Volatile Fuels Research Articles

Spray combustion characteristics and soot formation potential of Nano-Al2O3 diesel at low ambient temperatures

Nanoparticle additives have the potential to enhance combustion efficiency and reduce emissions in liquid combustion processes. This study thoroughly investigates the spray evaporation, ignition, and combustion characteristics of nanoparticle/fuel blends, especially under challenging environmental conditions, to improve combustion efficiency and reduce emissions. Employing diffused background illumination, shadowgraph, Mie scattering, high-speed natural luminosity, and two-color method, the spray combustion dynamics of thermally stable nano-Al2O3/diesel (NAD) blends were examined within a constant volume combustion chamber. Diesel, a prevalent primary or auxiliary fuel, represents other highly volatile renewable fuels, while Al2O3, a significant component in combustion fly ash, is noted for its specific catalytic properties and ability to re-burn, eliminating organic toxic elements. The results indicated that NAD blends exhibit a faster evolution rate for both liquid and vapor sprays compared to pure diesel, attributed to the increased kinetic energy of breakup droplets. Under most experimental conditions, incorporation of nano-Al2O3 slightly reduced the ignition delay time due to enhanced heat transfer. Notably, nano-Al2O3 altered the ignition mechanism of the diesel spray, transitioning it from partially premixed to diffusion combustion and relocating the ignition point nearer to the injector. The combustion flame of NAD blends demonstrated increased luminosity, a shorter flame lift-off length, and variations in start-of-injection and total-injection-nozzle-lift-off. However, due to a high equivalence ratio mixture between the liquid phase spray and combustion region, the soot concentration in NAD blends was higher than that in diesel. Additionally, the elevated flame temperature in NAD blends significantly increased the soot concentration. Overall, nano-Al2O3 markedly enhances diesel combustion, especially in low ambient temperatures, suggesting its impressive potential for the high-efficiency and low-emission utilization of renewable fuels or the combustion of recycled waste solvents.

Application of Zeolite in the Catalytic Cracking of Waste Vegetable Oil for the Production of highly Volatile Liquid Fuel

Application of Zeolite in the Catalytic Cracking of Waste Vegetable Oil for the Production of highly Volatile Liquid Fuel

The overpressure and temperature characteristics of high volatile liquid fuel explosions in extreme environments: Effects of low initial ambient temperatures and pressures

The explosion characteristics of petroleum ether-epoxy propane-air mixtures were studied in a 20 L spherical explosion vessel at low initial ambient temperatures (243–293 K) and absolute pressures (61.3–101.3 kPa). The effects of variations in single and coupled ambient conditions on the explosion pressure and temperature of high volatile liquid fuels were obtained through a series of experiments. The results showed that the peak explosion pressure and temperature were invertedly correlated with ambient temperature, and decreased with decreasing ambient pressure. Compared to ambient pressure, ambient temperature had a greater influence on explosion temperature, while ambient pressure had a greater influence on explosion pressure than ambient temperature. The variations of peak explosion pressure and temperature were more significant under the coupled effects of low temperature and pressure. Based on these results, the effects of low ambient temperature and pressure on the explosion characteristics of high volatile liquid fuels were systematically investigated, and a prediction model for peak explosion pressure and temperature was proposed.

Model for estimating the maximum water content that would maintain the flammability of an aqueous−organic mixture

Adding water to liquid fuels can make them nonflammable; substantial amounts of water are required to do so for highly volatile fuels. A limited amount of water being required to eliminate the flammability of low-volatility fuels would enable adjustments to be made to fire and explosion (F&E) hazard assessments for such fuels and the requirements for preventing F&E hazards of various regulations. This study developed a novel generic model for determining two critical parameters used to assess F&E hazards and that can be leveraged to eliminate these hazards: (1) the maximum water composition in the liquid phase for which the aqueous solution remains flammable and (2) the maximum flash point (FP). The model was verified using experimental data on nine low-volatility aqueous−organic mixtures and published data on eight high-volatility aqueous−organic mixtures. The model made acceptable predictions for ignitable chemicals with an FP range of −19 to 145 °C. Both the simulations and measurements revealed that only a small amount of water is required to render low-volatility fuels nonflammable, whereas substantial amounts of water are required for highly volatile fuels. The proposed model and present results can be employed to reduce the cost of F&E protection.

