The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design ...The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion chambers.Also,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction mechanisms.Within this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be given.Depending on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double bonds.Examples of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.展开更多
Ship operations are crucial to global trade,and their decarbonization is essential to mitigate climate change.This study evaluates the economic viability of existing and emerging decarbonization technologies in mariti...Ship operations are crucial to global trade,and their decarbonization is essential to mitigate climate change.This study evaluates the economic viability of existing and emerging decarbonization technologies in maritime shipping using the levelized cost of energy methodology.It includes a detailed comparative analysis based on essential criteria and sensitivity assessments to highlight the economic impacts of technological advancements.Key factors influencing total costs include fuel costs,carbon pricing,and energy demands for carbon capture.The findings reveal that methanol is more cost-effective than heavy fuel oil(HFO)when priced below 3000 CNY/t,assuming HFO costs 4400 CNY/t.Additionally,methanol with post-combustion carbon capture is less expensive than pre-combustion carbon capture.When carbon prices rise above 480 CNY/t,carbon capture technologies prove more economical than purchasing carbon emission allowances for HFO and liquefied natural gas.Enhanc-ing the use of exhaust gas waste heat is recommended for cost savings.Post-combustion carbon capture also shows greater efficiency,requiring about 1.1 GJ/t less energy than pre-combustion methods,leading to lower overall costs.Future research should focus on market mechanisms to stabilize fuel prices and develop less energy-intensive carbon capture technologies.This study offers critical insights into effective decarbonization strategies for advancing global maritime trade in the present and future.展开更多
Sulphur and emissions related limits which are imposed on marine fuels drive the maritime industry to look on alternative fuels. The maximum sulphur content of the fuel has already decreased in the ECAs SOx （Sulphur ...Sulphur and emissions related limits which are imposed on marine fuels drive the maritime industry to look on alternative fuels. The maximum sulphur content of the fuel has already decreased in the ECAs SOx （Sulphur Emission Control Areas） from 1.5% to 1% from 1 July, 2010, and to 0.1% from 1 January, 2015. Globally, the highest permitted sulphur content of fuel will be reduced, as from 1 January, 2020 to 0.5%. Increasing demand of low sulphur fuel is anticipated, leading to a substantial mitigation of marine fuels from residual to distillate ones. Biodiesel or else FAME （Fatty Acid Methyl Esters） and mixtures of it with conventional petroleum fuels, constitute alternative energy source for the maritime industry. The International Standard EN （European Norme） ISO （International Organization for Standardization） 8217 specifies the requirements of petroleum fuels for use in marine diesel engines. According to the previous version of EN ISO 8217：2012, distillate fuels should comply with the ＂de minimis level＂ of approximately 0.1% v/v FAME. Nevertheless, with the latest revision of EN ISO 8217 standard in 2017, the incorporation of FAME up to 7% v/v is allowed in specific marine distillate grades as DF （Distillate FAME） grades. Marine distillates can also include hydrocarbons from synthetic or renewable sources, similar to the composition of petroleum distillate fuels.展开更多
Coal is used as a traditional fuel for firing of clay bricks in kilns. The cost of coal is high and is increasing continuously. This paper describes the effect of alternate fuels on compressive strength, water absorpt...Coal is used as a traditional fuel for firing of clay bricks in kilns. The cost of coal is high and is increasing continuously. This paper describes the effect of alternate fuels on compressive strength, water absorption and density of fired clay bricks. The alternate fuels used in this study were 1) rapeseed husk (Type I), 2) combination of sugarcane-bagasse, rice husk and used clothes (Type II) and 3) coal (Type III). The results show that compressive strength of bricks fired using Type I and Type II fuels was decreased to 11% and 7%, respectively, compared to those fired with coal. However, the values of water absorption and density of bricks fired with Type I and Type II fuels were almost same as exhibited by those baked with coal. This study shows that a saving of 25%, and 18% could be achieved when the bricks were fired using Type I and Type II fuels, respectively, compared to those fired with coal.展开更多
The usage of alternative fuel as a substitute of oil fuel for transportation sector in developed countries has been commonly implemented in order to decrease crude oil consumption, where in a few years back, the crude...The usage of alternative fuel as a substitute of oil fuel for transportation sector in developed countries has been commonly implemented in order to decrease crude oil consumption, where in a few years back, the crude oil price is constantly increasing. In addition, global warming issue becomes one of reasons that motivate many countries to switch for a cleaner energy usage. As a country that has a relatively big reserve of natural gas, its appropriate natural gas could minimize subsidized oil fuel and also financing country＇s burden if Indonesia is optimizing the usage of energy resources. This paper will discuss about the background of gas fuel usage for road transportation sector in Indonesia, review of alternative fuel usage, the gas fuel usage status in Indonesia and gas usage recommendation for land transportation sector in Indonesia based on other countries experiences.展开更多
