Kerosene Research Articles

Modified Oxymethylene Ethers Based on Technical Alcohol Mixtures and their Fuel Properties

AbstractOxymethylene dimethyl ethers (OMDME) have attracted interest as renewably synthesized diesel substitutes with low soot formation and NOx emissions. In order to enable a high compatibility of this new type of fuel in the already existing infrastructure, a modified oxymethylene ether (OME) synthesis based on technical alcohol mixtures, i.e., C4‐based alcohol mixtures of isomers, was evaluated and the new compounds were thoroughly characterized. The synthesized compounds can be used as neat fuel or as blending component for fossil or paraffinic diesel fuels. The modification of OME offers the possibility to adjust desired properties. This versatility could also be used to synthesize compounds for the chemical sector according to its respective requirements, such as applications as solvents, plasticizers, or additives.

Endurance results of a refuels fleet test in a real application based on directly comparable truck test pairs

Synthetic fuels from a renewable base are an essential part of a greenhouse gas-neutral mobility, especially in transport sector. While scaling production of e-fuels (fuels based on electrolysis hydrogen) is ongoing, HVO called paraffinic diesel fuels are already available. Their production is based on the hydrogenation of waste and residues and they are established as diesel substitute in several applications. With regard to the approval of these fuels in German regulation, the question repeatedly arises as to whether they can be used easily and what effects can be achieved. This article describes an application in a real logistics application, in which both the everyday use and the concrete comparability to a refueling with conventional gas station diesel were ensured. The use of several parallel active and different truck pairs has shown that the use of HVO in existing vehicles has achieved the desired CO2 reduction. A detailed analysis of the engine oil also showed that no undesirable effects could be observed here either. From the perspective of this project, HVO fuels are ready for use for a significant greenhouse gas reduction in logistics.

Effects of fuel composition at varying air-fuel ratio on knock resistance during spark-ignition combustion

Knock resistance of liquid fuels for spark-ignition engines is determined using standardised tests (RON and MON), however, these measurements are not undertaken at the same air–fuel ratio for different fuels. In contrast, modern engines have a highly controlled air–fuel ratio, often operating in a very narrow range around stoichiometric in order to reduce pollutant emissions and achieve high thermal efficiencies. As global efforts to increase the utilisation of renewable fuels of varying composition intensify, understanding of the differing knock sensitivity to the air–fuel ratio at which the engine is operated provides a vital opportunity to further optimise combustion processes.This paper investigates the influence of varying relative air–fuel ratios, the exhaust λ, on the knock resistance of a range of fuels of varying RON values and chemical compositions. Binary component primary reference fuels and practical gasolines of equivalent RON values were tested with a Ricardo E6 variable compression engine operated at conditions similar to those used for RON tests. It was found that the engine compression ratio which could be utilised before a knock threshold was exceeded was the same for fuels of equivalent RON at fuel rich conditions but differed appreciably at stoichiometric conditions (λ = 1). The knock resistance of purely paraffinic reference fuels was observed to be more sensitive to changes in exhaust λ than the aromatic gasoline fuels, especially at λ = 1, where the former fuels required significantly higher engine compression ratios to achieve equivalent levels of knock.

Effects of knock intensity measurement technique and fuel chemical composition on the research octane number (RON) of FACE gasolines: Part 2 – Effects of spark timing

