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[Display omitted] • A new geothermal-solar energy based multigeneration system is proposed. • Energy and exergy approaches are used to carry out thermodynamic assessment. • Transient analysis is performed to better understand the effect of each parameter on each component's performance. • Multigeneration system developed for producing power, hydrogen, hot water, cooling and oleic acid. • Cost analysis for components of the system investigated. This study designs and develops an innovative multigenerational integrated solar-geothermal system that seeks to address a wide range of energy needs, including power generation, cooling, hot water production, oleic acid synthesis, biomass production, and hydrogen production. The examination of energy and exergy is conducted to demonstrate the system's performance. A parametric study investigation is undertaken to examine the impact of operating circumstances and environmental parameters on the efficiency of the system. According to the energy study, the multigeneration system has an energy efficiency of 11%. The analysis of exergy provides significant insights into the system's functioning, indicating an exergy efficiency of 26.5%. The energy and exergy efficiencies of the organic Rankine cycle are obtained to be 21.14% and 18.07%, respectively. The energy efficiencies of the primary subsystems, such as steam Rankine cycle, organic Rankine cycle, gasification unit and electrolyzer unit, are found to be 21.14%, 18.5%, 37.42%, and 61.1%, respectively. The cost rate of the overall system is then calculated to be 123.3$/h while it is 31.3$/h for the parabolic trough collectors. [ABSTRACT FROM AUTHOR]

• Gasoline, methane and propane are blended with hydrogen up to 20%vol. • A dual-fuel carburettor is included in the engine of a commercial power generator. • Methane/hydrogen blends show better performance in terms of emissions. • A 20% hydrogen compensates the power reduction with methane. This experimental work explores the use of hydrogen blends with gasoline, methane, and propane in power generators. A commercial gasoline engine-driven stationary power generator with a capacity of 3.65 kW is utilized during the tests. A dual-fuel carburetor is included in the engine to adjust the desired fuel mixture after a set of modifications. Gasoline, methane, and propane are then blended volumetrically with hydrogen with the ratios of 5 %, 10 %, 15 %, and 20 %. The tests with 100 % gasoline, methane, and propane are also conducted to make a proper comparison. The power output of the generator, temperature at the cylinder exit, and exhaust gases are experimentally tested, and the obtained measurements are then analyzed. The results reveal that increasing hydrogen content up to 20 % significantly has reduced CO 2 emissions by 42.8 % for gasoline, 46.9 % for propane, and 37.7 % for methane, while also reducing CO emissions by 44.8 %, 50 %, and 40 % for gasoline, propane, and methane, respectively. However, NO x emissions tend to increase significantly with hydrogen addition, particularly for propane (186.3 % increase) and methane (154.8 % increase). The power output of the generator and efficiency generally improved, with propane showing the highest increase in power (10 %) and methane exhibiting the most significant gain in efficiency (reaching parity with gasoline at 20 % hydrogen). With increasing hydrogen content, the operating cost per hour has decreased for all fuel types. [ABSTRACT FROM AUTHOR]

This review focuses on recent developments in catalytic cracking of waste polyolefins using zeolite-based catalysts. The effects of acidity, pore structure, and modification of different zeolites on catalytic cracking are discussed in each section. Additionally, the influence of various reaction parameters such as temperature, pressure, solvents, pre-mixing and blending with oils and residue are critically evaluated. Finally, the catalytic cracking mechanism and coke formation are discussed. [Display omitted] • Waste polyolefins can be converted into fuels using chemical pyrolysis methods. • Different pore sizes, and modified zeolites explored in the PO catalytic cracking. • Nano-zeolites exhibit superior catalytic activity and control product distribution. • Effects of different reaction parameters on catalytic cracking are being discussed. Plastics are deeply integrated into human life in various forms, especially in household applications and the food industry. The production of plastic has increased due to rising demand and population growth. Unfortunately, less than 10 % of plastic is recycled after use. The remainder is either disposed of in landfills, bodies of water, or incinerated. Among the various methods of recycling, catalytic cracking is particularly important because it produces fuel, which is in high demand, further reducing energy consumption and controlling product distribution. This review focuses on the catalytic cracking of polyethylene and propylene using a wide range of zeolites, demonstrating that the product distributions is highly dependent upon the nature of zeolites including pore size, acidity, composition, and morphology. Additionally, the review briefly discusses the various parameters that influence cracking and the reaction mechanism. Each section was critically evaluated, highlighting the recent research progress in this field. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel biomass gasification-based integrated plant is proposed. • Detailed thermodynamic and cost assessments for better design are performed. • Both energy and exergy efficiencies for the integrated plant are evaluated. • A study on exergoeconomic optimization of this plant is conducted. • An average cost of hydrogen is found to be 3.912 $/kg using the proposed system. Due to increased levels of local and global environmental concerns and energy problems, there is a strong need for alternative, clean, safe and cheap energy sources. Besides, there is an additional need that energy sources should be treated more efficiently and effectively. This may include optimizing energy conversion processes to maximize useful outputs and minimize losses, improving storage capacities to ensure a reliable and continuous supply, and integrating resilient grid systems to manage distribution more effectively. Advances in energy efficiency also involve developing materials and technologies that enhance the performance of renewable energy systems, such as high-efficiency solar panels, advanced wind turbine designs, and more efficient biomass conversion techniques. Biomass has been selected as a unique energy source for the present integrated energy plant. Likewise, an efficient plant type, multigeneration, is offered for biomass sources. This work uses a new biomass gasification-based multigenerational plant for power, hydrogen, ammonia, fresh water, and cooling production. The biomass gasification system, Brayton plant, Rankine cycle, freshwater production plant, hydrogen production and storage system, ammonia production system, Kalina plant, and single-effect absorption cooling system are integrated effectively to achieve these goals. Unlike previous studies, the present biomass-gasification-based multigeneration system proposed in this research stands out in terms of its components and products. The system is thoroughly examined through thermodynamic and economic analyses, as well as parametric investigations. To validate the study's findings, some comparisons are made with the study results drawn from the relevant literature. The results reveal that both energetic and exergetic analyses of the multigeneration plant yield efficiencies of 70.92 % energetically and 68.87 % exergetically. The overall exergy destruction rate of the proposed system is calculated as 28143 kW, underscoring the novelty and potential of this innovative approach. [ABSTRACT FROM AUTHOR]

• Ammonia is a carbon-free fuel that can act as hydrogen storage carrier etc. • Advancement in the integrated ammonia synthesis and separation were signposted. • The emission profile of ammonia-hydrogen and ammonia-methane blends were articulated. • TEA of ammonia production plant and challenges were discussed. • The contribution of green NH 3 to the hydrogen 2.0 economy was presented. Increased concerns about fossil fuel dependence have urged researchers to explore alternative and green fuels to pave the platform for a carbon-free economy. Among the renewable fuels, carbon-free fuels have recently received much interest in decarbonizing the energy sector. In this regard, ammonia is considered to be a potential hydrogen and energy storage vector as it is a carbon-free fuel with a higher energy density. However, technical and economic hurdles prevent ammonia from entering the energy market. Therefore, the current review summarizes the recent technologies and strategies involved in the integrated ammonia synthesis and separation from various sources that can further act as a hydrogen carrier for the decarbonization of the energy sector. Additionally, the emission profile of ammonia-hydrogen blends and ammonia-methane blends and the techno-economic analysis of ammonia production, along with challenges, were presented in detail. The techno-economic analysis suggested that the integrated cost of ammonia synthesis, including equipment, manpower, and other costs, can be analyzed before setting up the ammonia synthesis plant to avoid additional costs. The last section provides a discussion on ammonia for the Hydrogen 2.0 economy. [ABSTRACT FROM AUTHOR]

