Miscibility of Ethanol in Diesel Fuels

The primary barrier to the use of ethanol in diesel fuel is the poor miscibility at lower temperatures. The miscibilities of ethanol in 19 diesel fuels having a wide variation in compositions were evaluated by testing their phase separation temperatures. The result shows that aromatic contents and intermediate distillate temperatures have a significant impact on miscibility limits. The FCC diesels, which contain up to 50% of aromatics, exhibit different phase behavior trends in comparison with straight-run diesels and other diesel fuels.

Diesel and Jet Fuels from Bitumen-derived Middle Distillates

Narrow fractions of light gas oils obtained from various upgrading processes of Athabasca oilsands bitumen were investigated as diesel and jet fuels. The relationship among the boiling range, cetane number, smoke point, and other properties such as aromatics content, aniline point, and the sulfur and nitrogen content was also studied. The study reveals that when appropriate processes and distillation boiling ranges are selected, oilsands bitumen can produce diesel and jet fuels that meet stringent environmental regulations and future product specifications. New correlations to predict CN and smoke point were developed as a function of density, boiling ranges by simulated distillation, and mono- and total aromatics by supercritical fluid chromatography. The correlations apply to bitumen-derived middle distillates that have a wide range of boiling points.

Effects of Far-Infrared Composite Materials Doped with Rare Earth on Physicochemical Properties of Diesel Fuel

The rare earth, far-infrared natural mineral and clay were compounded to prepare the far-infrared composite materials. The effects of the far-infrared composite materials on the physicochemical properties of diesel fuel were studied. It shows that the composite materials can radiate higher intensity of far infrared; and the surface tension, viscosity and flash point decrease when the diesel fuel is dealt with the composite materials containing rare earth elements; and then the available effect mechanisms of the composite materials on the properties of diesel fuel were investigated by testing the activity changes of arene.

Economic Analysis of Diesel Fuel Subsidy Policy in China's Fishery

In this paper,on the basis of an overview of the evolution of diesel fuel subsidy policy in China's fishery,we perform an economic analysis of the existing diesel fuel subsidy policy,and believe that it is fishing shareholders rather than fishermen who benefit most from the diesel fuel subsidy policy. The diesel fuel subsidy policy is not conducive to fishery resources protection,it will cause no fluctuation in the supply price of aquatic products,and it can not effectively increase the income of all fishermen. It is necessary to focus on subsidy method,subsidy links and subsidy level to improve diesel fuel subsidy efficiency,lower production costs,stabilize fishery production,and increase the income of fishermen.

Performance and emission characteristics of a diesel engine operating on different water in diesel emulsion fuels:optimization using response surface methodology(RSM)

The nitrogen oxide(NOx)release of diesel engines can be reduced using water in diesel emulsion fuel without any engine modification.In the present paper,different formulations of water in diesel emulsion fuels were prepared by ultrasonic irradiation.The water droplet size in the emulsion,polydisperisty index,and the stability of prepared fuel was examined,experimentally.Afterwards,the performance characteristics and exhaust emission of a single cylinder air-cooled diesel engine were investigated using different water in diesel emulsion fuels.The effect of water content(in the range of 5%-10% by volume),surfactant content(in the range of 0.5%-2% by volume),and hydrophilic-lipophilic balance(HLB)(in the range of 5-8)was examined using Box-Behnken design(BBD)as a subset of response surface methodology(RSM).Considering multi-objective optimization,the best formulation for the emulsion fuel was found to be 5%water,2% surfactant,and HLB of 6.8.A comparison was made between the best emulsion fuel and the neat diesel fuel for engine performance and emission characteristics.A considerable decrease in the nitrogen oxide emission(-18.24%)was observed for the best emulsion fuel compared to neat diesel fuel.