The Research and Motor Octane Number (RON, MON) characterize a fuel’s knock resistance by rating the knock intensity of a sample fuel relative to that of Primary Reference Fuels (PRF) in a Cooperative Fuel Research (CFR) Engine. A fuel’s octane number is regulated to prevent damage from autoignition leading to knocking combustion in spark-ignition engines. The operational differences between the standard RON rating and modern engine operation are explored in a three-part publication series. The previous study focused on the effects of lambda and knock characterization. This second study primarily focuses on the effects of spark timing on RON determination. Following the findings from the first publication, the knock intensity was captured by the knockmeter and by the maximum amplitude of pressure oscillations (MAPO) at the lambda of peak knock intensity and stoichiometry. Knock-limited spark advance tests were conducted for a set of seven Fuels for Advanced Combustion Engines (FACE) from the Coordinating Research Council (CRC) with varying chemical composition, PRFs, and Toluene Standardization Fuels (TSFs). For retarded spark timings, pre-spark low-temperature heat release was found for low RON PRFs. Low RON PRFs also showed knocking characteristics before reaching the center of combustion suggesting that the use of knock-limited spark advance (KLSA) was preferred over the knock-limited combustion phasing. Primarily paraffinic fuels tended towards increased pressure oscillations while dominantly aromatic fuels experienced higher pressure rise rates. A MAPO-based KLSA correlated best to Octane Index at a negative K-factor suggesting beyond RON operation despite being at otherwise RON conditions. At stoichiometry, the MAPO-based KLSA did neither correlate to RON nor Octane Index. Good agreement was found between KLSA-based effective RON from this study to the MAPO-based effective RON from the first study.

Numerical investigation on the droplet entrainment from gas sheared liquid film of hydroxyl-terminated polybutadiene/paraffin fuels

Hydroxyl-terminated polybutadiene (HTPB)/paraffin fuels applied in hybrid rocket motors enjoy high regression rates and excellent mechanical properties; however, the special microscopic structure of the fuels leads to more complex droplet entrainment mechanisms. The two-dimensional heterogeneous HTPB/paraffin fuels geometry model was established by a dynamic packing algorithm. Dynamic evolution characteristics of a liquid film disturbed by the interaction between HTPB and paraffin were investigated by numerical calculation, and the controlling mechanism of droplet entrainment in a hot shear flow was explored. The results showed that the motion of high-strength HTPB fragments in the liquid film distorted the structure of interfacial wave and generated uncommon rough waves with an averaged wavelength of up to 9.05 mm, for the fuel containing 60 wt. % paraffin. Additionally, there were three pathways of droplet entrainment, i.e., rupturing of paraffin-coated HTPB filaments, splashing at the crest of paraffin wavelets, and the breakup of paraffin ligaments. However, periodic interfacial wavelets were generated for the fuel with a 30 wt. % content of paraffin due to the damping of HTPB, and most of the entrained droplets were generated when the exposed molten paraffin flowed to both ends of the fuel slab. The diameter of entrained droplets was in the range of 0.02–0.74 mm, and it was shown to be positively correlated with the paraffin content, the temperature of shear flow, and the mass flux of shear flow.

Measurement of the Autoignition Delay Time of Multi-Surrogate Paraffinic Fuel at Low-to-Intermediate Temperature Regime

Measurement of the Autoignition Delay Time of Multi-Surrogate Paraffinic Fuel at Low-to-Intermediate Temperature Regime

Performance of pure OME and various HVO–OME fuel blends as alternative fuels for a diesel engine

Since the potential for reducing CO2 emissions from fossil fuels is limited, suitable CO2-neutral fuels are required for applications which cannot reasonably be electrified, and therefore still rely on internal combustion engines in the future. Potential fuel candidates for CI engines are either paraffinic diesel fuels or new fuels like POMDME (polyoxymethylene dimethyl ether, short “OME”). Besides, also blends of these two types of fuels might be of interest. While many studies have been conducted on OME blends with fossil diesel fuel, the research on HVO–OME blends has been less extensive to date.In the current work, pure OME and HVO–OME blends are investigated in a single-cylinder research engine. The test results of the various fuel blend formulations are compared and evaluated, particularly with regard to soot-NOx trade-off behavior. The primary objective of the study is to examine whether the major potential of blending these two fuels is already largely exploited at low OME content, or if significant additional emission reduction potential can still be found with higher content blends, but still without the need to switch to pure OME operation. Furthermore, the fuel blend which is best suited for the realization of an ultra-low emission concept under the current technical conditions should be identified. In addition, three different injector designs were tested for operation on pure OME3-5, differing both in hydraulic flow and in the number of injection holes as well as their layout. The optimum configuration is evaluated with regard to emissions, normalized heat release and indicated efficiency.