• The temperature field in the bird's nest area of blast furnace tuyere is characterized. • The phase composition of coal-coke-slag is quantitatively characterized. • The radial physicochemical properties of coal-coke-slag are analyzed. • Modification suggestions of coal-coke-slag are proposed. Understanding the occurrence of phases and the evolution of physicochemical properties in coal-coke-slag powder within the blast furnace tuyere's bird's nest area is crucial for reducing carbon emissions and energy consumption in the blast furnace. By dissecting a 2200 m3 blast furnace in China, the temperature field and high-temperature physicochemical properties of coal-coke-slag powder in the tuyere bird's nest area along the radial direction were determined. Firstly, the temperature range in the tuyere bird's nest area spanned from 1523 °C to 1709 °C, with the maximum temperature near the end of the bird's nest area. Secondly, the mass proportions of coal, coke and slag in coal-coke-slag powder were 42.16 %, 25.90 % and 31.94 %, respectively. Along the radial direction of the blast furnace, the degree of graphitization of carbon components of coal-coke-slag increased gradually, and the melting temperature and viscosity of the slag phase also exhibited a gradual increase. Finally, the modification suggestions of the physicochemical properties of coal-coke-slag were put forward, with a focus on three factors: fuel, slag, and temperature. By employing tuyere injection operations with Ca-Fe flux, and using fuel with low ash content, larger particle size, fewer harmful elements, and excellent combustion performance, more heat input was provided to the front of the bird's nest area, which contributed to improved furnace efficiency and performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • An eco-friendly sample preparation procedure stands out for its minimal solvent usage. • Accurate non-destructive sample preparation can be applied to petrochemical samples. • Pareto's chart and the Doehlert matrix are helpful for optimizing RP-DLLME conditions. • The proposal not only saves time but can also be effectively applied to routine analyses. This study describe the development and first application of reverse-phase dispersive liquid–liquid microextraction (RP-DLLME) sample preparation for the determination of Ca, Cd, Cu, Fe, K, Mg, Mn, Ni, Pb, and Zn in petroleum-derived samples using inductively coupled plasma optical emission spectroscopy (ICP OES). Some factors inherent to RP-DLLME were optimized using multivariate statistical analysis through the 24 full factorial design followed by the Doehlert matrix. The established RP-DLLME procedure employs 5.0 g of samples, 1600 µL of the 3.75% (v/v) HNO 3 :isopropyl alcohol [3:1 (v/v)] extractive solution, 10 min of thermostatic bath at 80 °C, 60 s of vortexing, 3 min of sonication at 55 °C, and 15 min of centrifugation at 3500 rpm. The resulting aqueous phase volume was adjusted up to 15 mL with ultrapure water, and ICP OES carried out the measurements. Relative standard deviations (RSD) less than 3.5%, linear correlation coefficients better than 0.9985, and limit of detection (LOD) in the range of 0.57 ng g−1 (Mn) to 107.6 ng g−1 (K) were obtained for the determination of the analytes. Accuracy of the RP-DLLME using ICP OES was evaluated by analysis of the V21 + K metallo-organic standard, and recovery percentages within the 89.4–98.3% interval with RSD less than 6.4% were obtained. The accuracy and precision were also evaluated through a recovery test, and the results were in the range of 87.1–95.7% with RSD less than 4.9% for all analytes. Therefore, the RP-DLLME-ICP OES methodology was successfully applied to gasoline, diesel oil, JET-A1 (jet fuel), Avgas (aviation gasoline), lubricant oil, and vaseline samples, and the contents were obtained for almost all analytes. Although there are no regulatory resolutions for all petroleum-derived samples, the content of the analytes determined in JET-A1 and Avgas samples complied with ANP Resolution No. 856/2021 and 901/2022 legislation, respectively. Furthermore, the relative simplicity of the RP-DLLME combined with the accurate and precise measurements carried out by ICP OES can be a viable alternative in routine analysis. [ABSTRACT FROM AUTHOR]

• Amongst several advanced renewable fuels, ethanol is highlighted for its CO 2 abatement capacity through its low carbon index and high RON. • For turbulent engines, fuel E40, simulation over WLTC driving cycle allows a large range of operating point at higher efficiency. • CO 2 emissions gain vary from 2 to 15 % g/h over the operating range. • Combining high RON and higher laminar flame speed fuels with maximised engine turbulence could aggravate heat transfer, resulting in lower thermal efficiency. Despite the increasing efforts to electrify the transport sector, discussions remain on the interest of renewable and low-carbon fuels as an alternative solution to mitigate the impact on GHG. This work assesses the influence of liquid fuels' properties on engine-out GHG emissions through the optimisation of both thermal efficiency and fuel's carbon index, combined with highly efficient turbulent combustion chamber architecture, in an aim to maximise gains. The study helps underline the limitations and advantages associated to high efficiency fuels for spark-ignited combustion systems when applied to advance architectures. Limitations to the combination of such strategies have been observed, not commonly presented in previous studies. Indeed, the beneficial impact of optimised fuel properties on peak efficiency could be compromised when applied to high efficiency turbulent engines as their combination can aggravate heat transfer losses. Moreover, the fuel's capacity to increase the maximal dilution rate could depend on the engine's architecture. Despite these results, low-carbon fuels remain relevant to accelerate the decarbonisation of the transport sector due to benefits at higher load and a fuel's lower carbon emissions. However, the importance of the synergetic optimisation of low carbon fuel formulation's and combustion system's design is underlined for more advanced technologies. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of soot inception and condensation polycyclic aromatic hydrocarbon (PAH) species and fuel preheating on soot prediction in 2D coflow laminar CH 4 /air diffusion flames doped with vaporized gasoline surrogate fuels, i.e., n- heptane/toluene mixtures. To evaluate the importance of considering multiple PAHs in soot inception and condensation and fuel pyrolysis near fuel tube outlet in the prediction of soot distribution along the flame centerline, the pyrene-based soot inception and PAH condensation model was improved by considering multi-PAH (A 2 , A 2 R 5 , A 3 C 2 H, A 4 , BGHIF) as nucleation and condensation species. The fuel preheating effect upstream the fuel tube exit was taken into account. Inclusion of multiple PAHs in soot inception and condensation leads to greatly enhanced soot formation along the flame centerline region due to enhanced soot inception and surface growth via PAH condensation. As a result of soot inception through smaller PAH (A 2), soot appears at a lower flame height above the burner exit than experiments. The fuel preheating effect causes significantly higher fuel stream temperatures in the near burner wall region and appreciable fuel pyrolysis. Soot inception is further enhanced by the fuel preheating effect and soot appears at an even lower height above the burner exit with a reduced flame height. This study demonstrated that both multi-PAH coagulation and fuel preheating strengthen soot inception and improve the predicted soot volume fractions along the flame centerline, but they are still insufficient to achieve good agreement with available experiments. Plausible ways to further improve the soot model are discussed. [ABSTRACT FROM AUTHOR]

• A reduced model of PM index linking gasoline properties to PM emissions from was developed. • Distillating parameters of T90 and T70 are crucial fuel properties affecting PM emissions. • The reduced PM index was verified by mathematical analysis and comprehensive tests. Particulate matter (PM) emissions have become an increasingly noticeable concern for gasoline vehicles, especially for gasoline direct injection (GDI) one. The PM index (PMI) model developed by Aikiwa et al. provides an effective model linking the fuel properties to the PM emissions from gasoline vehicles. In this study, a more practical reduced PM index (RPMI) was developed based on the detailed analysis of 22 fuels with various physical properties and chemical compositions. Two approaches of statistical mathematics of correlation analysis and multivariate linear regression (MLR) were adopted in the modeling process. The RPMI involving two global fuel properties of T90 (distillation temperature of 90% by volume) and T70 (distillation temperature of 70% by volume) was tested to be statistically valid. In addition, the model was verified through the engine bench tests and the vehicle emissions tests. The results reveal that the RPMI showed good correlations to the engine-out particle number (PN) emissions under all of the typical test conditions, including PFI (port fuel injection) mode, GDI (gasoline direct injection) mode and compound injection (PFI + GDI) mode. In addition, the RPMI demonstrated a significantly high correlation to vehicle-out PN emissions over the New European Driving Cycle (NEDC) with the determination coefficient R2 = 0.947. Moreover, a moderate correlation (R2 = 0.801) of the index to the filter PM mass emissions was observed. In the light of no additional components analysis is needed except for the legitimate tests of fuels, the RPMI has the potential to be a useful tool for original equipment manufacturers (OEMs) and environmental certification departments to expediently evaluate the fuel effect on PM emissions. [ABSTRACT FROM AUTHOR]

• Particle image velocimetry was used to compare the computational results. • Effect of CH 4 /H 2 /CO syngas compositions with swirl combinations was investigated. • Effect of flame structure on NO x and CO emissions characteristics was performed. • Optimal operating procedure was observed during fuel changeover section. In an integrated gasification combined cycle (IGCC) power plant, the initial operating procedure is driven by natural gas first, and then by H 2 /CO syngas. This study attempted to find the optimal operating procedure in the fuel changeover section, such as from natural gas to syngas. Therefore, the influences of various swirl combinations and syngas compositions on flame structures and NO x and CO emissions characteristics were investigated through experimental and numerical analyses in a partially premixed dual swirl combustor. To observe the various flame structures, such as lifted, tubular, and attached flames, the two-dimensional particle image velocimetry (PIV) technique was applied and compared with the results obtained by computational fluid dynamics (CFD). The combustion characteristics of co– and counter-swirling flames were observed, and the optimal swirl combination was subsequently confirmed by using the parameter of modified unmixedness. When the flame shape and fuel and air mixing efficiency are considered, S co, 1.3/1.46 condition is the optimal swirl combination for stable conversion of the syngas fuel. In addition, the operating parts with a methane content of 25% and a hydrogen content of 75% are considered to be avoided in the operating part of fuel changeover. The operating part of fuel changeover can be divided into 10 paths for stable syngas operation. The optimal operating procedure to control the content of hydrogen and carbon monoxide after the syngas operation with the Path No. 2, such as H 2 = 25% and CO = 75%. [ABSTRACT FROM AUTHOR]

