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Electrochemical carbon dioxide (CO2) reduction reaction (CO2RR) to valuable liquid fuels, such as formic acid/formate (HCOOH/HCOO−) is a promising strategy for carbon neutrality. Enhancing CO2RR activity while retaining high selectivity is critical for commercialization. To address this, we developed metal‐doped bismuth (Bi) nanosheets via a facile hydrolysis method. These doped nanosheets efficiently generated high‐purity HCOOH using a porous solid electrolyte (PSE) layer. Among the evaluated metal‐doped Bi catalysts, Co‐doped Bi demonstrated improved CO2RR performance compared to pristine Bi, achieving ~90 % HCOO− selectivity and boosted activity with a low overpotential of ~1.0 V at a current density of 200 mA cm−2. In a solid electrolyte reactor, Co‐doped Bi maintained HCOOH Faradaic efficiency of ~72 % after a 100‐hour operation under a current density of 100 mA cm−2, generating 0.1 M HCOOH at 3.2 V. Density functional theory (DFT) results revealed that Co‐doped Bi required a lower applied potential for HCOOH generation from CO2, due to stronger binding energy to the key intermediates OCHO* compared to pure Bi. This study shows that metal doping in Bi nanosheets modifies the chemical composition, element distribution, and morphology, improving CO2RR catalytic activity performance by tuning surface adsorption affinity and reactivity. [ABSTRACT FROM AUTHOR]

High Test Peroxide (HTP) is a well-known green and energetic material, widely used in propulsion systems in a variety of applications, including hypergolic systems. This experimental work mixed fumed silica with liquid HTP to synthesize Gelled HTP (GHTP). A high-speed camera and a time-resolved infrared camera were employed to analyze liquid/gel phase mixing, ignition, and flame spread through drop tests, adopting a promising low toxicity liquid fuel as a GHTP hypergolic pair. Liquid/gel impinging jets in ambient air were also performed, simulating a basic element of a hybrid liquid/gel propulsion system. Prior to ignition, GHTP revealed a lower mixing ratio compared to HTP, which ultimately led to an ignition delay time of 20.6 ±6.4 ms, while HTP reached 14.6 ±3.7 ms when 1 wt% of catalyst was used. The flame area, used as a parameter to quantify gas-phase reaction, also showed sensitivity to liquid/gel phase mixing. Using a less concentrated HTP solution, ignition of GHTP/liquid fuel seemed to occur around 6 s faster than liquid HTP/liquid fuel in impinging jets, probably due to differences in propellant residence time and the vapor formation process. A theoretical performance analysis considering GHTP as an oxidizer in a hybrid liquid/gel hypergolic system revealed that the gelled propellant, made with the addition of 6 wt% of fumed silica, can achieve 96% of liquid HTP's specific impulse with the selected fuel. Furthermore, the theoretical density specific impulse of the hybrid gel/liquid system would significantly surpass that of the liquid/liquid system if 10 wt% of aluminum were mixed with GHTP. To take advantage of the hybrid system, a new propulsion system composed of pistons coupled to propellant tanks is proposed to properly infuse the gelled and liquid propellants. The results from this experimental work, together with theoretical analysis, suggest that the hybrid liquid/gel system may be suitable for military applications. [Display omitted] • Use of gelled hydrogen peroxide as oxidizer in hypergolic propulsion systems. • Drop and impinging jets test reveals vapor and ignition delay times with green fuel. • Analysis before and after ignition using visible and infrared high-speed cameras. • Infrared data quantifies mixing prior to ignition and flame spread. • Gelled hydrogen peroxide may ignite faster than its liquid counterpart. [ABSTRACT FROM AUTHOR]

Aqueous film-forming foam is being phased out due to the environmental impacts of fluorinated surfactants contained in the firefighting foams. To develop an environmentally friendly firefighting foam, it is important to understand the factors controlling the firefighting performance of surfactants. Fuel transport through foam has been considered as a dominant mechanism for foam collapse. Therefore, the impact of fuels (heptane, octane and trimethylbenzene (TMB)) on surfactant microstructure was studied for three different types of surfactants (Capstone, Glucopon, and siloxane) that have applications in firefighting foam. Multiple techniques were used to identify the microstructure and interfacial properties of surfactants with and without exposure to liquid fuel. The ignition time of fuel vapor through foam and solubility of fuel through liquid surfactant solution were measured as well. This work shows fuel solubility has an impact on the surfactant microstructure and interfacial properties. In addition, fuel solubility and vapor pressure affect the ignition time of fuel vapors. [ABSTRACT FROM AUTHOR]

The carbon footprint of methanol from cradle‐to‐grave is evaluated using three process concepts to capture CO2, i.e., one using CO2 from direct air capture (DAC) and the other two utilizing CO2 from a steel mill's blast furnace gas (BFG). Hydrogen is supplied by onsite electrolysis, or from a German offshore wind park, or an Australian solar park with ammonia as hydrogen carrier. The study is of interest to life cycle assessment (LCA) practitioners, policymakers, and industries' management who are involved in regulating, planning, implementing, and operating projects which aim to produce fuels using hydrogen from electrolysis (so‐called 'e‐fuels'). The influence of assumptions in the RED‐II delegated act regarding recycled carbon fuels and renewable liquid and gaseous fuels of non‐biological origin on the carbon footprint results is examined. The RED‐II assumption regarding the credits for captured CO2 after 2041 indicate that DAC‐based concepts are advantageous with respect to BFG, although the LCA results indicate the opposite. Using green hydrogen from nearby locations reduces carbon footprints more than faraway locations due to transport‐related emissions. [ABSTRACT FROM AUTHOR]

Fly ash is generally obtained as a by-product from the combustion of coal and other waste materials. It is used for making bricks, but it has few limitations. The fly ash consists of Silica, Alumina, and other metal oxide components in minor quantities. Fly ash particles are observed in the range of nanometers to micrometers and can act as a catalyst in various reactions. The use of low-cost catalysts in the pyrolysis of thermoplastic waste would achieve a high percentage of low molecular weight fractions in liquid form which increases its applicability in commercial sectors. Hence, there is a need to enhance these fractions to achieve a sustainable approach in the catalytic pyrolysis process. fly ash, being a side product, is very cheap, so its effect on the plastic waste pyrolysis process has been studied. In the present research paper, Physical & chemical characterization of fly ash has been carried out. As fly ash consists of different metal oxides in proportion, its applicability in the process of pyrolysis of HDPE, LDPE, and PP waste has been studied. The different weight percent of fly ash (i.e., 5, 10, 15, 20) have been tried in all pyrolysis experiments. It has been observed that 5 wt % fly ash is effective for enhancing the yield of liquid fuel as compared to that without a catalyst. Liquid fuel obtained from catalytic pyrolysis of HDPE, LDPE, and PP waste with Fly ash consists of a high percent of low molecular weight fractions as compared to that of liquid fuel without catalyst, which has been concluded by calorific values & GC-MS result. [ABSTRACT FROM AUTHOR]

