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This paper explores green hydrogen-based carbon dioxide (CO 2) hydrogenation for the production of oxygenates, presenting it as a pivotal strategy for mitigating carbon emissions and advancing sustainable energy solutions. The conversion of CO 2 into oxygenates through hydrogenation emerges as a promising avenue, particularly in the context of transportation applications where the storage of hydrogen poses challenges. The substitution of fossil diesel and gasoline fuels with green hydrogen-derived dimethyl ether, or methanol/ethanol, is advantageous from a life cycle analysis (LCA) CO 2 emission perspective even without the capture of the CO 2. However, the greatest sustainability appeal is contingent on the crucial aspect of capturing CO 2 when utilizing these fuels, which is an aspect currently absent in the literature. This narrative review comprehensively explores catalytic processes, mechanisms, sustainability perspectives, and the current state of research in this evolving area. It encompasses both the production of oxygenates through CO 2 hydrogenation and the subsequent utilization of these oxygenates in fuel cells or combustion systems, emphasizing the integration of CO 2 capture technologies. The paper contributes to the discourse surrounding the environmental and technological dimensions of energy storage ecosystems, providing a holistic view of their potential to foster sustainable energy solutions. [ABSTRACT FROM AUTHOR]

The ability for existing burners to operate safely and efficiently on hydrogen-blended fuels is a primary concern for the many industries looking to adopt hydrogen as an alternative fuel. This study investigates the efficacy of increasing fuel injector diameter as a simple modification strategy to extend the hydrogen-blending limits before flashback. The collateral effects of this modification are quantified with respect to a set of key performance criteria. The results show that the unmodified burner can sustain up to 50 vol% hydrogen addition before flashback. Increasing the fuel injector diameter reduces primary aeration, allowing for stable operation on up to 100% hydrogen. The flame length, visibility and radiant heat transfer properties are all increased as a result of the reduced air entrainment with a trade-off reported for NOx emissions, where, in addition to the effects of hydrogen, reducing air entrainment further increases NOx emissions. • Flashback limit of a self-aspirating burner extended up to 100 vol% H 2 by increasing d jet. • Primary air entrainment is reduced by increasing d jet. • Positive non-linear relationship between equivalence ratio and flame length. • Negligible reductions in radiant heat transfer with H 2 addition under in modified burner. • Negative linear relationship between NOx emissions and equivalence ratio. [ABSTRACT FROM AUTHOR]

• Validity check of a correlation for the lower heating value based on a common 'heat of oxidation' (Thornton's rule) • The correlation shows the same 'accuracy' as other state-of-the-art correlations. • The correlation implies several advantages over other correlations, e.g.,. − inclusion of non-CHO elements (e.g., halogens). − consistency with oxygen consumption. − clarification of commonalities between different fuels. Various correlations have been proposed to estimate the heat of combustion based on elemental compositions. Although these correlations have only an approximate character, they are very useful in practice since no detailed information about the chemical composition of the material is required. However, despite its successful application in explosion and fire safety, Thornton's approach of using the 'heat of oxidation' as basis for estimations is not very common in standard combustion applications. This communication intends to recall Thornton's approach, provide a validity check and comparison with other correlations against up-to-date recommended data, and highlight its advantages over other approaches. It is shown that none of the studied correlations shows a clear superiority in 'accuracy' over the full range of combustible materials. But Thornton's approach, which uses the relation between heat release and oxygen consumption, carries several advantages over other approaches: For instance, it is consistent regarding fully oxidized compounds, the inclusion of non–CHO elements is straightforward, it allows to make well-known commonalities between fuels explicit, and it provides a simple interpretation for outliers of general rules. These advantages make Thornton's approach preferable to other approaches. [ABSTRACT FROM AUTHOR]

• A novel system is developed for a sustainable airport for hydrogen and kerosene production. • The primary focus of this study involves geothermal, biomass, and PV solar as energy sources. • The performance is evaluated using thermodynamic approaches and Aspen Plus modeling. • The study finds the performance of the system is greatly impacted by the variation in PV solar. • The kerosene production rate increases with an increase in the carbon monoxide to hydrogen ratio. The advancement of sustainable solutions through renewable and clean energy sources is considered crucial to mitigate carbon emissions. This study reports a novel system developed for an airport utilizing geothermal, biomass, and PV solar energy sources. The proposed system is capable of producing five useful outputs, including electrical power, hot water, hydrogen, kerosene, and space heating. The system proposed in the study is further considered for the Vancouver Airport in British Columbia, Canada using the most recent available data. The geothermal sub-system introduced in this study is also unique, which utilizes the carbon dioxide captured from biomass gassification as the heat transfer medium for geothermal heat to the Rankine cycle for power generation and heating. The present system is modeled and analyzed using thermodynamic method through energetic and exergetic approaches to determine the variation in system performance based on different annual environmental conditions. The biomass gasification and kerosene production are evaluated based on the Aspen Plus models and simulation. The efficiencies of the geothermal system with the carbon dioxide reservoir are found to have energetic and exergetic efficiencies of 78% and 37% respectively. The total hydrogen production is potentially estimated to be 452 tons on an annual basis. The kerosene production mass flow rate is reported as 0.112 kg/s. The overall energetic and exergetic efficiencies of the system are found to be 41.8% and 32.9% respectively. Moreover, this study offers crucial information for the aviation sector to adopt sustainable solutions more effectively. [ABSTRACT FROM AUTHOR]

An investigation into the exhaust emissions of carcinogenic polycyclic aromatic hydrocarbons (PAHs) from a diesel engine was reported. The study is reinforced by the experimental results obtained from a tube reactor aimed at examining the PAH formation processes from these fuels. The paper cantered on the 16 priority PAHs suggested by the United States Environmental Protection Agency (US-EPA). These PAHs were produced by burning conventional diesel fuel and a few binary fuels prepared by blending various proportions of toluene into heptane. Special consideration was given to the B2 subgroup of PAHs which are known human-carcinogens. Both the gas born (smaller) PAHs, as well as the larger PAHs, adsorbed onto the particulate were investigated. The engine used was a single-cylinder, light duty, high speed, diesel automotive research engine run at an Indicated Mean effective pressure (IMEP) of 7 bar. Particulate matter was also produced in a tube reactor at temperatures ranging from 1050 to 1350 °C under pyrolysis (oxygen-free) conditions to study PAH and soot formation in conditions which resemble, to an extent, those found in the core of diesel engine fuel sprays. In the diesel engine, it was found that exhaust PAHs were influenced by combustion characteristics like heat release rates and ignition delay. However, in the quiescent oxygen-free conditions of the reactor, chemical composition of the fuels and temperature dominated PAH formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalytic pyrolysis of waste plastics over activated carbon spheres was studied. • The total selectivity of hydrocarbons belonged to gasoline and jet fuel reached 100%. • Changing the catalytic conditions can improve the obtained liquid quality. • After four regeneration cycles, the catalyst still exhibits high catalytic activity. Recovery of value-added fuels or chemicals from waste plastics by pyrolysis is a promising way to eliminate the waste plastics accumulation and alleviate the energy crisis, while developing efficient catalysts of high durability remains a challenge. Herein, activated carbon spheres of various surface chemistry were fabricated and subsequently used in ex-situ catalytic pyrolysis of low-density polyethylene to produce jet fuel and gasoline-ranged hydrocarbons. Experiment results indicate that with the increase of activation time and temperature, the acidity of activated carbon increased slightly owning to the oxygen-containing functional groups increased, and the specific surface area reached the maximum value (707 m2/g) at the activation condition of 800℃ for 60 min. The enlarged specific surface area promotes the C-C bond cleavage that releases more small gases at the expense of liquid yield, and the increase in density of oxygen-containing functional groups and acidity boosts the formation of aromatic hydrocarbons in liquid. When the activated carbon spheres were activated at 800℃ for 80 min, 100% of the hydrocarbons in the liquid belonged to jet fuel and gasoline, and their selectivity was 81.70 area.% and 96.25 area.%, respectively. More importantly, the catalyst exhibits excellent catalytic activity after four reactivation cycles, where the quality of the liquid product is similar to or even better than that achieved by the fresh catalyst. Furthermore, the catalyst still showed excellent performance in the catalytic pyrolysis of waste plastic mixture. [ABSTRACT FROM AUTHOR]