Effects of Chemical Compositions and Cetane Number of Fischer–Tropsch Fuels on Diesel Engine Performance

Fischer–Tropsch synthetic (FT) fuels are expected to be an ideal alternative for diesel fuel to achieve higher thermal efficiency and reduction in exhaust emissions because of their characteristics of being aromatic-free, sulfur-free, and high cetane number. In this study, the effects of chemical compositions and cetane number of FT fuels on diesel engine performance were investigated by using a commercial GTL (Gas-to-Liquids) diesel fuel synthesized by the FT method and blended paraffinic hydrocarbon fuels made to simulate FT fuels with different chemical compositions and cetane numbers. At first, a commercial diesel fuel (JIS No.2) and GTL were examined by varying the intake oxygen concentrations with cooled EGR. Compared with diesel fuel, GTL shows shorter premixed combustion, smaller heat release peak, and longer diffusion combustion duration at both high and medium conditions due to the higher cetane number. Further, by using the GTL, a limited improvement in thermal efficiency and exhaust emission reduction of NOx have been obtained, but no significant reduction in the smoke emissions is achieved, even though FT fuels have been considered smokeless due to their aromatic-free characteristics. Next, three types of paraffinic hydrocarbon fuels with cetane numbers of 78, 57, and 38 were blended as simulated FT fuels and were examined under the same experimental apparatus and operation conditions. For the low cetane number simulated FT fuel (cetane number 38 fuel), the results show that the ignition delay and premixing period are significantly longer at low intake oxygen concentration conditions, meaning that the premixing of low cetane number fuel is more sufficient than other fuels, especially under the high EGR rate conditions, resulting in fewer smoke emissions. Furthermore, with CN38 fuel, an excellent indicated thermal efficiency was obtained at the high load condition. To summarize the results, the low cetane number FT fuel shows a potential to achieve higher thermal efficiency and reduction in exhaust emissions on commercial diesel engines with EGR.

Pollutant emissions from Euro 6 light duty vehicle tested under steady state and transient operation on a roller test bench with hydrogenated paraffinic and biodiesel fuels

The effort to implement more environmental-friendly fuels has been enhanced not only by the desire to reduce the greenhouse effects but also for public health issues. This paper studies the effects on pollutant emissions from a light-duty Euro 6 vehicle with four types of fuel: diesel (fossil origin, used as reference), biodiesel (renewable origin), Gas-to-Liquid (fossil origin) and farnesane (renewable origin). Both stationary engine and real-world driving cycles are studied. First, each fuel was tested in stationary modes in a vehicle test-bench and then tested in a realistic driving cycle with the same vehicle. This allows the separation the transient effects of the driving cycle from stationary results. Stationary tests lead to engine emission maps and driving cycle tests allow weighting the importance of each stationary condition during a realistic route. Instantaneous and cumulative CO, THC (total hydrocarbon), NOx and PN (particle number) emissions on route were obtained. The fuel that presented a highest level of emissions at stationary conditions was, for CO, diesel, for THC, diesel, for NOx, biodiesel and for PN, diesel. The behaviour of fuels during the driving cycles, from less pollutant to more pollutant, was: for CO, diesel, farnesane, GTL and biodiesel; for THC, GTL, farnesane, biodiesel, diesel. For NOx, farnesane and diesel (very similar values), GTL and biodiesel; for PN, GTL, biodiesel, farnesane and diesel.

