•A new device named (FSD) for heavy-duty diesel engines was proposed.•A multi-vortex structure was formed after the application of the FSD.•Fuel/Air mixing process was improved after the application ...of the FSD.•The FSD showed a good performance on combustion and emission characteristics.
In order to improve the in-cylinder fuel/air mixing process of heavy-duty diesel engines, optimize the combustion process and reduce the soot emissions, a new device named fuel split device (FSD) was proposed. The related numerical research of the in-cylinder velocity fields, fuel/air mixing process, combustion performance and emission characteristics of a heavy-duty diesel engine at high load was performed. The numerical results showed that the FSD had a positive effect on improving fuel/air mixing process by splitting the fuel spray, which could increase air utilization and lead to efficient combustion. Firstly, the FSD had the ability to make a better utilization of fresh air by expanding the fuel injection area; secondly, the multi-vortex structure could be formed during the fuel injection process, which could greatly improve the fuel/air mixing process. Due to the improved fuel/air mixing process with the FSD, the combustion duration was shortened by 14°CA, the indicated power delivery was increased by 6.5%, and the soot, HC, CO mass were finally reduced by 73%, 90% and 54%, respectively. It is suggested that the FSD, with its excellent combustion performance and low soot emissions, has a better application prospect in heavy-duty diesel engines.
In collaboration with industry, Idaho National Laboratory is investigating uranium silicide for use in future light water reactor fuels as a more accident resistant alternative to uranium oxide base ...fuels. Specifically this project was focused on producing uranium silicide (U3Si2) pellets by conventional powder metallurgy with a density greater than 94% of the theoretical density. This work has produced a process to consistently produce pellets with the desired density through careful optimization of the process. Milling of the U3Si2 has been optimized and high phase purity U3Si2 has been successfully produced. Results are presented from sintering studies and microstructural examinations that illustrate the need for a finely ground reproducible particle size distribution in the source powder. The optimized process was used to produce pellets for the Accident Tolerant Fuel-1 irradiation experiment. The average density of these pellets was 11.54 ± 0.06 g/cm3. Additional characterization of the pellets by scanning electron microscopy and X-ray diffraction has also been performed. Pellets produced in this work have been encapsulated for irradiation, and irradiation in the Advanced Test Reactor is expected soon.
•A process to consistently produce high density U3Si2 pellets was developed.•Proper milling of the U3Si2 to produce the correct particle sized distribution was essential for final product consistency.•This process was used to produce pellets for irradiation in the Advanced Test Reactor at Idaho National Laboratory.
The hazardous effects of pollutants from conventional fuel vehicles have caused the scientific world to move towards environmentally friendly energy sources. Though we have various renewable energy ...sources, the perfect one to use as an energy source for vehicles is hydrogen. Like electricity, hydrogen is an energy carrier that has the ability to deliver incredible amounts of energy. Onboard hydrogen storage in vehicles is an important factor that should be considered when designing fuel cell vehicles. In this study, a recent development in hydrogen fuel cell engines is reviewed to scrutinize the feasibility of using hydrogen as a major fuel in transportation systems. A fuel cell is an electrochemical device that can produce electricity by allowing chemical gases and oxidants as reactants. With anodes and electrolytes, the fuel cell splits the cation and the anion in the reactant to produce electricity. Fuel cells use reactants, which are not harmful to the environment and produce water as a product of the chemical reaction. As hydrogen is one of the most efficient energy carriers, the fuel cell can produce direct current (DC) power to run the electric car. By integrating a hydrogen fuel cell with batteries and the control system with strategies, one can produce a sustainable hybrid car.
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•Biomass into bioethanol presents combined advantages of waste to value conversion and fuel production.•The paper explores the characteristics of bioethanol literature from 2009 to ...2019 based on the Web of Science database.•Most papers on bioethanol production was published by China, USA, Brazil, and India.