[Display omitted] Lignin and mixed lignocellulosic natural polymer wastes have been accumulated in landfills over the past hundred years. These wastes should be processed to produce added- value chemicals and materials. This mini-review presents a brief literature survey related to state-of-the-art methods developed recently by the world research community to solve the problem of rational conversion of lignocellulosic polymer wastes, including production of hydrogen, synthesis gas, phenols, and monomers. The focus is made on microwave and plasma technologies used for lignocellulosic wastes processing. [ABSTRACT FROM AUTHOR]

Plastic waste has become a major global concern, due to the widespread use of plastics, resulting in plastic waste accumulation in landfills, and poor plastic waste management that has caused discarded plastics to accumulate in oceans, worldwide. Pyrolysis, a thermochemical treatment technique, offers a sustainable and efficient solution by reducing pollution and recovering valuable energy and products. This paper provides an overview of existing pyrolysis techniques for plastic waste and discusses the parameters that influence product yield and selectivity. It explores the impact of different catalysts on the pyrolysis process and offers a comparative assessment with the conventional pyrolysis. By recovering plastic waste through pyrolysis, the dependence on non-renewable fossil fuels can be reduced, bolstering energy sustainability while mitigating plastic waste's environmental repercussions. This paper also discusses the deactivation and regeneration mechanisms of the catalysts, as well as strategies to optimize liquid oil production from plastic waste, highlighting the potential for utilizing pyrolysis-derived liquid oil as a more sustainable energy source. Lastly, the paper includes a discussion on the future outlook of the pyrolysis industry. This review would provide recommendations for future research directions, enabling researchers and stakeholders to identify key areas of interest and develop new projects accordingly. [Display omitted] • Pyrolysis technology has the capability to convert plastic waste into valuable fuels and chemicals. • A comprehensive review of recent advancements in plastics-to-fuels and chemicals technology was presented. • The product yield and selectivity are determined by operating parameters and catalysts. • Emphasis was placed on the importance and significance of establishing a circular economy for plastics. [ABSTRACT FROM AUTHOR]

[Display omitted] • PE was pyrolyzed to fuel oil over Fe/USY catalysts with varied Fe states. • The oil contains mainly alkanes and is abundant in gasoline and diesel range. • Fe/USY catalysts result in higher oil yield and lighter oil than USY zeolite. • Loading of Fe species on USY increased the alkene and aromatic yields in oil. • Fe is more active than Fe oxides in promoting PE cracking to produce light oil. Iron-modified zeolite catalyst has a good application prospect on recycling the waste plastics into value-added fuels via catalytic pyrolysis. Distinguishing the catalytic activities of varied iron states on catalyst is crucial to catalyst designation and plastic-to-fuel process. In this work, we prepared three Fe/USY catalysts, termed Fe(O-550)/USY, Fe(R-300)/USY and Fe(R-450)/USY, that contain different iron states – Fe 2 O 3 , Fe 3 O 4 + Fe (dominantly) and Fe respectively, and investigated their catalytic activities in polyethylene pyrolysis for fuel oils. The results show that loading of the iron species on USY zeolite decreases the catalyst acidity. H 2 reduction treatment in catalyst preparation has no significant influence on the total acidity but slightly changes the concentration of Brønsted and Lewis acid sites. The oil yield after catalysis with different catalysts follows the order: Fe(O-550)/USY (72.5 %) > Fe(R-300)/USY (69.9 %) > Fe(R-450)/USY (66.7 %) > USY (56.5 %). The oil includes a mixture of C 6 -C 34 compounds especially abundant in C 6 -C 10. It is mainly in gasoline and diesel range and consists of alkanes as majority. Generally, loading of the iron species on USY zeolite increases the oil yield and produces lighter oil and more aromatics and alkenes, while the Fe(R-450)/USY shows higher catalytic cracking activity than Fe(O-550)/USY, Fe(R-300)/USY and USY catalysts. Among the varied iron states, the metallic iron is more active than the other iron oxides to promote the catalytic cracking of PE to produce fuel oil, especially the light oil and aromatic fractions. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) from vehicular exhaust are the key precursors of ozone formation in urban areas. However, few studies have comprehensively investigated the diverse factors affecting VOC emissions from motor vehicles. This study performed emission tests on a chassis dynamometer with 15 motor vehicles, covering China IV to China VI standards, using compressed natural gas (CNG), E10, and E0 fuels and under different driving conditions. Results showed that the average VOC emission factors (EFs) were 98.8 ± 34.8 mg km−1, 55.8 ± 13.4 mg km−1, 19.5 ± 2.4 mg km−1 for China IV, China V, and China VI vehicles respectively, with an increasing proportion of oxygenated volatile organic compounds (OVOCs) with the upgrading of emission standards. Alkanes were the dominant component of VOCs emitted from natural gas vehicles, accounting for 84.5%–87.0% of the total VOC emissions; ethanol-containing gasoline reduced the VOC EFs by 16.8% but emitted more OVOCs. Driving conditions exhibited significant impacts on both EFs and VOC compositions. Notably, aromatics emissions decreased continuously with the increasing driving speeds, while alkenes and OVOCs had a rebound trend at the highest speeds due to the four-center reaction of alcohol and the oxidation of aromatics. Compared to evaporative VOC emissions measured with the same instrument, VOCs from tailpipe emissions have exhibited distinct features in the relative ratios among benzene, toluene, and ethylbenzene. In addition, OVOCs are becoming more important in terms of ozone formation potential for gasoline vehicle exhausts. Alkenes in high-cumulative mileage vehicles may also contribute significantly to ozone formation. This study enables a more comprehensive and accurate understanding of VOC emissions from vehicle exhausts and would be beneficial for mitigating urban O 3 pollution. [Display omitted] • The tailpipe VOC emissions under different factors were comprehensively and systematically investigated. • The proportion of OVOCs increased with the upgrading of emission standards. • Ethanol-containing gasoline could help to reduce the total VOC emissions but emit more OVOCs. • The cold-start condition has the highest VOC emissions. [ABSTRACT FROM AUTHOR]

Polythene exhibits low reactivity and slow biodegradability due to its highly reduced hydrocarbon structure. In this study, a process has been developed for the transformation of polythene waste into fuel and its precursor molecule by microbial and enzymatic treatments. In first step polythene was pretreated with Paenibacillus alvei. Through fermentation process for 15 days and products released after fermentation were subsequently bio-transformed into alcohols and acids corresponding to its hydrocarbons, employing Alkane hydroxylase (AlkB). On fermentation using Paenibacillus alvei, 16.8% weight loss was observed after 15 days and surface modification was analyzed through AFM and SEM. The major products released during microbial pretreatment analyzed through Chromatography–High-Resolution Mass Spectrometry (GC-HRMS) were pentane, hexane, heptadecane, dodecane, tetracontane, bromotetradecane, methyl esters, hexadecane, etc. which were converted in second step into hexadecanol, octadecanol, octadecanoic acid, and heptadecanoic acid, etc. with the help of Alkane hydroxylase on enzymatic transformation. These findings suggested that the microbial pretreatment results in a release of alkanes, some fatty acids, and esters using Paenibacillus alvei Among these, AlkB facilitated the transformation of C 16 and C 15 hydrocarbons into hexadecanol, and pentadecanol respectively. This process holds the potential as an alternative to traditional fuels, and an optimization process can be pursued to enhance the overall yield. [Display omitted] • Low-Density Polythene Waste (LDPE) waste has been microbially pretreated with Paenibacillus sp. • Microbial degradation of the polythene surface has been analyzed with AFM and FEG-SEM. • The maximum weight loss of 16.8% was achieved after microbial pretreatment. • Fermented broth of polythene waste was subjected to enzymatic transformation using the Alkane Hydroxylase enzyme. • Fuel and its precursor molecules were detected in GC-HRMS analysis after enzymatic transformation. [ABSTRACT FROM AUTHOR]