This paper presents findings of a study on solid wastes conversion into fuels through pyrolysis of plastic materials, presenting an alternative renewable approach for waste management. Investigations were conducted on...This paper presents findings of a study on solid wastes conversion into fuels through pyrolysis of plastic materials, presenting an alternative renewable approach for waste management. Investigations were conducted on conversion of polypropylene (PP), low-density polyethylene (LDPE) and high-density polyethylene (HDPE) under normal and catalyst mediated process conditions. Plastic wastes were collected from various dumpsites in Nairobi and segregated using plastic resin codes to various classes. Samples were cleaned, dried and shredded to 2 mm and fed into a pyrolysis reactor. The pyrolysis process was conducted at between 220˚C and 420˚C. Pyrolysis gases were condensed in a shell and coil condenser and the incondensable gases were stored in gasbags. Liquid fuels were analysed using Gas chromatograph with a mass spectroscopic detector and Fourier Transform Infrared Spectrometry. The results revealed that the most optimal process conditions were a temperature range of 220˚C - 420˚C at a heating rate of 10˚C per minute. Under these conditions, the oil yields were 53.72% for PP, 62.10% for LDPE, and 64.14% for HDPE. As the heating rate increased from 10˚C/min to 20˚C/min, gas yields increased, rising from 28.05% to 31.12% in PP, 14.96% to 30.62% in LDPE, and 18.51% to 29.49% in HDPE. The introduction of Fe2O3 and Al2O3 catalyst significantly enhanced gas production during pyrolysis, increasing yields from 18% to 61% and 47% respectively.展开更多
As global atmospheric carbon dioxide concentrations continue to rise,the utilization of environmentally friendly alternative fuels becomes increasingly crucial[1].Methane,with its high hydrogen-to-carbon(H/C)ratio,emi...As global atmospheric carbon dioxide concentrations continue to rise,the utilization of environmentally friendly alternative fuels becomes increasingly crucial[1].Methane,with its high hydrogen-to-carbon(H/C)ratio,emits less CO_(2) than petroleum upon combustion,making it an efficient and clean energy source[2].Efficient methane storage is therefore a critical challenge and goal.Adsorbed natural gas(ANG)has recently been widely reported as a promising methane adsorption method,which utilizes porous materials to adsorb methane at high pressure and desorb it at relatively low pressure,offering superior working capacity performance over conventional compressed natural gas systems[3].Covalent organic frameworks(COFs),porous crystalline materials with permanent porosity and highly ordered structures constructed via strong covalent bonds,show good potential as methane adsorbents due to their permanent porosity[4].However,achieving high specific surface area and appropriate pore size in COFs for enhanced methane adsorption capacity remains a challenge.展开更多
This study addresses the critical need for decarbonization in offshore marine logistics by developing an integrated modeling framework to support low-emission operations across complex,multi-echelon vessel networks.It...This study addresses the critical need for decarbonization in offshore marine logistics by developing an integrated modeling framework to support low-emission operations across complex,multi-echelon vessel networks.It focuses on port-to-platform supply chains serving offshore wind farms,oil rigs,and floating logistics hubs.A hybrid analytical approach was adopted,combining Mixed-Integer Linear Programming(MILP)for optimizing emission-minimizing routing,Discrete-Event Simulation(DES)to evaluate offshore scheduling performance under variability,and a Multi-Criteria Decision Analysis(MCDA)model using AHP-TOPSIS to rank alternative marine fuel types.Monte Carlo simulation was also employed to assess cost and delivery fluctuations across uncertain operational scenarios.Data inputs were compiled from real-world offshore fleet specifications,port emissions records,and marine fuel technology benchmarks.MILP-based network flow optimization reduced CO₂emissions by 22%while maintaining service reliability across all demand points.DES simulations revealed congestion-driven scheduling delays during peak vessel utilization.MCDA analysis ranked bio-LNG and hydrogen propulsion systems as optimal choices based on emission,cost,and availability trade-offs.Hypothesis testing confirmed significant relationships between fuel type,network structure,and emission performance.The study demonstrates how multi-echelon logistics planning,integrated with emissions-based modeling,can facilitate environmentally responsible marine supply chain design.The framework offers practical guidance for offshore fleet managers,port authorities,and policy regulators aiming to align operational efficiency with decarbonization objectives under IMO and EU directives.展开更多
In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent n...In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.展开更多
Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific t...Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific technical treatments are required to improve certain fuel properties such as viscosity and calorific value of the biodiesel being obtained from waste cooking oil methyl ester （WCOME）. Various treatments are applied depending on the source and therefore the composition of the cooking oil. This research investigated the performance of WCOME as an alternative biofuel in a four-stroke direct injection diesel engine. An 8-mode test was undertaken with diesel fuel and five WCOME blends. The best compromise blend in terms of performance and emissions was identified. Results showed that energy utilization factors of the blends were similar within the range of the operational parameters （speed, load and WCOME content）. Increasing biodiesel content produced slightly more smoke and NOx for a great majority of test points, while the CO and THC emissions were lower.展开更多
The central aim of this paper is to provide an upto-date snapshot of hybrid and hydrogen technology-related developments and activities in the North American heavy haul railway setting,placed in the context of the tra...The central aim of this paper is to provide an upto-date snapshot of hybrid and hydrogen technology-related developments and activities in the North American heavy haul railway setting,placed in the context of the transportation industry more broadly.An overview of relevant alternative propulsion technologies is provided,including a discussion of applicability to the transportation sector in general and heavy haul freight rail specifically.This is followed by a discussion of current developments and research in alternative and blended fuels,discussed again in both general and specific settings.Key factors and technical considerations for heavy haul applications are reviewed,followed by a discussion of non-technical and human factors that motivate a move toward clean energy in North American Heavy Haul systems.Finally,current project activities are described to provide a clear understanding of both the status and trajectory of hybrid and hydrogen technologies in the established context.展开更多
Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels （gaso...Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels （gasoline, diesel etc.）. Selectivity of Fischer-Tropsch hydrocarbon product （green fuel） is an important issue. In this study, the experimental data has been obtained from three factors; temperature, H2/CO ratio and pressure in the fixed bed micro reactor. T = 543-618 （K）, P = 3-10 （bar）, H2/CO = 1-2 and space velocity = 4500 （l/h） were the reactor conditions. The results of product modeling for methane （CH4）, ethane （C2H6）, ethylene （C2H4） and CO conversion with experimental data were compared. The effective parameters and the interaction between them were investigated in the model. H2/CO ratio and pressure and interaction between pressure and H2/CO in ethane selectivity model and CO conversion and interaction between temperature and H2/CO ratio in methane selectivity model and ethylene gave the best results. To determine the optimal conditions for light hydrocarbons, ANOVA and RSM were employed. Finally, products optimization was done and results were concluded.展开更多
Ni/YSZ fuel electrodes can only operate under strongly reducing conditions for steam elec- trolysis in an oxide-ion-conducting solid oxide electrolyzer （SOE）. In atmosphere with a low content of H2 or without H2, ca...Ni/YSZ fuel electrodes can only operate under strongly reducing conditions for steam elec- trolysis in an oxide-ion-conducting solid oxide electrolyzer （SOE）. In atmosphere with a low content of H2 or without H2, cathodes based on redox-reversible Nb2TiO7 provide a promising alternative. The reversible changes between oxidized Nb2TiO7 and reduced Nbl.33Tio.6704 samples are systematically investigated after redox-cycling tests. The conductivities of Nb2TiO7 and reduced Nb1.33Tio.6704 are studied as a function of temperature and oxygen partial pressure and correlated with the electrochemical properties of the composite electrodes in a symmetric cell and SOE at 830 ℃. Steam electrolysis is then performed using an oxide-ion-conducting SOE based on a Nb1.33Ti0.6704 composite fuel electrode at 830 ℃. The current-voltage and impedance spectroscopy tests demonstrate that the reduction and activation of the fuel electrode is the main process at low voltage; however, the steam electrolysis dominates the entire process at high voltages. The Faradic efficiencies of steam electrolysis reach 98.9% when 3%H2O/Ar/4%H2 is introduced to the fuel electrode and 89% for that with introduction of 3%H2O/Ar.展开更多
To use the renewable fuels for marine field is still very limited due to the need of newly developed technology, highly requested safety （for gas fuel） and high price of biodiesel. Therefore, with some advantages, s...To use the renewable fuels for marine field is still very limited due to the need of newly developed technology, highly requested safety （for gas fuel） and high price of biodiesel. Therefore, with some advantages, such as： simple producing process, reasonable price and simple modification technology needed, the blended SVO （straight vegetable oil） is recommended as suitable fuel for the marine application. Even though, there are some disadvantages of the blended SVO, such as a weak stability, layer separation in low temperature and some others. In order to apply the blended SVO as alternative fuel for marine diesel engines without the mentioned disadvantages, the paper will introduce a method to design and produce a fuel continuous mixer to make a blended SVO （palm oil）.展开更多
As global warming caused by greenhouse gases grows (GHGs) into a global environmental threat, carbon dioxide emissions are drawing increasing attention in these years. Among all emission sources, transportation is a m...As global warming caused by greenhouse gases grows (GHGs) into a global environmental threat, carbon dioxide emissions are drawing increasing attention in these years. Among all emission sources, transportation is a major contributor to climate change because of its high dependence on fossil fuels. The International Maritime Organization (IMO) has therefore been promoting the reduction of fuel usage and carbon emissions for container ships by such measures as improving shipping route selection, shipping speed optimization, and constructing clean energy propulsion systems. In this paper, a review of the impact of carbon dioxide emissions on climate change is presented;the current situations of carbon dioxide emissions, decarbonizing methods, IMO regulations, and possible future directions of decarbonizing in the maritime transportation industry are also discussed. Based on the result, it is found that in the case that non intelligent ships still occupy the vast majority of operating ships, the use of new energy as the main propulsion fuel has the defects of high renewal cost and long effective period. It is more likely to achieve energy conservation and emission reduction in the shipping industry in a short period of time by using intelligent means and artificial intelligence to assist ship operation. .展开更多
Aviation fuel is in great demand globally. The increased demand and high price for energy sources are driving efforts to convert natural non-renewable organic compounds into useful hydrocarbon fuel materials such as i...Aviation fuel is in great demand globally. The increased demand and high price for energy sources are driving efforts to convert natural non-renewable organic compounds into useful hydrocarbon fuel materials such as in form of aviation fuel. Alternate sources to these non-renewable hydrocarbon fuels are important and necessary. Much of these alternative sources are focused on biomass however, there are strong benefits of deriving fuels from waste plastic materials. Thermal processes can be used to convert waste plastics into hydrocarbon fuels like aviation fuel, which have unlimited applications in airline industries, as well as in transportation and power generation industries. These thermal processes are used to break down the long carbon chains found in plastics into the shorter chains in a temperature range from 300-450 ℃. This method has been carried out in succession in previous experiments. This simple and economically viable process has been developed to convert the hydrocarbon polymers of waste plastics into the short and medium chain hydrocarbons of liquid fuels. Based on the initial characterization, a fractionated portion of the developed fuel shows properties similar to some of the commercially available aviation fuels.展开更多