Boundary layer combustion of paraffin fuels for hybrid propulsion applications

Droplet entrainment offers paraffin fuels a regression rate of 3–4 times higher than classical polymer fuels, which is favorable for the hybrid rocket motor, however, the heterogeneous combustion reactions between droplets and oxidizer lead to a more complicated combustion mechanism. Combustion diagnosis was carried out for paraffin fuels combusted in a windowed 2D slab burner, and the boundary layer combustion was investigated by using high speed camera and schlieren in this study. The results showed that the presence of remarkable periodic flame and chamber pressure oscillation was due to the periodic accumulation and breakdown of liquid film layer; Kelvin−Helmholtz instability was a necessary but not the sufficient condition for droplet entrainment, and the critical oxidizer mass flux of Kelvin−Helmholtz instability and droplet entrainment was about 12.31 kg m−2 s−1 and 30.15 kg m−2 s−1; the thickness of turbulent boundary layer and the height of combustion flame were inversely correlated with the oxidizer mass flux, indicating the more efficient combustion under higher oxidizer mass flux; the entrainment droplets disappeared at elevated chamber pressures due to the inhibition of Kelvin−Helmholtz instability, meanwhile, the thickness of turbulent boundary layer was found to increase; entrainment droplets increased and the height of combustion flame decreased due to the acceleration of combustion reactions when the copper chromite was used as the combustion catalyst, which favored the enhancement of the regression rate of fuels and the combustion efficiency of hybrid rocket motors.

Particle emissions of a heavy-duty engine fueled with polyoxymethylene dimethyl ethers (OME)

OME as sustainable alternative diesel fuel burns without the agglomeration of soot particles which is the case for fossil and paraffinic diesel fuels. Nuclei mode particles are mainly of a volatile nature and do not survive exhaust aftertreatment.

Pollutant Emissions from Euro 6 Light Duty Vehicle Tested Under Steady State and Transient Operation on a Roller Test Bench with Hydrogenated Paraffinic and Biodiesel Fuels

Pollutant Emissions from Euro 6 Light Duty Vehicle Tested Under Steady State and Transient Operation on a Roller Test Bench with Hydrogenated Paraffinic and Biodiesel Fuels

Expandable graphite effect on solid fuel and propellant combustion

This paper presents an investigation on a novel method for manipulating and enhancing the burning of solid fuels and propellants by expandable graphite additive. Expandable graphite (EG) is a form of intercalated graphite. At elevated temperature it undergoes an increase in volume, forming elongated strings/fibers many folds longer than the original particles/flakes. It was found experimentally that the addition of 1-5% of expandable graphite (original particle size 100-150 micrometer, onset of expansion at 200-230°C) to a polymeric fuel matrix (polyester) in hybrid combustion, increased the fuel regression rate by 2 fold and more. It was hypothesized that the EG strings forming near the burning surface protrude into the hot gas environment increasing heat transfer into the fuel via conduction. Furthermore, the swelling effect at the surface layer might increase the effective surface area, hence further increasing the burning rate. High-speed photography of a surface subjected to flame in oxidizing atmosphere showed EG fibers protruding and growing on the surface, supporting the increased heat transfer hypothesis. On the other hand, the addition of the same EG to an ammonium perchlorate-based propellant showed a tendency to reduce burning rate and even extinguish the flame at EG fractions higher than about 3-5%. It is concluded that in the case of hybrid or solid fuel ramjet combustion, EG can serve as a novel and effective burning rate enhancer while employing polymeric fuels of good mechanical properties in contrast to paraffin fuels which have inferior mechanical properties. The influence of EG on the combustion of solid propellants needs further investigation, looking for combinations of EG and propellant types that may exhibit a similar effect.