• A broad variety of seven different fuels are ashed at 200, 450, and 815 °C. • Distribution of the ash species depends on type of fuel and it specific origin. • Fuel and particle properties determine the residual carbon in low temperature ash. • The distribution of the ash species affects alkali release and ash fusion behavior. In the present study, seven different fuels – comprising three coals (hard coal, two brown coals), two contaminated biomasses/anthropogenic wastes (refuse-derived fuel/RDF, sewage sludge), and two biomasses (oat husks, bamboo) – are investigated. A complete fuel analysis as well as a determination of the particle size distributions of all ground feedstocks are performed prior to ashing. Ashes of these fuels are generated with the aid of different ashing methods and related temperatures, i.e. a plasma-assisted low temperature ash (LTA) at around 200 °C, a medium temperature ash (MTA) at 450 °C, and a high temperature ash (HTA) at 815 °C. By SEM/EDX analysis, distinct differences in the distribution of ash species based on selected main elements in LTA ash of all fuels are detected. The ash particles generated by the LTA method illustrate both origin and distribution of ash species in the particles close to the initial state due to a comparably low temperature. For this method, the achieved carbon conversion can be directly related to specific fuel and particle properties. A selective release of alkali oxides (K 2 O, Na 2 O) into the gas phase due to vaporization is monitored as a function of ashing temperature. Thus, the presence or absence of a gas phase transfer of the alkali oxides is concluded based on the formation of mineral phases incorporating those species and the requirement of a homogeneous distribution of the alkali capturers. Finally, distinct changes are observed in the ash fusion behavior of the different fuels based on different ashing temperatures, element distribution, and the applied atmosphere, which have represented different thermochemical conversion techniques. [ABSTRACT FROM AUTHOR]

• Power level was a major parameter in affecting performance of torrefied products. • Dielectric materials and particle size affect significantly heating rate. • 150 to 250 W was sufficient to produce a good quality torrefied products. • Clean-products derived from microwave heating technique can be obtained. • Dedicated operating conditions in MW heating resulted in high EROI (6.1 to 34). Microwave (MW) heating offers numerous advantages over conventional heating. Its characteristics of fast internal heating, volumetric heating, and low energy consumption enable microwave torrefaction (MWT) of biomass to be performed. The purpose of this article is to review the current state of MWT of biomass. A brief explanation of MWT, including experimental setups and the effects of several important parameters, are reviewed and discussed. Potential future directions and challenges regarding MWT are also discussed. It is known that the MW power level, types of MW absorbers (catalyst), and particle size can significantly influence the performance of torrefied biomass in terms of energy and mass yields, mass loss, H/C and O/C ratios, fuel ratio, and high heating value. The effect of operating condition on products derived from MWT needs to be further investigated in order to make the technology feasible and reliable. Overall, MWT has the potential to serve as energy-efficient method to improve the performance of biomass. [ABSTRACT FROM AUTHOR]

Gasoline Direct Injection (GDI) engines equipped with a turbocharger or supercharger (known as boosted engines) have achieved significant market penetration due to their advantages in reducing CO 2 emissions compared to Port Fuel Injection (PFI) engines. These engines are known to emit particulate matter and recent studies have characterized these emissions. Fuel composition is known to have an impact on Particle Number (PN) emissions from GDI engines, however its effect on emissions from highly boosted engines is not known. In this work, 10 different fuels have been tested on an extremely highly boosted engine (at up to 35 bar BMEP) at several different operating conditions both unboosted and boosted and the PN emissions and size distributions have been measured using a Cambustion DMS500. The applicability of three previously developed indices linking fuel composition to PN emissions is tested with the results from these fuels. The results show that the PM index is a good predictor of PN emissions from this engine for all fuels at all operating points (unboosted and boosted). The Moriya and PN indices predict the PN emissions using fuels that are market representative, but are poor predictors of PN emissions over all of the fuels tested. Very small accumulation mode particle sizes of around 30 nm have been noted from all fuels at boosted conditions, which has relevance to future legislation and after treatment. [ABSTRACT FROM AUTHOR]

• Deflagration flame always occurs beyond the original premixed fuel zone. • Explosion state has significant effect on the flame area. • Higher explosion intensity will shorten the flame area. • Length of flame area is 1–2 times as long as original premixed fuel zone. Explosions are a major type of accident resulting in casualties in the processing industry. Fires frequently occur after a gas explosion. The attenuation rule of the deflagration state beyond the original premixed gas fuel area is the basis for determining the hazard risk once a gas explosion occurs. In this study, a numerical simulation was conducted using a finite element computational code for the fluid dynamics to reveal the attenuation law of the deflagration process of hydrogen–air mixtures in a tube 10 m long with a 0.1 m × 0.1 m sized section with one end closed and the other end open. The combustion characteristics beyond the original premixed hydrogen–air mixture region were examined. The numerical method was verified and its results showed good agreement with the experimental results. It was found that the fuel region can extend and enlarge the area of the flame, and thus a flame beyond the original fuel occupied zone can clearly be seen, which can expand the area of the damage. The explosion state inside the premixed region has a significant effect on the flame area, and a higher explosion strength will shorten the explosion time and reduce the disturbance of the unburned fuel. It was also found that a fuel-rich mixture has a larger flame area beyond the original premixed hydrogen–air mixture. Under all conditions considered in this study, the flame in the hydrogen–air mixture is 1–2 times as long as the one in the hydrogen–air mixture in the initially occupied area. [ABSTRACT FROM AUTHOR]

• Properties of large methyl esters can be predicted by small molecule fuels. • Species profiles of large methyl esters have been measured in a flow reactor. • Performance of surrogates has been validated by oxidation and ignition data. Biodiesel contains large methyl esters including methyl palmitate (MP), methyl oleate (MO), methyl linoleate (ML), etc. Long alkyl chains and asymmetric structures of these large methyl esters lead to complexity in development of kinetic models. In this paper, surrogate fuels for large methyl esters were proposed and developed. Surrogate models can be used to replace the detailed mechanisms of large methyl esters in prediction of oxidation and autoignition properties. Key characteristics in combustion have non-linear relationships with fuel components in a neural network diagram, which indicates that surrogates with the same functional groups can exhibit similar combustion properties as large methyl esters. In formulation of surrogate fuels, candidates consist of small species such as methyl decanoate, n-hexadecane, methyl trans-3-hexenoate, and 1, 4-hexadiene. To compare the oxidation properties, point-to-point experimental validations were conducted in laminar flow reactor. Oxidation properties of surrogate and target fuels were in satisfactory agreements. Surrogate fuels not only successfully captured the discrepancies in reactivity of different methyl esters, but also reproduced species concentrations of intermediate and products at various equivalence ratios. To test the performance in predicting autoignition characteristics, simulations based on surrogate models were compared with previous experimental data. Surrogate models not only predicted ignition delay times at various pressure and equivalence ratios, but also reproduced the trends of apparent activated energy under different conditions. To sum up, oxidation and autoignition characteristics of large methyl esters can be predicted by the combined kinetic model of small molecule compounds, which will have great potentials in the development of kinetic models for fuels with complicated molecular structures. [ABSTRACT FROM AUTHOR]

• Lignocellulose conversion via various technologies has documented. • Influencing parameters of each pathway were analyzed and discussed. • Integrative approaches towards bioenergy production has been proposed. • Perspective of lignocellulosic biorefinery has been recommended. In this review, the conversion (thermochemical, biological and hybrid) of chemical energy chiefly enclosed in biomass structures i.e. as 30–50% cellulose, 15–35% hemicellulose and 10–20% lignin into various forms of fuels/energy products is comparatively analyzed. Cellulose and hemicelluloses formulate almost ∼70% of the biomass and are definitely linked to the lignin structural units all the way through covalent and hydrogenic bonds; thereby, the structure formulated is tremendously rigid and resistive against processing. Hence, the vital confront towards the conversion of lignocellulosic biomass into important bio-yields via biorefining is to overcome this obstacle. This article gives an outlook over the major conversion technologies to produce biofuels from lignocellulosic biomass feedstock, by focusing on their typical performances. The core points outlined and argued will be the currently positioned pathways, utilizing the lignocellulosic materials to produce (bio) fuels, prospect on biomass supplies, and discussion on the impact of sustainability criteria, main influencing factors and uncertainties. [ABSTRACT FROM AUTHOR]

• Under non-evaporation condition, high ambient increases the fuel adhesion mass, area and average thickness by decelerating the droplets. • Under evaporation condition, the high ambient pressure inhibits the evaporation of the fuel to a certain degree is another reason for the increased fuel adhesion on the wall. • High ambient pressure improves the uniformity of the adhesion on the wall. The formation of the fuel adhesion on the wall is demonstrated as the major cause for the efficiency loss and particle number (PN) emission increase in direct-injection spark-ignition (DISI) engines, making it difficult to meet the regulation of the future standards. In this study, experiments were performed in a constant high-pressure chamber to clarify the characteristics of impinging spray injected by a mini-sac gasoline injector with a single hole. The fuel spray and adhesion were measured by Mie scattering and Refractive Index Matching (RIM) methods, respectively. The effects of ambient pressure on the spray-wall interaction under room and high temperature conditions were checked. The results showed that the increased ambient pressure decreases the spray tip penetration but increases the impinging spray height by strong air-fuel entrainment under both room and high temperature conditions. However, for fuel adhesion, under room temperature, the ambient pressure promotes better atomization by stronger air drag force, resulting in more fuel adhesion on the wall. Moreover, the increased ambient pressure decelerates the droplets, leading to the transition of droplets behavior from "splashing" to "spread" or even "stick", thus increasing the fuel adhesion on the wall. While, when evaporation occurs, apart from these reasons above, higher ambient pressure suppresses the fuel evaporation, leading to more fuel adhesion on the wall. [ABSTRACT FROM AUTHOR]