A series of experiments were performed on indigenously synthesized catalyst pallets of cobalt as a very active metal on ceramic support like SiC, A1203 ＆ TiO2 in a fixed bed reactor configuration with an aim to study...A series of experiments were performed on indigenously synthesized catalyst pallets of cobalt as a very active metal on ceramic support like SiC, A1203 ＆ TiO2 in a fixed bed reactor configuration with an aim to study the catalyst activity ＆ selectivity, chemical kinetics, design flexibility, temperature, pressure by characteristics diffusion distance. Catalyst pallets were prepared and then characterized by N2 adsorption, X-ray Diffraction, Scanning Electron Microscope, and Temperature Programmed Reduction. The results showed the Brunaner, Emmett and Teller area of SiC was the lowest among the three supports prepared for testing. However, its reducibility showed improvement with use of cobalt acetate, as a precursor, rather than cobalt nitrates. Mechanical strength and behavior was checked by the hardness testing machine. Fischer Tropsch （FT） synthesis experiments were performed in the fixed bed reactor set at 450-500 K and 2.3-2.5 MPa using synthetic gas having HJCO ration = 2.0. FT synthesis showed that cobalt/silicon carbide catalyst gives high CO conversion and lower methane selectivity, compared to Co/A1203 and Co/TiO2, as well as high C5＋ selectivity of almost 90%. Moreover, its stability was enhanced by the addition of Zr02, as without this addition, the Co/SiC interactions are weaker and can cause carbon sintering, and thus, the deactivation rate to increase.展开更多
This article aims to investigate the effects of using an alternative fuel on the emissions of carbon dioxide (CO_(2)) and carbon monoxide (CO) in a reactive flow spraying inside a model combustor. The study highlights...This article aims to investigate the effects of using an alternative fuel on the emissions of carbon dioxide (CO_(2)) and carbon monoxide (CO) in a reactive flow spraying inside a model combustor. The study highlights the trade-offs between CO_(2) and CO emissions, encouraging further investigation into alternative fuels, considering their environmental impact. The bio-synthetic fuel comprises Jatropha Bio-Synthetic Paraffinic Kerosene (JSPK) blended with Jet-A at five different weight ratios to make the alternative fuels. The two-phase flow of the fuel and air mixture is assessed by the Eulerian-Lagrangian approach. The realizable κ-ε model is employed to model the turbulent flow. The discrete ordinates method is applied to model radiative heat transfer, and the steady flamelet combustion model is utilized to model combustion. The distributions of mean mixture fraction and mole fractions of CO_(2) and CO at the combustion chamber outlet are presented. Results reveal that variations in fuel properties affect the emission of pollutants since adding JSPK increases the emission rate of the mean mixture fraction and the mole fraction of CO and decreases the mole fraction of CO_(2) at the combustor outlet. Also, employing a weight ratio of 80% Jet-A with 20% JSPK leads to achieving the lowest mean mixture fraction and mole fraction of CO with a maximum reduction of 25% relative to utilizing only the base fuel. In addition, the lowest amount of CO_(2) is obtained for 70% Jet-A / 30% JSPK, which is about 15% less than other weight ratios.展开更多
Scarcity of conventional petroleum resources has promoted research in alternative fuels for internal combustion engines.Among various possible options,fuels derived from triglycerides(vegetable oils/animal fats)are pr...Scarcity of conventional petroleum resources has promoted research in alternative fuels for internal combustion engines.Among various possible options,fuels derived from triglycerides(vegetable oils/animal fats)are promising for the substitution of fossil diesel fuel.Vegetable oils poses some characteristics like durability,high viscosity and low volatility compared to mineral diesel fuel.In the present work,experiments were designed to study the effect of reducing kusum and karanja oil’s viscosity by preheating the fuel,using a shell and tube heat exchanger.The acquired engine data were analyzed for various parameters such as brake thermal efficiency,brake specific energy consumption(BSEC),emission of exhaust gases like CO,CO_(2),HC and NO_(x).In operation,the engine performance with kusum and karanja oil(preheated),was found to be very close to that of diesel.The preheated oil's performances were found to be slightly inferior in efficiency due to low heating value.The performance of karanja oil was found better than kusum oil in all respects.展开更多
A good understanding of the thermophysical properties of hydrocarbon fuels at supercritical pressure is important to research on experiment and numerical simulation of fuel supercritical spray.Experimental measurement...A good understanding of the thermophysical properties of hydrocarbon fuels at supercritical pressure is important to research on experiment and numerical simulation of fuel supercritical spray.Experimental measurements are difficult to conduct directly because of the extremely high pressure and high temperature.In this study,back propagation(BP)neural network,BP optimized by mind evolution algorithm(MEA-BP)and BP neural network optimized by genetic algorithm(GA-BP)are established to determine the nonlinear temperature-dependent thermophysical properties of density,viscosity,and isobaric specific heat(C_(2))of hydrocarbon fuels at supercritical pressure.Meanwhile,approximate formulas for these properties prediction are primarily proposed using polynomial fitting.In this paper,models that can predict three types of physical properties of three kinds of hydrocarbon fuels and their mixtures in a wide temperature range under supercritical pressure are established.In the prediction of density and C_(2),BP neural network has a good prediction effect.The results show that the MAPE is lower than 2%in the prediction of density and C_(2),but the MAPE of viscosity prediction is slightly higher than 5%using BP.Furthermore,MEA and GA are used to optimize the prediction of viscosity.The optimization effect and computation of the MEA is better than that of GA because MEA does not have the local optimization and prematurity problems.The present work offers an efficient tool to predict the thermophysical properties of hydrocarbon fuels over a wide range of temperatures under supercritical pressure which can be easily extended to other fuels of interest.It will be beneficial to the experiment and numerical simulation studies of supercritical sprays.展开更多
文摘The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion chambers.Also,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction mechanisms.Within this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be given.Depending on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double bonds.Examples of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.