One of the primary sources contributing to vibrations in operational marine diesel engines is the combustion process of fuel injected into the cylinders. Hence, alterations in the injection process and the quality and type of fuel supplied to the engine can modulate the combustion parameters, consequently impacting noise and vibration levels. A literature review on this subject suggests that while some research has been conducted, mainly focusing on small engines in the automotive sector, there's been a limited exploration in the marine domain. Despite the recent surge in manufacturers' interest in electrifying road transport vehicles, a similar trend has not been observed in sea transport besides short-range ferries, mainly due to the substantial range requirements of vessels. It is conceivable that the utilisation of liquid fuels in shipbuilding will persist. Presently, the predominant marine fuels are fossil-based, the reserves of which are progressively declining. However, the widespread adoption of alternative fuel additives like butanol holds promise in curbing fossil fuel consumption. One of the conditions to be met by a new commonly used fuel for marine engines is its good properties in limiting the parameters of accompanying processes like vibrations. The article delineates a comparative analysis of parameter values related to the vibrations of a marine engine fueled by different blends of butanol and diesel oil. Laboratory tests were conducted on a sixcylinder marine engine under load using a water brake, encompassing various engine loads to replicate real-world operating conditions accurately. [ABSTRACT FROM AUTHOR]

The rising demand for portable energy conversion devices has spurred the advancement of direct liquid fuel cells (DLFCs) employing fuels such as alcohol, ammonia, hydrazine, and vitamin C. In these devices, various precious metal platforms have been explored to increase the de-electronation kinetics and reduce catalyst poisoning, but with substantial cost implications. We demonstrate the crucial role of ligands in non-precious organometallic complexes in influencing the de-electronation kinetics of fuel molecules through a unique substrate–ligand synergistic interaction. This unique chemistry imparts electron deficiency at the catalytic metal center while simultaneously populating the ligand with an extensive proton charge assembly. This distinct substrate–ligand interaction enhances the DLFC performance by coulombically dragging the substrate with a distinct amplification in its de-electronation kinetics. By integrating this approach with a ferricyanide/ferrocyanide half-cell reaction, a precious metal-free vitamin C fuel cell is developed, which is capable of generating an open circuit voltage of ∼950 mV, a peak power density of ∼97 mW cm−2 at a peak current density of ∼215 mA cm−2 with the performance metrics nearly 1.7 times higher than a precious metal based DLFC. This highlights the potential of the substrate–ligand synergy in the design of efficient molecular catalysts for energy conversion applications. [ABSTRACT FROM AUTHOR]

The term "e-fuel" typically refers to synthetic fuels produced using renewable energy sources, primarily starting with green hydrogen. Hydrogen serves as the foundational e-fuel, but there are also proposed solutions involving combining hydrogen with carbon dioxide to produce e-fuels that resemble today's alkanes or alcohols. The production process integrates water electrolysis, CO₂ capture, and fuel synthesis, all powered by renewable sources like wind and solar energy. Key processes include hydrogen generation using various electrolyzers and CO₂ capture from either direct air capture or industrial sources. Subsequently, hydrogen and captured CO₂ are synthesized into hydrocarbons using methods such as Methanol Synthesis, Fischer-Tropsch Synthesis, and the Sabatier Process. Advances in catalyst technology, reactor design, and renewable energy integration are enhancing production efficiency and feasibility. Although currently more expensive than fossil fuels, e-fuels are expected to become cost-competitive with technological advancements and supportive policies. They offer significant environmental benefits, including carbon neutrality and reduced pollution. One crucial enabler of e-fuels is the development of novel combustion systems for internal combustion engines. Innovations such as direct injection and jet ignition improve combustion efficiency when using e-fuels. These systems enable optimized premixed or diffusion combustion, balancing efficiency and performance for both liquid and gaseous fuels resembling diesel or gasoline. E-fuels are poised to play a vital role in achieving a sustainable, low-carbon energy future, particularly in sectors where direct electrification is challenging. Continued research and policy support are essential for their further development, with direct injection and jet ignition systems playing an integral part in this transformative journey. [ABSTRACT FROM AUTHOR]

The detection and deterrence of collusive agreements among firms, such as price-fixing cartels, remain pivotal in maintaining market competition. This study investigates the application of machine learning methodologies in the behavioral screening process for detecting collusion, with a specific focus on parallel pricing behaviors in the wholesale fuel market. By employing unsupervised learning techniques, this research aims to identify patterns indicative of collusion—referred to as collusion markers—within time series data. This paper outlines a comprehensive screening research plan based on the CRISP-DM model, detailing phases from business understanding to monitoring. It emphasizes the significance of machine learning methods, including distance measures, motifs, discords, and semantic segmentation, in uncovering these patterns. A case study of the Polish wholesale fuel market illustrates the practical application of these techniques, demonstrating how anomalies and regime changes in price behavior can signal potential collusion. The findings suggest that unsupervised machine learning methods offer a robust alternative to traditional statistical and econometric tools, particularly due to their ability to process large and complex datasets without predefined models. This research concludes that these methods can significantly enhance the detection of collusive behaviors, providing valuable insights for antitrust authorities. [ABSTRACT FROM AUTHOR]

The self-excited oscillation system, owing to its capability of harvesting environmental energy, exhibits immense potential in diverse fields, such as micromachines, biomedicine, communications, and construction, with its adaptability, efficiency, and sustainability being highly regarded. Despite the current interest in track sliders in self-vibrating systems, LCE fiber-propelled track sliders face significant limitations in two-dime nsional movement, especially self-rotation, necessitating the development of more flexible and mobile designs. In this paper, we design a spatial slider system which ensures the self-rotation of the slider propelled by a light-fueled LCE fiber on a rigid circular track. A nonlinear dynamic model is introduced to analyze the system's dynamic behaviors. The numerical simulations reveal a smooth transition from the static to self-rotating states, supported by ambient illumination. Quantitative analysis shows that increased light intensity, the contraction coefficient, and the elastic coefficient enhance the self-rotating frequency, while more damping decreases it. The track radius exhibits a non-monotonic effect. The initial tangential velocity has no impact. The reliable self-rotating performance under steady light suggests potential applications in periodic motion-demanding fields, especially in the construction industry where energy dissipation and utilization are of utmost urgency. Furthermore, this spatial slider system possesses the ability to rotate and self-vibrate, and it is capable of being adapted to other non-circular curved tracks, thereby highlighting its flexibility and multi-use capabilities. [ABSTRACT FROM AUTHOR]

Transition metal phosphide nanoparticles supported on silica were used as catalysts to investigate the hydrodeoxygenation of methyl laurate (used as a model compound for vegetable oils). Ni2P, Ni1Mo1P, and Ni1.6Mo0.4P were synthesized using a molecular precursor route. The nanoparticles were added to the silica support without any changes in their structure or particle size. As a reference and for comparison, MoP/SiO2 was also prepared by the phosphite method. The prepared catalysts were characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, transmission electron microscopy, and chemical analysis. A higher conversion is reached with the MoP/SiO2 monometallic catalyst, close to that with Ni1Mo1P/SiO2. However, this observation is misleading because the differences in dispersion obscure the result that the intrinsic activity (turnover frequency) of the bimetallic catalyst, prepared by a molecular precursor route, is significantly higher than that of the monometallic catalyst, prepared by the phosphite route, revealing a synergistic effect on the catalytic activity due to the formation of the bimetallic phosphide. [ABSTRACT FROM AUTHOR]