This work investigated the effects of different ash co-products on the combustion of solid fuels, in particular the fuel-nitrogen behaviour: The fuel-ash additive combinations investigated were: Firstly, biomass ashes added to bituminous coals, representative of those used in power stations; Secondly, a low reactivity coal; Thirdly, a high-N biomass (olive cake) was chosen as a high reactivity fuel and studied with a power-station pulverised coal fly ash as an additive. These five solid fuels have a wide fuel ratio, FR (i.e. the ratio of fixed carbon to volatile matter content). The ash additives were a pulverised fly ash (PFA) and a furnace bottom ash (FBA) from wood pellet combustion in a UK power station. Fuels (with and without additives) were studied for nitrogen partitioning during (i) devolatilisation and for (ii) NO x formation during combustion, using two different electrically heated drop tube furnaces (DTF) operating at 1373 K. Devolatilisation was also studied via ballistic-heated thermogravimetric analysis (TGA). The extent of impact of additives on volatile yield under devolatilisation conditions was dependent on fuel ratio, high FR has the greatest increase in volatile release when co-feeding the additive. Under devolatilisation conditions, there is a correlation between volatile nitrogen and carbon conversion for all the fuels tested. Thus, additives liberate more volatile-nitrogen from the coals and also deliver enhanced carbon conversion. A mechanism is proposed whereby ultra-fine particles and vapours of reactive compounds from the additives interact with the reacting fuel/char particle and influence N-release during both devolatilisation and char burn-out. The enhanced conversion of fuel-nitrogen to volatile-nitrogen and the reduction of char-nitrogen can lead to reductions of NO x emissions in emissions-controlled furnaces. This approach could assist fuel-flexible power stations in achieving their NO x emission targets. [ABSTRACT FROM AUTHOR]

• Real-world hot-stabilized fuel use and exhaust emission rates were measured. • E0, regular and premium E10 with different octane ratings, and E27 were tested. • All five vehicles, including four non-flexible fuel vehicles, adapted to each fuel. • E27 can increase engine efficiency and reduce CO and PM emissions. Differences in fuel use and emission rates of carbon dioxide (CO 2), carbon monoxide (CO), hydrocarbons (HC), nitrogen oxide (NO x), and particulate matter (PM) were quantified for three gasoline-ethanol blends and neat gasoline measured for one flexible-fuel vehicle (FFV) and four non-FFVs using a portable emission measurement system (PEMS). The purpose was to determine if non-FFVs can adapt to a mid-level blend and to compare the fuel use and emission rates among the fuels. Each vehicle was measured on neat gasoline (E0), 10% ethanol by volume (E10) "regular" (E10R) and "premium" (E10P), and 27% ethanol by volume (E27). Four real-world cycles were repeated for each vehicle with each fuel. Second-by-second fuel use and emission rates were binned into Vehicle Specific Power (VSP) modes. The modes were weighted according to real-world standard driving cycles. All vehicles, including the non-FFVs, were able to adapt to E27. Octane-induced efficiency gain was observed for higher octane fuels (E10P and E27) versus lower octane fuels (E0 and E10R). E27 tends to lower PM emission rates compared to E10R and E10P and CO emission rates compared to the other three fuels. HC emission rates for E27 were comparable to those of E10R and E10P. No significant difference was found in NO x emission rates for E27 versus the other fuels. Intervehicle variability in fuel use and emission rates was observed. Lessons learned regarding study design, vehicle selection, and sample size, and their implications are discussed. [ABSTRACT FROM AUTHOR]

• Solketal methyl ether (SME) has been prepared from glycerol via two-step procedure. • Ketalization of glycerol and its monomethyl ether ran analogously. • Measured bRON values for SME (52–62) were twice lower than for solketal (100–110). • Free –OH group of solketal is proposed to be the "bearer" of anti-knock properties. • Antiknock properties for solketal – MTBE (MTAE, ethanol) mixtures were estimated. Solketal methyl ether (SME) was synthesized from glycerol by conversion with methanol followed by ketalization with acetone. The values for the equilibrium constant of the ketalization of glycerol and glycerol 1-monomethyl ether in the temperature range of 298–323 K were determined experimentally, and its thermodynamic parameters (Δ H 0, Δ S 0, Δ G 0) have been calculated, which appear to be very close for these two reactions. The gasoline blending properties of SME have been studied in comparison with solketal by examining the effects of solketal and SME additives on the fractional composition, saturated vapor pressure, oxidation induction period, existent gum content, density, and antiknock value of gasoline components and a model fuel blend. It has been shown that SME has better volatility, but a much lower antiknock value than solketal. The influence of the solketal additive on the antiknock value of components of compounded gasoline (alkylate, reformate, FCC gasoline) and the performance of composite additives based on solketal with ethanol, MTBE, and TAME are described. [ABSTRACT FROM AUTHOR]

Highlights • Chars were obtained from fast pyrolysis to 1600 °C in a high temperature wire mesh reactor. • Volatile yield for different coal and biomass fuels was calculated. • Nitrogen partitioning for different coal and biomass fuels was obtained. Abstract Nitrogen oxides (NO x) are atmospheric pollutants specifically targeted by legislation which imposes limits on emissions from large scale plant. During combustion, part of the Nitrogen fuel will be released as a component of the volatile matter compounds and as volatile nitrogen, while part will remain in the char. Thus, the fate of volatile-N and char-N becomes crucial for the formation of NO x and, consequently, for determining the concentrations of NO in solid fuels combustion systems. In pulverized fuel combustion, major routes for conversion of the volatile-N are either NO or N 2 , while char-N reacts through a set of heterogeneous reactions as the char is oxidized. Measuring high temperature char nitrogen content of the fuels directly reduces the likely uncertainty in NO x emissions from solid fuels on modern power stations using deep furnace air staging High temperature volatile-N and char-N partitioning is investigated by pyrolyzing fuels in a high temperature (1600 °C) wire mesh apparatus (HTWM) and analyzing the resulting char. White wood biomass, olive waste, torrefied wood, two bituminous coals and one anthracite coal were used on this study. The volatile yield at high temperatures has been obtained for each sample. The fate of nitrogen released during the pyrolysis as volatile matter and the nitrogen retained in the char has been evaluated for different biomass samples. The nitrogen in the char was measured using a total nitrogen analyzer. Results show a large change in on the volatile yield compared with proximate analysis values for both coals. Only moderate change was observed on the volatile yield for both of the woody biomass that already have high values on proximate analysis, and just a slight increase was obtained on the volatile yield for the olive waste. Differences were found on the fate of nitrogen retained in the char that would lead to NO x formation. The biomass samples release most of their fuel-nitrogen as volatile (between 80 and 95%) while on the coals the volatile nitrogen is wide more variable depending on the coal sample. [ABSTRACT FROM AUTHOR]

Abstract Octane rating is an essential property for gasoline-type fuels because it is the major factor that determines the maximum compression ratio (CR) allowed in spark-ignition engines. In practice, a base gasoline, which is a mixture of various refinery streams, is dosed with octane-booster additives for meeting the minimum octane requirements set by regulation standards. Coal-based methanol is widely used in China as a gasoline octane-booster. In addition to its high octane rating, methanol's cooling effect derived from its low latent heat and its high octane sensitivity also contribute to engine knocking suppression in spark-ignition direct-injection (DISI) engines. Thus, fully understand the role of methanol addition in gasoline is highly relevant to estimate the potential thermal efficiency gain for methanol blends. The novelty of this paper is that methanol's chemical effect, cooling effects and octane sensitivity effects on engine knocking suppression are quantitatively converted to an effective octane index (EOI), a parameter for comprehensively describing the anti-knocking properties of a gasoline-type fuel. Then ΔEOI of methanol blends (EOI_blend − EOI_base) was used for estimating engine thermal efficiency gain in compression ratio (CR) matched DISI engines. Results suggest that methanol's cooling effect is as significant as its high octane rating. For example, the cooling effect of methanol corresponds to 19 unit of octane in a blend with 70 vol% methanol (M70). The indicated thermal efficiency gain is up to 30% for M70 with RON81.1 base gasoline. The reduction in the lower heating value (LHV) of methanol blends lead to higher fuel consumption, which can be partially or even entirely offset by the improved indicated thermal efficiency. Overall, this paper highlighted the effectiveness of methanol as an octane and thermal efficiency booster. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the homogeneous formation and reduction of NO from the oxidation of CH 4 /NH 3 to understand the effect of the high concentrations of H 2 O on NO emissions. The experimental results about the effects of excess oxygen ratio, gas compositions including H 2 O, CO 2 , NH 3 and recycled NO, on NO formation and reduction were presented. The mechanism about the effects of high concentration of H 2 O and combined effect of H 2 O/CO 2 on NO formation and reduction has been discussed. The results indicates that NO formation was markedly enhanced at high concentrations of H 2 O, which were mainly attributed to the increased OH radicals with steam addition at oxygen-rich conditions. By contrast, the radicals were consumed by reduction radicals, such as CO, H, and CH i radicals, under oxygen-lean conditions. NO concentrations followed the sequence of H 2 O/Ar > H 2 O/CO 2 > CO 2 /Ar under both the oxygen-rich and oxygen-lean conditions, which meant that the highest and lowest NO emissions were recorded in Ar/H 2 O and CO 2 /Ar respectively. The combined H 2 O/CO 2 concentration accordingly exerted an effective impact on NO reduction. The results about the effect of NH 3 concentration in fuel on NO emission showed that NO emission increased with increasing NH 3 concentration. Furthermore, NO reburning results implied that with increasing NO concentration, the total NO reduction increased, whereas the reduction ratio decreased. [ABSTRACT FROM AUTHOR]