Controllable synthesis of polyoxymethylene dimethyl ethers by ionic liquids encapsulated in mesoporous SBA-16

The promising combustion and emission properties of polyoxymethylene dimethyl ethers(PODEn)are of significant interest.However,the synthesis of PODEn products with desired chain lengths is still a problem facing synthetic PODEn.Herein,a series of unique IL@SBA16Cx solid catalysts are prepared by encapsulation of ionic liquids(ILs)within the nanocage of SBA16 through a silylation method.The structure of the encapsulated catalyst was characterized by UVvis spectra,Fourier transform infrared(FTIR),N2 adsorptiondesorption isotherms,Powder Xray diffraction(XRD),Transmission electron microscopy(TEM)and Elemental analysis.The encapsulated catalysts show similar catalytic activity to the homogeneous counterparts and display higher selectivity to the targeted PODE35 products than their homogeneous counterparts in the synthesis of PODEn from methanol(MeOH)and trioxymethylene(TOM).The encapsulated catalysts exhibit a superior PODE35 selectivity and could be the promising catalysts for PODEn synthetic reaction.

Importance Analysis of a Multi-state System Based on Direct Partial Logic Derivatives and Multi-valued Decision Diagrams

Importance analysis quantifies the critical degree of individual component. Compared with the traditional binary state system,importance analysis of the multi-state system is more aligned with the practice. Because the multi-valued decision diagram( MDD) can reflect the relationship between the components and the system state bilaterally, it was introduced into the reliability calculation of the multi-state system( MSS). The building method,simplified criteria,and path search and probability algorithm of MSS structure function MDD were given,and the reliability of the system was calculated. The computing methods of importance based on MDD and direct partial logic derivatives( DPLD) were presented. The diesel engine fuel supply system was taken as an example to illustrate the proposed method. The results show that not only the probability of the system in each state can be easily obtained,but also the influence degree of each component and its state on the system reliability can be obtained,which is conducive to the condition monitoring and structure optimization of the system.

A review and evaluation of nonroad diesel mobile machinery emission control in China

China’s emission control for nonroad diesel mobile machinery(NDMM)must deal with a fast increase in stock as well as regulations that are two decades behind those for on-road vehicles.This study provides the first large-scale review and evaluation of China’s NDMM policies,along with emission measurements and an investigation on diesel fuel quality.The sulfur contents of the investigated diesel declined from 430 ppm(median value)in 2011 to6-8 ppm during the 2017-2018 period.The emission control of NO_(x)and PM greatly improved with the shift from the China II to China IV standards,as demonstrated by engine tests and field NO_(x)measurements.However,the NO_(x)emission factors for non-type-approved engines were approximately twice the limits of the China II standards.Emission compliance based on bench tests was not sufficient to control actual emissions because the field-measured NO_(x)emission factors of all machinery ranged from 24%to 225%greater than the respective emission limits for the engines.These circumstances adversely affected the effectiveness of the regulations and policies for China’s emission control of NDMM.Nevertheless,the policies on new and in-use NDMM,as well as diesel fuel quality,prevented NO_(x)and PM emissions amounting to 4.4 Tg and 297.8 Gg during the period 2008-2017,respectively.The emission management strategy contributed to enhancing the international competitiveness of China’s NDMM industries by promoting advanced technologies.For effective NDMM emission control in the future,portable testing and noncontact remote supervision should be strengthened;also,the issue of noncompliant diesel should be addressed through rigorous control measures and financial penalties.

A Numerical Investigation on the Effects of Intake Swirl and Mixture Stratification on Combustion Characteristics in a Natural-Gas/Diesel Dual-Fuel Marine Engine

Natural gas/diesel dual-fuel combustion strategy has a great potential to reduce emissions for marine engines while the high fuel consumption is the major problem.Pre-chamber system is commonly employed as the ignition system on large-bore dual-fuel marine engines especially under lean-burn condition,due to its advanced ignition stability and engine efficiency.However,the ignition and combustion mechanism in such dual-fuel pre-chamber engine is still unclear and the effects of in-cylinder swirl flow and mixture stratification on combustion require further investigation specifically.This paper numerically studied the detailed ignition mechanism and combustion process in a marine engine equipped with a pre-chamber ignition system,and revealed the flame development process in main chamber.Moreover,the effects of mixture stratification and swirl ratio on the combustion rate and further engine thermal efficiency are investigated under decoupled condition.The results mainly show that the jet flame develops along the pre-chamber orifice centerline at the initial stage and premixed combustion play an important role,while after that,heat release zone only exist at flame surface,and premixed flame propagation controls the combustion process.In addition,with higher swirl ratio the combustion rate increases significantly due to the wider ignition area.Mixture stratification degree plays a role in accelerating the combustion,either too high or too low stratification degree reduce the combustion rate,while a moderate stratification increases the combustion rate.And appropriate stratification degree by verifying the gas injection parameters can reduce fuel consumption in 0.3%.