Numerical Modeling of Chemical Kinetics, Spray Dynamics, and Turbulent Combustion towards Sustainable Aviation

With growing interest in sustainable civil supersonic and hypersonic aviation, there is a need to model the combustion of alternative, sustainable jet fuels. This work presents numerical simulations of several related phenomena, including laminar flames, ignition, and spray flames. Two conventional jet fuels, Jet A and JP-5, and two alternative jet fuels, C1 and C5, are targeted. The laminar burning velocities of these fuels are predicted using skeletal and detailed reaction mechanisms. The ignition delay times are predicted in the context of dual-mode ramjet engines. Large Eddy Simulations (LES) of spray combustion in an aeroengine are carried out to investigate how the different thermodynamic and chemical properties of alternative fuels lead to different emergent behavior. A novel set of thermodynamic correlations are developed for the spray model. The laminar burning velocity predictions are normalized by heat of combustion to reveal a more distinct fuel trend, with C1 burning slowest and C5 fastest. The ignition results highlight the contributions of the Negative Temperature Coefficient (NTC) effect, equivalence ratio, and hydrogen enrichment in determining ignition time scales in dual-mode ramjet engines. The spray results reveal that the volatile alternative jet fuels have short penetration depths and that the flame of the most chemically divergent fuel (C1) stabilizes relatively close to the spray.

Evaluation of GDI spray structures under flash boiling and strong collapse conditions with diverse fuels

GDI (Gasoline Direct Injection) sprays are a matter of continuous research due to their potential for higher thermal efficiency and power output. Injections in GDI engines tend to happen at relatively high temperatures, which, combined with volatile fuels, are a perfect environment for flashing sprays, which are present in recently developed GDI engine passenger cars. Phenomena like flash boiling and especially spray collapse are still being investigated due to their complexity and impact on the engine performance. In the present research, the impact of different levels of flash boiling in the sprays is analyzed. Four surrogate mono-component fuels were tested with different volatile properties. Two optical techniques were carried out simultaneously: light extinction images (DBI) and frontal MIE scattering. The spray width was used to represent the radial expansion and study its relation with the spray collapse due to flash boiling. The degree of collapse was quantified by means of the instantaneous spray width variation for which three levels of collapse were identified. A novel MIE frontal approach was employed to study the spray surface evolution and the collapsing time by monitoring the nozzle tip clouding (opaquing) by the fuel. Results showed an increment of the width with the ratio of saturation to ambient pressure (Rp), as well as a strong correlation between the spray surface and the Rp at each fuel temperature when the spray is stabilized. Based on the MIE technique, three collapse instants were identified throughout the injection time depending on the Rp.

Optical diagnosis study of fuel volatility on combustion characteristics of spray flame and wall-impinging flame

Finding suitable alternative fuels and reducing carbon emissions are important development directions for future engines. Many carbon-neutral fuels, such as alcohol fuels are widely used, and they are more volatile than traditional diesel fuel. Therefore, exploring the development characteristics of spray flames and near-wall flames of different volatile fuels has important theoretical significance and application value for the optimization of fuel characteristics and the development of efficient and clean combustion technology. In this paper, the flame structure, flame development characteristics and soot evolution of three fuels, including n-hexane, 74%v n-heptane mixed 26%v isooctane (PRF26) and 53%v n-dodecane mixed 47%v isooctane (D53) were tested, that the cetane number of three fuels is essentially same. High speed self-luminous imaging and RGB two-color method were used to investigated the effect of fuel volatility on combustion. Results can be seen as following. Firstly, during the early stages of n-hexane combustion, a blue premixed flame can be found, and there is a pale-yellow flame in the later stage. As the boiling point increases, the area of the blue flame in the first stage gradually decreases, the area of the yellow flame in the later stage gradually increases, and the spatially integrated natural luminosity (SINL) of flame gradually increases. In addition, as the boiling point increases, the initial spontaneous combustion ignition point is away from the nozzle, the ignition delay time reduces and flame area becomes larger. Furthermore, the flame of high boiling fuels result in higher soot emissions. Secondly, in the event of flame wall-impingement, the near-wall flame of the three fuels has higher flame SINL and more soot formation in comparison to the free spray flame. The flame development of the three fuels is similar. However, there are some differences in the flame brightness distribution. The bright flame areas in n-hexane and PRF26 are concentrated near the wall, while the bright flame area in the D53 flame is concentrated on the wall and the flame head area rolled up with a larger distribution area. The flame near the wall is impacted by the wall temperature that the lower wall temperature leads to prolonged fuel evaporation and mixing time, which increases the ignition delay time. In conclusion, fuel volatility has less influence on flame structure and development, but a significant impact on ignition delay time and emissions. Regardless of whether wall impingement occurs, higher volatile fuels can extend the ignition delay time, increase the flame area and decrease soot emissions from combustion.

