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Modification of lignin in feedstocks via genetic engineering aims to reduce biomass recalcitrance to facilitate efficient conversion processes. These improvements can be achieved by expressing exogenous enzymes that interfere with native biosynthetic pathways responsible for the production of the lignin precursors. In planta expression of a bacterial 3-dehydroshikimate dehydratase in poplar trees reduced lignin content and altered the monomer composition, which enabled higher yields of sugars after cell wall polysaccharide hydrolysis. Understanding how plants respond to such genetic modifications at the transcriptional and metabolic levels is needed to facilitate further improvement and field deployment. In this work, we acquired fundamental knowledge on lignin-modified poplar expressing 3-dehydroshikimate dehydratase using RNA-seq and metabolomics. The data clearly demonstrate that changes in gene expression and metabolite abundance can occur in a strict spatiotemporal fashion, revealing tissue-specific responses in the xylem, phloem, or periderm. In the poplar line that exhibited the strongest reduction in lignin, we found that 3% of the transcripts had altered expression levels and ~19% of the detected metabolites had differential abundance in the xylem from older stems. The changes affected predominantly the shikimate and phenylpropanoid pathways as well as secondary cell wall metabolism, and resulted in significant accumulation of hydroxybenzoates derived from protocatechuate and salicylate.

Microwave (MW)‐assisted catalytic pyrolysis represents a promising method for transforming petroleum‐based plastic waste into valuable chemicals, offering a pathway towards more sustainable circular economy. In this study, catalytic pyrolysis of low‐density polyethylene (LDPE) was conducted under MW irradiation. The influence of various catalyst types (HZSM‐5, Ga/ZSM‐5, Ga/Ni/ZSM‐5, Ga/Co/ZSM‐5, and Ga/Cu/ZSM‐5) on product yield and distribution was examined. The results revealed that the Ga/ZSM‐5 catalyst yielded the maximum liquid oil, approximately 41%. Ga/Ni/ZSM‐5 performed excellently in the production of long‐chain olefins, constituting about 27% of the liquid fraction. However, Ga/Co/ZSM‐5 led to the production of heavy pyrolysis oil containing nearly 25% long‐chain paraffins, rendering it unsuitable for producing high‐value chemicals. Conversely, the Ga/Cu/ZSM‐5 catalyst yielded an aromatic‐rich pyrolysis oil, with benzene derivatives constituting approximately 90% of the liquid oil fraction, thus proving to be a suitable catalyst for the intended application. The liquid product distribution was compared with a petroleum assay by SimDist, and this suggested that utilizing the HZSM‐5 catalyst could yield an 86.4% naphtha fraction. The study also revealed that the Ga/Cu/ZSM‐5 catalyst generated the largest amounts of hydrogen and syngas, as determined by a MicroGC analysis of the gas products. This catalyst also exhibited the maximum coke deposition (1.35%) postreaction, which was attributed to its high aromatic hydrocarbon content in the pyrolysis oil and maximal hydrogen release. A comparison of fresh and spent catalyst properties was conducted to gain insights into catalyst activity and to correlate the effects of metal doping on product distribution. These findings underscore the potential of MW‐assisted catalytic pyrolysis, particularly with the Ga/Cu/ZSM‐5 catalyst, for the efficient conversion of plastic waste into valuable chemicals, thereby contributing to sustainable resource utilization and environmental conservation. [ABSTRACT FROM AUTHOR]

Modified atmosphere packaging (MAP) alters the gaseous composition of air surrounding packaged goods to prevent deleterious oxidation associated reactions. MAP has been adopted for the storage of cannabis, though a recent study revealed little difference in terpene content under MAP conditions. Questions regarding its efficacy for preservation of high value compounds like terpenes and cannabinoids lost during postharvest storage remain. The goal of this research is to determine weather N2 MAP preserves high value compounds of cannabis during its postharvest storage. This experiment followed a completed randomized block design. There were two factors of interest. The first was storage atmosphere (atmospheric or N2 MAP). The second was storage duration (18, 46, or 74 days). The experiment was then blocked by cannabis chemovar using 5 different chemovars. The concentration of 17 cannabinoids was evaluated through UPLC-UV and 61 volatile terpene compounds through GC–MS. Concentrations were compared over time and between storage treatments. There were no significant differences in total cannabinoids and volatile terpene compounds over time or between storage treatments. Individual cannabinoids Δ9-THC, CBG, CBNA, CBC, THCV, and THCVA all increased during storage time while THCA decreased. CBG and THCV only increased under MAP storage. Individual aromatics limonene, β-pinene, α-pinene, camphene, and terpinolene all only decreased during storage under N2 MAP. Only caryophyllene oxide and α-humulene increased under N2 MAP storage. β-Myrcene decreased under atmospheric storage, but not under N2 MAP. While N2 MAP had no effect on the preservation of total cannabinoids and aromatics during storage, it did influence several individual compounds. CBG, THCV, and α-humulene all increased under N2 MAP. N2 MAP also maintained the concentration β-myrcene over time, though the preservation of β-myrcene was offset by a decrease limonene. Overall, N2 MAP was not needed for preservation of most high value compounds but did have an effect of some compounds with reputed therapeutic benefits. [ABSTRACT FROM AUTHOR]

