Integration of pyrolysis bio-oils of varying upgrading levels in FCC co-processing with VGO: Benefits and limitations

Damages on arctic seabird feathers: Exposure to low sulphur fuel oils is comparable to exposure to conventional oil.

Evaluation of geotextile-based adsorption system in a pilot scale test simulating runoff contaminated with petroleum products and heavy metals.

Hydrodesulfurization of characteristic sulfur-containing fractions isolated from vacuum gas oil: Apparent and intrinsic kinetics

As iconic vessels of the Aegean and Mediterranean coasts, gulets play a central role in Blue Voyage, presenting a valuable opportunity for advancing sustainable marine tourism through cleaner propulsion solutions. This study investigates the hydrodynamic performance and environmental impacts of two Bodrum Gulet-type hull forms, with overall lengths of 24 and 33.8 m, through Computational Fluid Dynamics (CFD) analyses and environmental sustainability assessments. The hydrostatic characteristics of the modeled hulls are determined, and flow characteristics, total resistance, and power requirements are evaluated. A case study based on a typical Blue Voyage route is conducted to evaluate the environmental implications of operating gulets with marine diesel oil (MDO), liquefied natural gas (LNG), and methanol (MeOH). Emission Ratio (ER) and Energy Efficiency Index (EEI) are calculated to quantify the performance of each fuel type. Results show that the current gulet hull forms can be optimized to reduce total resistance, enhancing the feasibility of adopting alternative fuels. The use of LNG and MeOH can lower CO₂ emissions by up to 9.8 % and 15.8 %, respectively, compared to MDO, with corresponding reductions in EEI of 8.3 % and 12.3 %. In addition, these benefits are found to be more pronounced for larger gulets operating at high occupancy levels. While LNG and MeOH offer notable environmental advantages, their application to gulets presents significant challenges, such as increased space requirements, safety considerations, and retrofitting constraints, making them more appropriate for new constructions or long-term planning.

Weld quality is an important parameter in ensuring the overall safety and integrity of pipelines made from high-strength steel used for the transmission of oil and natural gas. In multi-layer pipeline welding, poor heat input control can result in excessive reinforcement, lack of fusion, unsatisfactory microstructural changes, and poor mechanical properties. Hence, in the current research, the effects of Low Heat Input (LHI) and High Heat Input (HHI) on the shape, thermal behaviour, and mechanical properties of API 5L L415Q pipeline steel were analyzed via welding using the GTAW-SMAW process. The GTAW process is used for the root pass, while the SMAW process is used for the hot, fill, and cap passes. A combination of Taguchi experimental design and desirability-based multi-response optimization was used to determine the optimal values of welding current, welding voltage, welding travel speed, heat input, and reinforcement properties for individual passes. Welding parameters were verified through tensile tests, impact energy tests, hardness tests, bend tests, macroexamination, non-destructive testing, and field-scale application of the developed welding technique. Both LHI and HHI welding conditions produced welded joints that met the API pipeline welding specifications. LHI welding conditions offered better penetration consistency and a more uniform hardness distribution, since the thermal cycle was lower and the cooling rate was higher. In contrast, HHI welding conditions yielded higher impact energy in the weld metal at the fusion line and in the heat-affected zones, due to variations in the thermal cycle. The heat-input optimization strategy also resulted in reduced grain coarsening and a balanced metallurgical balance between strength and toughness. Moreover, industrial-scale validation of 250 pipeline girth welds has indicated consistent welding quality, acceptable geometry, and the absence of critical weld defects on radiographic testing.

The successful implementation of the Clean Air Act has reduced anthropogenic nitrogen oxide (NOx) emissions, significantly reducing acid rain and improving air quality in the U.S. However, particulate nitrate (pNO3) concentrations have remained elevated, posing persistent challenges to link NOx emission sources with pNO3 formation, which limits the ability to evaluate the effectiveness of emission controls for particulate end points. Measured nitrogen isotopes (δ15N) in pNO3 from a 2005-2015 aerosol record in the northeastern U.S. provide direct empirical confirmation of the effectiveness of emission regulations in reducing coal-derived NOx, concurrent with an increasing influence from oil and natural gas combustion. These findings have broad implications for improving our understanding of how changes in NOx emission sources influence pNO3 formation and evaluating the success of past clean air policies.