Fuel modification flash boiling atomization and combustion in reciprocating engines

With the current goals and regulations in reducing carbon emissions, flash boiling atomization is considered a promising method for liquid fuel energy conversions, for instance, alternative fuel combustions and zero/negative carbon fuel combustions. One scheme to enable flash boiling atomization is to dope highly volatile fuel into low volatile fuels and trigger phase change during combustion, but the impacts of such modifications on the performance of the combustor, especially soot formation mechanisms and gaseous emissions characteristics, are not illustrated systematically yet. This investigation focuses on the combustion of commercial gasoline fuel doped with iso-pentane at different volume fractions. The combustion experiments are made using a reciprocating optical engine facility with spark-ignition direct-injection combustion modes. Typical engine conditions such as low fuel temperature and high ambient pressure conditions are examined. The flame chemiluminescence is captured by a high-speed color camera, and the emission characteristics are quantified by emission analyzers. The results show that flash boiling achieved via fuel modification can generally reduce soot formation by suppressing spray impingement and wall film combustion. A more homogenous fuel-air mixture can further reduce the hot spots/rich combustions from unburnt droplets or fuel-rich zones.

Dimensional analysis of vapor bubble growth considering bubble–bubble interactions in flash boiling microdroplets of highly volatile liquid electrofuels

Electrofuels (e-fuels) produced from renewable electricity and carbon sources have gained significant attention in recent years as promising alternatives to fossil fuels for the transportation sector. However, the highly volatile e-fuels, such as short-chain oxymethylene ethers (OMEx) are prone to flash vaporization phenomena, which is associated with the formation and growth of vapor bubbles, followed by explosive bursting of the liquid jet. This phenomenon is important in many practical applications, for example, superheated liquid sprays in gasoline direct injection engines as well as cryogenic engines. The simulation of a flash boiling spray of such highly volatile liquid fuels is numerically challenging due to several reasons, including (1) the complexity of the bubble growth process in the presence of multiple vapor bubbles and (2) the need to use an extremely small time step size to accurately capture the underlying physics associated with the flash boiling process. In this paper, we first present a bubble growth model in flash boiling microdroplets considering bubble–bubble interactions along with the finite droplet size effects. A dimensional analysis of the newly derived Rayleigh–Plesset equation (RPE) with bubble–bubble interactions is then performed for Reynolds numbers of different orders of magnitude to estimate the relative importance of different forces acting on the bubble surface. Based on this analysis, a simplified nondimensional semi-analytical solution for bubble growth, which also includes the bubble–bubble interactions, is derived to estimate the bubble growth behavior with reasonable accuracy using the larger time step sizes for a wide range of operating conditions. The derived semi-analytical solution is shown to be a good approximation for describing the bubble growth rate over the whole lifetime of the bubble, thus making it useful for simulations of superheated sprays with large numbers of droplets and even more bubbles. The bubble–bubble interactions are found to have a significant impact on the bubble growth dynamics and result in delaying the onset of droplet bursting due to the slower growth of the vapor bubble compared to the bubble growth without bubble–bubble interactions. Furthermore, in a comparison with DNS results, the proposed bubble growth model is shown to reasonably capture the impact of bubble interactions leading to smaller volumetric droplet expansion.

Simulation study on fuel-nitrogen migration characteristics of oxy-fuel co-combustion of various ultra-low volatile coal-based solid fuels