Unlike cyclopropanes, the analogous B2C species (diboriranes) tend to adopt non‐classical Hückel‐aromatic structures with bridging moieties R between the boron atoms. The coordination of the thus generated cyclic 2e− π‐system to transition metals is completely unexplored. We here report that complexation of non‐classical diboriranes cyclo‐μ‐RB2Dur2CPh (R=H, SnMe3; Dur=2,3,5,6‐tetramethylphenyl) to Fe(CO)3 fragments allows for the carbonylative ring expansion of the B2C ring to either four‐ or five‐membered rings depending on the nature of the BRB 3‐center‐2‐electron bond (3c2e): The H‐bridged diborirane (R=H) initially reacts with Fe2(CO)9 to the allylic π‐complex with an agostic BH/Fe interaction. Subsequent formal hydroboration of CO from excess Fe2(CO)9 results in the side‐on ring expansion under formation of a five‐membered B2C2O ring, coordinated to the Fe(CO)3 moiety. In contrast, in case of the stannyl‐bridged diborirane (R=SnMe3) under the same conditions, CO is added end‐on to the B−B bond with the carbon terminus formally inserting into the B2Sn 3c2e‐bond. The two carbonylative ring expansion products can also be described as nido and closo clusters, respectively, according to the Wade‐Mingos rules. [ABSTRACT FROM AUTHOR]

There has been significant interest in developing new catalytic systems to convert linear chain alkanes into olefins and aromatics. In the case of higher alkanes (≥C6), the production of aromatic compounds such as benzene‐toluene‐xylenes is highly desirable. However, as the length of the carbon chain increases, the dehydrogenation process becomes more complex, not only due to the challenges of C−H activation but also the need for selectivity towards the desired products by the possibility of side reactions such as isomerization and cracking. Here, we present a detailed analysis of the dehydroaromatization of n‐hexane, n‐heptane, and n‐octane, using PtSn intermetallic nanoparticles supported on SBA‐15 as the catalyst. Through in situ spectroscopic and kinetic analysis, we have probed the reaction kinetics and catalyst deactivation, and provided a mechanistic understanding of the dehydroaromatization process on the surface of the PtSn intermetallic nanoparticles. Introducing Sn has been shown to be crucial not only for enhancement of catalytic activity, but also for higher aromatics selectivity and stability on stream. Furthermore, the analysis of dehydroaromatization reaction rates of reactant and possible intermediates indicates that the dehydroaromatization of n‐hexane to benzene likely proceeds through initial dehydrogenation steps followed by ring closing. [ABSTRACT FROM AUTHOR]

In this study, we investigated the pyrolysis of cellulose, lignin, phenylalanine and textile wool waste using microscale thermogravimetric analysis (TGA) and a gram-scale fixed bed reactor. The pyrolysis was conducted at 500 °C and 1 bar N2, using Al- and Li-doped mesoporous KIL-2 and ZSM-5 catalysts for comparison. Our results show that amorphous Al-KIL-2 catalyst was the most efficient in producing aromatics from cellulose and lignin. This efficiency is attributed to Al-KIL-2 large mesoporosity, wide pore size distribution, and mild acid sites. Additionally, Al-KIL-2 promoted esterification and denitrogenation reactions, indicating its potential application in the pyrolysis of biomass and protein-rich feedstocks. Conversely, the Li-KIL-2 catalyst demonstrated activity primarily in the depolymerisation of cellulose to sugars and promoted ketonisation and alcohol formation. In summary, our findings indicate that Al-KIL-2 is a promising catalyst for efficient aromatic production from biomass. [ABSTRACT FROM AUTHOR]