ABSTRACT The inland waterway transport sector faces challenges such as digitalization, adaptation to climate change and the integration of alternative propulsion technologies. Given the long service life of ships, the targets agreed in the Mannheim Declaration for reducing air pollutant and greenhouse gas emissions and the taxonomy screening criteria require the rapid development of measures to increase environmental sustainability. Simply further improving the already inherently good efficiency of shipping is not enough. The introduction of the EU Emissions Trading System, the Corporate Sustainability Reporting Directive and approaches currently being developed to assess greenhouse gas intensity of inland waterway transport will further promote the avoidance of CO 2 and other greenhouse gases. Today, fossil diesel fuel is still widely used in inland waterway transport. The bio-based fuel HVO has also been available for some time, but its availability is limited by the need for sustainable feedstock. A large number of pilot projects have been launched in recent years with the alternative energy sources hydrogen and methanol, as well as batteries. As no clear trend towards a particular technology is yet apparent, other options such as ammonia are being considered in the sector. Ammonia is also a suitable storage and transport medium for renewable green hydrogen. However, the combustion properties and safety requirements of ammonia pose major challenges for its use as a motor fuel. The CAMPFIRE consortium is running several projects on the conversion and storage of green ammonia as part of future energy systems. One of these projects is developing a propulsion system for inland waterway vessels that runs on pure ammonia as fuel. The main components of this system are an ammonia cracker, which converts a partial flow of the fuel into hydrogen, and a high-speed combustion engine that runs on liquid ammonia and a small amount of hydrogen as an ignition enhancer. The CAMPFIRE Open Innovation Lab (COIL) is currently being built in Poppendorf near Rostock to test the technologies developed. Various configurations (ignition, injection, combustion chamber design, etc.) were tested and evaluated as part of systematic combustion process investigations for the engine as the central energy converter for ship propulsion. The engine achieves comparable performance values and efficiencies to the conventionally operated basic diesel engine. An exhaust gas aftertreatment system will be used to comply with emission limits. It can be assumed that this system can consist of already known technologies. Based on the results obtained, a concept for a prototype engine was derived, which will be examined in detail at COIL in conjunction with the ammonia cracker. The use of ammonia as a fuel also leads to new requirements for ship design. Due to the hazardous substance classification of ammonia and the potential environmental hazard, appropriate safety precautions must be taken. Using the example of an existing ammonia tanker that operates on the Rhine and its tributaries, a concept was developed for the integration of the above-mentioned propulsion system, including the fuel tank and the fuel treatment system. The planning of the conversion of the inland vessel, taking into account the necessary safety measures, was evaluated as part of a risk analysis.

Strict environmental regulations require the production of ultra-low sulfur diesel (ULSD); however, the conventional hydrodesulfurization (HDS) process remains highly energy-intensive. Photocatalytic oxidative desulfurization (PODS) at room conditions has emerged as a promising green alternative. However, industrial applications of UV-based PODS are severely hampered by the Inner Filter Effect (IFE), in which the aromatic-rich diesel matrix strongly absorbs UV radiation, leading to severe photon starvation within the liquid volume and strictly limiting the reaction to the interface. This critical review highlights a paradigm shift towards visible- and near-infrared (red and NIR) light-driven PODS to overcome this optical deadlock. Although red light has excellent penetrating power on diesel matrices, its low photon thermodynamic energy (2.0eV) fundamentally hinders direct C-S bond breaking, which actually demands a much higher activation energy. To bridge this energy deficit, advanced nonlinear photon manipulation strategies are comprehensively evaluated. This review shows that simultaneous Two-Photon Absorption (TPA) is the most superior mechanistic pathway, fundamentally outperforming Second Harmonic Generation (SHG) and Triplet-Triplet Annihilation (TTA). While simultaneous TPA utilizing sensitizers with giant absorption cross-sections (> 1000 GM) provides direct access to highly excited states (Sn or Q1), it fundamentally requires high-intensity laser excitation. Alternatively, defect-mediated Two-Step Two-Photon Absorption (TS-TPA) exploits real intermediate states to bridge the energy gap, triggering highly efficient photochemical degradation at highly accessible, low excitation densities (~ 0.1W cm- 2). Finally, future prospects emphasizing continuous-flow microreactors and advanced optical encapsulation strategies are discussed to realize commercially viable red-light PODS.