Low-Emission Alternative Energy for Transport in the EU: State of Play of Research and Innovation

The 2030 Climate target plan of the European Commission (EC) establishes a greenhouse gases (GHG) emissions reduction target of at least 55% by 2030, compared to 1990. It highlights that all transport modes—road, rail, aviation and waterborne—will have to contribute to this aim. A smart combination of vehicle/vessel/aircraft efficiency improvements, as well as fuel mix changes, are among the measures that can reduce GHG emissions, reducing at the same time noise pollution and improving air quality. This research provides a comprehensive analysis of recent research and innovation in low-emission alternative energy for transport (excluding hydrogen) in selected European Union (EU)-funded projects. It considers the latest developments in the field, identifying relevant researched technologies by fuel type and their development phase. The results show that liquefied natural gas (LNG) refueling stations, followed by biofuels for road transport and alternative aviation fuels, are among the researched technologies with the highest investments. Methane-based fuels (e.g., compressed natural gas (CNG), LNG) have received the greatest attention concerning the number of projects and the level of funding. By contrast, liquefied petroleum gas (LPG) only has four ongoing projects. Alcohols, esters and ethers, and synthetic paraffinic and aromatic fuels (SPF) are in between. So far, road transport has the highest use of alternative fuels in the transport sector. Despite the financial support from the EU, advances have yet to materialize, suggesting that EU transport decarbonization policies should not consider a radical or sudden change, and therefore, transition periods are critical. It is also noteworthy that there is no silver bullet solution to decarbonization and thus the right use of the various alternative fuels available will be key.

Production Cost and Carbon Footprint of Biomass-Derived Dimethylcyclooctane as a High-Performance Jet Fuel Blendstock

Near-term decarbonization of aviation requires energy-dense, renewable liquid fuels. Biomass-derived 1,4-dimethylcyclooctane (DMCO), a cyclic alkane with a volumetric net heat of combustion up to 9.2% higher than Jet A, has the potential to serve as a low-carbon, high-performance jet fuel blendstock that may enable paraffinic bio-jet fuels to operate without aromatic compounds. DMCO can be produced from bio-derived isoprenol (3-methyl-3-buten-1-ol) through a multistep upgrading process. This study presents detailed process configurations for DMCO production to estimate the minimum selling price and life-cycle greenhouse gas (GHG) footprint considering three different hydrogenation catalysts and two bioconversion pathways. The platinum-based catalyst offers the lowest production cost and GHG footprint of $9.0/L-Jet-Aeq and 61.4 gCO2e/MJ, given the current state of technology. However, when the supply chain and process are optimized, hydrogenation with a Raney nickel catalyst is preferable, resulting in a $1.5/L-Jet-Aeq cost and 18.3 gCO2e/MJ GHG footprint if biomass sorghum is the feedstock. This price point requires dramatic improvements, including 28 metric-ton/ha sorghum yield and 95–98% of the theoretical maximum conversion of biomass-to-sugars, sugars-to-isoprenol, isoprenol-to-isoprene, and isoprene-to-DMCO. Because increased gravimetric energy density of jet fuels translates to reduced aircraft weight, DMCO also has the potential to improve aircraft efficiency, particularly on long-haul flights.

Regression rate performance of paraffin wax and bees wax –Gox with varied grain configuration in a hybrid rocket motor

Purpose This paper aims to determine the regression rate using wax fuels for three different grain configurations and find a suitable grain port design for hybrid rocket application. Design/methodology/approach The design methodology of this work includes different grain port designs and subsequent selection of solid fuels for a suitable hybrid rocket application. A square, a cylindrical and a five-point star grained were designed and prepared using paraffin and beeswax fuels. They were tested in a laboratory-scale rocket with gaseous oxygen to study the effectiveness of solid fuels on these grain structures. The regression rate by static fire testing of these wax fuels was analyzed. Findings Beeswax performance is better than that of paraffin wax fuel for all three designs, and the five-slotted star fuel port grain attained the best performance. Beeswax fuel attained an average regression rate ≈of 1.35 mm/s as a function of oxidizer mass flux Gox ≈ 111.8 kg/m2 s and for paraffin wax 1.199 mm/s at Gox ≈ 121 kg/m2 s with gaseous oxygen. The local regression rates of fuels increased in the range of 0.93–1.194 mm/s at oxidizer mass flux range of 98–131 kg/m2 s for cylindrical grain, 0.99–1.21 mm/s at oxidizer mass flux range of 96–129 kg/m2s for square grain and 1.12–1.35 mm/s at oxidizer mass flux range of 91–126 kg/m2 s for a star grain. A complete set of the regression rate formulas is obtained for all three-grain designs as a function of oxidizer flux rate. Research limitations/implications The experiment has been performed for a lower chamber pressure up to 10 bar. Originality/value Different grain configurations were designed according to the required dimension of the combustion chamber, injector and exhaust nozzle of the design of a lab-scale hybrid rocket, and input parameters were selected and analyzed.