CO 2 serves as a crucial precursor for synthesizing aromatic, offering a resultful pathway for utilizing non-petroleum carbon sources. Nonetheless, the Anderson-Schulze-Flory (ASF) distribution limits aromatics selectivity, challenging the direct conversion of CO 2 into specific aromatic products. Bifunctional catalysts consisting of ZnCr 2 O 4 , ZnAl 2 O 4 and ZnIn 2 O 4 spinel with nano-flake ZSM-11 zeolite were constructed and investigated for converting CO 2 to valuable aromatics. Remarkably, the selectivity towards aromatics greatly surpasses the constraints of ASF. Under identical reaction conditions, the single pass CO 2 conversion of the ZnCr 2 O 4 /ZSM-11 increased by 7.2% and 5.2%, while the aromatic selectivity rose by 9.5% and 10.5%, respectively, compared to the ZnAl 2 O 4 /ZSM-11 and ZnIn 2 O 4 /ZSM-11. Additionally, under optimal conditions (300 °C, 3.5 MPa and a gas hourly space velocity (GHSV) of 1800 mL·g cat −1·h−1), ZnCr 2 O 4 /ZSM-11 displayed outstanding aromatic selectivity of 90.5% (without CO) alongside a single pass CO 2 conversion of 23.6%. Simultaneously, the synthetic ZSM-11 facilitates the timely diffusion of monocyclic aromatics and the production of C 8 –C 12 monocyclic aromatics, which constitute 97.2% of the total aromatic products, while polycyclic aromatics account for only 0.2%. Even after 100 h, the ZnCr 2 O 4 /ZSM-11 catalyst maintained its significant catalytic activity with CO 2 conversion and aromatic selectivity at 22.0% and 88.0%, respectively. These results highlight the potential of ZnCr 2 O 4 /ZSM-11 for directly converting CO 2 to valuable aromatics. [Display omitted] • ZnX 2 O 4 (X = Cr, In, Al) spinels were designed to compare the catalytic properties. • ZnCr 2 O 4 /ZSM-11 bifunctional catalyst enables direct CO 2 to aromatics conversion. • ZnCr 2 O 4 /ZSM-11 achieved 90.5% aromatics selectivity, 23.6% CO 2 conversion. • Remarkably, C 8 –C 12 monocyclic aromatics constitute 97.2% of the total aromatic. • Post 100 h, catalyst still gave 22.0% CO 2 conversion, 88.0% aromatics selectivity. [ABSTRACT FROM AUTHOR]

Hydrocracked kerosene represents an additional source of jet fuel in oil refineries. The objective of this study was to re-distill hydrocracked kerosene (distillation range of 155-211 °C) into narrow cuts (distillation range of 10 °C) and to determine the dependence of the critical parameters of jet fuel, i.e., density, aromatics, smoke, and freezing point on the mean boiling point (tmean) of these cuts, utilizing modern and well established analytical methods. Re-distillation yielded seven narrow cuts composed of hydrocarbons with maximally three different carbon numbers. The analyzed properties deteriorated significantly with increasing tmean of cuts. Already the cuts with tmean of 190 °C + did not meet the jet fuel specification for aromatics and the 210 °C + cut did not meet any of the studied properties. Aromatics were crucial in controlling the distillation range and this provided an explanation for why hydrocracked jet fuel can be produced only as a narrow fraction. Since a low freezing point characterized all narrow cuts, this property represents a crucial synergy of blending of the hydrocracked kerosene with a straight-run kerosene or SAF. Overall, we demonstrated that narrow-cut research provides new insights into the characteristics of the hydrocracked kerosene. [ABSTRACT FROM AUTHOR]

The Kingdom of Saudi Arabia (KSA) is the leading oil-exploring and -exploiting country in the world. As a result, contamination of the environment by petroleum products (mainly hydrocarbons) is common, necessitating strategies for their removal from the environment. Much work has been conducted on bacterial degradation of hydrocarbons in the KSA. This review comprehensively analyzed 43 research investigation articles on bacterial hydrocarbon degradation, mainly polyaromatic hydrocarbons (PAHs) within the KSA. More than 30 different bacterial genera were identified that were capable of degrading simple and complex PAHs, including benzo[a]pyrene and coronene. Different strategies for selecting and isolating these bacterial strains and their advantages and disadvantages were highlighted. The review also discussed the origins of sample inocula and the contributions of various research groups to this field. PAH metabolites produced by these bacteria were presented, and biochemical pathways of PAH degradation were proposed. More importantly, research gaps that could enrich our understanding of petroleum product biodegradation mechanisms were highlighted. Overall, the information presented in this paper will serve as a baseline for further research on optimizing bioremediation strategies in all petroleum-contaminated environments. [ABSTRACT FROM AUTHOR]