The increased global consumption of plastics prompts concerns about disposal methods and management. The castoff plastics (of any kind) majorly end up in landfills or are incinerated or disposed of into the oceans. However, these methods are not sustainable in the long run and harm the ecosystem. A better approach to tackle these wastes is the need of the hour, as the climate change crisis negatively impacts the environment. In this work, a process is ideated and implemented in Aspen Plus® V12.0, which involves the simulation of a fractionation column with a feed that is obtained by the pyrolysis of the waste plastic to yield an array of distillate cuts consisting of different hydrocarbon mixtures. Analysis of the fractionation column performance with sieve and bubble-cap tray configurations and the effect of tray efficiency, temperature, pressure, and other factors on the composition of the hydrocarbon mixture in different product streams were studied and outlined with the equilibrium tray and rate-based calculation mode. A techno-economic analysis of the process was also performed, and the relevant comparative analyses were illustrated and outlined. [Display omitted] • A fractionation column design for the separation of waste plastic pyrolysis oil. • Optimal temperature and pressure conditions were obtained for the desired separation. • The impact of the separation into fuels with different tray types was discussed. • Comparative analysis of the results from equilibrium and rate-based calculations. • The economic analysis of the process for technology transfer was discussed. [ABSTRACT FROM AUTHOR]

The EU Horizon2020 consortium PHOTOFUEL joined academic and industrial partners from biology, chemistry, engineering, engine design, and lifecycle assessment, making tremendous progress towards engine-ready fuels from CO 2 via engineered photosynthetic microbes. Technical, environmental, economic, and societal opportunities and challenges were explored to frame future technology realization at scale. [ABSTRACT FROM AUTHOR]

Clostridium ljungdahlii is a representative autotrophic gas-fermenting acetogen capable of converting CO 2 and CO into biomass and multiple metabolites. The carbon fixation and conversion based on C. ljungdahlii have great potential for the sustainable production of bulk biochemicals and biofuels using industrial syngas and waste gases. With substantial recent advances in genetic manipulation tools, it has become possible to study and improve the metabolic capability of C. ljungdahlii in gas fermentation. The product scope of C. ljungdahlii has been expanded through the introduction of heterologous production pathways followed by the modification of native metabolic networks. In addition, progress has been made in understanding the physiological and metabolic mechanisms of this anaerobe, contributing to strain designs for expected phenotypes. In this review, we highlight the latest research progresses regarding C. ljungdahlii and discuss the next steps to comprehensively understand and engineer this bacterium for an improved bacterial gas bioconversion platform. [ABSTRACT FROM AUTHOR]

Biotechnology offers a green alternative for the production of fuels and chemicals using microbes. Although traditional model hosts such as Escherichia coli and Saccharomyces cerevisiae have been widely studied and used, they may not be the best hosts for industrial application. In this review, we explore recent advances in the use of nonconventional hosts for the production of a variety of fuel, cosmetics, perfumes, food, and pharmaceuticals. Specifically, we highlight twenty-seven popular molecules with a special focus on recent progress and metabolic engineering strategies to enable improved production of fuels and chemicals. These examples demonstrate the promise of nonconventional host engineering. • Advances using nonconventional hosts for bioproduction of fuels and chemicals. • Progress for twenty-seven molecules from ten classes of precursors. • Advantages of using nonmodel hosts for various metabolite building-blocks are demonstrated. • Nonconventional hosts possess unique metabolic and physiological advantages. [ABSTRACT FROM AUTHOR]

• Mild desilication conditions introduced mesopores without affecting the ZSM-5 structure and the micropore surface area. • TEM and BJH pore analysis proved that the desilication process was an effective path for generating intracrystalline porosity. • Enhanced activity and selectivity to jet fuel/diesel range products were achieved over the desilicated ZSM-5 catalyst. • Introducing mesopores enhanced catalyst stability up to 72 h time on stream with ˜90% 1-hexene conversion. Zeolites with various pore structures and sizes such as microporous ZSM-5, desilicated ZSM-5, Beta zeolite and ZSM-48 were investigated as catalysts in the oligomerization of propylene and 1-hexene to fuel-range hydrocarbons. Mesoporous ZSM-5 was prepared via a post-synthesis alkaline treatment. Physicochemical properties of the zeolite catalysts were characterized by XRD, XRF, SEM, TEM, MAS NMR, BET, and NH 3 -TPD techniques to analyze the crystallinity, element composition, morphology, textural properties as well as acidity distribution. The catalyst characterization confirmed that NaOH post-treatment by mild desilication is an effective method to tune the pore structure of medium pore ZSM-5 zeolite by introducing mesoporosity without damaging the microporous structure. Enhanced activity and selectivity to jet fuel/diesel range (C 12) products of ˜90% and 55% respectively was achieved over a modified ZSM-5 catalyst at optimum reaction conditions of 220 °C and weight hourly space velocity (WHSV) of 4 h−1 in the oligomerization of 1-hexene. Good selectivity to gasoline-range hydrocarbons with high octane number was achieved over modified ZSM-5 in the oligomerization of propylene. The spent catalysts were characterized by thermogravimetric and NH 3 -TPD analyses which confirmed that carbonaceous deposits were prevalent inside the micropores of the catalysts but its effects were less severe on the modified ZSM-5. [ABSTRACT FROM AUTHOR]

Combustion involves chemical reactions that are often highly exothermic. Combustion systems utilize the energy of chemical compounds released during this reactive process for transportation, to generate electric power, or to provide heat for various applications. Chemistry and combustion are interlinked in several ways. The outcome of a combustion process in terms of its energy and material balance, regarding the delivery of useful work as well as the generation of harmful emissions, depends sensitively on the molecular nature of the respective fuel. The design of efficient, low-emission combustion processes in compliance with air quality and climate goals suggests a closer inspection of the molecular properties and reactions of conventional, bio-derived, and synthetic fuels. Information about flammability, reaction intensity, and potentially hazardous combustion by-products is important also for safety considerations. Moreover, some of the compounds that serve as fuels can assume important roles in chemical energy storage and conversion. Combustion processes can furthermore be used to synthesize materials with attractive properties. A systematic understanding of the combustion behavior thus demands chemical knowledge. Desirable information includes properties of the thermodynamic states before and after the combustion reactions and relevant details about the dynamic processes that occur during the reactive transformations from the fuel and oxidizer to the products under the given boundary conditions. Combustion systems can be described, tailored, and improved by taking chemical knowledge into account. Combining theory, experiment, model development, simulation, and a systematic analysis of uncertainties enables qualitative or even quantitative predictions for many combustion situations of practical relevance. This article can highlight only a few of the numerous investigations on chemical processes for combustion and combustion-related science and applications, with a main focus on gas-phase reaction systems. It attempts to provide a snapshot of recent progress and a guide to exciting opportunities that drive such research beyond fossil combustion. [ABSTRACT FROM AUTHOR]

The present study explores net carbon-neutral road transport options in the EU27 in 2050 from a well-to-wheel (WtW) perspective. To this aim, three scenarios have been developed regarding the evolution of the road vehicle fleet composition in terms of the degree of electrification of powertrains, and technical measures such as vehicle efficiency improvements, transport flow, and transport volumes have been considered. The fleet scenarios are further combined with four scenarios deploying different mixes of alternative fuels in 2050, including electricity, e-fuels, liquid/gaseous advanced biofuels and remaining fossil fuel components. Two different electricity production pathways are considered, as well, one of them assuming fully renewable electricity production, and an alternative one including residual shares of nuclear and natural gas power plants plus carbon capture and storage. The Joint Research Centre's DIONE model was used for the scenario calculations. From a tank-to-wheel (TtW) perspective, each scenario reduces energy consumption, mainly due to powertrain electrification, with EU27 TtW road vehicle energy consumption in 2050 ranging from roughly 650 to 1650 TWh, which is 20%–53% of that of 2019. For the most strongly electrified fleet scenario with optimistic assumptions on measures to improve vehicle efficiency, transport flow and transport volumes and renewable electricity production, well-to-tank (WtT) energy consumption is around 110–160 TWh, depending on the fuel scenario. If a moderately electrified fleet is propelled with e-fuels, even when assuming fully renewable electricity and optimistic measures, the WtT energy consumption increases ten times or more, to 1300 TWh (2150 TWh with pessimistic measures). The results show that fleet electrification is the strongest lever for WtW transport energy consumption reduction among the options considered. Other efficiency measures contribute significantly to energy savings, but their benefit decreases with increasing fleet electrification. The production pathways of fuels make a substantial difference for WtW fleet energy requirement if the fleet is moderately electrified, in which case e-fuels require significant amounts of additional renewable electricity. Nevertheless, fuel production pathways become irrelevant from an energetic point of view under very ambitious electrification scenarios since fuel volumes become marginal. The economic feasibility and the societal acceptability of different pathways towards WtW carbon-neutrality of road transport is out of scope of this paper and requires further investigation. • The study examines well-to-wheel scenarios for 2050 carbon neutral road transport. • Electrification is the strongest driver in transport energy consumption reduction. • Vehicle efficiency and activity impacts decrease with fleet electrification. • With high fleet electrification fuel production barely impacts energy consumption. • E-fuels require particularly large amounts of additional renewable electricity. [ABSTRACT FROM AUTHOR]