Highlights • Dynamic model is developed and well validated against biomass CLG experiments. • Elevation of H 2 yield is mainly due to partial oxidation and iron-steam reaction. • Excessive steam accelerates the gasification of char and water-gas shift reaction. • Oxygen carrier enhances the quality of syngas based on energy and exergy analyses. Abstract Chemical looping gasification (CLG) is an innovative technology for the thermochemical conversion of biomass to produce high quality synthesis gas. In this study, a one-dimensional transient model considering partial oxidation of fuels and iron-steam reaction for biomass CLG fuel reactor was developed and validated against the experimental study utilizing Fe 2 O 3 as oxygen carrier (OC) and microalgae as fuel. The simulation results and the experimental data are in good agreement in terms of the detailed time-varying outlet gas species concentrations, gas yield, carbon conversion efficiency, and gasification efficiency. The effects of different operating temperature and steam flow on the gasification performance are also well predicted by the adopted reaction mechanisms. Energy and exergy analyses are applied to evaluate the energy sources based on the validated model, which demonstrates that the presence of OC can enhance both the quantity and quality of the valuable syngas. [ABSTRACT FROM AUTHOR]

Abstract The reactivities of n -heptane, n -pentane, PRF50, PRF80, iso -pentane and iso -octane were investigated by separated weak flames in a micro flow reactor with a controlled temperature profile at a pressure of 500 kPa. At this elevated pressure condition, low-temperature reactions in the cool flame and blue flame were enhanced. High temperature reactions in the hot flame became weaker and independent of the base fuel as they mainly consist of CO and hydrogen–oxygen reactions. By conducting simulations, it was found that the ratio of heat that is released in the blue flame to the total released heat is a measure that well describes the reactivity of a given fuel. This ratio was named the Blue flame Heat Contribution Index (Blue flame- HCI). It is primarily governed by the molecular structure that controls the low-temperature isomerization reaction RO 2 ⇌ QOOH. This step is important, as the QOOH, in turn, reacts with O 2 to form OOQOOH, which decomposes to keto–hydroperoxide and OH, where the keto–hydroperoxide immediately dissociates and releases another OH. This formation of two additional OH radicals controls the chain branching at low temperatures. As straight-chain alkanes have more pathways for the isomerization reaction to form QOOH, n -heptane and n -pentane showed higher reactivity than the branched iso -pentane and iso -octane. In the experiments, formaldehyde (CH 2 O) concentrations were measured in the cool flame to evaluate the fuel reactivity using the newly introduced FormAldehyde Index (FAI). The FAI and the Blue flame- HCI were in good agreement with each other and described well the fuel reactivity. Furthermore, the FAI showed a linear correlation with the critical compression ratio as the reactivity of a given fuel is governed by low-temperature chain branching that is initiated by the isomerization reaction. [ABSTRACT FROM AUTHOR]

Abstract The physicochemical properties of a substance, such as a fuel, can vary significantly with composition. Determining these properties with ASTM standard methods is both expensive and time-consuming, which has led to a desire to use chemometric modeling as an alternative. In this study, we compare the accuracy and robustness of two chemometric models, partial least squares (PLS) regression and support vector machine (SVM) with uncertainty estimation to determine how the physicochemical properties depend on the composition. A set of hydrocarbon mixtures, including crude oil, oil, gasoline, and biodiesel, were collected. Gas chromatography/mass spectrometry (GC-MS) profiles were taken, and physicochemical properties were measured for these mixtures using ASTM standard methods. PLS and SVM were used to develop predictive models of the physicochemical properties. Uncertainty in the estimated property values was estimated using a bootstrapping technique. With this uncertainty estimate, it is possible to assess the trustworthiness of any prediction, which ensures that the chemometric models can be applied for general purposes. SVM was found to be generally better for predicting the physicochemical properties, although we expect that with a more comprehensive data set the performance of the PLS models can be improved. We show in this work that PLS and SVM can be used to generate a predictive model of physicochemical properties based on the GC-MS data. Combined with uncertainty analysis, these models provide robust predictions that can be used for regulatory, economic, and safety purposes. [ABSTRACT FROM AUTHOR]

Abstract Pyrolysis has been identified as a possible process for producing alternative fuels from thermal degradation of residue materials. In this work, a steam distillation process was applied to extract a light fuel fraction from tire pyrolysis oil. The light fuel fraction (LFF) was a light yellow, translucent liquid with a specific gravity of 0.76 g·cm−3 and dynamic viscosity of 0.4 mPa.s at 20 °C. LFF was mainly composed of volatile organic components of the tire pyrolysis oil. GC-MS analysis shows the light fraction composed mostly of benzene-substituted compounds (62.06%), mainly ethylbenzenes (14.84%) and methylbenzenes (13.02%) derivatives. Saturates were mainly branched alkanes containing eight carbon atoms (21.94%) and cycloalkanes in minor amount (1.35%). Olefins were essentially alkyl-branched cyclohexenes (14.66%), highlighting limonene (8.2%). The standard mid-infrared spectroscopy revealed the light fuel fraction resembles very closely the petroleum-derived gasoline. In addition, typical distillation properties (such as T50, T90, and driveability index) and octane number (Motor Octane Number and Research Octane Number) for the light fuel fraction matched to the gasoline properties. The results point out to the feasibility to replace conventional gasoline by the light fraction obtained from tire-derived oil by means of steam distillation. [ABSTRACT FROM AUTHOR]

Highlights • PDA tests were carried out to compare ambient and flash boiling spray characteristics. • Larger hole results in larger droplet size under both ambient and flash boiling conditions. • Divergent hole offers greater resistance towards spray collapse under flash boiling condition. • Higher injection pressure leads to a longer distance before spray eventually collapse. • Injector hole design features influence injector's resistance towards spray collapse. Abstract The effect of injector nozzle design on the Gasoline Direct Injection (GDI) fuel spray characteristics under atmospheric and flash boiling conditions was investigated using Phase Doppler Anemometry (PDA) measurements. To understand the impact of hole diameter and conicity, experiments were conducted on two bespoke 3-hole injectors in a pressure and temperature controlled constant volume chamber and in the open air. The measurements were taken radially outward from the injector axis to the outer extent of the plume at distances of 15 mm, 25 mm and 40 mm from the injector tip. Observations of the influence of surrounding gas and temperature conditions and hole design on the injector spray performance were made. Under non-flash boiling conditions, it was found that the injection pressure dictates the length of the spray penetration before collapse occurs, with an increase in pressure resulting in an increase in this length. Comparison of mean velocity and droplet diameter data are also made to understand the performance under flash boiling conditions. Results show that, under flash boiling conditions, the droplet velocity significantly increases while the droplet size reduces. More importantly, it is found that the impact of the flash boiling environment on sprays of different hole geometries is different. Some hole designs offer more resistance against spray collapse. It was found that the mid-sized of the three hole diameters tested here was found to produce a spray that more readily collapsed than that of the smaller or larger hole diameters. In addition, it was found that under flash boiling conditions, the convergent hole had a greater propensity to exhibit spray collapse. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • CdSe quantum dots tested as fuel markers for diesel oil. • Nanocrystals produced by one step colloidal growth in hexadecane. • Nanomarker detected either by electronic absorption or fluorescence spectroscopy. • Fluorescent nanoparticles detected down to 1 mg/kg level. Abstract Markers are regularly used to detect fraud and adulteration in fuel as well as to track products in a distribution chain. Herein, we tested the use of CdSe semiconductor fluorescent nanocrystals, quantum dots, as a new class of fuel markers. Quantum dots show bright fluorescence and they can be excited by light sources covering a broad spectral range, from ultraviolet up to the near infrared region. This class of markers presents great advantages over conventional ones, such as high detectability potential, fluorescence emission in multicolor wavelengths, high photostability, and easy preparation procedures. In this work, we prepared CdSe quantum dots by colloidal controlled growth in an organic medium to be used for evaluation of diesel oil. The detection method was either by electronic absorption or fluorescence spectroscopies. The nanomarkers could be detected down to 1 mg/kg level in diesel fuel. The overall results indicated that CdSe quantum dots have the potential for use as a new class of fuel nanomarkers. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • New apparatus for fast and non-intrusive measurement of VLE. • VLE data can be measured for fuels at IC-engine conditions. • Method to correct for liquid film cross talk in capillary measurements. • Extensive VLE data for ethanol/nitrogen and decane/nitrogen provided. Abstract A fuel, here ethanol or decane, and nitrogen are fed at elevated pressure and temperature through a micro capillary of fused silica. The flow inside the capillary is characterized by alternating liquid- and vapor-phase segments that accommodate to thermodynamic equilibrium at the set temperature and pressure. The composition of the equilibrated liquid or vapor segments is measured in situ and remotely inside the micro capillary by Raman spectroscopy. Temperature-composition (Tx) vapor-liquid equilibria were measured for pressures between 3 MPa and 8 MPa and up to the highest mixture critical temperature of 593 K in this pressure range. Comparison to the scarce literature data for these conditions and to the GERG-2008 model, resembling the conditions in IC-engines at the time of injection, is shown. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Laminar burning velocity measurements of n -pentanol-air mixtures at high temperatures measured using diverging channel method. • High temperature experimental data for mixture temperature upto 560 K reported for first time. • Predictions of skeletal model match well with current experimental results at different temperatures. • Non-linear variation of temperature exponent with equivalence ratio with minimum at Φ = 1.1. Abstract Long chain alcohols are potential fuels for engine applications, however, their combustion characteristics need to be adequately investigated compared to short chain alcohols (C 1 –C 4), especially at high mixture temperatures, and other conditions relevant to engine temperatures. In the present work, meso-scale diverging channel method has been used to measure the laminar burning velocity of n -pentanol + air mixtures at elevated temperatures due to existence of very limited data at higher mixture temperatures (∼473 K). The present experiments are carried out at atmospheric pressure with unburnt mixture temperature varying up to 560 K. The dependence of laminar burning velocity on temperature was correlated using the power law: S u = S u , 0 T u / T u , 0 α , where α is the temperature exponent. The results show the existence of a minimum value of α for slightly rich mixtures. A reduced kinetic model based on the previous detailed kinetic model of Sarathy (2014) for C 1 –C 5 straight-chain alcohols was generated with 199 species and 1427 reactions. Experimental results of laminar burning velocity of n -pentanol + air mixtures at high temperatures were compared with the present model and other kinetic models from the literature. The skeletal model accurately reproduces the measurements at various conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Thermal pyrolysis of Cassia siamea was studied. • Maximum yield was 39.86 wt% of organic liquid (oil) and 10.35 wt% of aqueous liquid. • Pyrolytic oil was basic with a pH of 8.75 and calorific value of 30.18 MJ kg−1. • Pyrolytic oil includes phenols, aromatics, esters, alkanes, acids, and nitriles. • Pyrolytic char was rich in carbon (57.34%) with a calorific value of 21.894 MJ kg−1. Abstract Thermal pyrolysis of the Cassia siamea seed was carried out in a fixed bed reactor in the temperature range of 450 °C and 575 °C at a heating rate of 50 °C min−1. The reactor was maintained inert using nitrogen gas at a flow rate of 40 mL min−1. It was observed that the highest yield of pyrolytic liquid was 50.21% obtained at 550 °C which includes 39.86 wt% of organic liquid (oil) and 10.35 wt% of aqueous liquid. The fuel properties of pyrolytic oil confirmed that the oil was slightly basic with a pH of 8.75, having viscosity and calorific value of about 373 cSt and 30.18 MJ kg−1 respectively. The GC-MS based composition analysis quantified the occurrence of many valuable bio-chemicals such as heptadecanenitrile, 1,2-benzene dicarboxylic acid, butyl octyl ester, phenol, p-cresol as major compounds. [ABSTRACT FROM AUTHOR]