基金supported by the National Key R&D Program of China(No.2022YFC3701500)the Key R&D Plan Projects of Zhejiang Province(No.2024SSYS0072)Zhejiang Provincial Natural Science Foundation(No.LDT23E0601).
文摘Ship operations are crucial to global trade,and their decarbonization is essential to mitigate climate change.This study evaluates the economic viability of existing and emerging decarbonization technologies in maritime shipping using the levelized cost of energy methodology.It includes a detailed comparative analysis based on essential criteria and sensitivity assessments to highlight the economic impacts of technological advancements.Key factors influencing total costs include fuel costs,carbon pricing,and energy demands for carbon capture.The findings reveal that methanol is more cost-effective than heavy fuel oil(HFO)when priced below 3000 CNY/t,assuming HFO costs 4400 CNY/t.Additionally,methanol with post-combustion carbon capture is less expensive than pre-combustion carbon capture.When carbon prices rise above 480 CNY/t,carbon capture technologies prove more economical than purchasing carbon emission allowances for HFO and liquefied natural gas.Enhanc-ing the use of exhaust gas waste heat is recommended for cost savings.Post-combustion carbon capture also shows greater efficiency,requiring about 1.1 GJ/t less energy than pre-combustion methods,leading to lower overall costs.Future research should focus on market mechanisms to stabilize fuel prices and develop less energy-intensive carbon capture technologies.This study offers critical insights into effective decarbonization strategies for advancing global maritime trade in the present and future.
文摘Sulphur and emissions related limits which are imposed on marine fuels drive the maritime industry to look on alternative fuels. The maximum sulphur content of the fuel has already decreased in the ECAs SOx （Sulphur Emission Control Areas） from 1.5% to 1% from 1 July, 2010, and to 0.1% from 1 January, 2015. Globally, the highest permitted sulphur content of fuel will be reduced, as from 1 January, 2020 to 0.5%. Increasing demand of low sulphur fuel is anticipated, leading to a substantial mitigation of marine fuels from residual to distillate ones. Biodiesel or else FAME （Fatty Acid Methyl Esters） and mixtures of it with conventional petroleum fuels, constitute alternative energy source for the maritime industry. The International Standard EN （European Norme） ISO （International Organization for Standardization） 8217 specifies the requirements of petroleum fuels for use in marine diesel engines. According to the previous version of EN ISO 8217：2012, distillate fuels should comply with the ＂de minimis level＂ of approximately 0.1% v/v FAME. Nevertheless, with the latest revision of EN ISO 8217 standard in 2017, the incorporation of FAME up to 7% v/v is allowed in specific marine distillate grades as DF （Distillate FAME） grades. Marine distillates can also include hydrocarbons from synthetic or renewable sources, similar to the composition of petroleum distillate fuels.
文摘Coal is used as a traditional fuel for firing of clay bricks in kilns. The cost of coal is high and is increasing continuously. This paper describes the effect of alternate fuels on compressive strength, water absorption and density of fired clay bricks. The alternate fuels used in this study were 1) rapeseed husk (Type I), 2) combination of sugarcane-bagasse, rice husk and used clothes (Type II) and 3) coal (Type III). The results show that compressive strength of bricks fired using Type I and Type II fuels was decreased to 11% and 7%, respectively, compared to those fired with coal. However, the values of water absorption and density of bricks fired with Type I and Type II fuels were almost same as exhibited by those baked with coal. This study shows that a saving of 25%, and 18% could be achieved when the bricks were fired using Type I and Type II fuels, respectively, compared to those fired with coal.