This work studied the production of biodiesel from waste cooking oil using an ultrasonic reactor and the testing of biodiesel fuel performance in a diesel engine on a light truck. The process for biodiesel production consisted of several steps, including waste cooking oil filtration, esterification, ultrasonic-assisted transesterification, biodiesel separation using the decantation process, washing, and drying. The main transesterification reaction was conducted using methanol with a molar ratio to the oil of 6:1 and a KOH catalyst of 1%. The reaction was accomplished at 60℃ in 30 minutes. Biodiesel produced was tested to reveal its main characteristics, i.e., flash point, density, viscosity, FAME content, and caloric values. Biodiesel was then mixed with commercial diesel fuel at various ratios (B40, B45, B50, B55, B60, and B65) and tested to evaluate their performance as fuel in a diesel engine on a light truck. A chassis dynamometer was used to measure vehicle torque and power in light trucks that resulted from biodiesel fuel, which was mixed with fossil diesel fuel at a range of ratios. The test revealed that the biodiesel fuels met the standards of fuel characteristics, and the performance in a diesel engine was comparable to that of a diesel engine powered by diesel oil.

Endotamponade selection is best understood as a physics-informed, phenotype-based decision rather than one driven mainly by tamponade duration or material class. This narrative review integrates density, interfacial tension, contact angle, viscosity, and drug-tamponade interactions with phenotype-specific clinical outcomes. The result is a practical framework linking tamponade behavior to retinal geography, disease complexity, and postoperative feasibility. Lighter-than-water agents (air, expansile gases, and light silicone oils [LSOs]) preferentially support the superior retina, whereas heavy silicone oils (HSOs) and perfluorocarbon liquids (PFCLs) provide stronger inferior support. In uncomplicated rhegmatogenous retinal detachment (RRD) and many idiopathic macular holes (MHs), air or sulfur hexafluoride (SF₆) usually achieves high anatomical success with less early intraocular pressure (IOP) elevation and cataract burden than longer-acting gas or silicone oil when brief postoperative positioning is feasible. LSO remains the principal long-term option for complex, tractional, and traumatic disease because it provides durable, relatively posture-independent support, but at the cost of emulsification, cataract, pressure-related, and corneal complications. HSO and staged short-term PFCL are best viewed as selective strategies for inferior-predominant giant retinal tear (GRT) or posture-limited phenotypes, where the mechanistic rationale is strong but comparative evidence remains largely observational. Hydrogel-based vitreous substitutes are promising but remain investigational. Current evidence supports a physics-informed, phenotype-based approach to endotamponade selection. Future research should prioritize phenotype-stratified comparative studies with standardized anatomical and emulsification endpoints and rigorous evaluation of emerging vitreous substitutes in well-defined clinical settings. Not applied.

To compare functional and anatomical results after 1- vs. 3-month heavy silicone oil (HSO) tamponade to repair complex inferior rhegmatogenous retinal detachment recurrence (Re-RRD). A retrospective, comparative, cohort study was conducted involving 46 eyes from 46 patients who were affected by complex inferior Re-RRD and had previously undergone tamponade with either gas or silicone oil. All the eyes were treated using HSO (DENSIRON®68), which was removed after 1 (Group A) or 3 months (Group B). The outcomes included the attachment rate, best-corrected visual acuity (BCVA), and intraocular pressure (IOP), comparing these results at 3, 6, and 12 months after HSO removal. Out of 46 eyes that experienced a complex inferior Re-RRD after initial surgery and received HSO, 24 were in Group A and 22 in Group B, with HSO removal after 1 and 3 months, respectively. The re-attachment rates were similar: 91.6% for Group A and 81.8% for Group B (p=0.4). In Group A a significant visual gain occurred during all follow-up (p<0.001), in Group B the significant improvement (p≤0.03) was lost at 12 months. Mean BCVA was better in Group A than B at 6 and 12 months (p≤0.02). Group B exhibited a significant increase in mean IOP after 3 months (p<0.001), consistently exceeding the values observed in Group A throughout the follow-up (p≤0.002). Macular edema occurred in 7 eyes, with no notable differences between the groups. A 1-month HSO endotamponade has a similar re-attachment rate but provides better visual recovery and controlled IOP than a 3-month endotamponade in complex Re-RRD with inferior involvement.