The hydrogen-diesel dual-fuel mode is an efficient way of lowering exhaust emissions from compression-ignition engines. Along with exhaust emissions, mechanical vibration and noise emissions are also problems for these engines. In dual fuel mode, it is possible to reduce all emissions by using the appropriate injection strategy. In this study, different injection strategies were used in an engine with an ECU-controlled liquid and gas fuel system. In experiments, constant load (5 Nm), constant speed (1850 rpm), constant hydrogen energy ratio (12%), 4 different hydrogen injection pressures (1, 1.5, 2.0, and 2.5 Bar), and 5 different hydrogen injection starts (25, 35, 45, 55, and 65 °CA aTDC) were performed. In the study, exhaust, mechanical vibration, and noise emissions were recorded and analysed. When a few of the study's data were looked at, it was determined that CO 2 emissions decreased by 33.4% and PM emissions by 40.7% at 25 °CA aTDC injection start and 2.5 bar injection pressure. Under the same experimental conditions, NO emissions increased by 8.7%, mechanical vibration emissions increased by 19.9%, and noise emissions increased by 2 dBA. [Display omitted] • H 2 -diesel dual fuel use is effective in reducing CO, CO 2 and soot emissions. • In dual fuel mode, H 2 increased NO, mechanical vibration, and noise emissions. • Increasing the injection timing in dual fuel mode reduces emissions. • H 2 injection being lower than 25 °CA aTDC risks combustion safety. [ABSTRACT FROM AUTHOR]

Although the direct conversion of syngas to gasoline fuel offers a promising route to produce liquid fuel from non-petroleum carbon resources, it remains a great challenge owing to low target product selectivity and poor catalyst stability. Hence, we designed a bifunctional catalyst consisting of SiO2-coated novel hierarchical porous cage active particles and hierarchical porous zeolite, which provided a C5–C11 hydrocarbon selectivity of 63.5 wt%, and the yield reached 99.3% in C5+ hydrocarbons, with an aromatic content of 25.7% at 280 °C. Particularly, this value is within the range of the restricted aromatic content. As the reaction temperature was elevated to 310 °C, zeolite-24 presented an excellent aromatic selectivity of 64.4% in liquid hydrocarbons. This is mainly because the zeolite provides higher acidity at a rather high reaction temperature, facilitating the formation of hydrocarbons in the liquid phase, which were predominantly aromatics rather than i-C5+. Besides aromatics, a high i-C5+ content of 77.4% in liquid hydrocarbons was obtained at 280 °C over FeZ-16. At the given condition, the synthesized hybrid catalysts were beneficial for the production of gasoline fuels consisting of aromatics and i-C5+. Particularly, 280 °C offered optimum selectivity to i-C5+, and 310 °C was suitable for the formation of aromatics. This work provides a strategy for the design and preparation of novel and efficient catalysts for gasoline production. [ABSTRACT FROM AUTHOR]

This work investigates the physical properties and swelling behavior of additively manufactured (AM) and traditionally manufactured (TM) polyurethane (PU) and silicone O-rings when exposed to organic liquids and military fuels. Polymer properties were explored using differential scanning calorimetry, thermal gravimetric analysis, and tensile testing, and two AM print orientations (vertical and horizontal) were investigated. The AM polyurethane vertical and horizontal O-rings formed from a selective laser sintering (SLS) process had similar thermal features to each other and differed slightly from the un-sintered polymer in the temperature at which the greatest rate of mass loss occurred in the TGA analysis. The thermal features of the AM silicone O-rings formed using stereolithography (SLA) were more similar to those of a commercial soft silicone than to those of a commercial high purity silicone. The horizontal print orientation for each polymer had a higher tensile strength than its respective vertically oriented print. A 1-week exposure of the AM O-rings to the various organic liquids reduced the tensile strength of AM O-rings by as much as 80% (tensile strength exposed/tensile strength unexposed = 0.2). Polyurethane AM O-rings swelled from 3 to 74% with the greatest swelling occurring from exposure to acetone. Silicone AM O-rings swelled from 13 to 258% with the greatest swelling occurring from exposure to iso-octane. In general, the commercial O-rings swelled less than their AM counterparts, had higher tensile strengths, and had smoother surfaces. The maximum swelling for the PU O-rings occurred at an overall Hansen solubility parameter (HSP) between 18 and 20 MPa1/2, while the maximum for silicone occurred at an HSP of 14.3 MPa1/2. These values are consistent with literature values, which can vary widely. [ABSTRACT FROM AUTHOR]

Human efforts to overcome environmental problems from using fossil fuels continue, such as hydroconversion of biomass into bio-jet fuel. Research on producing a jet fuel range of bio-hydrocarbons from used palm cooking oil catalyzed by sulfated zirconia impregnated with nickel-molybdenum bimetal has been successfully conducted. The hydrothermal method synthesized the nano-catalyst material in the sulfation and impregnation processes. The hydroconversion process was carried out at atmospheric pressure and a temperature of 300-600 °C for 2 h with a hydrogen gas flow rate of 20 mL/min and a catalyst-to-feed ratio of 1:100 (wt%). Compared with zirconia and sulfated zirconia, NiMo-impregnated sulfated zirconia showed the best activity and selectivity in bio-jet fuel production with liquid product and selectivity of 61.07% and 43.49%, respectively. This catalyst also performed well in three consecutive runs, with bio-jet fuel selectivity in the second and third runs of 51.68% and 30.86%, respectively. [ABSTRACT FROM AUTHOR]

Global warming and urbanization are likely to increase fires in natural and urbanized areas, requiring advanced fire management techniques such as the use of aqueous film forming foams. However, these foams contains in particular toxic fluorinated compounds that belongs to the class of the so-called 'forever chemicals'. Here we review aqueous film forming foams with focus on classification, film forming, composition, toxicity, and standards. Foams are classified into aqueous film forming foams, alcohol-resistant foams, and fluoroprotein foams. Foams contain hydrocarbon surfactants, fluorosurfactants, organic solvents, and additives such as pH buffers, stabilizers, salts, corrosion inhibitors, and anti-freeze agents. Firefighting foams are aggregates of small bubbles that efficiently combat liquid fuel fires by forming a vapor-suppressing blanket over the fuel surface. Aqueous film forming foams contain 2–15% of stable perfluorinated molecules. Concerning toxicity, perfluorooctanoic acid has a half-life of more than five years in adult humans. Alternative compounds such as perfluorobutane sulfonate has a shorter half-life of 45 days in adult humans, yet its impact on soil and aquatic ecosystems is not fully understood. The proprietary nature of the aqueous film forming foam formulations is a challenge in developing sustainable firefighting foams. [ABSTRACT FROM AUTHOR]

This study examines the impacts of equivalence ratio and temperature for different liquid–gas fuel mixtures such as hydrogen, methane, propane and benzene, ethanol, gasoline, hexane, isooctane, methanol and toluene on the variation of power output, thermal efficiency, efficiency of exergy (second law efficiency) and NO formation were examined. The mixtures consist of 50% of liquid fuels and 50% of gaseous fuels. The results revealed that the equivalence ratios and fuel temperatures remarkably affect the NO and performance of the spark ignition engine. The minimum values of performance characteristics of the fuels are attained at 1.5 of equivalence ratio. Maximum power output values are observed at 1 of the equivalence ratio. Power, thermal and exergy efficiencies decrease with increasing fuel temperatures. However, NO formation has reverse relation with temperature. Maximum and minimum values of power output are 16.21 kW and 1.03 kW which are observed with toluene–hydrogen and methanol–hydrogen mixtures. Maximum and minimum values of thermal efficiency are 45.04% and 3.29% which are observed with benzene–hydrogen and methanol–hydrogen mixture combustion. The same mixture kinds provided maximum and minimum values of exergy efficiency and NO formation as 45.24–3.28% and 1.83E-06 mol/cm3–2.97E-32 mol/cm3, respectively. In the results, the performance characteristics are changed depending on equivalence ratios and fuel temperatures. [ABSTRACT FROM AUTHOR]