文摘The usage of alternative fuel as a substitute of oil fuel for transportation sector in developed countries has been commonly implemented in order to decrease crude oil consumption, where in a few years back, the crude oil price is constantly increasing. In addition, global warming issue becomes one of reasons that motivate many countries to switch for a cleaner energy usage. As a country that has a relatively big reserve of natural gas, its appropriate natural gas could minimize subsidized oil fuel and also financing country＇s burden if Indonesia is optimizing the usage of energy resources. This paper will discuss about the background of gas fuel usage for road transportation sector in Indonesia, review of alternative fuel usage, the gas fuel usage status in Indonesia and gas usage recommendation for land transportation sector in Indonesia based on other countries experiences.
文摘This paper presents findings of a study on solid wastes conversion into fuels through pyrolysis of plastic materials, presenting an alternative renewable approach for waste management. Investigations were conducted on conversion of polypropylene (PP), low-density polyethylene (LDPE) and high-density polyethylene (HDPE) under normal and catalyst mediated process conditions. Plastic wastes were collected from various dumpsites in Nairobi and segregated using plastic resin codes to various classes. Samples were cleaned, dried and shredded to 2 mm and fed into a pyrolysis reactor. The pyrolysis process was conducted at between 220˚C and 420˚C. Pyrolysis gases were condensed in a shell and coil condenser and the incondensable gases were stored in gasbags. Liquid fuels were analysed using Gas chromatograph with a mass spectroscopic detector and Fourier Transform Infrared Spectrometry. The results revealed that the most optimal process conditions were a temperature range of 220˚C - 420˚C at a heating rate of 10˚C per minute. Under these conditions, the oil yields were 53.72% for PP, 62.10% for LDPE, and 64.14% for HDPE. As the heating rate increased from 10˚C/min to 20˚C/min, gas yields increased, rising from 28.05% to 31.12% in PP, 14.96% to 30.62% in LDPE, and 18.51% to 29.49% in HDPE. The introduction of Fe2O3 and Al2O3 catalyst significantly enhanced gas production during pyrolysis, increasing yields from 18% to 61% and 47% respectively.
基金support by the National Natural Science Foundation of China(Nos.22201247,22471237)the startup funding from Zhejiang Universitysupported by the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2023R01007).
文摘As global atmospheric carbon dioxide concentrations continue to rise,the utilization of environmentally friendly alternative fuels becomes increasingly crucial[1].Methane,with its high hydrogen-to-carbon(H/C)ratio,emits less CO_(2) than petroleum upon combustion,making it an efficient and clean energy source[2].Efficient methane storage is therefore a critical challenge and goal.Adsorbed natural gas(ANG)has recently been widely reported as a promising methane adsorption method,which utilizes porous materials to adsorb methane at high pressure and desorb it at relatively low pressure,offering superior working capacity performance over conventional compressed natural gas systems[3].Covalent organic frameworks(COFs),porous crystalline materials with permanent porosity and highly ordered structures constructed via strong covalent bonds,show good potential as methane adsorbents due to their permanent porosity[4].However,achieving high specific surface area and appropriate pore size in COFs for enhanced methane adsorption capacity remains a challenge.
文摘This study addresses the critical need for decarbonization in offshore marine logistics by developing an integrated modeling framework to support low-emission operations across complex,multi-echelon vessel networks.It focuses on port-to-platform supply chains serving offshore wind farms,oil rigs,and floating logistics hubs.A hybrid analytical approach was adopted,combining Mixed-Integer Linear Programming(MILP)for optimizing emission-minimizing routing,Discrete-Event Simulation(DES)to evaluate offshore scheduling performance under variability,and a Multi-Criteria Decision Analysis(MCDA)model using AHP-TOPSIS to rank alternative marine fuel types.Monte Carlo simulation was also employed to assess cost and delivery fluctuations across uncertain operational scenarios.Data inputs were compiled from real-world offshore fleet specifications,port emissions records,and marine fuel technology benchmarks.MILP-based network flow optimization reduced CO₂emissions by 22%while maintaining service reliability across all demand points.DES simulations revealed congestion-driven scheduling delays during peak vessel utilization.MCDA analysis ranked bio-LNG and hydrogen propulsion systems as optimal choices based on emission,cost,and availability trade-offs.Hypothesis testing confirmed significant relationships between fuel type,network structure,and emission performance.The study demonstrates how multi-echelon logistics planning,integrated with emissions-based modeling,can facilitate environmentally responsible marine supply chain design.The framework offers practical guidance for offshore fleet managers,port authorities,and policy regulators aiming to align operational efficiency with decarbonization objectives under IMO and EU directives.
文摘In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.
文摘Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific technical treatments are required to improve certain fuel properties such as viscosity and calorific value of the biodiesel being obtained from waste cooking oil methyl ester （WCOME）. Various treatments are applied depending on the source and therefore the composition of the cooking oil. This research investigated the performance of WCOME as an alternative biofuel in a four-stroke direct injection diesel engine. An 8-mode test was undertaken with diesel fuel and five WCOME blends. The best compromise blend in terms of performance and emissions was identified. Results showed that energy utilization factors of the blends were similar within the range of the operational parameters （speed, load and WCOME content）. Increasing biodiesel content produced slightly more smoke and NOx for a great majority of test points, while the CO and THC emissions were lower.