Ionic Liquid polyoxomolybdate (ILPOM) and ILPOM functionalized silica nanoparticles are efficient catalysts to remove sulfur from diesel by oxidative and extractive processes. This work compares the stability and the catalytic efficiency of different ionic liquid phosphomolybdates ([BPy] 3 [PMo 12 O 40 ] and [BMIM] 3 [PMo 12 O 40 ]) with a cationic (propylpyridinium) functionalized mesoporous silica nanoparticle composite (PMo 12 O 40 @PPy-MSN). These were used as solid catalysts for the oxidative desulfurization of a multicomponent model diesel using hydrogen peroxide as oxidant and a polar immiscible extraction solvent. Ionic liquid ([BMIM][PF 6 ] was successfully used as solvent to extract sulfur compounds from model diesel. The ionic liquid phosphomolybdates showed partial solubility in the ionic liquid phase, occurring some decomposition of their Keggin structure in the soluble reaction media, probably caused by their interaction with oxidant. On the other hand, the phosphomolybdate composite PMo 12 O 40 @PPy-MSN presented high structural stability and only negligible leaching occurrence after various consecutive reaction cycles. The model diesel was near complete desulfurized after 3 h and consecutive desulfurization cycles were performed without loss of activity. Therefore, the immobilization of Keggin phosphomolybdate structure [PMo 12 O 40 ]3− using cationic propylpyridinium silica nanoparticle is an assertive strategy to produce stable and active heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

The aviation sector implementing state-of-the-art engine technologies has made significant progress in reducing the threat of emissions through effective air traffic strategies. Unlike the developments in motor technologies, alternative solutions related to fuels are evaluated in many ways. In order to achieve the objective of emission reduction, thermodynamic performances of low-sulfur diesel and synthetic paraffinic kerosene (SPK), which are preferred as alternative fuel, were investigated. In this study, first, energy and exergy analyses were performed by comparing the fuel consumption of a turboprop engine whilst in a flight period. Energy efficiencies were found lower 6.31% and 7.73% for ultra-low sulfur jet fuels and SPK compared to jet A-1, respectively. At the end of the study, some evaluations about performance effects and improvement processes were made. • The thermodynamic performance of alternative fuel preference were investigated. • Thermodynamics analyses were performed by comparing the fuel preference behavior. • Via gains can be achieved by improving for existing fuels especially sulfur. • Preference of the synthetic paraffinic kerosene was seen that quite effective. • Advanced exergy analysis is useful method for improve performance of components. [ABSTRACT FROM AUTHOR]

A quick and simple procedure is described to determine pyridine and quinoline using voltammetric methods and carbon paste electrodes modified with activated carbon in the proportion of 50:20:30 w /w graphite:activated carbon:silicon. Studies with cyclic voltammetry indicated that reduction of organic nitrogen molecules is irreversible in ammonium chloride solution acidified to pH 2.5 with Britton-Robinson buffer. Under the best optimum conditions for the differential pulse voltammetry for pyridine and square wave voltammetry for quinoline, the analytical curve was linear from 1.0 × 10−4 to 9.0 × 10−7 mol L−1 for both analytes with limits of detection of approximately 2.0 × 10−7 mol L−1 and limits of quantification of approximately 7.0 × 10−7 mol L−1. The proposed methods were successfully applied to determine pyridine and quinoline in samples of textile effluents and fuel with minimum sample treatment. • The molecules pyridine and quinoline are molecules model for studies in monitoring of environmental contamination. • The proposed methodology was used for quantification of pyridine and quinoline in textile effluents and organic matrices. • The EPCM / CA were easy to construct and satisfactory sensitivity for the quantification of pyridine and quinoline molecules. • The proposed method was satisfactory for determination of pyridine and quinoline as required by current legislation. [ABSTRACT FROM AUTHOR]

• HDPE pyrolysis waxes are cracked under industrial FCC unit conditions. • Gases and naphtha are the main products of the HDPE waxes catalytic cracking. • An increase in the conditions severity entails an increase in achieved conversion. • The conversion reached with HDPE waxes is similar to that of VGO. • Refineries and FCC units could be included in plastics management chain. The catalytic cracking of high–density polyethylene pyrolysis waxes under fluidized catalytic cracking conditions has been investigated with the aim of producing fuels at large–scale from waxes obtained in pyrolysis plants located nearby collection and segregation points. Additionally, preliminary information about the capacity of these units to valorize waste polyolefins has been obtained. The catalytic cracking runs have been performed in a riser simulator reactor under industrial conditions: 500–560 °C; catalyst to oil mass ratio, 3, 5 and 7 g cat g oil −1; and, contact time, 6 s. The product distribution has been quantified determining the yields of different fractions, which have been defined according to their boiling point range: dry gas, liquefied petroleum gas, naphtha, light cycle oil, heavy cycle oil and coke. The concentration of the families of compounds has been also determined, which are n–paraffins, iso–paraffins, olefins, naphthenes and aromatics. For the shake of comparison, the results of catalytic cracking of a common stream fed to the industrial units, i.e., vacuum gasoil, have been included. Globally, promising results have been obtained in the valorization of waste polyolefins by means of this combination of pyrolysis–cracking stages that expose, at the same time, the capacity of this unit to manage waste plastics. [ABSTRACT FROM AUTHOR]

Abstract A general and efficient technique is developed to predict the thermal conductivity of well-characterized hydrocarbon mixtures, rocket propellant (RP) fuels, and jet fuels up to high temperatures and high pressures (HTHP). The technique is based upon entropy scaling using the group contribution method coupled with the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state. The mixture number averaged molecular weight and hydrogen to carbon ratio are used to define a single pseudo-component to represent the compounds in a well-characterized hydrocarbon mixture or fuel. With these two input parameters, thermal conductivity predictions are less accurate when the mixture contains significant amounts of iso-alkanes, but the predictions improve when a single thermal conductivity data point at a reference condition is used to fit one model parameter. For eleven binary mixtures and three ternary mixtures at conditions from 288 to 360 K and up to 4,500 bar, thermal conductivities are predicted with mean absolute percent deviations (MAPDs) of 16.0 and 3.0% using the two-parameter and three-parameter models, respectively. Thermal conductivities are predicted for three RP fuels and three jet fuels at conditions from 293 to 598 K and up to 700 bar with MAPDs of 14.3 and 2.0% using the two-parameter and three-parameter models, respectively. [ABSTRACT FROM AUTHOR]

Abstract An entropy scaling based technique using the Perturbed-Chain Statistical Associating Fluid Theory is described for predicting the viscosity of hydrocarbon mixtures and diesel fuels up to high temperatures and high pressures. The compounds found in diesel fuels or hydrocarbon mixtures are represented as a single pseudo-component. The model is not fit to viscosity data but is predictive up to high temperatures and pressures with input of only two calculated or measured mixture properties: the number averaged molecular weight and hydrogen to carbon ratio. Viscosity is predicted less accurately when the mixture contains high concentrations of iso-alkanes and cyclohexanes. However, it is shown that predictions for these mixtures are improved by fitting a third parameter to a single viscosity data point at a chosen reference state. For hydrocarbon mixtures, viscosity is predicted with average mean absolute percent deviations (MAPDs) of 12.2% using the two-parameter model and 7.3% using the three-parameter model from 293 to 353 K and up to 1000 bar. For two different diesel fuels, viscosity is predicted with an average MAPD of 21.4% using the two-parameter model and 9.4% using the three-parameter model from 323 to 423 K and up to 3500 bar. [ABSTRACT FROM AUTHOR]