Highlights • The spray outline distortion caused by cross-flow in the leeward side is larger than that in the windward side. • In cross-flow, the droplet horizontal velocity shows a large fluctuation in the downstream region. • Smaller droplets are more easily affected by cross-flow than larger droplets. Abstract The air flow and wall impingement in a direct-injection spark-ignition (DISI) gasoline engine affect the fuel-air mixture formation and the quality of fuel combustion. In this work, a comprehensive experimental investigation on the effect of cross-flow on the spray structure, droplet diameter and velocity distributions was carried out. The transient impinging spray behavior at different cross-flow velocities was recorded using high-speed photography with a continuous wave laser sheet. It was seen that a higher cross-flow velocity significantly increases the spray area, i.e., the cross-flow favors spray dispersion. Moreover, the spray outline distortion caused by cross-flow in the leeward side is larger than that in the windward side. By employing the particle image analysis (PIA) optical diagnostic method, the Sauter mean diameter (SMD) and the droplet velocity components were investigated. The results show that a higher cross-flow velocity causes an increased proportion of large droplets in the windward side of spray, and the enhanced droplet breakup, resulting in a larger SMD in the windward side of spray and smaller SMD in the leeward side of spray. In the leeward side of spray, the droplet horizontal velocity gradually increases along the cross-flow direction, and after it reaches approximately the cross-flow velocity, the droplet horizontal velocity shows a large fluctuation in the downstream region. Moreover, the droplet vertical velocity decreases sharply from the center line of the main spray body to the spray periphery. By comparing the velocities of droplets, we found that compared with larger droplets, the smaller droplets are more easily affected by a cross-flow owing to the effect of drag acceleration. [ABSTRACT FROM AUTHOR]

A closed loop temperature controlled glow-plug has been used to control the incidence of surface pre-ignition of n-pentane, iso-pentane, n-heptane, iso-octane, ethanol, cyclohexane, ethyl-benzene, toluene and xylene, and four representative mixtures of these components. Statistical data on the incidence of pre-ignition compared with spark ignition has been derived from the in-cylinder maximum pressure, and the glow-plug temperature has been characterised on a cycle-by-cycle basis. The alkanes and alcohols were found to be rather susceptible to surface pre-ignition, with the straight chained molecules having a higher pre-ignition tendency than branched chain molecules. The pre-ignition tendency of ring-structured components depends on the length of the attached chain, with shorter side-chain molecules (xylene, toluene) being less susceptible to pre-ignition than longer side-chain molecules like ethyl-benzene; cyclohexane was more susceptible to pre-ignition than any of the aromatic fuels. A higher glow-plug temperature was found to be needed for pre-igniting stoichiometric or rich mixtures, and this was attributed to the weaker mixture having a higher compression index and a lower specific heat capacity. [ABSTRACT FROM AUTHOR]

• XRD, CPMAS, NMR, FTIR,TGA Characterization of different waste PE and PP. • Pyrolytic conversion of waste plastics and degradation pathway. • Composition and performance analysis of pyrolytic liquid from waste plastics. • Correlation between composition of plastics and pyrolysis liquid. • Recommendation for optimal use of different types of plastics for management. Thermal pyrolysis of polyolefins has been proposed as one of the possible ways to obtain petroleum-derived products (fuels and chemicals) from waste plastics however, there is a lack of deep understanding of the correlation between the structure and composition of polyolefin feedstock with pyrolysis oil. Pyrolysis oil has been obtained from polyethylene (PE) and polypropylene (PP) in a tubular reactor at 500 °C. TGA-DTG, 13C CP-MAS NMR, FTIR, and XRD were used to analyze the polyolefin (PE and PP) feedstock, while pyrolysis oil was characterized by GC–MS, FTIR, and 1H NMR techniques. The pyrolysis oil from virgin and waste PP yielded branched alphaolefins and cycloparaffins, while virgin and waste PE produce linear alpha olefins and linear paraffins. Mixed waste plastic (MWP) produces major amount of linear paraffins and linear alpha olefins, indicating the overall trend of branching in polyolefins (PE and PP) from feedstock to product oil is retained after pyrolysis. The alpha olefins can be used as chemical intermediates, while 2,4 dimethyl 1-heptene from PP can be used as a fine chemical precursor better feedstock for gasoline. Segregation of waste plastics is challenging task in real life but source segregation and selective collection of waste plastics from various sources can produce useful products like high octane gasoline range hydrocarbons and high-value chemicals. [ABSTRACT FROM AUTHOR]

Improved electrochemical conversion of NH 3 into N 2 and H 2 over PdO and RuO 2 promoted ZnO mesoporous electrocatalysts. [Display omitted] • We report PdO and RuO 2 promoted ZnO/Al 2 O 3 ternary materials as efficient and robust electrocatalysts towards AEO. • A innovative way to produce clean biofuel. • Nanoparticles were characterized using FTIR, DLS, FE-SEM and XRD techniques. • RuO 2 -ZnO/Al 2 O 3 and PdO-ZnO/Al 2 O 3 gave the promoted and upgraded response owing to admirable efficacy of Pd and Ru. Ammonia is an ideal alternative of hydrogen with high hydrogen content and environmental safety but production of hydrogen from ammonia is deterred by developing active and affordable catalysts. Herein, we report PdO and RuO 2 promoted ZnO/Al 2 O 3 ternary materials as efficient and robust electrocatalysts towards AEO. Little weight percentages of PdO and RuO 2 i.e., 0.1 %, 0.5 % and 1 % are added into 20 % ZnO/Al 2 O 3 via co-impregnation method followed by rotatory ball milling to achieve uniform morphology. Prepared metal oxide catalysts exhibited nanocrystallite sizes and mesoporous structure thereby enhancing the electronic and catalytic properties. Adsorption-desorption isotherms and BJH diagrams revealed mesoporous structure of the catalysts with nanosized pores endorsing high surface area. Electroanalytical techniques applied to study AEO using 1 M NH 3 showed that the developed materials effectively electro-catalyzed the reaction observed in alkaline medium i.e. 0.1 M KOH. Varying scan rate indicated it as a diffusion controlled process offering high diffusion coefficient. Ternary metal oxides gave the promoted and improved catalytic output displaying high current density " j " (307 µA cm−2 and 742 µA cm−2 at 10 mV s−1) and low charge transfer resistance "R ct " (24.1 and 9.7 kΩ) with RuO 2 -ZnO/Al 2 O 3 and PdO-ZnO/Al 2 O 3 , respectively. These electrochemical possessions are attributed to half-filled d-orbitals of Pd and Ru. In this way, PdO and RuO 2 promoted ZnO mixed metal oxide electrocatalysts reported for the first time could be employed to accelerate high-performance efficient energy generating technologies. [ABSTRACT FROM AUTHOR]