The co-combustion of various ultra-low volatile coal-based solid fuels (UVCFs) under oxy-fuel condition could consume semi-coke and residual carbon cleanly and efficiently. However, the fuel-nitrogen (fuel-N) migration behaviors of various UVCFs blends in O2/CO2 atmosphere are still unclear. In addition, the heterogeneous reactions on surfaces of char could also affect the synergistic effects between various UVCFs blend. Here, the fuel-N migration features of various UVCFs in O2/CO2 atmosphere were investigated by Chemkin simulation and the oxy-fuel co-combustion mechanism of various coal-based solid fuels (OCF mechanism) included heterogeneous reactions was developed. Moreover, the methods of sensitivity and rate of production analyses were both employed to clarify the synergistic effects on nitrogen conversion pathways of various blends. The heterogeneous reaction between char and NO (R15) is the key reaction for NO reduction in primary zone. The free radicals OH and H provided by UVCFs could react with main NO precursors NCO, HNCO, HOCN, NH and NH2 to generate NO. The conversion pathways of HCN to NO are more complex than those of NH3 to NO. The rises of residual carbons proportions and temperature in primary zone (T1) could both reduce the NO formation amount due to the promoted R15. The sensitivity coefficients (S) on NO formation of 50% SS/50% CR blend in the burnout zone are lower than those of 50% SS/50% FR blend. The transformations of HNCO, HNO and NO2 to NO and the heterogeneous reactions of NO could both be enhanced with the O2 concentration in burnout zone. The increasing burnout air position (Pb) results in the rise of NO generation owing to that the NO reducing reactions R15 and R16 are greatly inhibited with the Pb raised. The present study could be beneficial for the clean and effective utilization of UVCFs, together with the reduce of NOx emission and realization of carbon neutral in China.

Co-gasification behaviors of various coal-based solid fuels blends at initial stage of oxy-fuel Co-combustion

The technology of oxy-fuel co-combustion is beneficial to consume the large amount of ultra-low volatile coal-based solid fuels (UCF). Moreover, the oxy-fuel co-combustion of various UCFs could also promote the development of coal-chemical industry and reduce the carbon emission in power plants. However, the co-gasification behaviors of various coal-based solid fuels blends at initial oxy-fuel co-firing stage are still vague, which need to be further studied. In the present, the co-gasification features of various coal-based solid fuels blends during initial oxy-fuel co-combustion process were investigated by oxy-fuel co-combustion system experimentally. The rise of O2 concentration could obtain low Brunner−Emmet−Teller surface area and high Barrett-Joyner-Halenda average pore owing to the collapse of internal structures. The nitrogen gases (X–N) yields show a decreasing trend with the UCF proportion raised. The increasing temperature could promote the gas release of sample. The ash droplets observed on the surface of blend were formed by reactions between oxygen and carbon on the sample surface in 3% O2/97% CO2 atmosphere, which are enlarged with temperature significantly. The present research could be beneficial for efficiency utilization of low-rank coal, together with the reduction of NOx emission and realization of carbon neutrality.

Oxyfuel Cofiring Characteristics of Biomass with Ultralow Volatile Carbon-Based Fuels

Biomass from agricultural production is a renewable energy source with a high-volatile content. Semicoke (SC) and gasification residual carbon, which are ultralow volatile carbon-based fuels (LVFs), are by-products of the coal chemical industry, which are over capacity and urgently need to be cleanly and effectively consumed. Biomass and LVFs exhibit complementary fuel characteristics, particularly the volatile content, which can potentially be coprocessed efficiently. Furthermore, oxyfuel combustion technology can not only realize carbon dioxide (CO2) capture and benefit from carbon neutrality, but also effectively reduce NOx emissions. The cocombustion of biomass and ultralow volatile fuel under oxyfuel conditions can both use individual benefits and effectively control pollutant emissions. However, the cofiring characteristics and interaction mechanisms of LVF with biomass in an oxyfuel atmosphere are yet to be fully understood. In this study, three ultralow volatile fuels and one typical biomass were selected to explore the oxyfuel cocombustion characteristics via thermogravimetric experiments. The experimental results indicated that blending with wheat straw (WS) improved the overall combustion performance, the ignition point was close to that of WS, and the burnout temperature was close to the average value of the two individual fuels. An increase in the oxygen content can effectively enhance the combustion feature of ultralow volatile fuels while it has little effect on the burnout performance of biomass. In the presence of high-content CO2, the decomposition of carbonate in ultralow volatile fuel is impeded and the decomposition temperature is slightly increased. The present investigation can promote the efficient co-utilization of inferior LVFs and biomass, which also benefits CO2 capture, carbon neutrality, and even negative carbon emissions.