Experimental characterization of GTL, HVO, and OME based alternative fuels for diesel engines

A promising way to reduce the environmental impact of compression ignition engines is represented by alternative fuels. These can be advantageous regarding both CO2 intensity and/or because of favourable combustion and emission characteristics. In the present study, eight fuels were tested experimentally. Conventional diesel was used as reference fuel. GTL and HVO were tested neat and blended with diesel at 20 vol%. 7 vol% and 15 vol% OME in diesel were tested as well. Finally a blend of 18 vol% OME in HVO was also investigated. This last blend, called R100, represents a potentially fully renewable fuel compliant with the EN590 standard regarding viscosity and density. The combustion and emissions behaviour of the test fuels were investigated in order to find distinguishing features. All the alternative fuels improve the emissions of soot and NOx. Oxygenated fuels were found to mix faster with air while the behaviour of the paraffinic fuels depends on their molecular length.

SINTETIK YOQILG’ILARNING EKOLOGIK HOLATIDAN KELIB CHIQQAN HOLDA BUGUNGI KUN TALABI

The article discusses the possibilities of solving the problem of using connected petroleum gas using GTL technologies. The most important difference between hydrocarbon products of Fisher-Tropsh synthesis and petroleum products is that they do not contain sulfur, nitrogen, and in some cases aromatic compounds, which determines their environmental importance. Synthetic oil is a mixture of normal and isostrotic hydrocarbons C5-C19used for processing in paraffin and motor fuels, as a rawmaterial for the chemical and petrochemical industries, or as a commercial product.Key words:synthesis gas, utilization, GTL technologies, Euro-5, synthetic fuel, reactor, torch, catalyst

Applying the handprint approach to assess the air pollutant reduction potential of paraffinic renewable diesel fuel in the car fleet of the city of Helsinki

Abstract Ambient air pollution is a global environmental challenge, especially in densely populated regions. In urban areas, road traffic is an important source of fine particulate matter (PM2.5) and nitrogen oxide (NOx) emissions, primarily due to exhaust gases. The adoption of paraffinic renewable diesel fuels for urban transportation has been suggested as a more sustainable and less air polluting alternative to conventional fossil fuels. The aim of this study is, therefore, to examine whether the transition from the conventional fossil fuel diesel to paraffinic renewable diesel (hydrotreated vegetable oil [HVO] according to the EN 15940 standard) can reduce PM2.5 and NOx emissions in an urban environment. The life cycle assessment-based handprint approach is utilized to calculate and demonstrate the emissions reduction. The reduction potential is quantified for Euro 4, 5 and 6 passenger diesel cars using actual car fleet, mileage, local temperature, and laboratory emissions measurements for 2018 in Helsinki, Finland. Our study shows that the use of HVO can reduce PM2.5 and NOx emissions in urban areas. According to our results, PM2.5 emissions could be reduced by 49% for the defined location and car fleet by replacing conventional fossil-fuel diesel with HVO. In the case of NOx emissions, the local reduction potential is 7%. Overall life cycle emissions reduction potentials of NOx and PM2.5 emissions are 11% and 44%, respectively, if conventional diesel is replaced by HVO. Thus, the manufacturer of HVO can communicate the air quality handprint, and in particular, the NOx and PM2.5 handprints, that their product can achieve.

Characteristics of Low Temperature Diesel Combustion with Paraffinic Hydrocarbon Fuels

Characteristics of Low Temperature Diesel Combustion with Paraffinic Hydrocarbon Fuels