文摘The central aim of this paper is to provide an upto-date snapshot of hybrid and hydrogen technology-related developments and activities in the North American heavy haul railway setting,placed in the context of the transportation industry more broadly.An overview of relevant alternative propulsion technologies is provided,including a discussion of applicability to the transportation sector in general and heavy haul freight rail specifically.This is followed by a discussion of current developments and research in alternative and blended fuels,discussed again in both general and specific settings.Key factors and technical considerations for heavy haul applications are reviewed,followed by a discussion of non-technical and human factors that motivate a move toward clean energy in North American Heavy Haul systems.Finally,current project activities are described to provide a clear understanding of both the status and trajectory of hybrid and hydrogen technologies in the established context.
文摘Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels （gasoline, diesel etc.）. Selectivity of Fischer-Tropsch hydrocarbon product （green fuel） is an important issue. In this study, the experimental data has been obtained from three factors; temperature, H2/CO ratio and pressure in the fixed bed micro reactor. T = 543-618 （K）, P = 3-10 （bar）, H2/CO = 1-2 and space velocity = 4500 （l/h） were the reactor conditions. The results of product modeling for methane （CH4）, ethane （C2H6）, ethylene （C2H4） and CO conversion with experimental data were compared. The effective parameters and the interaction between them were investigated in the model. H2/CO ratio and pressure and interaction between pressure and H2/CO in ethane selectivity model and CO conversion and interaction between temperature and H2/CO ratio in methane selectivity model and ethylene gave the best results. To determine the optimal conditions for light hydrocarbons, ANOVA and RSM were employed. Finally, products optimization was done and results were concluded.
文摘Ni/YSZ fuel electrodes can only operate under strongly reducing conditions for steam elec- trolysis in an oxide-ion-conducting solid oxide electrolyzer （SOE）. In atmosphere with a low content of H2 or without H2, cathodes based on redox-reversible Nb2TiO7 provide a promising alternative. The reversible changes between oxidized Nb2TiO7 and reduced Nbl.33Tio.6704 samples are systematically investigated after redox-cycling tests. The conductivities of Nb2TiO7 and reduced Nb1.33Tio.6704 are studied as a function of temperature and oxygen partial pressure and correlated with the electrochemical properties of the composite electrodes in a symmetric cell and SOE at 830 ℃. Steam electrolysis is then performed using an oxide-ion-conducting SOE based on a Nb1.33Ti0.6704 composite fuel electrode at 830 ℃. The current-voltage and impedance spectroscopy tests demonstrate that the reduction and activation of the fuel electrode is the main process at low voltage; however, the steam electrolysis dominates the entire process at high voltages. The Faradic efficiencies of steam electrolysis reach 98.9% when 3%H2O/Ar/4%H2 is introduced to the fuel electrode and 89% for that with introduction of 3%H2O/Ar.
文摘To use the renewable fuels for marine field is still very limited due to the need of newly developed technology, highly requested safety （for gas fuel） and high price of biodiesel. Therefore, with some advantages, such as： simple producing process, reasonable price and simple modification technology needed, the blended SVO （straight vegetable oil） is recommended as suitable fuel for the marine application. Even though, there are some disadvantages of the blended SVO, such as a weak stability, layer separation in low temperature and some others. In order to apply the blended SVO as alternative fuel for marine diesel engines without the mentioned disadvantages, the paper will introduce a method to design and produce a fuel continuous mixer to make a blended SVO （palm oil）.
文摘As global warming caused by greenhouse gases grows (GHGs) into a global environmental threat, carbon dioxide emissions are drawing increasing attention in these years. Among all emission sources, transportation is a major contributor to climate change because of its high dependence on fossil fuels. The International Maritime Organization (IMO) has therefore been promoting the reduction of fuel usage and carbon emissions for container ships by such measures as improving shipping route selection, shipping speed optimization, and constructing clean energy propulsion systems. In this paper, a review of the impact of carbon dioxide emissions on climate change is presented;the current situations of carbon dioxide emissions, decarbonizing methods, IMO regulations, and possible future directions of decarbonizing in the maritime transportation industry are also discussed. Based on the result, it is found that in the case that non intelligent ships still occupy the vast majority of operating ships, the use of new energy as the main propulsion fuel has the defects of high renewal cost and long effective period. It is more likely to achieve energy conservation and emission reduction in the shipping industry in a short period of time by using intelligent means and artificial intelligence to assist ship operation. .
文摘Aviation fuel is in great demand globally. The increased demand and high price for energy sources are driving efforts to convert natural non-renewable organic compounds into useful hydrocarbon fuel materials such as in form of aviation fuel. Alternate sources to these non-renewable hydrocarbon fuels are important and necessary. Much of these alternative sources are focused on biomass however, there are strong benefits of deriving fuels from waste plastic materials. Thermal processes can be used to convert waste plastics into hydrocarbon fuels like aviation fuel, which have unlimited applications in airline industries, as well as in transportation and power generation industries. These thermal processes are used to break down the long carbon chains found in plastics into the shorter chains in a temperature range from 300-450 ℃. This method has been carried out in succession in previous experiments. This simple and economically viable process has been developed to convert the hydrocarbon polymers of waste plastics into the short and medium chain hydrocarbons of liquid fuels. Based on the initial characterization, a fractionated portion of the developed fuel shows properties similar to some of the commercially available aviation fuels.