Real-world emission characteristics of semivolatile/intermediate-volatility organic compounds originating from nonroad construction machinery in the working process

Detailed emission characterization of semivolatile/intermediate-volatility organic compounds (S/IVOCs) originating from nonroad construction machines (NRCMs) remains lacking in China. Twenty-one NRCMs were evaluated with a portable emission measurement system in the working process. Gas phase S/IVOCs were collected by Tenax TA tubes and analyzed via thermal desorption-gas chromatography–mass spectrometry (TD–GC–MS). Particle phase S/IVOCs were collected by quartz filters and analyzed via GC–MS. The average emission factors (EFs) for fuel-based total (gas + particle phase) IVOCs and SVOCs of the assessed NRCMs were 221.45 ± 194.60 and 11.68 ± 10.67 mg/kg fuel, respectively. Compared to excavators, the average IVOC and SVOC EFs of loaders were 1.32 and 1.55 times higher, respectively. Compared to the working mode, the average IVOC EFs under the moving mode (only moving forward or backward) were 1.28 times higher. The IVOC and SVOC EFs for excavators decreased by 69.06% and 38.37%, respectively, from China II to China III. These results demonstrate the effectiveness of emission control regulations. In regard to individual NRCMs, excavators and loaders were affected differently by emission standards. The volatility distribution demonstrated that IVOCs and SVOCs were dominated by gas- and particle-phase compounds, respectively. The mode of operation also affected S/IVOC gas-particle partitioning. Combined with previous studies, the mechanical type significantly affected the volatility distribution of IVOCs. IVOCs from higher volatile fuels are more distributed in the high-volatility interval. The total secondary organic aerosol (SOA) production potential was 104.36 ± 79.67 mg/kg fuel, which originated from VOCs (19.98%), IVOCs (73.87%), and SVOCs (6.15%). IVOCs were a larger SOA precursor than VOCs and SVOCs. In addition, normal (n-) alkanes were suitably correlated with IVOCs, which may represent a backup solution to quantify IVOC EFs. This work provides experimental data support for the refinement of the emission characteristics and emission inventories of S/IVOCs originating from NRCMs.

Numerical simulation on co-firing ultra-low volatile carbon-based fuels with bituminous coal under oxy-fuel condition

The oxy-fuel combustion allows the large-scale CO2 capture from coal-fired power plant, which is an effective approach to reduce CO2 emission and achieve carbon neutrality. The ultra-low volatile carbon-based fuels (LVFs, mainly including gasification residual carbon and pyrolyzed semi-coke) generated from the coal chemical industry cannot be directly disposed effectively, but co-firing with other fuels (bituminous coal for example) is a potential option. However, many nitrogen oxides (NOx) are possibly generated with the absence of combustion stability. Here, the present study aimed at co-combusting LVFs with bituminous coal under oxy-fuel condition to take advantages of oxy-fuel technology to deeply reduce NOx and realize large-scale CO2 capture. The effects of atmosphere and fuel property on co-combustion performances were numerically investigated. The simulation results of co-combustion demonstrate that the NOx emission increases as the mass fraction of bituminous coal falls. The effects of oxidizing gas distribution method on the co-combustion characteristics are highly related to the properties of co-firing fuels. The premixed combustion for bituminous coal/semi-coke co-combustion and in-furnace blending (residual carbon injected from the E layer) for bituminous coal/residual carbon co-combustion could yield less NOx. It is recommended that the oxy-fuel O2 concentration could be kept between 27% and 30% considering the balance between NOx generation and combustion behavior. The 50% bituminous coal/50% semi-coke co-combustion is applicable to co-fire using premixed combustion and appropriate reduction of secondary oxidizing gas flow in the semi-coke layers. The present research will contribute to a further understanding of the efficient and environmentally-friendly utilization of LVFs, as well as better knowledge of CO2 capture and carbon neutrality during electricity generation.