Highlights • In situ measures of fuel moisture exchange reveal complex responses to meteorology variables among dominant fuel types. • Pine and saw palmetto litter showed multiple lagged responses to precipitation, relative humidity, and net radiation. • Fine dead fuel moisture prediction for fire management cannot rely on current assumptions and simplified tools in humid forests. Abstract Fine dead fuel moisture has a major influence on wildland fire behavior yet the dynamics driving water exchange of fuel particles in forested environments remain poorly understood. Most fire behavior models rely on simple, stand-level fuel moisture estimates, ignoring potentially important variation occurring within fuelbeds that could influence fire behavior. This is especially true in surface fire regimes where variation in fine-scale fuel properties drive fire behavior and subsequent fire effects. Saw palmetto [ Serenoa repens (Bartr.) Small] dominated fuelbeds in the pine forests of the southeastern United States have high within stand variation in one of the most fire prone habitats in the world. Pine needles and palmetto fronds dominate the biomass of fine dead fuel types that produce extreme fire behavior. To assess predictors of fine dead fuel moisture, we analyzed fuel moisture dynamics of these two fine dead fuel types over a two-year period in conjunction with under- and overstory forest meteorological data. Using multiple models and time lag analysis of within-stand moisture dynamics, the results indicate that saw palmetto and pine dramatically differ in drying regimes, primarily resulting from different responses to cumulative rainfall, net radiation, and antecedent atmospheric moisture content. Despite being responsive to changes in relative humidity, saw palmetto was significantly dryer than pine under nearly all meteorological conditions, and it was capable of maintaining extremely low fuel moisture despite high relative humidity or rainfall. Our results point to the need to capture additional drivers of microclimatic variation to aid fire managers in accurately predicting within-stand fuel moisture and subsequent fire behavior. Improving the scientific community's understanding of variation in complex fuel beds is critical for effectively managing risk in fire prone ecosystems. [ABSTRACT FROM AUTHOR]

Highlights • CO 2 potential from biochemical conversion in Germany (2015–2050). • CO 2 potential from cement production in Germany (2015–2050). • Conversion pathways and H2 demand for CO 2 surplus. Abstract Apart from its negative effects on the climate, CO 2 is also a valuable resource, containing carbon – one of the most used and processed elements on Earth. Today, more than 30 Gt of CO 2 is emitted each year, with an increasing tendency. Of this, the main share results from the burning of fossil fuels; only a small fraction derives from renewable fuels. In this study the renewable sources of CO 2 are examined in terms of their current, near-term (2030) and long-term (2050) potential. Current and potential future market output is based on a literature review concerning the future energy market and policy frameworks. As a reference for the utilization of CO 2 , three promising fuel options (methanol, methane and future Fischer-Tropsch fuels) are investigated. Along with the production capacities, H 2 demand for the conversion was calculated on the basis of chemical process simulations. One aim of this study was to provide a comprehensive overview of the expected range of CO 2 recycling from non-fossil sources. It was found that quantities of non-fossil CO 2 lie far behind fossil CO 2 quantities (6.8% of fossil CO 2 provision in 2015). However, with rising demand for CO 2 -based products and a concurrent decrease in the amount and willingness to use fossil CO 2 , in the future non-fossil CO 2 will grow in importance (reaching up to 23% of fossil CO 2 provision in 2050). The study shows that CO 2 from non-fossil sources is a reliable and available source of carbon. [ABSTRACT FROM AUTHOR]

Abstract Mesoporous silica nanoparticles (MSNs) strategically functionalized were used to immobilize a homogeneous polyoxomolybdate catalyst [PMo 12 O 40 ]3- (PMo 12), active but unstable. The PMo 12 @TBA-MSN composite (where TBA refers to surface-tethered tributylammonium groups) conferred high stability to the polyoxomolybdate catalytic center and displayed an increase in efficiency for the oxidative desulfurization (ECODS) of a diesel simulant under sustainable conditions (using H 2 O 2 as oxidant and an ionic liquid, [BMIM]PF 6 , as solvent). Continuous reuse of the catalyst and ionic liquid solvent in consecutive ECODS cycles was successfully performed, avoiding the production of residual wastes. The performance of the PMo 12 @TBA-MSN catalyst improved upon its reuse, leading to complete desulfurization of a multicomponent model diesel containing benzothiophene derivatives after just 1 h of the catalytic stage of the process. The robust nature of the supported catalyst was indicated by characterization of the recovered solid which showed retention of the structural and chemical integrities. Graphical abstract Novel mesoporous nanosilica-supported polyoxometalate showing high efficiency and reusability in the desulfurization of model diesel is described. Image 1 Highlights • Strategically functionalized MSNs as supports for immobilization of [PMo 12 O 40 ]3-. • Complete desulfurization achieved after only 2 h using both catalysts. • The catalyst has shown its efficiency and reusability under sustainable conditions. • Continuous reuse of catalyst and extraction solvent reduced of residual wastes. [ABSTRACT FROM AUTHOR]

Ethylene oligomerization into liquid fuels at slightly over atmospheric pressure has been studied due to its interest to valorize online the excess of ethylene in sustainable olefins production processes and to intensify the production of fuel from refinery secondary streams. Runs were carried out in a fixed-bed reactor under the following conditions: 1.5 bar; 275–375 °C; space time, 2.7–16.2 g catalyst h mol C −1; time on stream, 5 h. The catalyst was prepared by agglomerating a HZSM-5 zeolite (SiO 2 /Al 2 O 3 of 30) in a mesoporous matrix (γ-Al 2 O 3 /α-Al 2 O 3). The hierarchical porous structure of the catalyst enables to reach a pseudo-steady state with a remarkable remnant activity after an initial deactivation period of 2–3 h. Temperature shows a relevant effect on ethylene conversion and product distribution, where a C 5+ liquid fuel yield of 55% above 325 °C and 10.6 g catalyst h mol C −1 is obtained. At 325 °C, gasoline yield is 60%, with high olefin content (49%), which decreases at higher temperature, due to an increase in aromatic and paraffin concentration. Soft and hard coke analysis reveal the role of the matrix to attenuate deactivation. Moreover, above 325 °C the cracking of hard coke precursors deposited in the zeolite micropores prevails respect to their formation. [Display omitted] • Reaction maps (temperature-space time) to maximize ethylene conversion and fuel yield. • At 1.5 bar, both true- and hetero-oligomerization pathways take place above 300 °C. • Maximum gasoline (olefinic) yield (C 5+ , ∼60%) at 325 °C and 16.2 g catalyst h mol C -1. • Catalyst matrix allows maintaining a pseudo-steady state after 3 h on stream. • Soft coke (oligomers) and hard coke (I & II), responsible for catalyst deactivation. [ABSTRACT FROM AUTHOR]

Biomass is regarded as the only carbon-containing renewable energy source and has performed an increasingly important role in the gradual substitution of conventional fossil energy, which also contributes to the goals of carbon neutrality. In the past decade, the academic field has paid much greater attention to the development of biomass pyrolysis technologies. However, most biomass conversion technologies mainly derive from the fossil fuel industry, and it must be noticed that the large element component difference between biomass and traditional fossil fuels. Thus, it's necessary to develop biomass directional pyrolysis technology based on the unique element distribution of biomass for realizing enrichment target element (i.e., element economy). This article provides a broad review of biomass directional pyrolysis to produce high-quality fuels, chemicals, and carbon materials based on element economy. The C (carbon) element economy of biomass pyrolysis is realized by the production of high-performance carbon materials from different carbon sources. For efficient H (hydrogen) element utilization, high-value hydrocarbons could be obtained by the co-pyrolysis or catalytic pyrolysis of biomass and cheap hydrogen source. For improving the O (oxygen) element economy, different from the traditional hydrodeoxygenation (HDO) process, the high content of O in biomass would also become an advantage because biomass is an appropriate raw material for producing oxygenated liquid additives. Based on the N (nitrogen) element economy, the recent studies on preparing N-containing chemicals (or N-rich carbon materials) are reviewed. Moreover, the feasibility of the biomass poly-generation industrialization and the suitable process for different types of target products are also mentioned. Moreover, the enviro-economic assessment of representative biomass pyrolysis technologies is analyzed. Finally, the brief challenges and perspectives of biomass pyrolysis are provided. [ABSTRACT FROM AUTHOR]