Taking the Paleozoic of the Sichuan and Tarim basins in China as example, the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petroleum in China have been elaborated. By discussing the development of "source-reservoir-seal" controlled by the breakup and assembly of supercontinents and regional tectonic movements, and the mechanisms of petroleum generation and accumulation controlled by temperature-pressure system and fault conduit system, Both the South China and Tarim blocks passed through the intertropical convergence zone (ITCZ) of the low-latitude Hadley Cell twice during their drifts, and formed hydrocarbon source rocks with high quality. It is proposed that deep tectonic activities and surface climate evolution jointly controlled the types and stratigraphic positions of ultra-deep hydrocarbon source rocks, reservoirs, and seals in the Sichuan and Tarim basins, forming multiple petroleum systems in the Ediacaran--Cambrian, Cambrian--Ordovician, Cambrian--Permian and Permian--Triassic strata. The matching degree of source-reservoir-seal, the type of organic matter in source rocks, the deep thermal regime of basin, and the burial-uplift process across tectonic periods collectively control the entire process from the generation to the accumulation of oil and gas. Three types of oil and gas enrichment models are formed, including near-source accumulation in platform marginal zones, distant-source accumulation in high-energy beaches through faults, and three-dimensional accumulation in strike-slip fault zones, which ultimately result in the multi-layered natural gas enrichment in ultra-deep layers of the Sichuan Basin and co-enrichment of oil and gas in the ultra-deep layers of the Tarim Basin. [ABSTRACT FROM AUTHOR]

Pyrolysis is a thermal conversion process in the absence of air to derive energy components from the residues. Renewable-energy technologies will play a major role in addressing future challenges related to environmental safety and energy security. One of the many easily available renewable energy sources is biomass—an organic material that is thought to be carbon-neutral. Pyrolysis technology is a thermochemical process that can be used to produce useful products from biomass, such as biochar, bio-oil and combustible pyrolysis gases. The structure and relative product yield are impacted by the pyrolysis method employed. This article evaluates different approaches for biomass pyrolysis. Fast, slow and advanced pyrolysis methods using various pyrolyser reactors have been studied in the literature and are provided to increase the variety and use of these methods in upcoming studies and research. Slow pyrolysis can lead to increased ecological well-being, as it increases the amount of biochar produced using auger and rotary-kiln reactors. Rapid pyrolysis, mainly in fluidized-bed reactors with bubbling and rotating circulation, can be used to obtain bio-oil. Advanced pyrolysis methods offer a good probability of yielding great prosperity for specific applications. The selection of a pyrolysis process is based on the required output in terms of solid, liquid and gaseous fuels, and the parameter plays a crucial role in the pyrolysis performance. [ABSTRACT FROM AUTHOR]

The fuel measurement pump is an installation used to measure the quantity of liquid fuel (BBM) to be sold or delivered to consumers. In the transaction of buying and selling fuel at gas stations, the fuel measurement pump plays a crucial role. Therefore, this measuring device needs to be calibrated or re-verified, and supervision is carried out using a standard measuring vessel with capacities of 10 L or 20 L. Errors in reading the measuring vessel can occur due to differences in individual visual acuity. To address this issue, a prototype for automatic reading of measuring vessels is created using a webcam camera. This prototype utilizes the Raspberry Pi 3 B+ as an image processor and the Logitech C270 webcam as an image capturer. The image processing process involves segmentation steps, transforming the image into a grayscale and then into a binary image. This research involves two different types of fluids in the volume measurement of the measuring vessel, namely distilled water (equates) and petalite. The measurement results with the prototype show an average accuracy level of around 99,23%, an average precision level of about 99,37%, and an average error rate of about 0,77%. For the equated fluid, the accuracy, precision, and error levels are 99,48%; 99.76%; and 0,52%, respectively. Meanwhile, for the petalite fluid, the accuracy, precision, and error levels are 98,98%; 98,80%; and 1,02%, respectively. [ABSTRACT FROM AUTHOR]

The food supply chain's heavy reliance on electricity poses significant vulnerabilities in the event of prolonged and widespread power disruptions. This study introduces a system-dynamics model that integrates five critical infrastructures—electric grid, liquid fossil fuels, Internet, transportation, and human workforce—to evaluate the resilience of food supply chains to major power outages. We validated the model using the 2019 Venezuelan blackouts as a case study, demonstrating its predictive validity. We then explored how more extreme electricity losses would disrupt the supply chain. More specifically, we modeled the impact of a large-scale cyberattack on the US electric grid and a high-altitude electromagnetic pulse (HEMP) event. A cyberattack severely damaging the US electric grid and allowing for recovery within a few weeks or months would lead to substantial drops in food consumption. However, it would likely still be possible to provide adequate calories to everyone, assuming that food is equitably distributed. In contrast, a year-long recovery from a HEMP event affecting most of the continental United States could precipitate a state of famine. Our analysis represents a first attempt at quantifying how food availability progressively worsens as power outages extend over time. Our open-source model is made publicly available, and we encourage its application to other catastrophic scenarios beyond those specifically considered in this work (for example, extreme solar storms, high-lethality pandemics). [ABSTRACT FROM AUTHOR]

This paper presents a framework for energy, exergy utilization, and economic analysis of industrial steam boiler system in Nigerian Bottling Company (NBC), Enugu, Nigeria. The study was carried out by an investigative approach in which all other parameters were kept constant, and a particular one was varied, and the desired quantity measured. The results of the effects of burner rotary cup speed and fuel nozzle sizes on emissions show that for boiler having liquid fuel nozzle sizes 3mm, 4mm and 6mm and with constant fuel inlet temperature of 82°C were analysed. Nozzle size of 4mm diameter with burner rotary cup operating at speed of 2920rev/min to 3200rev/min generated minimum emission while burning fuel oil of 82°C with excess air of 12.36%. Similarly, nozzle size of 6mm with rotary cup burner operating between 3950rev/min to 4400rev/min at 12.36 % excess air generated no emission of CO and NOx. It was concluded that the combustor yielded the highest energy efficiency of 99.8% while the heat exchanger gave the lowest energy efficiency of 94% when run on both fuel oil and natural gas. This improved efficiency translates to a savings of approximately 89 million naira annually for a boiler operating at 46% availability yearly. [ABSTRACT FROM AUTHOR]

The electrocatalytic oxidation of carbon-based liquid fuels, such as formic acid and alcohols, has important applications for our renewable energy transition. Molecular electrocatalysts based on transition metal complexes provide the opportunity to explore the interplay between precise catalyst design and electrocatalytic activity. Recent advances have seen the development of first-row transition metal electrocatalysts for these transformations that operate via hydride transfer between the substrate and catalyst. In this Frontier article, we present the key contributions to this field and discuss the proposed mechanisms for each case. These studies also reveal the remaining challenges for formate and alcohol oxidation with first-row transition metal systems, for which we provide perspectives on future directions for next-generation electrocatalyst design. [ABSTRACT FROM AUTHOR]

