, direct H2O/CO2 gasification of organic feedstocks like biomass, sewage sludge wastes (SSW) and municipal solid wastes (MSW) to demonstrate the pros and cons of the approaches and provide future perspectives. The environmental friendliness of H2O/CO2 gasification is well known as it is accompanied by considerably less harmful emissions into the environment as compared to O2/air gasification. Comparative analysis of the various gasification technologies includes low-temperature H2O/CO2 gasification at temperatures up to 1000 °C, high-temperature plasma- and solar-assisted H2O/CO2 gasification at temperatures above 1200 °C, and an innovative gasification technology applying ultra-superheated steam (USS) with temperatures above 2000 °C obtained by pulsed or continuous gaseous detonations. Analysis shows that in terms of such characteristics as the carbon conversion efficiency (CCE), tar and char content, and the content of harmful by-products the plasma and detonation USS gasification technologies are most promising. However, as compared with plasma gasification, detonation USS gasification does not need enormous electric power with unnecessary and energy-consuming gas–plasma transition.
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