Abstract Modified atmosphere packaging (MAP) alters the gaseous composition of air surrounding packaged goods to prevent deleterious oxidation associated reactions. MAP has been adopted for the storage of cannabis, though a recent study revealed little difference in terpene content under MAP conditions. Questions regarding its efficacy for preservation of high value compounds like terpenes and cannabinoids lost during postharvest storage remain. The goal of this research is to determine weather N2 MAP preserves high value compounds of cannabis during its postharvest storage. This experiment followed a completed randomized block design. There were two factors of interest. The first was storage atmosphere (atmospheric or N2 MAP). The second was storage duration (18, 46, or 74 days). The experiment was then blocked by cannabis chemovar using 5 different chemovars. The concentration of 17 cannabinoids was evaluated through UPLC-UV and 61 volatile terpene compounds through GC–MS. Concentrations were compared over time and between storage treatments. There were no significant differences in total cannabinoids and volatile terpene compounds over time or between storage treatments. Individual cannabinoids Δ9-THC, CBG, CBNA, CBC, THCV, and THCVA all increased during storage time while THCA decreased. CBG and THCV only increased under MAP storage. Individual aromatics limonene, β-pinene, α-pinene, camphene, and terpinolene all only decreased during storage under N2 MAP. Only caryophyllene oxide and α-humulene increased under N2 MAP storage. β-Myrcene decreased under atmospheric storage, but not under N2 MAP. While N2 MAP had no effect on the preservation of total cannabinoids and aromatics during storage, it did influence several individual compounds. CBG, THCV, and α-humulene all increased under N2 MAP. N2 MAP also maintained the concentration β-myrcene over time, though the preservation of β-myrcene was offset by a decrease limonene. Overall, N2 MAP was not needed for preservation of most high value compounds but did have an effect of some compounds with reputed therapeutic benefits.

Bioremediation provides an environmentally sound solution for hydrocarbon removal. Although bioremediation under anoxic conditions is slow, it can be coupled with methanogenesis and is suitable for energy recovery. By altering conditions and supplementing alternative terminal electron acceptors to the system to induce syntrophic partners of the methanogens, this process can be enhanced. In this study, we investigated a hydrocarbon-degrading microbial community derived from chronically contaminated soil. Various hydrocarbon mixtures were used during our experiments in the presence of different electron acceptors. In addition, we performed whole metagenome sequencing to identify the main actors of hydrocarbon biodegradation in the samples. Our results showed that the addition of ferric ions or sulphate increased the methane yield. Furthermore, the addition of CO2, ferric ion or sulphate enhanced the biodegradation of alkanes. A significant increase in biodegradation was observed in the presence of ferric ions or sulphate in the case of all aromatic components, while naphthalene and phenanthrene degradation was also enhanced by CO2. Metagenome analysis revealed that Cellulomonas sp. is the most abundant in the presence of alkanes, while Ruminococcus and Faecalibacterium spp. are prevalent in aromatics-supplemented samples. From the recovery of 25 genomes, it was concluded that the main pathway of hydrocarbon activation was fumarate addition in both Cellulomonas, Ruminococcus and Faecalibacterium. Chloroflexota bacteria can utilise the central metabolites of aromatics biodegradation via ATP-independent benzoyl-CoA reduction. Key points: • Methanogenesis and hydrocarbon biodegradation were enhanced by Fe3+ or SO42− • Cellulomonas, Ruminococcus and Faecalibacterium can be candidates for the main hydrocarbon degraders • Chloroflexota bacteria can utilise the central metabolites of aromatics degradation [ABSTRACT FROM AUTHOR]