In recent times, there has been an amplified interest in exploring fresh applications of biogas, attributed to the rising concerns surrounding climate change and an enhanced emphasis on the utilization of renewable energy sources. This manuscript undertakes a comprehensive assessment of recent advancements in the domains of dry, bi-, and tri-reforming. Notably, it emphasizes situations in which the CO 2 present in biogas assumes the role of an oxidant or partial oxidant. A comparative evaluation of various techniques and the exploration of recent catalysts employed in the reforming process and techno-economic biogas conversion applications are also deliberated in this analysis. Biogas conversion exhibits economic feasibility, typically with a payback period ranging from 4 to 8 years. Opting for a higher reaction temperature within the range of 830–900 °C is typically favored as it results in increased CH 4 and CO 2 conversions within the bi-reforming of the biogas process. Similarly, the temperature range is maintained between 750 and 850 °C and 850–1000 °C or above (depending on various factors) for dry reforming and tri reforming respectively. In general, biogas can undergo conversion processes to produce hydrogen, methanol, compressed natural gas, liquid fuel, wax, and form of heat. The inclusive conversion of biogas efficiency ranges from around 35%–80%, depending on the specific type of product being generated. [Display omitted] • Study investigates biogas valorization for H 2 production. • Desire H 2 /CO molar ratio decreases for H 2 production above 2.2. • Ni/CeO 2 –ZrO 2 nanoparticles appear promising as a catalyst. • Bi, dry, and tri-reforming optimize at 830–900 °C, 750–850 °C, and 850–1000 °C or higher, respectively. • Biogas conversion is 35–80% efficient, with a 4–8 year average payback period based on economic analysis. [ABSTRACT FROM AUTHOR]

Iron (Fe) has profound impacts on Earth's ecosystem and global biogeochemical cycles. Fe deposited onto glacier surfaces reduces snow and ice albedo, thereby accelerating glacier melting, and supplying downstream ecosystems with dissolved Fe. However, the origins of atmospheric Fe deposition in glacier regions of western China remain unclear. This study presents novel insights into Fe isotopic composition (refer to δ56Fe) and origins, gained from geochemical analysis of large‐scale cryoconite samples collected from glaciers in western China, which encompass the Tibetan Plateau (TP) and the Tianshan Mountains. Results showed that cryoconite δ56Fe ranged from −1.06 ± 0.07‰ to 0.33 ± 0.04‰, regardless of their concentration. Moreover, anomalous δ56Fe values deviating significantly from the upper continental crust values (with an average of 0.09‰) were detected, indicating a significant impact of anthropogenic Fe materials on the investigated glaciers. This impact was particularly prominent in the margin regions of the TP and its surroundings, but was less apparent in the interior and southern of the plateau. Using MixSIAR isotope mixing model, we determined that coal combustion and other anthropogenic combustion sources (such as liquid fuel combustion and steel smelting) contributed to cryoconite Fe in the range of 6.9%–43.1% and 0.8%–23.4%, respectively. Among these, coal combustion was the predominant anthropogenic source of cryoconite Fe in western China's glaciers. Compared with other sink areas in the Northern Hemisphere, glaciers in western China are obviously affected by anthropogenically sourced Fe. This study has significant implications for understanding glacier‐fed downstream ecosystems and the regional biogeochemical cycle. Plain Language Summary: Iron (Fe) has profound impacts on snow/ice albedo and the biogeochemical cycle of downstream ecosystems in glacier basins. However, the origins of atmospheric Fe deposition in remote glacier regions of western China remain unclear. Fe isotopes (refer to δ56Fe), serve as a distinctive tool for tracing the sources of aerosol Fe materials that leave their mark on glaciers. Based on a comprehensive data set of Fe isotopes within cryoconite samples collected from 12 high‐altitude glaciers spanning a broad spatial range in western China, this study found that remote glaciers in western China are significantly affected by anthropogenically sourced Fe, with potential implications for glacier‐fed downstream ecosystems and the regional biogeochemical cycle. Key Points: Remote glaciers in western China are significantly affected by anthropogenically sourced FeAnthropogenic Fe impact is particularly prominent in the marginal glacier regions of western ChinaCoal combustion provides the main anthropogenic source of cryoconite Fe in western China's glaciers [ABSTRACT FROM AUTHOR]

This study investigates the potential of utilizing pyrolysis byproducts, including char and non-condensable gases, as an energy source to promote autothermal pyrolysis. A total of six pyrolysis experiments were conducted at three distinct cracking temperatures, namely, 450 °C, 500 °C, and 550 °C. The experiments utilized two types of biomasses, i.e., 100% pine chips and 75% pine chips mixed with 25% refuse-derived fuels (RDF). The findings from the experiments were subsequently incorporated into a process simulation conducted on Aspen Plus for an energy balance and a techno-economic analysis. The results of the experiments revealed that the energy produced by the byproducts utilizing only pine chips is 1.453 kW/kg, which is enough to fulfill the energy demand of the pyrolysis reactor (1.298 kW/kg). However, when 25% of RDF is added, the energy demand of the reactor decreases to 1.220 kW/kg, and the produced energy increases to 1.750 kW/kg. Furthermore, adding RDF increases bio-oil's lower heating value (LHV). The techno-economic study proposed three scenarios: optimistic, conservative, and tragic. The optimistic has a payback period (PBP) of 7.5 years and a positive net present value (NPV). However, the other two scenarios were unfavorable, resulting in unfeasibility. [ABSTRACT FROM AUTHOR]

The co-pyrolysis of polyethylene terephthalate (PET) with low-density polyethylene (LDPE) and high-density polyethylene (HDPE) was carried out in a batch steel pyrolyzer in order to convert the PET into pyrolysis oil as its pyrolysis alone resulted in wax and gases. The study also aimed to increase the aromatic content of pyrolysis oil by the interaction of degradation fragments of linear chains of LDPE and HDPE with the benzene ring of PET during the pyrolysis. The reaction conditions were optimized for a higher yield of pyrolysis oil which were found to be 500 °C pyrolysis temperature with a heating rate of 0.5 °Cs−1, 1 h reaction time and 20 g of the initial mass of polymer mixture having 20% PET, 40% LDPE and 40% HDPE. Waste aluminium particles were applied as an economical catalyst in the process. The thermal co-pyrolysis yielded 8% pyrolysis oil, 32.3 wax, 39.7 wt% gases and 20% coke while the catalytic co-pyrolysis produced 30.2% pyrolysis oil, 4.2% wax, 53.6 wt% gases and 12% coke. The fractional distillation of catalytic oil resulted in 46% gasoline range oil, 31% kerosene range oil and 23% diesel range oil. These fractions resembled the standard fuels in terms of their fuel properties as well as FT-IR spectra. The GC-MS analysis revealed that the catalytic co-pyrolysis favoured the formation of relatively short-chain hydrocarbons with olefins and isoparaffins as major components while the thermal co-pyrolysis formed long-chain paraffins. The naphthenes and aromatics were also found in higher amounts in the catalytic oil compared with the thermal oil. [ABSTRACT FROM AUTHOR]

Solar‐driven CO2 reduction and water oxidation to liquid fuels represents a promising solution to alleviate energy crisis and climate issue, but it remains a great challenge for generating CH3OH and CH3CH2OH dominated by multi‐electron transfer. Single‐cluster catalysts with super electron acceptance, accurate molecular structure, customizable electronic structure and multiple adsorption sites, have led to greater potential in catalyzing various challenging reactions. However, accurately controlling the number and arrangement of clusters on functional supports still faces great challenge. Herein, we develop a facile electrosynthesis method to uniformly disperse Wells‐Dawson‐ and Keggin‐type polyoxometalates on TiO2 nanotube arrays, resulting in a series of single‐cluster functionalized catalysts P2M18O62@TiO2 and PM12O40@TiO2 (M=Mo or W). The single polyoxometalate cluster can be distinctly identified and serves as electronic sponge to accept electrons from excited TiO2 for enhancing surface‐hole concentration and promote water oxidation. Among these samples, P2Mo18O62@TiO2‐1 exhibits the highest electron consumption rate of 1260 μmol g−1 for CO2‐to‐CH3OH conversion with H2O as the electron source, which is 11 times higher than that of isolated TiO2 nanotube arrays. This work supplied a simple synthesis method to realize the single‐dispersion of molecular cluster to enrich surface‐reaching holes on TiO2, thereby facilitating water oxidation and CO2 reduction. [ABSTRACT FROM AUTHOR]