Emission profiling of diesel and gasoline cars at a city traffic junction

In congested urban roads, cars must stop at intersections because of city traffic lights. As a result, pedestri- ans and traffic police personnel are exposed to pollutants emanating from the tailpipe of various vehicles at such city trafficjunctions. In this study, various gasoline- and diesel-fueled cars complying with differ- ent emission standards were tested for their emissions in simulated city traffic junction conditions. The engine exhaust from these cars was subjected to physicochemical characterization at different engine speeds under no-load conditions. These engine conditions were chosen because the cars idle at differ- ent engine speeds at a city traffic junction. Gravimetric and real-time measurements were performed for the tailpipe exhaust sampled from these vehicles. Exhaust particles were collected on 47 mm diameter quartz filter papers and subjected to gravimetric analysis for determining the total particulate mass （TPM） and trace metals while the engines were operated at two different engine idling speeds, 1500 rpm （representing low idling） and 2500 rpm （representing high idling）. At similar engine operating condi- tions, TPM and trace metals were lower for the exhaust from gasoline engines compared to the exhaust from diesel engines. Real-time measurements were performed for particle-bound poly-aromatic hydro- carbons （PAHs）, particle number and size distribution, regulated gaseous emissions and smoke opacity of the exhaust at four different engine speeds, 1500, 2000, 2500, and 3000 rpm. Particle-bound PAHs showed a decreasing trend for the vehicles that complied with stricter vehicular emission standards. Higher particle peak number concentrations were observed for diesel exhausts compared to the results for gasoline exhaust. Regulated gaseous emissions were also comoared.

Real-world fuel efficiency and exhaust emissions of light-duty diesel vehicles and their correlation with road conditions

The real-world fuel efficiency and exhaust emission profiles of CO, HC and NOx for light-duty diesel vehicles were investigated. Using a portable emissions measurement system, 16 diesel taxies were tested on different roads in Macao and the data were normalized with the vehicle specific power bin method. The 11 Toyota Corolla diesel taxies have very good fuel economy of （5.9 ± 0.6） L/100 km, while other five diesel taxies showed relatively high values at （8.5 ± 1.7） L/100 km due to the variation in transmission systems and emission control strategies. Compared to similar Corolla gasoline models, the diesel cars confirmed an advantage of ca. 20% higher fuel efficiency. HC and CO emissions of all the 16 taxies are quite low, with the average at （0.05 ± 0.02） g/km and （0.38 ± 0.15） g/km, respectively. The average NOx emission factor of the 11 Corolla taxies is （0.56 ± 0.17） g/km, about three times higher than their gasoline counterparts. Two of the three Hyundai Sonata taxies, configured with exhaust gas recirculation （EGR） ＋ diesel oxidation catalyst （DOC） emission control strategies, indicated significantly higher NO2 emissions and NO2/NOx ratios than other diesel taxies and consequently trigger a concern of possibly adverse impacts on ozone pollution in urban areas with this technology combination. A clear and similar pattern for fuel consumption and for each of the three gaseous pollutant emissions with various road conditions was identified. To save energy and mitigate CO2 emissions as well as other gaseous pollutant emissions in urban area, traffic planning also needs improvement.

Performance, emission and combustion characteristics of DI diesel engine running on blends of honne oil/diesel fuel/kerosene/DMC

Honne oil(tamanu)(H),a non-edible vegetable oil is native for northwards of Northern Marianas islands and the Ryukyu Islands in southern Japan and westward throughout Polynesia.It has remained as an untapped new possible source of alternative fuel that can be used as diesel engine fuel.Literature pertaining to use of vegetable oil in diesel engine with kerosene and dimethyl carbonate(DMC)is scarce.The present research is aimed to investigate experimentally the performance,exhaust emission and combustion characteristics of a direct injection(DI)diesel engine,typically used in agricultural sector,over the entire load range,when fuelled with neat diesel(ND)and blends of diesel fuel(D)/DMC/H/kerosene(K).DMC/D/H/K blends have a potential to improve the performance and emissions and to be an alternative to ND.Experiments have been conducted when fuelled with H20(20%H+80%D),HK(20%H+40%K+40%D)and HKD5(20%H+40%K+35D+5%DMC)to HKD15 in steps of 5%DMC keeping H and K percentages constant.The emissions(CO,HC and smoke density(SD))of fuel blend HKD15 are found to be lowest,with SD dropping significantly.The NOx level is slightly higher with HKD5 to HKD15 as compared to ND.The brake thermal efficiency of HKD5 to HKD15 is same and it is higher than that of ND.There is a good trade off between NOx and SD.Peak cylinder pressure and premixed combustion phase increases as DMC content increase.