Large cargo that cannot be moved worldwide by air or rail transportation is typically conveyed via marine transportation, which relies on fossil fuels and contributes to global emissions. However, a more cost-effective solution is to utilize eco-friendly fuels to reduce carbon emissions. The design of a new hybridized powering system using environmentally friendly hydrogen-based fuel blends is investigated. This paper presents a new hybrid combined marine engine, which involves an internal combustion engine paired with a hybrid solid oxide fuel cell and gas turbine. The exergy, exergoeconomic, and exergoenvironmental analyses are conducted on this proposed engine. It is found that the average net power is about 27 MW with an increase of 30% and the energy and exergy efficiencies are 31% and 41%, respectively. In addition, the average exergetic efficiency based on fuel and product principle is 60%. This new marine engine has 228 $/h Levelized cost rate and 1109 mPt/h environmental rate. Finally, the average overall specific product exergy cost and environment are 64 $/GJ and 22 mPt/MJ, respectively. Also, carbon emissions are significantly reduced by 35%–61%, depending on the fuel blend. Comparing five fuel blends, the methane and hydrogen fuel blend is the most economical and has the least impact on the environment, and the second option is the ethanol blend. • Five alternative fuels are chosen with different concentrations. • Hybrid marine engine produces 27 MW overall power with 60% exergetic efficiency. • Hybrid marine engine has a total levelized cost rate of 228 $/h. • Total component-related environmental of hybrid marine engine is 1109 mPt/h. • Specific product cost and environment are 64 $/GJ and 22 mPt/MJ, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • A valorization alternative for rejected plastic wastes from mechanical-biological treatment. • In-situ catalytic pyrolysis for obtaining products with similar properties to traditional fuels. • Fuel fraction identification by Simulated Distillation along with a hydrocarbon types analysis. • Screaming of the products by analogy with hydrocarbon of the petroleum industry. The contribution provides a valorization alternative for rejected plastic wastes from mechanical-biological treatment (non-recyclable material) via an in-situ catalytic pyrolysis process focused on the production of a liquid fraction with similar properties to traditional fuels (i.e., gasoline, kerosine, and diesel). According to the ASTM recommendations, on small samples without prior physical separation, fuel fraction identification was carried out by Simulated Distillation along with a hydrocarbon types analysis and complemented with CHNS-O analysis and Fourier Transform Infrared Spectroscopy. Two catalytic structures were employed named Sepiolite and Montmorillonites, both K 10 and K30, which after simple heat treatment to stabilize the structure, were characterized to analyze the main properties affecting the catalytic activity and product yields (i.e., morphological and acidity properties). A whole screaming of the products by analogy with hydrocarbon of the petroleum industry is presented. Such an approach allows a real evaluation of the studied technology in the current energy scenario. [ABSTRACT FROM AUTHOR]

Carbon dioxide conversion into value-added products including fuels and chemicals (such as methanol, ethanol, acetic acid and liquid hydrocarbons) has drawn particular attention. This process helps mitigate not only the greenhouse effect but also the unsustainability of fossil fuel extraction. However, a significant amount of energy is needed for converting the highly stable CO 2 into chemicals and fuels. The conventional thermocatalytic route is energy-intensive and thus not sustainable. In this circumstance, non-thermal plasma approach appears as an attractive alternative approach for converting CO 2 into fuels and chemicals at near ambient conditions. This review is a critical analysis of selected literature on plasma-catalytic and plasma photocatalytic interaction for CO 2 conversion. The combination of a catalyst and non-thermal plasma has shown promising results for improving selectivity to desired products with enhanced CO 2 conversion under mild conditions. The challenges of plasma-assisted catalytic CO 2 conversion into oxygenates such as methanol are also highlighted. A combination of photocatalyst and plasma discharge offers a way to further improve the reaction efficiency. The photocatalyst may get activated in the plasma reactor and can influence the reaction performance. The discussions also cover emerging topics for further study in the field of CO 2 conversion. [Display omitted] • Non-thermal plasma coupled with catalyst promising for improving efficiency of CO 2 conversion under mild conditions. • CO 2 conversion routes with H 2 , CH 4 and H 2 O using plasma have been considered and progress reviewed for chemicals and fuels production. • Plasma-catalysis and plasma photo-catalysis have potential to enhance the selective CO 2 conversion to chemicals and fuels. [ABSTRACT FROM AUTHOR]

Highlights • Mass spectral loadings, combined with library matching, yield a data deconvolution quality metric. • An evolving window factor analysis-multivariate curve resolution algorithm can utilize this metric. • The algorithm improves fuel component resolution via gas chromatography-mass spectrometry. Abstract Fuel chromatography is inherently limited by the high complexity of petroleum fuel compositions. In practice, almost no fuel components are fully resolved in gas chromatography. This is due to both insufficient peak capacity for the large number of individual components within time and chromatographic efficiency constraints, and insufficient resolving power of the stationary phase in the gas chromatography column relative to the many structurally similar isomers or homologs present in petrochemical fuels. Multidimensional approaches, longer columns and slower heating rates can offer some benefits but will not necessarily fully resolve co-eluting fuel compounds, especially within reasonable analysis times. The following work details how deconvolved mass spectral loadings, combined with library matching, provide a quality metric against which to automatically evaluate results obtained from an experimental evolving window factor analysis-multivariate curve resolution deconvolution algorithm applied to gas chromatography-mass spectrometry data. This algorithm was evaluated in the context of trace component detection in synthetic fuel data sets, dodecane and tetradecane detection in petrochemical fuels, and the detection of natural products unlikely to be present in petrochemical fuels. In the case of the trace component detection challenge, the experimental algorithm outperformed a control algorithm that utilized a singular value-based quality metric. Meanwhile, when detecting dodecane, tetradecane, and natural products in petrochemical fuels, the experimental algorithm allowed for higher-quality compound identification results than could be obtained without peak deconvolution, thus reliably improving fuel component resolution in an automated fashion. [ABSTRACT FROM AUTHOR]

Highlights • ProCAPD, a computer aided chemical product design software tool is presented. • Large collection of data, models and calculation methods are available through ProCAPD. • ProCAPD includes design options for single species products, blended products, liquid formulated products and functional products. • Results from four blend design problems covering fuels and lubricants are presented. Abstract In chemical product design, application of computer-aided methods helps to design as well as improve products to reach the market faster by reducing time-consuming experiments at the early stages of design. That is, experiments are performed during the later stages as a verification or product refinement step. Computer-aided molecular and mixture-blend design methods are finding increasing use because of their potential to quickly generate and evaluate thousands of candidate products; to estimate a large number of the needed physico-chemical properties; and to select a small number of feasible product candidates for further verification and refinement by experiments. In this paper, an extended computer-aided framework and its implementation in a product design software tool is presented, highlighting the new features together with an overview on the current state of the art in computer-aided chemical product design. Results from case studies involving tailor-made blend design are presented to highlight the latest developments. [ABSTRACT FROM AUTHOR]

To defossilize the current liquid energy backbone a sustainable renewable substitute for fossil crude oil is required. The long–term aim is to increase the co-feed of renewables beyond the current level. However, technical constrains and certain properties limit the conventional biogenic co-feed level to less than 10%. The potential of identifying refinery compatible entry points to directly co-feed bio-based refinery intermediates and further co-process in existing petroleum crude oil refineries is investigated in the current study. The studied pyrolysis bio-oil has been upgraded via mild hydrotreatment (HDT) in order to fulfil specifications and become a “drop-in” biofuel in compatible refinery “location”. The properties of HDT-Bio-oil as well as fossil-based refinery intermediates were compared and five fossil-based refinery intermediates have been concluded as potential candidates for co-processing. The miscibility of the aforementioned renewable and conventional fuels has been investigated. Among all refinery streams, Fluid Catalytic Cracking Light Cycle Oil (FCC LCO) and secondly Light Vacuum Gas Oil (LVGO) have been concluded to be the most promising candidates for co-processing, resembling HDT-Bio-oil’s properties. [ABSTRACT FROM AUTHOR]