The goal of the present study is to build a computational combustion model and numerically investigate the stoichiometric mixture fraction generated from blending liquid n-pentane fuel with liquid hydrogen applied in the form of combustible spray droplets. The mixture fraction-probability density function is used to construct the combustion model. The role of the mixture fraction that is generated from blending n-pentane and hydrogen at different mass fraction ratios. From the numerical results, the increase in H 2 blending in the C 5 H 12 /H 2 mixture increases the temperature and velocity of the flame. Furthermore, the addition of hydrogen expands the reaction zone to locations downstream of the flame. The enrichment of the reactive mixture with H 2 reduces the emission of CO. Only in the reaction zone does hydrogen fuel enrichment decrease the mass fractions of CO and OH. The results confirm that the PDF-RANS model gives satisfactory agreement with the experimental data. [Display omitted] • The addition of liquid hydrogen to the n-pentane liquid fuel. • New implementation for the PDF combustion model. • The spray combustion model is being examined in relation to the addition of liquid hydrogen. • Simulation for the spray combustion cases in different blending ratios. • The analyses of the spray combustion zones are made. [ABSTRACT FROM AUTHOR]

[Display omitted] The potential for directly converting CO 2 to valuable liquid fuels utilizing green and renewable electricity has sparked significant interest in CO 2 electroreduction (CO 2 RR). In recent years, CO 2 conversion to formate/formic acid (HCOO−/HCOOH) has witnessed fast growth due to its economic and technological viability combined with the development of highly selective catalysts and practical electrolyzes. In this review, we summarize and discuss recent advances in HCOOH generation from CO 2 reduction in terms of (1) the rationale behind choosing HCOOH as a CO 2 electroreduction product, (2) mechanistic pathways to form HCOOH, (3) novel electrocatalyst developments for enhanced HCOOH production, and (4) electrolyzer designs that tackle practical challenges in scalability, reaction rate, and product impurities. Finally, a brief outlook on future opportunities in this field is offered to accelerate the industrialization of CO 2 RR to HCOOH. [ABSTRACT FROM AUTHOR]

An isooctane spray from a high-pressure multihole GDI injector (Bosch HDEV6) was characterised by means of optical extinction tomography, relying on collimated illumination by a focused shadowgraph setup. The tests were carried out in air under ambient conditions at an injection pressure of 300 bar. Spray images were acquired over a 180-degree angular range in 1-degree increments. The critical issues of optical extinction tomography of sprays, related to the strong light extinction by the dense liquid core of fuel jets, were addressed. To mitigate artefacts arising from the reconstruction process, the extinction data were subjected to spatially-variant filtering steps for both raw and post-log data before being analytically inverted through the inverse Radon transform. This approach made it possible to process extinction data at very large optical depths. A nearly complete three-dimensional reconstruction of the spray was obtained, providing significant details of the spray morphology and the internal structure of the jets throughout spray development. Different phases of the atomization process, from the near-field to the far-field regions of the spray, were observed. [ABSTRACT FROM AUTHOR]

Current global challenges associated with energy security and climate emergency, caused by the combustion of fossil fuels (e.g., jet fuel and diesel), necessitate the accelerated development and deployment of sustainable fuels derived from renewable biomass-based chemical feedstocks. This study focuses on the production of long-chain (straight and branched) ketones by direct α-alkylation of short chain ketones using both homogenous and solid base catalysts in water. Thus, produced long-chain ketones are fuel precursors and can subsequently be hydrogenated to long-chain alkanes suitable for blending in aviation and liquid transportation fuels. Herein, we report a thorough investigation of the catalytic activity of Pd in combination with, (i) homogenous and solid base additives; (ii) screening of different supports using NaOH as a base additive, and (iii) a comparative study of the Ni and Pd metals supported on layered double oxides (LDOs) in α-alkylation of 2-butanone with 1-propanol as an exemplar process. Among these systems, 5%Pd/BaSO4 with NaOH as a base showed the best results, giving 94% 2-butanone conversion and 84% selectivity to alkylated ketones. These results demonstrated that both metal and base sites are necessary for the selective conversion of 2-butanone to alkylated ketones. Additionally, amongst the solid base additives, Pd/C with 5% Ba/hydrotalcite showed the best result with 51% 2-butanone conversion and 36% selectivity to the alkylated ketones. Further, the screening of heterogenous acid-base catalysts 2.5%Ni/Ba1.2Mg3Al1 exhibited an adequate catalytic activity (21%) and ketone selectivity (47%). [ABSTRACT FROM AUTHOR]

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This study investigated the effects of different proportions of waste polyethylene (WP) and waste cooking oil (WCO) on the chemical and physical properties of the resulting co‐pyrolysis oil produced in an indigenously developed laboratory‐scale fixed bed batch‐type reactor. The proportion of WCO was altered in increments of 10% from 10% to 90%, and correspondingly, the proportion of WP was adjusted from 90% to 10% (by weight). The highest liquid fuel yield, reaching 70.9% by weight, was achieved using a 40:60 ratio of WCO to WP (W40P60) at a constant heating rate of 12°C and a temperature of 500°C. The obtained fuel exhibits promising properties, including a high calorific value (max HHV around 45.63 MJ/kg) and other advantageous properties such as low viscosity, low oxygen and nitrogen content, and absence of sulfur. Fourier‐transform infrared spectroscopy (FTIR) and gas chromatography–mass spectroscopy (GCMS) were examined on the resulting liquid fuel. The GC–MS spectra predominantly display alkanes, constituting approximately 41% by weight, and alkenes, making up roughly 20% by weight. These analyses revealed properties akin to commercial diesel, emphasizing the potential of waste cooking oil and waste polyethylene proportions in liquid diesel like fuel production. [ABSTRACT FROM AUTHOR]

Hypothesis Foaming in diesel fuels is not well understood and leads to operational challenges. To combat deleterious effects of foaming, diesel formulations can include additives called antifoams. Existing antifoams, unfortunately, are inherently ash-generating when combusted, with unknown environmental impacts. They are prohibited in certain countries, so identifying effective alternative ash-free antifoam chemistries is needed. Experiments We conduct systematic characterization of foam stabilization and antifoaming mechanisms in diesel for two different antifoams (silicone-containing & ashless chemistries). Employing a custom technique combining single-bubble/single-antifoam-droplet manipulation with white light interferometry, we also obtain mechanistic insights into foam stability and antifoam dynamics. Results Coalescence times from both bulk foam and single bubble experiments confirm ashless antifoams are effective at reducing foaming, demonstrating the potential of ashless antifoams. Further, we perform single-antifoam-droplet experiments and obtain direct experimental evidence revealing the elusive antifoaming mechanisms. Interestingly, the silicone-containing and ashless antifoams seemingly function via two different mechanisms: spreading and dewetting respectively. This surprising finding refutes conventional wisdom that spreading is likely the only antifoam mechanism in diesels. These results and the reported experimental framework significantly enhance the scientific understanding of non-aqueous foams and will accelerate the engineering of alternative antifoam chemistries for non-aqueous systems. • Single bubble/drop experiments facilitate mechanistic insight driven research into antifoams across non-aqueous systems. • This ashless antifoam is successfully incorporated as microdroplets and is effective at reducing foam. • Direct evidence of underlying antifoam mechanisms from modified antifoam droplet experiments. • Mechanism of action of tested ashless and silicone-containing antifoams are different. [ABSTRACT FROM AUTHOR]