The huge demand for high-quality coal in China has resulted in increased generation of preparation plant wastes of various properties. A series of beneficiation products collected from a preparation plant were characterized to understand their petrographic and mineralogical characteristics, as well as thermochemical and trace element behavior during combustion. The minerals in the Luling preparation plant wastes from Huaibei coalfield mainly included kaolinite and quartz, with minor calcite, ankerite, pyrite, illite, chalcopyrite, albite, K-feldspar, anatase/rutile, and iron-oxide minerals. Massive clay lumps of terrigenous origin, cleat-infilling carbonate, and pyrite of epigenetic origin were prone to be enriched in the middlings and coal gangue. Minor or trace heavy minerals also reported to the preparation plant wastes. The contents of low-density density vitrinite and liptinite were enhanced in the clean coal, while inertinite-maceral group were enriched in the middlings. The modes of occurrences of toxic elements differed between raw coal and the waste products; and their transformation behavior during heavy medium separation is largely controlled by clay minerals (V, Cr, Co, Sb, and Pb), carbonate minerals (Co and Pb), sulfide minerals (As, Cu, Ni, Cd, and Zn) and organic matters (V, Cr, Se, and Cu). Three groups were classified based on the volatile ratio (Vr) of toxic elements. Group 1 includes the highly volatile element Se with Vr > 85%; Group 2 contained elements As, Pb, Zn, Cd and Sb, with the Vr in the range of 20–85% and V, Cr, Co, Ni and Cu with Vr less than 20% were placed into Group 3. Thermal reactivity of coal inferred from the combustion profiles could be significantly improved after coal beneficiation, whereas the increased inorganic components probably inhibited the thermal chemical reaction of wastes. [ABSTRACT FROM AUTHOR]

Foamed emulsion containing biochar particles can serve as a perspective type of fuel for contemporary power engineering. Such a combustible system represents a multiphase system consisting of oxygen bubbles dispersed in the oil-in-water emulsion which in turn contains biochar microparticles. The paper considers the issues related with combustion of foamed emulsion containing biochar particles. In the process of experimental study we determined the dependencies of flame speed in the foamed emulsion on the concentration of biochar microparticles for different types of aliphatic hydrocarbons (hexane, heptane, isooctane and nonane). It is found that the use of biochar microparticles could lead to rather significant increase in total burning rate of the foamed emulsion. Thus, for example, the addition of biochar particles into the isooctane-based foam leads to the four-times increase in total burning rate. Herewith, the dependence of total burning rate of the foam on the biochar particles concentration is non-monotonic, so the maximum burning rate is achieved at some moderate biochar particles concentration. With the help of laser-lighted photography of multiphase flow the experimental data is obtained for the diameter of water droplets forming in the process of foamed emulsion decay during its combustion. It is obtained that biochar particles favor finer dispersing of liquid phase of the foam since they represent by themselves heterogeneous centers of vapor bubbles nucleation. In turn the diameter of water droplets defines the heat losses from the flame front and therefore the flame speed. On the basis of simple phenomenological representations we obtained the estimate for flame speed in the foamed emulsion containing biochar microparticles. Obtained relations makes it possible to substantiate the non-monotonic manner the total burning rate depends on the biochar microparticles content in the emulsion. [ABSTRACT FROM AUTHOR]

A bifunctional Fe/HZSM-5 catalyst was prepared for direct synthesis of aromatics from syngas. The influence of iron loading on acidity and syngas to aromatics (STA) performances over the Fe/HZSM-5 catalysts was studied. An increasing iron loading increased the amounts of active iron species, enhancing synergistic effect of active iron sites and HZSM-5 for the STA reaction. Higher iron loading in the Fe/HZSM-5 catalyst resulted in the decrease of Brönsted acid sites and increase of Lewis acid sites, promoting the formation of C 5 + hydrocarbons and aromatics selectivity via weakening the cracking ability and enhancing the dehydrogenation property of HZSM-5. Excessive adding of iron loading induced the formation of graphitic carbon deposition, leading to a decrease of catalytic activity and stability. [ABSTRACT FROM AUTHOR]

The vegetable oil has become a frontier area of research in rural and remote areas for small or decentralized power generation applications. However, the biggest challenge in use of straight vegetable oil (SVO) in a diesel engine is the problem of injector deposits. Soy-lecithin has been identified as bio-additive to overcome the deposits problem due to its natural surfactant and emulsifying properties. Though short-term performance test using soy-lecithin as bio-additive with non-edible karanj oil showed quite good results, its effect on engine performance during long-term test needs to be experimentally investigated for its reliability. The key objective of the current work is to examine the performance of diesel engine operated with karanj oil ( Pongamia pinnata ) by adopting a novel strategy of periodic dosing of bio-additive during a long-term test. This study also intends to focus on lubricating oil analysis to evaluate the effectiveness of soy-lecithin as bio-additive with karanj oil. Long-term engine test was performed on a Cummins DXP, direct injection diesel genset at a constant speed and load for 130 h. A test was conducted by adopting a novel strategy of periodic dosing of bio-additive in karanj oil in a repeated cycle during engine running condition. Experimental results showed that immediately switched over to additive improved the performance of engine but its continuous use lead to degradation of engine performance. Thus, running of engine continuously with either additive or w/o additive independently would lead to degradation of the engine performance but with periodic dosing of soy-lecithin as bio-additive improved the performance of the engine. The present work suggests the strategy of running the engine with bio-additive in discreet dosages for 2 h after every 7–8 h of engine run without additive in a repeated cycle. This approach would lead to smooth running of the engine which is an improvement over the baseline performance of karanj oil either with or without soy-lecithin alone. The lubricating oil analysis revealed the normal physicochemical properties and normal wear metal level within the discarding limit after 130 h of the long run test. The information coming out of this research would be helpful to researchers working with SVO to overcome the engine problems for its long-term durability or endurance test by adding an additive in a strategic manner. [ABSTRACT FROM AUTHOR]

Biodiesel is an evolution toward the attempt to substitute fossil fuel by renewable biomass. Typically, blends of diesel and biodiesel are commercialized instead of pure biodiesel for economic and technical reasons. It would be of interest for customers, regulations agencies, and dealers regarding custody transfer of biodiesel blends to have a rapid and reliable method to analyses the mixture on site and in real time. The aim of this research is to use a previously developed ultrasonic method to analyse mixtures of diesel and biodiesel. The samples were blends which proportion varied from 0% (pure diesel) to 20%. The ultrasonic quantities were speed of sound and ultrasonic attenuation. Those parameters were determined in a transmission/reception scheme. The measurement uncertainties were evaluated according to the Guide to the Expression of Uncertainty in Measurement (BIPM JCGM 100:2008). Complementary, commercial samples (B2 and B10) were obtained from a local supplier and evaluated accordingly. The expanded definitional uncertainty was 2.0 m s −1 for speed of sound and 0.032 dB cm −1 (p = 0.95). The method has shown capability to identify less than 4% of biodiesel in diesel blends for both parameters. [ABSTRACT FROM AUTHOR]

The utilization of polymer wastes for volatile fuel production has been considered as a sustainable and environmental-friendly approach for achieving better waste management, pollution protection, and renewable energy security. Polymer pyrolysis, as an ideal method for polymer waste converted into storable fuel, was explored thoroughly in this study from pyrolysis kinetics to evolved gas analysis. Two typical building-used polymer wastes, extruded polystyrene (XPS) and rigid polyurethane (RPU), were selected to conduct a series of thermogravimetry (TG) experiments. Then commonly-used isoconversional methods were employed to calculate the kinetic parameters of the pyrolysis during the whole conversion. Kinetic models of XPS and RPU thermal degradations were identified from nineteen reaction models by Coats-Redfern and masterplots methods. Then accommodation function was employed to adjust the theoretical model for reconstruction. Considering the complexities of RPU component and degradation process, Py-GC/MS was used to identify the volatile product component at 250, 340, and 460 °C, respectively. Results showed that there are large parts of volatile alcohols and ethers escaped during RPU pyrolysis process. The results of this study have implications concerning kinetic triplet determination method and escaped gas analysis during polymer waste pyrolysis process. [ABSTRACT FROM AUTHOR]