A novel synthesis method is presented for the preparation of nanosized-semiconductor cobalt oxide formed successively from a single-source solid various fuel (starch, urea and glycine). The as obtained samples were characterized by the X-ray diffraction, scanning electron microscopy, transmission electron microscopy; diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy and vibrating sample magnetometer (VSM). XRD pattern confirmed the formation of cubic phase Co 3 O 4 . The materialization of Co 3 O 4 nanoparticles is confirmed by HR-SEM and HR-TEM. The optical absorption and photoluminescence emissions were determined by DRS and PL spectra, respectively. The relatively high saturation magnetization (starch) of Co 3 O 4 shows that it is ferromagnetic and low saturation magnetization (urea and glycine) confirms the super paramagnetic behavior. [ABSTRACT FROM AUTHOR]

Ethylene oligomerization is an important step for upgrading light olefins to liquid fuels or value-added chemicals such as butene monomers. Ethylene oligomerization catalyzed by mono-Ni substituted polyoxometalate (POM) catalysts is promising due to the observed selectivity toward linear butene products and stability of these well-defined materials. In this work, two approaches to tailor the catalytic properties of isolated Ni sites in POMs were experimentally tested, both of which perturbed the surrounding molecular environment of the active sites. First, structural modifications were performed to alter the size of the polyoxometalates, evaluating between Wells-Dawson and Keggin structures while maintaining the same elemental components. When comparing these two structures, it was observed that the Ni active sites were kinetically independent from the effect of POM size, even when the POM consisted of the same elements. This was evidenced by the identical product distributions and kinetic parameters observed with both structures. However, a localized kinetic effect was observed when Keggin POM structures containing different internal heteroatoms (e.g, P, Si, Al) were included in close proximity to the Ni active site. Specifically, a notable periodic trend was observed between the electronegativity of internal heteroatoms and the measured apparent activation energy for the catalyzed ethylene coupling reaction to butene. [Display omitted] • The kinetic effects for ethylene oligomerization on Ni-modified POMs was investigated for different POM sizes and heteroatom composition. • No structurally-induced kinetic effects were observed between Ni-modified Keggin (KG) and Ni-Modified Wells-Dawson (WD) POM structures. • Ni-POMs with P, Si, and Al heteroatoms provided activation energies that correlated with the electronegativity between Ni and the internal atom. • Ethylene dimerization appears to follow a coordination-insertion pathway regardless of the size and composition of the of the Ni-POMs studied here. [ABSTRACT FROM AUTHOR]

A sustainable method is employed to remove polycyclic aromatic sulphur heterocycles (PASHs) from fuels by using a series of high surface area nanoporous adsorbents synthesized from polycyclic aromatic hydrocarbons (PAHs). The hypercrosslinking of PAHs has been used to synthesize high surface area (SA BET of 620–1565 m2 g−1) nanoporous polymeric materials via a microwave assisted method. The adsorbent poly-naph (highest SA BET , i.e., 1565 m2 g−1) display best performance for desulphurization of fuels from batch to fixed bed column mode. In batch mode, the adsorption capacity of 12.1 (up to 9 ppm sulphur) and 8.9 mgS g−1 (up to 43 ppm sulphur), has been estimated for model (100 ppm sulphur) and real fuels (110 ppm sulphur), respectively. Furthermore, from ultra-low sulphur model (10 ppm sulphur) and real fuel (9 ppm sulphur), the adsorption capacity of 16.1 (up to 0.3 ppm sulphur) and 10 mgS g−1 (up to 3 ppm sulphur) has been estimated. In fixed-bed column mode, the high concentrated model and real fuel have been desulphurized to final concentration of 1 and 12 ppm, respectively. While, at low concentrations, the final concentration of 100 ppb and 1 ppm is achieved for model and real fuels, respectively. The adsorption mechanism revealed that π-electron density in the polymeric framework plays prominent role in the adsorption process apart from high surface area. This approach to control carcinogenic aromatic pollutants like PAHs and PASHs can be sustained over time through technological advancement, financial assistance and governmental regulation. [Display omitted] • Polycyclic aromatic hydrocarbon pollutants are used to develop adsorbents. • A rapid microwave assisted 60 min synthesis is used. • Desulphurization of fuel at high (∼100 ppm) and low (∼10 ppm) sulphur concentration. • Batch to fixed-bed column mode desulphurization of model and real fuels. • Polycyclic aromatic sulphur heterocycles are removed by developed adsorbents. [ABSTRACT FROM AUTHOR]

Rapid urbanization is increasing the world's energy demand, making it necessary to develop alternative energy sources. These growing energy needs can be met by the efficient energy conversion of biomass, which can be done by various means. The use of effective catalysts to transform different types of biomasses will be a paradigm change on the road to the worldwide goal of economic sustainability and environmental protection. The development of alternative energy from biomass is not easy, due to the uneven and complex components present in lignocellulose; accordingly, the majority of biomass is currently processed as waste. The problems may be overcome by the design of multifunctional catalysts, offering adequate control over product selectivity and substrate activation. Hence, this review describes recent developments involving various catalysts such as metallic oxides, supported metal or composite metal oxides, char-based and carbon-based substances, metal carbides and zeolites, with reference to the catalytic conversion of biomass including cellulose, hemicellulose, biomass tar, lignin and their derivative compounds into useful products, including bio-oil, gases, hydrocarbons, and fuels. The main aim is to provide an overview of the latest work on the use of catalysts for successful conversion of biomass. The review ends with conclusions and suggestions for future research, which will assist researchers in utilizing these catalysts for the safe conversion of biomass into valuable chemicals and other products. [Display omitted] • Sustainable catalytic conversion of biomass into added value useful products. • Perovskites-type and metal-based catalysts for biomass transformation are reviewed. • Metal-based oxides, nanomaterials, supported and mixed metals are deliberated for lignocellulose conversion. • Carbon, biochar-based, and zeolites are highlighted as non-metallic catalyst for biomass conversion. [ABSTRACT FROM AUTHOR]

Forest mega-fires have become a global phenomenon in recent decades including in south-eastern Australia where large areas of forest have been fire-killed with loss of human lives and property and impacting carbon sequestration and greenhouse gas emissions. The vast extent and impact of mega-fires has induced a re-evaluation of fuel reduction methods as a key management strategy in wildfire risk mitigation in many countries. This study investigated the impact of a commercial thinning in Eucalyptus delegatensis forest on fuel hazard, fuel loads and wildfire behaviour, eight years after completion of a bay and outrow thinning operation. At the stand level, thinning reduced overstorey tree stocking by more than 50%, increased canopy openness and stimulated the growth of retained trees. Thinning also encouraged the profuse regeneration of over 1000 saplings ha −1 of E. delegatensis, mostly in the outrows, compared with no sapling regeneration in unthinned forest. A system of additive biomass equations was developed to estimate total biomass and component biomass (stem wood, bark, branches and foliage) of individual trees. The aboveground tree carbon was 433 ± 49 Mg C ha −1 in unthinned forest and 322 ± 47 Mg C ha −1 in thinned forest. Thinning decreased surface fuel hazard ratings and fuel loads but had no significant effect on the mass of coarse woody fuels. Fire simulation under severe to extreme weather conditions, as occurred in the 2006/7 Great Divide Fires, indicated an almost 30% reduction in fireline intensity and about 20% reduction in the rate of spread and spotting distance in thinned forest compared with unthinned forest. This study indicates the potential of thinning to reduce wildfire severity and to increase the fire-survival of E. delegatensis . [ABSTRACT FROM AUTHOR]

Prototypes of FCC catalysts containing 30%wt. Y zeolite with different intracrystalline mesoporosity generated by alkaline desilication, on an inert silica matrix, were tested in cracking a conventional vacuum gasoil (VGO) feedstock, alone and mixed with an atmospheric tower residue (ATR). The experiments were performed in a fluidized bed CREC Riser Simulator reactor (reaction time: 5–30 s, temperature: 550 °C, catalyst/feedstock: 4.5). Independently of the catalyst, the conversions of the ATR-VGO mixture were higher than those of the VGO at the same conditions. With both feedstocks, the catalyst including the zeolite with increased intracrystalline mesoporosity and higher acidity showed a higher observed activity than the catalyst with the parent zeolite. In addition, the catalyst with the modified zeolite showed higher selectivity to LCO, which is an intermediate product in FCC and a contributor to the diesel pool, especially with the ATR-VGO mixture. This effect was the consequence of the enhanced diffusion transport of primary product molecules in the zeolite pore system which, in diffusing faster, have fewer chances to be further cracked. The catalyst with higher mesoporosity showed higher coke selectivity, coke being less condensed, due to the higher free volume in the porous system allowing accommodate precursors of coke. [ABSTRACT FROM AUTHOR]