DRIVEABILITY INDEX OF COMMERCIAL GASOLINE IN ASEAN COUNTRIES

Motor gasoline is essentialy a complex mixture of hydrocarbons distilling between about 40°C and 225°C and consisting of compounds generaly in the range C5 to C12. Small amounts of additives are also used to exchange various aspects of the performance of the fuel. Gasoline produced from different refin[1]eries can vary widely in compositions, even at the same octane level.The primary requirement of a gasoline is that should burn smoothly without exploding, under the conditions existing in the combustion chamber of the spark-ignition, so that themaximum amount of useful energy is liberated[1].The volatility of a gasoline has a vital influence on the both performance of a car emission. It affects the way car starts, the time it takes to warm up, the exten to which ice will form in the carburator, causing stalling and other problems; it influences vapour lock in the fuel system and indirectly it determines overall fuel economy. Volatility is a measure of the ability of a fuel to pass from the liquid to the vapour state under varying conditions.In cold weather, cars can take a very significant time to warm-up i.e., be capable of smooth, non-hesitating accelerations without the use of the choke. The fuel parameter that is found to have the grestest influence on warm-up is the mid-boiling range volatility as characterized by for example; the 50 per cent distillation temperature. Even after the car has warmed up, fuel volatility can still have an influence on acceleration time. Low volatility fuels obviously give leaner mixture and as mixtures leaner, acceleration performance can fall off quite rapidly.The fraction of the fuel that influences acceleration behaviour to the greatest extent is in the mid and to a lesser extent the higher boiling range. Thus, the 50% distillation temperature, sometimes together with the 90% distillation, must be controlled to ensure optimum acceleration behaviour. The factors which influence vapour lock is the volatility characteristics of the fuel. The degree to which a fuel is liable to give vapour lock depends mainly on its front end volatility. A number of different front-end volatility parameters have been used to define the vapour locking tendency of a fuel, such as RVP, percentage evaporated at 70°C, the 10 and 15% slope of the distillation curve, the vapour/liquid ratio at a given temperature and pressure. These distillation characteristics affect the following performance characteristics: starting, vapour lock and driveability.ASTM D4814-98a the standard specification for Automotive Spark-Ignition Engine Fuel has included Driveability Index as an item of performance requirement of the fuel. The inclusion of the parameter is to provide control of distillation parameters that influence cold start and warm up driveabilities.

Experimental evaluation on NOx formation and burnout characteristics of oxy-fuel co-combustion of ultra-low volatile carbon-based solid fuels and bituminous coal

Pyrolyzed semi-coke (SC) powder and gasification residual carbon are usually regarded as solid wastes, which feature high NOx formation amount and inferior burnout performance during burning process. Oxy-fuel co-firing of these ultra-low volatile carbon-based solid fuels (LVFs) with bituminous coal (BC) could reduce the NOx generation and realize the carbon capture to a large extent. However, the NOx formation and burnout features of oxy-fuel co-combustion of BC and LVFs are still unclear. Here, a two-staged drop-tube co-firing experimental system was employed to probe the oxy-fuel co-combustion characteristics of various blends. The experimental results show that the low ash melting temperature of coal-water-slurry gasification residual carbon yields an increase in Cfh with the temperature of burnout zone. The Cfh of BC/SC blend is decreased by 64.3% with the oxygen flow rate of primary air raised from 0.25 to 0.45 L min−1, which is the largest among all blends. The rise of difference between tube lengths in furnace of BC and LVF generates a decrease in NOx formation and an increase in Cfh. The present research could offer guidance for clean and efficient utilization of carbon-based solid wastes using oxy-fuel co-combustion technique, together with the encouraged development of carbon capture technology.

On the determination of the distillation curve of fatty acid methyl esters by gas chromatography

Given the increased concern for environmental protection and the need for finding viable alternatives for replacing fossil fuels in internal combustion engines, the research carried out in the recent past on the use of biodiesel has increased.Out of the physico-chemical characteristics of fuels, the volatility has a great influence on the combustion process. It is therefore important to accurately obtain all the data related to the volatility of the fuels. A way to assess the fuel’s volatility is the distillation curve (DC). The simplest way to determine DC is at atmospheric pressure. However, for low volatility fuels such as biodiesel, atmospheric distillation is not indicated, therefore, using of alternative methods is needed. One method that can be used in this case is the determination of the boiling range distribution by gas chromatography (GC). The GC equipment used for this purpose is specifically designed for this aim, meaning that the determination of DC by the GC itself is a given or standard feature of the equipment. However, in many labs, such specifically designed GC equipment is not available.In this context, the paper aims at providing a GC based method for finding the boiling points of fatty acid methyl-esters (FAME) on standard FID based GC instrument for those researchers wishing to add new capabilities to their existing GC instruments. To validate the method, five different samples of pure biodiesel were analyzed, and the results obtained by applying this method were confirmed by comparison with the distillation curve obtained via vacuum distillation.