In numerical fire simulations, the calculation of thermal feedback from the flame to the solid and liquid fuel surface plays a critical role as it connects the fundamental gas-phase flame burning and condensed-phase fuel gasification. However, it is a computationally intensive task in CFD fire modelling methods because of the requirement of a high-resolution grid for calculating the interface heat transfer. This paper proposed a real-time prediction of the flame-to-fuel heat transfer by using simulated flame images and a computer-vision deep learning method. Different methanol pool fires were selected to produce the image database for training the model. As the pool diameters increase from 20 to 40 cm, the dominant flame-to-fuel heat transfer shifts from convection to radiation. Results show that the proposed AI algorithm trained by flame images can predict both the convective and radiative heat flux distributions on the condensed fuel surface with a relative error below 20%, based on the input of real-time flame morphology that can be captured by a larger grid size. Regardless of growing or decaying fires or puffing flames induced by buoyancy, this method can further predict the non-uniform distribution of heat transfer coefficient on the interface rather than using empirical correlations. This work demonstrates the use of AI and computer vision in accelerating numerical fire simulation, which helps simulate complex fire behaviours with simpler models and smaller computational costs. [ABSTRACT FROM AUTHOR]

The utilization of liquid fuel will greatly expand the application scope of rotating detonation engines, and there are still great challenges to achieve high-performance liquid-fuel rotating detonation operation. In this paper, aviation kerosene was used as the liquid fuel to investigate the effects of fuel temperature on the propagation characteristics of rotating detonation waves in two combustor structures: annular and cavity. An electric heating tape was employed to heat the kerosene up to 390 K. The results demonstrate that increasing the temperature of kerosene enhances its atomization efficiency, leading to a marked enhancement in the peak pressure and propagation stability of detonation waves. Moreover, the duration required to establish a detonation wave is notably reduced, as low as 11.2 ms. Furthermore, the detonation wave velocity increases with fuel temperature, with significantly higher velocities observed in the cavity combustor structure compared to the annular combustor structure. In the cavity combustor, the detonation wave velocity can reach up to 74 % of the theoretical CJ value. The results verify the feasibility of improving the rotating-detonation performance via increasing liquid-fuel temperature, which can provide reference for the engineering application of rotating detonation. • Experiments and numerical simulations on liquid fuel RDW were well conducted. • Atomization characteristics of liquid fuel under two combustors were analyzed. • RDW propagation characteristics with changing liquid temperature were obtained. [ABSTRACT FROM AUTHOR]

With the development of society, environmental protection is receiving increasing attention, and higher requirements have been put forward for the cleanliness of traditional energy sources. Fuels from distilled natural crude oils contain a variety of sulfur-containing compounds, which lead to serious environmental pollution. New technologies for deep desulfurization of fuels are urgently needed to meet the various stringent sulfur standards for liquid fuels (<15 ppm). In recent years, metal-organic frameworks (MOFs) have shown great potential in a variety of applications, especially in fuel desulfurization, such as hydrodesulfurization, oxidative desulfurization, and adsorptive desulfurization, due to their high porosity, high specific surface area and availability. In addition, the combination of MOFs with membranes or ionic liquids also has high desulfurization efficiency. In this review, the applications of MOFs and their composites in fuel desulfurization over the past decade are summarized. The factors affecting the desulfurization performance are pointed, and the desulfurization mechanism is tentatively clarified. Moreover, future recommendations have been discussed briefly. [ABSTRACT FROM AUTHOR]

We report here on the reductive rearrangement of biomass-derived furfural to cyclopentanone, a promising non-fossil feedstock for fuels and chemicals. An underreported aspect of this reaction is the inevitable formation of heavy byproducts. To mitigate its formation, process condition such as, solvent, catalyst, temperature, acidity, and feed concentration were varied to unravel the chemistry and improve the reaction performance. Water medium was confirmed to play a crucial role, as organic solvents were unable to deliver cyclopentanone or heavy by products. Copper-based catalyst showed the highest selectivity for ring-rearrangement, reaching 50 mol% under the conditions investigated. The main factor influencing the yields of cyclopentanone (CPO), and promote oligomer formation, are the feed concentration and the pH, as high feed concentrations and high acidity facilitate the self-polymerization of furfuryl alcohol (FALC). This was confirmed by dedicated experiments using FALC and the hydroxypentenone intermediate as feed. The concentration challenge could be mitigated by slowly dosing the feed, which increased the desired product yields by 4-12 mol%. Nevertheless, most oligomers appeared to fall in the range of common liquid fuels and could be converted to diesel by hydrodeoxygenation. [ABSTRACT FROM AUTHOR]

Waste glycerol can be subjected to various processing operations, including purification and refining, to obtain glycerol of an appropriate purity. Alternative methods for utilising waste glycerol are also being sought, e.g., by converting it into other valuable chemical products or biofuels. Therefore, various technologies are being developed to ensure effective and sustainable utilisation of this type of waste. The production of value-added products from waste glycerol strongly determines the improvement of the economic viability of biofuel production and corresponds to the model of a waste-free and emission-free circular economy. This paper characterises the mechanisms and evaluates the efficiency of existing methods for microbiological utilisation of waste glycerol into liquid biofuels, including biodiesel, bioethanol and biobutanol, and identifies further production avenues of value-added products. In addition, it presents the results of a bibliographical analysis of publications related to the production of liquid fuels and economically valuable products from glycerol, assesses the progress of research and application work and, finally, identifies areas for future research. [ABSTRACT FROM AUTHOR]

In the current context of fossil energy depletion and the requirement for low carbon emissions, the efficient use of energy and a diversified energy mix have become increasingly important. The use of cleaner and low-carbon alternative fuels is rapidly growing. However, corrosion remains a key issue limiting the large-scale application of alternative fuels. This paper describes the corrosion characteristics of different alternative fuels. Also, the mechanisms of fuel corrosion, corrosion measurement methods, and the future of corrosion inhibitor applications are discussed. Corrosion causes changes in material weight and surface morphology and generates electrical signals as it progresses. Although there are well-established methods to characterize corrosion by recognizing these changes, there is still a need to identify a universal standard signal for their detailed description. For the foreseeable future, corrosion in fuels will continue to be mitigated by the addition of corrosion inhibitors. The research on corrosion inhibitors focuses on green corrosion inhibitors and multifunctional corrosion inhibitors. However, further analysis is needed to understand the active ingredients in green corrosion inhibitors, and the mechanism of corrosion inhibition for different types of corrosion inhibitors needs further research. [ABSTRACT FROM AUTHOR]