Effect of nanocomposite as pour point depressant on the cold flow properties and crystallization behavior of diesel fuel

The high effective nano-hybrid pour point depressant(PPD)has attracted extensive attention for its po-tential application in improving the cold flow properties of diesel fuel.In this paper,the nano-hybrid PPD was prepared by melt-blending method using three different alkyl chain lengths(i.e.,tetradecyl,hexade-cyl,and octodecyl)of n-alkyl methacrylate-maleic anhydride copolymers(R 1 MC-MA,R 1=C_(14),C_(16),C_(18))and SiO_(2)nanoparticles.The effect of those nano-hybrid PPDs on the cold filter plugging point(CFPP)and solidifying point(SP)depressing of diesel fuel were studied.Results indicated that nano-hybrid PPD showed much better performance on diesel fuel.The diesel fuel treated with 0.2 wt%C_(14)MC-MA/SiO_(2)nano-hybrid PPD exhibited the best depression in CFPP and SP by 6℃ and 18℃,respectively,which higher than that of single C 14 MC-MA.Viscosity-temperature curves and polarized optical microscopy were conducted to explore the performance mechanism;and results presented that nano-hybrid PPD of C_(14)MC-MA/SiO_(2)could effectively lower the low-temperature viscosity,and modify the crystallization behavior and crystal morphology of diesel.Therefore,the cold flow properties of diesel were significantly improved.

Interaction between a diesel-fuel spray and entrained air with single- and double-injection strategies using large eddy simulations

Interaction between fuel and air in a combustion chamber is one of the main drivers of the mixing process.Experimentally,flow visualizations are limited by high droplet density in the spray.Numerically,the ability of large eddy simulations(LES)to resolve large scales of flow offers good perspectives on capturing flow structures issued from the interaction between the Lagrangian(fuel droplets)and Eulerian(ambient gas)phases.This study examined these interactions first during a single injection using 3D and 2D criteria for both phases.As for the 3D criteria,the spray shape was analyzed in parallel to the Q-criteria applied to the Eulerian phase,making it possible to relate the spray deformations to some specific Eulerian structures.Secondly,2D criteria were the fuel mass-fraction field and Eulerian streamlines,both taken in the mid-plane of the spray.This last analysis allows for identifying certain mechanisms involved in the Eulerian phase’s structure generation and relates it to high fuel-concentration areas in the fuel mass-fraction visualizations.

An experimental study of diesel fuel cloud and pour point reduction using different additives

An experimental study was conducted to investigate the effects of four different additives on pour point and cloud point temperatures of a diesel fuel.Sample mixtures were prepared in different volumetric percentages of four different additives(Ethanol,Toluene,n-Heptane and Xylene)and diesel fuel mixture.Pour point and cloud point temperatures of the blends were measured using standard ASTM D2500 and ASTM D97-96a methods,respectively.Introducing the additives to the diesel fuel did not lead to a significant reduction in cloud point temperature of the fuel.In fact,the greatest obtained reduction in cloud point temperature was achieved using 20 vol%or more of Toluene-diesel fuel mixtures.Although cloud points did not change significantly,even the slightest amounts of additives caused a high reduction in the pour point temperature of the fuel.Ethanol was the most effective additive in lowering the pour point temperature of the fuel.A 20%ethanol-fuel mixture caused nearly a 30
reduction in the fuel pour point temperature.Therefore,knowing that none of the additives has a significant effect on cloud point temperature,while the greatest reduction in pour point temperature is achieved using ethanol even in low Vol%s,it can be concluded that the most efficient additive among these four additives to alter cold flow properties of a certain diesel fuel is Ethanol.