Conversion of lignocellulosic biomass into ethanol presents combined advantages of waste to value conversion and alternative fuel generation. Synthesis of fermentable sugars from the biomass fractions, namely cellulose, hemicellulose, and lignin, is a challenging process. Bioethanol, identified as a sustainable solution to fossil fuels, has gained significant attention with an annual global production of 29 billion tonnes. The need for pre-treatment of biomass is justified to enhance the bioethanol conversion efficiency. This study is aimed to present the current research in the field of bioethanol production and analyze the research conducted on bioethanol production during the period 2009 to 2019. The searching keyword is “bioethanol” and the related data were collected from the WoS database and VOSviewer. The literatures are analysed by various modes such as type of document, language, leading authors, journals, institutions, and keywords. The results show that, the highest number of publications in bioethanol production was done by China, USA, Brazil, and India. It was also observed that the increase in number of author’s contributions lead to higher number of publications. A total of 37,935 authors contributed in the bioethanol production research and average author per publication (AAPP) is 4.72. The average productivity per author (PPA) is 0.21. This study provides statistical information to the researchers to facilitate an impactful sharing of their research results.
In the context of climate change and the depletion of fossil fuels, there is a great need for alternatives to petroleum in the transport sector. This review provides an overview of the production of ...second generation bioethanol, which is distinguished from the first generation and subsequent generations of biofuels by its use of lignocellulosic biomass as raw material. The structural components of the lignocellulosic biomass such as cellulose, hemicellulose and lignin, are presented along with technological unit steps including pretreatment, enzymatic hydrolysis, fermentation, distillation and dehydration. The purpose of the pretreatment step is to increase the surface area of carbohydrate available for enzymatic saccharification, while minimizing the content of inhibitors. Performing the enzymatic hydrolysis releases fermentable sugars, which are converted by microbial catalysts into ethanol. The hydrolysates obtained after the pretreatment and enzymatic hydrolysis contain a wide spectrum of sugars, predominantly glucose and xylose. Genetically engineered microorganisms are therefore needed to carry out co-fermentation. The excess of harmful inhibitors in the hydrolysate, such as weak organic acids, furan derivatives and phenol components, can be removed by detoxification before fermentation. Effective saccharification further requires using exogenous hemicellulases and cellulolytic enzymes. Conventional species of distiller's yeast are unable to ferment pentoses into ethanol, and only a very few natural microorganisms, including yeast species like
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, metabolize xylose to ethanol. Enzymatic hydrolysis and fermentation can be performed in a number of ways: by separate saccharification and fermentation, simultaneous saccharification and fermentation or consolidated bioprocessing. Pentose-fermenting microorganisms can be obtained through genetic engineering, by introducing xylose-encoding genes into metabolism of a selected microorganism to optimize its use of xylose accumulated in the hydrolysate.
With increasing concerns over fuel cost, environmental pollutions, and energy security, the development of alternative fuels from renewable sources has gained considerable attention in the past ...decade. To evaluate the sooting propensities of representative conventional and alternative jet fuels, the present study has investigated soot formation in non-premixed combustion for three conventional reference jet fuels, i.e., Jet-A, JP-8, and JP-5, and three selected alternative jet fuels, i.e., Fischer-Tropsch Synthetic Paraffinic Kerosene (FT-SPK), Hydroprocessed Esters and Fatty Acids from camelina (HEFA-Camelina), and Alcohol-to-Jet (ATJ). The soot volume fraction profiles of these jet fuels in the atmospheric-pressure counterflow non-premixed flame configuration were measured using Laser-Induced Incandescence technique. In addition, the effects of global strain rate and reactant concentration on soot formation were investigated. At the same stoichiometric mixture fraction, the experimental results show that the sooting level increases with increasing fuel and O2 concentrations, while it decreases with increasing global strain rate, as expected. It is also worth noting that the three alternative jet fuels tested demonstrated greater sensitivity to variations in global strain rate and reactant concentration, as compared to the three conventional jet fuels. Based on the measured soot volume fractions, the sooting propensity of the six jet fuels are ranked as follows: JP-5>Jet-A>JP-8>ATJ>FT-SPK>HEFA-Camelina. The observed ranking is consistent with the aromatics content in each jet fuel except when comparing FT-SPK and ATJ. While ATJ has a lower aromatics content than FT-SPK, it contains much heavier hydrocarbon components, thereby leading to higher sooting propensity. Furthermore, the correlations of soot volume fraction with aromatics content and hydrogen content are examined for all six jet fuels. Although such correlations work well for the three conventional jet fuels, the present results suggest that they cannot be directly transferable to the alternative jet fuels, as these alternative fuels are composed of negligible amounts of aromatics, as well as composed of distinct chemical compositions.