Catalytic co-pyrolysis of two different refinery oily sludge (ROS) samples was conducted to facilitate resource recovery. Non-catalytic pyrolysis in temperatures ranging from 500 to 600°C was performed to determine high oil yields. Higher temperatures enhanced the oil yields up to ~ 24 wt%, while char formation remained unchanged (~ 45%) for S1. Conversely, S2 exhibited a notably lower oil yield (~ 4 wt%) than S1. Pyrolysis oil of S1 consisted of phenolics (~ 50% at 600 °C) whereas hydrocarbons were predominant in S2 oil (~ 80% at 600 °C). Catalytic pyrolysis of S1 did not exhibit a substantial impact on oil yields but the oil composition varied significantly. High hydrocarbons, phenolics, and aromatics were obtained with molecular sieve (MS), metal slag, and ZSM-5, respectively. Catalytic co-pyrolysis of S2 with sawdust (SD) in the presence of MS enhanced the oil yield, and the resulting oil consisted of high hydrocarbons (~ 54%) and aromatics (~ 44%). [ABSTRACT FROM AUTHOR]

Copyright of Advances in New & Renewable Energy is the property of Editorial Office of Advances in New & Renewable Energy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of purely microporous zeolites for transforming ethylene into aromatics is hampered by low activity and deactivation due to restricted channels and coke formation. In contrast, hierarchical zeolites have demonstrated improved catalytic performance. In this study, we investigate the effect of the zeolite properties and operation conditions on ethylene conversion. The results show that the appropriate amount of templates is crucial for optimizing the benefits of hierarchical zeolites. Notably, a liquid yield up to 54 % and a two-fold reduction in coke formation were observed compared to commercial samples. Moreover, 75 % of the aromatic product with 68 % selectivity to BTX in aromatics product was obtained.

This work presents the synthesis of N‐doped nanoporous carbon materials using the Ionic Liquid (IL) 1‐butyl‐3‐methylimidazolium tricyanomethanide [BMIM][TCM] as a fluidic carbon precursor, employing two carbonization pathways: templated precursor and pyrolysis/activation. Operando monitoring of mass loss during pyrolytic and activation treatments provides insights into chemical processes, including IL decomposition, polycondensation reactions and pore formation. Comparatively low mass reduction rates were observed at all stages. Heat treatments indicated stable pore size and increasing volume/surface area over time. The resulting N‐doped carbon structures were evaluated as electrocatalysts for the oxygen reduction reaction (ORR) and adsorbents for gases and organic vapors. Materials from the templated precursor pathway exhibited high electrocatalytic performance in ORR, analyzed using Rotating Ring‐Disk electrode (RRDE). Enhanced adsorption of m‐xylene was attributed to wide micropores, while satisfactory CO2 adsorption efficiency was linked to specific morphological features and a relatively high content of N‐sites within the C‐networks. This research contributes valuable insights into the synthesis and applications of N‐doped nanoporous carbon materials, highlighting their potential in electrocatalysis and adsorption processes. [ABSTRACT FROM AUTHOR]