The main driver to investigate low temperature combustion concepts, such as partially premixed combustion (PPC), is the promise of low particulate matter (PM) and nitric oxide (NOx) emissions. A critical prerequisite for PPC is to temporally isolate the fuel injection and combustion events. In practice, exhaust gas recirculation (EGR) is applied in order to sufficiently extend the ignition delay to that effect. Hereby, in general, higher EGR rates are necessary for fuels with higher cetane numbers (CN). Against this background, the objective of this paper is to investigate the efficacy, with respect to PM-NOx emissions and engine efficiency, of gasoline as a potential gas-to-liquid (GTL) CN suppressant in various dosages. The performance of the resulting GTLine blend will be evaluated under PPC operating conditions in a heavy-duty direct-injected diesel engine. Setting aside for a moment any potential practical issues (e.g., flash point, vapor pressure) that fall outside the scope of this study, our data suggest that blending gasoline to otherwise high CN GTL appears to be a promising route to improve not only the efficiency, but also PM and NOx emissions, particularly when operating in PPC mode. Interestingly, this benefit is notwithstanding the high aromaticity of the gasoline compared to GTL. Given the ongoing dieselization trend and associated surplus of gasoline in many regions, notably Europe, along with the fact that the cost price of gasoline is significantly lower than that of GTL, the proposed GTLine approach promises to be a cost effective way to accommodate GTL in a world wherein low temperature combustion concepts, such as PPC, appear to be really taking off. [ABSTRACT FROM AUTHOR]

The combustion predictive model was developed based on the results of experiments with coal water slurry and coal water slurry containing petrochemicals. Unlike other known models, it takes into account the effect of liquid flammable component (in particular, engine oil waste) on the main mass and heat transfer as well as other physical and chemical processes in the combustion chamber. The main differences, conditions and characteristics of the combustion of coal water slurries containing petrochemicals and without additives have been studied theoretically with different defining parameters: fuel composition, component properties, and furnace chamber temperature. Temperature fields and volumetric concentration distribution of combustion products in the furnace chamber are established for fuel compositions based on water, coal, and industrial oil waste. Temperatures and concentrations for both the initial fuel components and their combustion products are established at different points of the furnace chamber for various component concentrations, properties, and furnace air temperatures. The main research findings are the quantitative differences between the characteristics of ignition and combustion of slurries with and without a liquid fuel component. These differences are critical to illustrate the benefits of using coal water slurries containing petrochemicals in heat and power plants. Adding as little as 10% (relative mass fraction) of waste industrial oils was shown to significantly reduce the ignition delay times and improve the combustion efficiency of fuel compositions. Possible ranges, in which the ignition delay of slurry fuels can be reduced, and the displacement of their ignition zones in the combustion chamber were determined when changing the temperature and the main fuel component – coal (as illustrated by brown and bituminous coals, as well as anthracite). [ABSTRACT FROM AUTHOR]

The fire and explosion hazards for a mixture demonstrating minimum flash point behavior (MinFPB) are greater than for those of its individual components. Studies of MinFPB for ternary solutions are extremely rare, although such solutions are frequently encountered in real processes. A new type of MinFPB for ternary mixtures with three binary constituents showing MinFPB is reported in this study. This new type of MinFPB was observed in methyl butyrate + ethanol + octane and propyl acetate + ethanol + octane. The minimum flash point value for the two studied mixtures is not only lower than that of the individual components but was also lower than the minimum ones of the three constituent binary mixtures. Such an observation has not formerly been reported. This finding has implications for fuel design, hazard assessment, process safety design, and process safety operation. [ABSTRACT FROM AUTHOR]

Alpha-alumina (α-Al 2 O 3 ) materials has a wide range of applications because of its excellent properties at high temperature. Tabular α-Al 2 O 3 was unexpectedly synthesized by etching mullite from Si x Al y O z composites since our original intention was highly porous α-Al 2 O 3 . Silica-alumina xerogels with different Al/Si molar ratio as 3, 6, 9 and ∞ (pure alumina) were prepared via sol-gel route, followed by calcination at 1400 °C to obtain Si x Al y O z composites. XRD results showed that the composite existed as mullite when the Al/Si ratio equaled to 3 and as the combination of mullite and corundum (α-alumina) when the Al/Si ratio equaled to 6 and 9, while pure α-Al 2 O 3 was obtained when Al/Si ratio equaled to ∞ signed as sol-gel α-Al 2 O 3 . The mullite phase in Si x Al y O z composites could be etched completely by hydrofluoric acid under room temperature in terms of the treating time was long enough and left tabular α-Al 2 O 3 for the samples with Al/Si molar ratio as 6 and 9. The interaction between mullite and α-Al 2 O 3 during the thermo process may direct the formation of tabular morphology. Structural and property characterizations show the tabular morphology, low surface area, perfect crystallinity and weak acidity of α-Al 2 O 3 . Furthermore, the adsorption of dibenzothiophene, a molecular with planar morphology, on tabular α-Al 2 O 3 , sol-gel α-Al 2 O 3 as well as γ-Al 2 O 3 was investigated at room temperature in comparison. Tabular α-Al 2 O 3 exhibited the highest adsorption capacity and best regeneration ability than other two. [ABSTRACT FROM AUTHOR]

An experiment was carried out in a gasoline direct injection (GDI) spark ignition engine to research the effect of gasoline components on fuel economy, combustion and emissions. According to the main components of gasoline, isooctane was selected as the base fuel. Short-chain, medium-chain and long-chain alkanes, ethers and aromatics were respectively blended with isooctane for comparison tests. Results show that aromatics benefit fuel economy under all operating conditions. T20 (20% toluene blended with isooctane) shows a comparatively lower break-specific fuel consumption (BSFC) for its lower cyclical variation while its maximum fuel saving ratio (FSR) could reach 5.42%. At light and medium loads of low speeds, short-chain alkanes shows great potential in the improvement of fuel economy. P20 (20% n-pentane blended with isooctane) whose maximum FSR could reach 4.64% presents better performance of fuel consumption under these operating conditions. By contrast, M20 (20% methyl tertiary butyl ether blended with isooctane) presents the higher BSFC for its higher cyclical variation and lower heat value, with the mean FSR being −2.75%. Medium-chain alkanes, long-chain alkanes and oxygenated fuels are conducive to the optimization of combustion process of the engine because they are able to advance combustion phase due to the shorter ignition delay. In conclusion, medium-chain and long-chain alkanes could reduce CO and THC emissions, to some extent. Compared with pure isooctane and T20, lower CO, NOx and THC emissions are observed for M20 and P20. [ABSTRACT FROM AUTHOR]

Fungi are known to produce hundreds of different polyketide, terpene, and terpenoid compounds and based on their chemical structures, 33 of these were selected for further assessment to identify compounds with potential for liquid transportation fuels. Eight of the 33 compounds were identified as having potential as gasoline blend components. Based on predicted boiling points and octane numbers, 2-ethyl-5,5-dimethyl-1,3-cyclopentadiene, sabinene, isobutyric acid,1,8-cineole and linalool met the boiling point and octane number requirements used for the assessment, while 2-ethyl-5,5-dimethyl-1,3-cyclopentadiene and isobutyric acid would require some upgrading. Limonene, isoamyl acetate, and 2,2,5,5-tetramethyl-3-hexanone also have gasoline blend potential without upgrading. For diesel fuel, only 3,3,5-trimethyldecane met the boiling point, cetane number, and flashpoint requirements used for the assessment; however, with upgrading, 18 of the 33 compounds evaluated could potentially serve as blend components of diesel fuel. None of the 33 compounds without upgrading met the four ASTM D1655 specifications for Jet A and Jet A-1 fuel, but 3,3,5-trimethyldecane and limonene were very close. With chemical upgrading, 22 of the 33 compounds could have potential as jet fuel blend components. The monoterpene limonene and six sesquiterpenes were identified as fungal-derived compounds that with upgrading potentially could serve as components of high-energy jet, missile, or diesel fuels. The increasing availability of fungal genomes and transcriptomes enables the identification of important metabolic pathways for hydrocarbon production. The number of fungal-based compounds having potential for use in hydrocarbon fuels and products is increasing as new compound and pathway discoveries are made and advances in metabolic engineering and synthetic biology enable the production of these compounds. Several challenges remain including increasing carbon flux toward hydrocarbon fuel precursors in primary metabolism, increasing the low titers of hydrocarbons produced, and establishing robust host strains. Also, more fuel property testing of fungal-derived compounds individually or in fuel blendstocks is needed to determine the true potential of these compounds in liquid transportation fuels. [ABSTRACT FROM AUTHOR]

Bio-jet fuel range alkanes were prepared by catalytic deoxygenation reaction of non-edible acid oils with no added hydrogen. A WOx[6]/Pt[1.6]/TiO 2 was used for the deoxygenation of stearic acid and Jatropha fatty acid derived from Jatropha oil by hydrolysis. Tungsten addition to the Pt/TiO 2 showed remarkably enhanced performance, a degree of deoxygenation of 86%, which is more than two times higher than that of the Pt/TiO 2 , even though the WOx/TiO 2 had almost no activity for deoxygenation reaction. The enhanced Pt-related hydrogen uptake, measured by H 2 -TPR, and XPS analysis showed the intimate contact of tungsten with Pt nanoparticles supported on TiO 2 . This tight contact allows for easier C C cleavage over Pt nanoparticles and this is assisted by the strong bonding between tungsten and oxygen in the reactant, resulting in more C 17 hydrocarbon production on the WOx/Pt/TiO 2 . [ABSTRACT FROM AUTHOR]