A demonstrative Fischer-Tropsch fuel without any cost intensive post-processing treatment has been investigated for its application potential as a synthetic blending component with conventional ...petroleum-derived aviation fuels. As a first step, the focus of the analysis was purely on combustion related properties. The Fischer-Tropsch fuel was obtained via a specific Power-to-Liquid Fischer-Tropsch process, developed by Ineratec. Whereas the already approved Fischer-Tropsch–SPK process (ASTM D7566 Annex A1) utilizes hydrotreatment and is applied in large-scale plants, the herein presented plant features a unique and compact container-scale set-up, with no further downstream hydrotreatment, which allows for a significant reduction of production time and costs. Main objective of this paper is to provide the fuel producer with fast feedback to find the minimum complexity of fuel processing technology to achieve a synthetic blending component for aviation fuels directly from a container plant. As a first step in the ongoing process, the combustion properties of the non-hydroprocessed Fischer-Tropsch fuels are assessed regarding their suitability for aviation purposes.
Fuel characterization was carried out regarding the physiochemical properties of the fuels and their chemical composition to monitor selected “fit-for-purpose” properties for aviation with regard to combustion properties. Additional combustion experiments were conducted in a high-temperature flow-reactor with coupled molecular beam mass spectrometer (MBMS) for two stoichiometries to map lean and rich combustion (Φ = 0.8 and 1.2), allowing quantitative access to the chemical reaction species formed within the combustion. The general combustion chemistry and reaction temperature regime was found similar to Jet A-1 and pure n-alkane decane. This indicates the dominant species for the observed combustion process are aliphatic hydrocarbons. The detailed evaluation of relevant intermediates allows for an observation on typical soot precursors (e.g. benzene, naphthalene) in the combustion process and enables the estimation on the pollutant reduction potential of the Fischer-Tropsch fuel when used as blending component to Jet A-1.
Blending analysis has been performed utilizing the data from the CRC world fuel survey to evaluate the range of blending ratios of the Fischer-Tropsch fuel with conventional jet fuels determined by identified limiting factors. The presented evaluations demonstrate the potential of the Fischer-Tropsch fuel as a blending component with conventional jet fuels considering the combustion behavior only.
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•Unique container-sized Fischer Tropsch plant•Fischer Tropsch Fuel (FT Light) was investigated for aviation applicability.•Significant emission reduction in comparison to Jet A-1•Blending simulations performed•Excellent combustion behavior of FT Light
•Waste-derived biogas is used for powering a diesel engine in a dual-fuel model.•Experimental data used for BRT and ANN-based prognostic model development.•Statistical indices i.e., RBRT > RANN, ...R2BRT > R2ANN, and KGEBRT > KGEANN show the superiority of BRT over ANN.•Low modeling errors (RMSE less than 0.1154), Theil’s statistics (U2 less than 0.081), and Taylor’s diagram demonstrated superior prediction ability of BRT.
The current study looks at using waste-derived biodiesel as pilot fuel and waste-derived biogas as a gaseous fuel to power a diesel engine in dual-fuel mode. A new ensemble approach called Boosted Regression Trees (BRT) was utilized to model the performance and emissions of a variable compression ratio diesel engine. The model's input parameters were selected to be load, fuel injection time, and compression ratio. The BRT-based model was created based on experimental data to predict brake thermal efficiency (BTE), Biogas Fuel Ratio (BFR), NOx, CO, and HC. As indicated by correlation values ranging from 0.9947 to 0.9997, low Theil's values (0.081), and high Kling-Gupta efficiency (>98 percent), the suggested BRT model predicted performance and emission parameters with reasonable accuracy. The BRT model was compared to an ANN model under similar operating conditions. The BRT-based model outperformed the ANN-based model on all statistical metrics. The efficacy of BRT models was demonstrated further by employing a novelmethod of comparing prediction models using Taylor's diagram.
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