The conversion of CO2 into fuels and value-added chemicals over heterogeneous catalysts may help realize a carbon-neutral or carbon-negative society. Recently, the direct conversion of CO2 to aromatics has been extensively explored. However, the requirement of multifunctional active sites, complexity of tandem cascade reactions, and difficulty in understanding reaction mechanisms present significant challenges to the design of effective heterogeneous catalysts. In this review, catalytic systems used for the direct production of aromatics from CO2 via the methanol-mediated and modified Fischer–Tropsch synthesis pathways are critically discussed. The initial section discusses the role of acid sites in HZSM-5 for the formation of aromatics. This is followed by a thorough review of recent progress on aromatic syntheses in terms of their catalytic performance, Si/Al ratios of zeolites, proximity between metal oxide and zeolite, and reaction conditions. The reaction mechanisms and the stability of existing catalysts are also discussed. Finally, the current challenges and future prospects of the catalytic conversion of CO2 to aromatics are highlighted. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Asian tiger mosquito, Aedes albopictus, is a competent vector for the spread of several viral arboviruses including dengue, chikungunya, and Zika. Several vital mosquito behaviors linked to survival and reproduction are primarily dependent on a sophisticated olfactory system for semiochemical perception. However, a limited number of studies has hampered our understanding of the relationship between the A. albopictus acute olfactory system and the complex chemical world. RESULTS: Here, we performed a qRT‐PCR assay on antennae from A. albopictus of differing sex, age and physiological states, and found that AalbOr10 was enriched in blood‐fed female mosquitoes. We then undertook single sensillum recording to de‐orphan AalbOr10 using a panel of physiologically and behaviorally relevant odorants in a Drosophila 'empty neuron' system. The results indicated that AalbOr10 was activated by seven aromatic compounds, all of which hampered egg‐laying in blood‐fed mosquitoes. Furthermore, using a post‐RNA interference oviposition assay, we found that reducing the transcript level of AalbOr10 affected repellent activity mediated by 2‐ethylphenol at low concentrations (10−4 vol/vol). Computational modeling and molecular docking studies suggested that hydrogen bonds to Y68 and Y150 mediated the interaction of 2‐ethylphenol with AalbOr10. CONCLUSION: We reveal a potential link between aromatics‐induced oviposition repellency behaviors and a specific odorant receptor in A. albopictus. Our findings provide a foundation for identifying active semiochemicals for the monitoring or controlling of mosquito populations. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nowadays, the chemical recycling is applied for only 1% of total waste plastics, largely due to contaminants in plastic waste and difficulty in product control. As the major contaminant, polyvinyl chloride (PVC) often forms corrosive hydrogen chloride (HCl) during the chemical recycling, which may cause severe catalyst deactivation and equipment damage. However, the investigation on catalytic pyrolysis (the major route for plastics chemical recycling) of the PVC containing mixed plastics has been rarely reported. Here, catalytic co-pyrolysis of PVC and polyethylene (PE) was studied over an aromatization catalyst, Pt/ZSM-5, since the basic building block aromatics are desired products from plastics chemical recycling. The poisoning effect of PVC vapor on the catalyst stability was explored by collective efforts of thorough product analysis and catalyst characterization. It was found that the HCl evolving from PVC has an autocatalytic effect that promotes the scission of dehydrochlorinated PVC, resulting in the high yield of benzene and acetylene from PVC. On the other hand, the presence of PVC suppressed the aromatics formation from PE, largely due to the poisoning effect of PVC-derived HCl on the Pt/ZSM-5. The deactivation is irreversible as evidenced by the decreased zeolite crystallinity and the loss of strong acid sites that are key to the aromatization, possibly due to the removal of framework Al upon the interaction with HCl. The modification with octadecylphosphonic acid only slightly alleviated the PVC poisoning effect. The insights on the PVC poisoning of zeolite catalysts provided in this work may guide the process design of chemical recycling of PVC containing waste plastics. [ABSTRACT FROM AUTHOR]

This work presents the synthesis of N‐doped nanoporous carbon materials using the Ionic Liquid (IL) 1‐butyl‐3‐methylimidazolium tricyanomethanide [BMIM][TCM] as a fluidic carbon precursor, employing two carbonization pathways: templated precursor and pyrolysis/activation. Operando monitoring of mass loss during pyrolytic and activation treatments provides insights into chemical processes, including IL decomposition, polycondensation reactions and pore formation. Comparatively low mass reduction rates were observed at all stages. Heat treatments indicated stable pore size and increasing volume/surface area over time. The resulting N‐doped carbon structures were evaluated as electrocatalysts for the oxygen reduction reaction (ORR) and adsorbents for gases and organic vapors. Materials from the templated precursor pathway exhibited high electrocatalytic performance in ORR, analyzed using Rotating Ring‐Disk electrode (RRDE). Enhanced adsorption of m‐xylene was attributed to wide micropores, while satisfactory CO2 adsorption efficiency was linked to specific morphological features and a relatively high content of N‐sites within the C‐networks. This research contributes valuable insights into the synthesis and applications of N‐doped nanoporous carbon materials, highlighting their potential in electrocatalysis and adsorption processes. [ABSTRACT FROM AUTHOR]

At present, under the background of the excess product oil market, "reducing oil products and increasing chemical raw materials" has become the mainstream trend in the chemical industry. In recent years, ZSM-5 zeolite catalyst has been widely used in the aromatization of FCC gasoline, but its modification to improve its aromatization catalytic performance is still not perfect. Therefore, based on the existing process technology, the effect of pseudo-boehmite on the aromatization performance of Zn-P-Al/ZSM-5 catalysts was investigated on a small continuous fixed-bed reactor using 75-120 °C fractions of FCC gasoline as feedstock. The results show that the aromatization performance of Zn-P-Al/ZSM-5 catalyst is better than that of Zn-P/ZSM-5 and HZSM-5, and the best aromatization performance is obtained when the pseudo-boehmite ratio is 30%, the aromatics content and aromatics yield in liquid products are 90.82% and 54.38%, respectively. The results of catalyst characterization are consistent with those of catalyst evaluation. [ABSTRACT FROM AUTHOR]