The conversion of methane or natural gas into turquoise H2 and carbon represents a promising pathway towards decarbonised energy. The pyrolysis of biogas (mainly a mixture of methane and CO2) is considered to be a negative carbon-emission technology, as the carbon source comes from biomass and the carbon is captured in solid form. In addition, the presence of CO2 in the gas mixture enables the dry reforming of methane into syngas. In this study, we show that direct biogas conversion in a fluidised catalytic reactor can produce a syngas whose composition meets the requirements for methanol synthesis or for liquid hydrocarbon production via the Fischer-Tropsch process. Confirmed by thermodynamic analysis, we show that the reaction proceeds at temperatures above 900 1C to produce carbon materials, whereas at lower temperatures the carbon is converted to CO by the Boudouard reaction. At 950 1C, very high methane and CO2 conversions are achieved (490% and 99%, respectively), accompanied by high hydrogen yield (490%) and the sequestration of carbon into a turbostratic structure. We believe that the direct catalytic reforming of biogas in a fluidised bed, when combined in series with an FTS process, could allow the production of liquid fuels with no need for costly gas separation units, in particular those implemented for CO2 capture. [ABSTRACT FROM AUTHOR]

Syngas conversion serves as a gas‐to‐liquid technology to produce liquid fuels and valuable chemicals from coal, natural gas, or biomass. During syngas conversion, sintering is known to deactivate the catalyst owing to the loss of active surface area. However, the growth of nanoparticles might induce the formation of new active sites such as grain boundaries (GBs) which perform differently from the original nanoparticles. Herein, we reported a unique Cu‐based catalyst, Cu nanoparticles with in situ generated GBs confined in zeolite Y (denoted as activated Cu/Y), which exhibited a high selectivity for C5+ hydrocarbons (65.3 C%) during syngas conversion. Such high selectivity for long‐chain products distinguished activated Cu/Y from typical copper‐based catalysts which mainly catalyze methanol synthesis. This unique performance was attributed to the GBs, while the zeolite assisted the stabilization through spatial confinement. Specifically, the GBs enabled H‐assisted dissociation of CO and subsequent hydrogenation into CHx*. CHx* species not only serve as the initiator but also directly polymerize on Cu GBs, known as the carbide mechanism. Meanwhile, the synergy of GBs and their vicinal low‐index facets led to the CO insertion where non‐dissociative adsorbed CO on low‐index facets migrated to GBs and inserted into the metal‐alkyl bond for the chain growth. [ABSTRACT FROM AUTHOR]

The research impact of catalysts on the hydrothermal carbonization (HTC) process remains an ongoing debate, especially regarding the quest to enhance biomass conversion into fuels and chemicals, which requires diverse catalysts to optimize bio-oil utilization. Comprehensive insights and standardized analytical methodologies are crucial for understanding HTC's potential benefits in terms of biomass conversion stages. This review seeks to understand how catalysts enhance the HTC of biomass for liquid fuel and hydrochar production, drawing from the following key sections: (a) catalyst types applied in HTC processes; (b) biochar functionality as a potential catalyst; (c) catalysts increasing the success of HTC process; and (d) catalyst's effect on the morphological and textural character of hydrochar. The performance of activated carbon would greatly increase via catalyst action, which would progress the degree of carbonization and surface modification, alongside key heteroatoms. As catalytic HTC technology advances, producing carbon materials for thermochemical activities will become more cost-effective, considering the ever-growing demands for high-performance thermochemical technologies. [ABSTRACT FROM AUTHOR]

The Energy Return On Investment (EROI) is a recognised indicator for assessing the relevance of an energy project in terms of net energy delivered to society. For woody biomass divergences remain on the right methodology to assess the EROI leading to large variations in the published estimates. This article presents an in‐depth discussion about the EROI of woody biomass in three different forms: woodchips, pellets and liquid fuels. The conceptualisation of EROI is further developed to reach a consistent definition for biomass post‐processed fuels. It considers, on top of the external energy investments, the grey energy associated with the energy used to enrich the fuel. With the proposed methodology, all woodchips have an EROI of the same order of magnitude, between 20 and 37, depending on forestry types, operations and machineries. For secondary residues, the first estimate is 170 if, as co‐products, no energy investment is allocated to the forestry operations and transport. On the basis of a mass allocation for forestry operations and transport, the EROI for secondary residues becomes of the same order of magnitude as that for wood chips. Woodchips can be further post‐processed into pellets or liquid fuels. Pellets have an EROI of 4–7 if the heat is externally supplied and 8–23 if internally supplied (self‐consumption of part of the raw material). Liquid fuels derived from primary wood and residues through gasification and Fischer‐Tropsch synthesis have an EROI between 4 and 16. Fuel enhancement with hydrogen (Power & Biomass to Liquids) impacts negatively the EROI due to the low EROI of hydrogen produced from renewable electricity. However, these fuels offer other advantages such as improved carbon efficiency. A correct estimate of EROI for forestry biomass, as proposed in this work, is a necessary dimension in assessing the suitability of a project. [ABSTRACT FROM AUTHOR]

Fuel injection systems significantly impact the combustion process and play a key role in reducing harmful exhaust emissions in internal combustion engines. For dual-fuel (DF) engines operating in gas mode, ignition of the main fuel is typically controlled by directly injected liquid pilot fuel. Liquid pilot fuel's initial penetration and total mass considerably impact exhaust emissions and combustion stability. We investigated the spray morphology of a multi-hole diesel fuel injector within a constant-volume spray chamber using high-speed shadowgraphy and Mie-scattering measurements. Two methodologies were employed. The first one utilized a nozzle equipped with a thimble structure to isolate a single plume. The second methodology known as plume-blocking, involved sealing the orifices of the multi-hole nozzle to generate a single-spray plume. Our findings revealed that the plume-blocking approach demonstrated greater penetration than the thimble-equipped nozzle. The rapid penetration of this method may restrict its applicability to single-spray studies. Sprays generated from this partially sealed nozzle exhibited noticeable disparities compared to an unblocked nozzle, whereas a nozzle equipped with a thimble produced similar outcomes to the standard nozzle. The orifices when sealed, modify the flow distribution within the sac volume, which consequently affects the spray characteristics. In summary, this research provides insights into the impacts of various plume isolation methods on spray morphology, thereby enhancing the understanding of spray behaviour in transient conditions by comparing plume variations and disturbances under various fuel pressure and ambient conditions. [ABSTRACT FROM AUTHOR]

Theoretical research into the heat and mass transfer, hydrodynamic and physicochemical processes in combustion chambers of gas turbine engines usually implies that multi-component jet fuels are modeled using single-component liquids (saturated or cyclic hydrocarbons) and their substitutes. Due to an insoluble dispersed phase (e.g., water) in their composition, droplets consist of a noncombustible core and a liquid fuel shell. During heating, water droplets coalesce in fuel droplets to produce explosion-triggering volumes of liquid superheated to the boiling point. When heated, these heterogeneous droplets breakup in the micro-explosion and puffing modes. This study reports the numerical simulation results providing the temporal characteristics of heating and evaporation of heterogeneous droplets until puffing/micro-explosive breakup, when varying the composition of the fuel shell in the homologous series of saturated and cyclic (as illustrated by monocycloparaffins) hydrocarbons from C7 to C16. The conducted research has revealed that the variations in the breakup delay times in the homologous series of saturated and cyclic hydrocarbons are nonlinear. The breakup delay rates were found to increase substantially in the boundary points of the investigated series. Mechanisms to control droplet fragmentation delay time were identified for different initial and boundary conditions. A dimensionless complex reflecting the correlation between the critical conditions of composite liquid droplet breakup and the physicochemical properties of the fuel shell components was proposed. [ABSTRACT FROM AUTHOR]