文摘A series of experiments were performed on indigenously synthesized catalyst pallets of cobalt as a very active metal on ceramic support like SiC, A1203 ＆ TiO2 in a fixed bed reactor configuration with an aim to study the catalyst activity ＆ selectivity, chemical kinetics, design flexibility, temperature, pressure by characteristics diffusion distance. Catalyst pallets were prepared and then characterized by N2 adsorption, X-ray Diffraction, Scanning Electron Microscope, and Temperature Programmed Reduction. The results showed the Brunaner, Emmett and Teller area of SiC was the lowest among the three supports prepared for testing. However, its reducibility showed improvement with use of cobalt acetate, as a precursor, rather than cobalt nitrates. Mechanical strength and behavior was checked by the hardness testing machine. Fischer Tropsch （FT） synthesis experiments were performed in the fixed bed reactor set at 450-500 K and 2.3-2.5 MPa using synthetic gas having HJCO ration = 2.0. FT synthesis showed that cobalt/silicon carbide catalyst gives high CO conversion and lower methane selectivity, compared to Co/A1203 and Co/TiO2, as well as high C5＋ selectivity of almost 90%. Moreover, its stability was enhanced by the addition of Zr02, as without this addition, the Co/SiC interactions are weaker and can cause carbon sintering, and thus, the deactivation rate to increase.
文摘This article aims to investigate the effects of using an alternative fuel on the emissions of carbon dioxide (CO_(2)) and carbon monoxide (CO) in a reactive flow spraying inside a model combustor. The study highlights the trade-offs between CO_(2) and CO emissions, encouraging further investigation into alternative fuels, considering their environmental impact. The bio-synthetic fuel comprises Jatropha Bio-Synthetic Paraffinic Kerosene (JSPK) blended with Jet-A at five different weight ratios to make the alternative fuels. The two-phase flow of the fuel and air mixture is assessed by the Eulerian-Lagrangian approach. The realizable κ-ε model is employed to model the turbulent flow. The discrete ordinates method is applied to model radiative heat transfer, and the steady flamelet combustion model is utilized to model combustion. The distributions of mean mixture fraction and mole fractions of CO_(2) and CO at the combustion chamber outlet are presented. Results reveal that variations in fuel properties affect the emission of pollutants since adding JSPK increases the emission rate of the mean mixture fraction and the mole fraction of CO and decreases the mole fraction of CO_(2) at the combustor outlet. Also, employing a weight ratio of 80% Jet-A with 20% JSPK leads to achieving the lowest mean mixture fraction and mole fraction of CO with a maximum reduction of 25% relative to utilizing only the base fuel. In addition, the lowest amount of CO_(2) is obtained for 70% Jet-A / 30% JSPK, which is about 15% less than other weight ratios.
文摘Scarcity of conventional petroleum resources has promoted research in alternative fuels for internal combustion engines.Among various possible options,fuels derived from triglycerides(vegetable oils/animal fats)are promising for the substitution of fossil diesel fuel.Vegetable oils poses some characteristics like durability,high viscosity and low volatility compared to mineral diesel fuel.In the present work,experiments were designed to study the effect of reducing kusum and karanja oil’s viscosity by preheating the fuel,using a shell and tube heat exchanger.The acquired engine data were analyzed for various parameters such as brake thermal efficiency,brake specific energy consumption(BSEC),emission of exhaust gases like CO,CO_(2),HC and NO_(x).In operation,the engine performance with kusum and karanja oil(preheated),was found to be very close to that of diesel.The preheated oil's performances were found to be slightly inferior in efficiency due to low heating value.The performance of karanja oil was found better than kusum oil in all respects.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51922076 and 91941102)
文摘A good understanding of the thermophysical properties of hydrocarbon fuels at supercritical pressure is important to research on experiment and numerical simulation of fuel supercritical spray.Experimental measurements are difficult to conduct directly because of the extremely high pressure and high temperature.In this study,back propagation(BP)neural network,BP optimized by mind evolution algorithm(MEA-BP)and BP neural network optimized by genetic algorithm(GA-BP)are established to determine the nonlinear temperature-dependent thermophysical properties of density,viscosity,and isobaric specific heat(C_(2))of hydrocarbon fuels at supercritical pressure.Meanwhile,approximate formulas for these properties prediction are primarily proposed using polynomial fitting.In this paper,models that can predict three types of physical properties of three kinds of hydrocarbon fuels and their mixtures in a wide temperature range under supercritical pressure are established.In the prediction of density and C_(2),BP neural network has a good prediction effect.The results show that the MAPE is lower than 2%in the prediction of density and C_(2),but the MAPE of viscosity prediction is slightly higher than 5%using BP.Furthermore,MEA and GA are used to optimize the prediction of viscosity.The optimization effect and computation of the MEA is better than that of GA because MEA does not have the local optimization and prematurity problems.The present work offers an efficient tool to predict the thermophysical properties of hydrocarbon fuels over a wide range of temperatures under supercritical pressure which can be easily extended to other fuels of interest.It will be beneficial to the experiment and numerical simulation studies of supercritical sprays.