Objective The aim is to increase the aromatics content in the No.3 jet fuel produced by the diesel and wax oil mixed feed hydrocracking unit, so that it can meet the requirements of military No.3 jet fuel products. Methods The content of aromatics in No.3 jet fuel was increased by adjusting the following parameters: increasing the proportion of wax oil in the mixed raw material, increasing the oil density of the mixed raw material, reducing the temperature of the refining reactor bed, optimizing the temperature of the graded catalyst bed of the cracking reactor, and reducing the saturation depth of aromatics hydrogenation. Results Firstly, the aromatics content in jet fuel could be significantly increased by increasing the proportion of wax oil and the density of mixed raw material oil under constant treatment capacity. Secondly, under the condition of high diesel ratio raw material, by significantly reducing the temperature of the refining reactor bed, simultaneously reducing the bed temperature of the light oil catalyst, improving the bed temperature of the flexible and medium oil catalyst, the saturation depth of aromatics hydrogenation was reduced, the aromatics volume fraction in jet fuel products was greater than or equal to 8%, while ensuring the BMCI value of the tail oil was less than 13. Conclusions By increasing the wax oil proportion and mixed raw materials density to a specific value and reducing the bed temperature of the refined reactor and the saturation depth of aromatics hydrogenation, the target of aromatics volume fraction in jet fuel products greater than or equal to 8% can be achieved, which solves the problem of producing military No.3 jet fuel by diesel and wax oil mixed feed hydrocracking unit and has certain production guiding significance. [ABSTRACT FROM AUTHOR]

Plastics are one of the most produced synthetic materials and largest commodities, used in numerous sectors of human life. To upcycle waste plastics into value-added chemicals is a global challenge. Despite significant progress in pyrolysis and hydrocracking, which mainly leads to the formation of pyrolysis oil, catalytic upcycling to value-added aromatics, including benzene, toluene and xylene (BTX), in one step, is still limited by high reaction temperatures (>500°C) and a low yield. We report herein CO2-facilitated upcycling of polyolefins and their plastic products to aromatics below 300°C, enabled by a bifunctional Pt/MnOx-ZSM-5 catalyst. ZSM-5 catalyzes cracking of polyolefins and aromatization, generating hydrogen at the same time, while Pt/MnOx catalyzes the reaction of hydrogen with CO2, consequently driving the reaction towards aromatization. Isotope experiments reveal that 0.2 kg CO2 is consumed per 1.0 kg polyethylene and 90% of the consumed CO2 is incorporated into the aromatic products. Furthermore, this new process yields 0.63 kg aromatics (BTX accounting for 60%), comparing favorably with the conventional pyrolysis or hydrocracking processes, which produce only 0.33 kg aromatics. In this way, both plastic waste and the greenhouse gas CO2 are turned into carbon resources, providing a new strategy for combined waste plastics upcycling and carbon dioxide utilization. [ABSTRACT FROM AUTHOR]

Copyright of Argentinian Horticulture / Horticultura Argentina is the property of Revista Horticultura Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Kingdom of Saudi Arabia (KSA) is the leading oil-exploring and -exploiting country in the world. As a result, contamination of the environment by petroleum products (mainly hydrocarbons) is common, necessitating strategies for their removal from the environment. Much work has been conducted on bacterial degradation of hydrocarbons in the KSA. This review comprehensively analyzed 43 research investigation articles on bacterial hydrocarbon degradation, mainly polyaromatic hydrocarbons (PAHs) within the KSA. More than 30 different bacterial genera were identified that were capable of degrading simple and complex PAHs, including benzo[a]pyrene and coronene. Different strategies for selecting and isolating these bacterial strains and their advantages and disadvantages were highlighted. The review also discussed the origins of sample inocula and the contributions of various research groups to this field. PAH metabolites produced by these bacteria were presented, and biochemical pathways of PAH degradation were proposed. More importantly, research gaps that could enrich our understanding of petroleum product biodegradation mechanisms were highlighted. Overall, the information presented in this paper will serve as a baseline for further research on optimizing bioremediation strategies in all petroleum-contaminated environments.