This paper explores the environmental and economic aspects of fast pyrolytic conversion of lignin, obtained from 2G ethanol plants, to transport fuels for both the marine and automotive markets. Various scenarios are explored, pertaining to aggregation of lignin from several sites, alternative energy carries to replace lignin, transport modalities, and allocation methodology. The results highlight two critical factors that ultimately determine the economic and/or environmental fuel viability. The first factor, the logistics scheme, exhibited the disadvantage of the centralized approach, owing to prohibitively expensive transportation costs of the low energy-dense lignin. Life cycle analysis (LCA) displayed the second critical factor related to alternative energy carrier selection. Natural gas (NG) chosen over additional biomass boosts well-to-wheel greenhouse gas emissions (WTW GHG) to a level incompatible with the reduction targets set by the U.S. renewable fuel standard (RFS). Adversely, the process’ economics revealed higher profits vs. fossil energy carrier. [ABSTRACT FROM AUTHOR]

This paper aims to examine the potential of waste biorefineries in developing countries as a solution to current waste disposal problems and as facilities to produce fuels, power, heat, and value-added products. The waste in developing countries represents a significant source of biomass, recycled materials, chemicals, energy, and revenue if wisely managed and used as a potential feedstock in various biorefinery technologies such as fermentation, anaerobic digestion (AD), pyrolysis, incineration, and gasification. However, the selection or integration of biorefinery technologies in any developing country should be based on its waste characterization. Waste biorefineries if developed in developing countries could provide energy generation, land savings, new businesses and consequent job creation, savings of landfills costs, GHG emissions reduction, and savings of natural resources of land, soil, and groundwater. The challenges in route to successful implementation of biorefinery concept in the developing countries are also presented using life cycle assessment (LCA) studies. [ABSTRACT FROM AUTHOR]

Promising Renewable Energy solutions could be installed in cities, but they require specific morphological conditions as well as architectural integration. Transport sector is still neglected from a strong policy initiative. A first attempt along with a defined framework to attract economic resources as well as interested stakeholders is the Covenant of Mayors (CoM). Within this agreement, the Municipality has to design a plan, the so-called Sustainable Energy Action Plan (SEAP). The plan must contain a clear outline of the strategy and relative actions to be taken by the local authority to reach its commitments in 2020, in terms of sustainability goals set by EU 20-20-20. The aim of this paper is to discuss and evaluate the differences of fuel usage and transport sector interaction in Italian urban scenarios, taking into account geographical and morphological constraints, and to compare the forecasts for 2020 and 2030scenarios, in accordance with European and National laws in force. [ABSTRACT FROM AUTHOR]

Since the beginning of the 2000’s, comprehensive GC × GC chromatography brought a totally new way to characterize complex matrices. This disruptive technique is well adapted to fuels and rapidly gained importance in R&D laboratories of oil (and related) companies. Therefore, this analytical tool has been applied to many aspects of refining and especially the challenge of reducing the sulfur content in fuels. The present article reviews the use of comprehensive GC × GC for understanding the nature of sulfur compounds in refinery products (from gasoline to VGO) and their catalytic conversion through various catalytic processes such as HDS, AOTS, ODS. Various types of detectors (universal or specific) as well as HT GC × GC have been applied and can be combined in order to get a better description of the S compounds in oil products. [ABSTRACT FROM AUTHOR]

With the recent abundant discoveries of shale gas, there are tremendous opportunities and challenges for the creation of value-added shale gas supply chains. The paper provides an overview of shale gas monetization with focus on downstream processing. First, a background is given on shale gas reserves, production, and characteristics. Then, an overall monetization map is discussed by outlining the primary intermediates and products that can be manufactured from the main hydrocarbon components in shale gas and the common conversion technologies. Next, attention is given to five key products: methanol, liquid transportation fuels, ethylene, propylene, and butadiene. For each product, the markets, chemical pathways, conversion technologies, derivatives, and common uses are given. The paper also provides statistics, challenges, opportunities, and insights related to the main factors impacting shale gas usage in the production of value-added chemicals and products. [ABSTRACT FROM AUTHOR]

The oligomerization of the light olefins ethene, propene, and butenes into fuels and chemicals has been investigated and commercially practiced for many years. While the area appears on the surface to be mature, many advances have been made in recent years. In this feature article, I discuss the mechanisms of reaction and showcase catalysts and processes useful for oligomerization from both the open and patent literature. Commercially practiced processes are spotlighted. Among the catalysts utilized in the art are acidic catalysts such as solid phosphoric acid and zeolites, as well as metal based catalysts including aluminum alkyls, and nickel and zirconium based complexes and solids. A short section on catalysts and processes which utilize a metallacycle mechanism in order to achieve high selectivity to 1-hexene or 1-octene is followed by a discussion of multi-functional materials possessing both acid and metal active sites. Finally, processes where oligomerization is a key step in a multi-step or multi-reaction process are discussed. [ABSTRACT FROM AUTHOR]

Nowadays, the environmental aspects of transport are very actual issues, mainly the energy consumption and GHG production. This paper analyzes and evaluates final energy intensity and GHG production of two passenger transport modes - individual road and railway. Comparison is made for diesel railway vehicle, as well as for passenger cars with different fuel types (gasoline and diesel). The European standard EN 16 258:2012 was used for calculation. The results show the final environmental aspects counted absolutely and also per capita. [ABSTRACT FROM AUTHOR]

In contrast to the nonrenewable fossil resources, biomass, the only renewable resource of organic carbon in the nature, is considered as a special kind of inexhaustible feedstocks, which can be used for the synthesis of numerous valuable products in a sustainable manner. Among many biomass-derived products, 5-hydroxymethylfurfural (HMF) is identified to be a crucially important versatile compound due to its marvelous structure that is composed of an aldehyde group, a hydroxyl group and a furan ring. Hence, HMF possesses a very strong chemical reactivity, and it can be further transformed into a wide variety of value-added derivatives. In recent years, the synthetic methods, physicochemical properties and commercial prospects of HMF-based conventional derivatives such as 2,5-dimethylfuran (DMF), 5-ethoxymethylfurfural (EMF), ethyl levulinate (EL), long chain alkane (LLA), levulinic acid (LA), 2,5-diformylfuran (DFF) and 2,5-furandicarboxylic acid (FDCA) have been intensively reviewed by many researchers. However, up to now, the preparation of HMF-based innovative derivatives such as 2,5-dihydroxymethylfuran (DHMF), 2,5-dihydroxymethyltetrahydrofuran (DHMTHF), 1,2,6-hexanetriol (HTO), 1,6-hexanediol (HDO), 1-hydroxyhexane-2,5-dione (HHD), 3-hydroxymethylcyclopetanone (HMCPN), furan-2,5-dimethylcarboxylate (FDMC), maleic anhydride (MA), 5-hydroxy-5-(hydroxymethyl)furan-2(5H)-one (HHMFO), 5-alkoxymethylfurfural (AMF), 5,5-oxy-(bismethylene)-2-furaldehyde (OBMF), 5-arylaminomethyl-2-furanmethanol (AAMFM), 2,5-furandiamidine dihydrochloride (FDADHC), 1-alkyl-5-hydroxy-2-(hydroxymethyl)pyridinium (AHHMP), 5,5-bis(hydroxymethyl)furoin (BHMF), 5-(dialkyloxymethyl)-2-furanmethanol (DAMFM), 5-chloromethylfurfural (CMF), 5-alkanoyloxymethylfurfural (AOOMF) and furfuryl alcohol (FFA) has not yet been comprehensively summarized. In order to fill this gap, the latest studies and advancements on the preparation of HMF-based innovative derivatives via various catalytic approaches such as hydrogenation, oxidation, etherification, amination, condensation, halogenation, esterification and decarbonylation are systematically outlined and discussed in this review. Furthermore, a few potential research trends in the future studies are also proposed to provide some useful ideas for the further preparation of HMF-based innovative derivatives in a much more green, simple, efficient and economical way. [ABSTRACT FROM AUTHOR]