Decrease in evaporative loss of volatile fuels using new mixture of surfactants

Despite the economic aspects of evaporative losses of volatile hydrocarbons such as gasoline, problems in the form of fire hazards and environmental pollutions are also concerned. Today many options to reduce the evaporation of hydrocarbon liquids are offered and used worldwide but none of them can impressively prevent the process. In this work, the potential use of mixture of surfactants as liquid film coating layer on free surface of volatile fuels was investigated to decrease the evaporative loss of gasoline and oil in fuel tanks. A combination of surfactants and polyethylene glycol were considered as liquid film that can be applied to spread on the surface of gasoline and oil. The prepared liquid film can remain on the surface of gasoline for about 5 hr and on the surface of oil for more than 55 hr. Obtained results indicate that by using the covering film, the evaporation losses of gasoline and oil at 25° C and atmospheric pressure in a time interval of 200 min are reduced by 20.92 and 70.83%, respectively. So, using a mixture of surfactant and polymer (as a covering film) can reduce the evaporation loss of hydrocarbons appreciably. The use of non-carcinogenic surfactants, increasing the durability of the coating layer on the gasoline surface and significantly reducing the evaporative loss of gasoline are some of the innovations of this research.

Influence of fuel volatility on particulate matter emissions from a production DISI engine

An investigation into the influence of fuel volatility on the resultant particulate matter (PM) emissions from a DISI engine is reported. Testing was performed at a steady-state highway cruise condition to investigate phenomena leading to seasonal changes in PM emissions observed in published roadside studies. Fuel volatility, which varies with season was the prime focus of the investigation, with a secondary goal of investigating the influence of ethanol blended fuels at the varied volatility levels. In tests with both surrogate and commercial fuels, high volatility fuels presented elevated emissions of both particle number (PN) and gravimetric mass emissions. Furthermore, the effect of 10% ethanol match-blending was investigated at both the high and low volatility conditions. Inclusion of ethanol in match-blended high volatility fuels was found to result in no significant change in PM emissions versus the neat fuel complement, while a considerable enhancement of PM emissions resulted from ethanol match-blending in low volatility fuels. Evidence from the literature, changes in the measured PN concentrations & size distributions over the length of a test, and post-run imaging of the fuel injector face, all suggest that an increase in intensity of flash-boiling conditions & fuel wetting of the injector tip drive the observed changes for the test conditions and engine architecture used in this study.

123 A Novel Way of Thinking About Blast Injury Classification

Abstract Introduction Blast injuries present unique challenges to civilian and military healthcare providers because of the complex and often severe nature of injuries spanning numerous anatomical regions, tissue types, and organ systems. Due to these factors, we devised a novel wound-focused classification system for implementation during triage and management of blast injuries to optimize outcomes and applied this system to patients treated at an ABA-certified burn center over 5 years. Methods A retrospective analysis of patients treated by an ABA-certified burn center for blast-related injuries from September 1, 2014 to October 31, 2019 was performed. Demographics, mechanism and distribution of injuries, interventions, and outcomes were evaluated. Injuries were classified using a wound-focused classification comprised of four zones: 1) areas closest to blast epicenter that had total or near-total tissue loss from the blast; 2) adjacent areas with thermal and chemical burns; 3) distant sites with shrapnel-related wounds; 4) injuries arising from barotrauma. Results We identified 64 patients who were mostly male (84%), averaging 38 ± 14 years old. Injury mechanisms included fireworks (19%), industrial accidents (16%), volatile fuels and drug labs (45%), and others including can, battery, lighter explosions (20%). All mechanisms had equivalent frequency of Zone 2 injuries with an average TBSA of 17 ± 18%. Drug-related blasts caused the highest TBSA (34 ± 23%) and the most full-thickness burns (33% vs average 23%). Fireworks had over five times (17% vs. 3%) more Zone 3 and three times (25% vs 8%) more Zone 4 injuries compared to the other mechanisms. Upper extremities were involved at twice the rate of other body regions (43% vs 19%). Patients presenting to our burn team over 24 hours after initial injury had infections in 50% of cases – a four-fold increase compared to non-delayed presentations (50% vs 13%). Overall, 45% required surgery (32% grafting, 3% flaps) but 100% of the drug-related blasts needed surgical intervention. Some patients (58%) required ICU admission with the highest rate (83%) in the drug-related group. Conclusions Blast injuries most often required admission for management of the Zone 2 component. Each blast mechanism resulted in distinct distributions of injury although fireworks had the greatest number of Zone 1, 3, and 4 injuries. Firework blasts were often less severe and more likely to present delayed with infectious complications. Larger blast mechanisms including drug-related lab explosions as well as industrial blasts had the highest rates of ICU admission, TBSA, full thickness depth, upper extremity involvement, and need for surgical intervention.