Radiocarbon analysis of biogenic carbon in liquid fuels using accelerator mass spectrometry.

ABSTRACT Renewable diesel (RD) and sustainable aviation fuel (SAF) are lower-carbon alternatives to conventional petroleum fuels that have begun to enter the U.S. market at commercial scale, largely driven by policy. The most widely deployed forms of RD and SAF are hydrotreated lipids, produced by similar processes, using vegetable or waste oil as the feedstock. Both RD and SAF typically result in lower air pollutant emissions than their petroleum equivalents, especially particulate matter and sulfur oxides (SOx), however the quantity and location of these reductions are different. The dependence of both RD and SAF on the same pool of feedstock and production capacity means that in the near term, increased SAF production may come at the expense of RD. This study investigates the possible air quality effects of such a shift, with a focus on potential impacts in disadvantaged communities. We develop two emissions scenarios in California, for which diesel and aviation emissions are scaled to reflect policies that favor SAF or RD. The air quality associated with each emissions scenario is then simulated using a chemical transport model. Health impacts from the air quality exposure fields are estimated for three major urban areas and exposure disparities are calculated based on historical socioeconomic data. The results of this show minimal air quality and public health changes between the high SAF and high RD scenarios for the California cities analyzed in the present study because California’s current diesel emission regulations limit the potential air quality benefit from RD. This suggests that air quality considerations should not be a dominant motivation when evaluating policy-driven shifts in the relative prevalence of RD and SAF in California. Other regions using less advanced diesel engine technology may see more significant air quality tradeoffs between SAF and RD. Implications: Hydrotreated alternative fuels like renewable diesel (RD) and sustainable aviation fuel (SAF) are entering the market at large scale, drawing from a limited global pool of feedstock (vegetable oil and non-fossil waste oils) and using similar production processes. Policymakers have explored expanding SAF consumption; likely near-term approaches to this would result in a commensurate reduction in RD. This paper evaluates whether this trade-off would cause significant impacts on air quality if it were to occur in California, where a SAF-focused policy change was considered in 2024. We find no significant regional air quality impact from such a shift.

ABSTRACT This study investigates volatility spillovers, network connectedness, and hedging strategies among major fossil fuels and energy stock indices in the five highest fossil fuels-consuming countries from 2008 to 2024. Using TVP-VAR and DCC-GARCH models, we examine how geopolitical and economic shocks influence market interactions. Results show that volatility connectedness increases during turbulent periods, peaking during the COVID-19 pandemic. Brent crude oil incurs the highest hedging cost and delivers the strongest hedging effectiveness in the full sample. However, its effectiveness deteriorates during oil-specific supply shocks. Natural gas and coal display low correlations with energy stock indices, making them the most cost-effective hedges. Regime-based hedging effectiveness analysis reveals that natural gas is countercyclical, strengthening precisely when oil-based hedges weaken. Coal hedging is highly regime-dependent, with its viability contingent on a country’s energy structure and the source of market stress. The findings highlight the need for adaptive, regime-sensitive hedging strategies.

Steam-assisted gravity drainage (SAGD) is widely used to recover super-heavy oil, during which high-temperature steam reduces viscosity and triggers aquathermolysis reactions that generate associated gases. Field data from the Du84 block in the Liaohe Oilfield show significant gas accumulation—mainly CO2 and CH4—at the top of the steam chamber, though the formation mechanisms remain unclear. This study conducted autoclave experiments under SAGD-like conditions to investigate gas generation in Liaohe super-heavy oil. Aquathermolysis occurred primarily between 240–280 °C, with CO2 comprising ∼80% of the gases and a 0.193% conversion rate at 240 °C. Gas yield increased with both temperature and reaction time. The addition of clay minerals boosted gas production by ∼32%, indicating catalytic activity. This study develops a comprehensive five-component (CO2, CH4, H2S, H2 and C2+) parallel reaction kinetic model specifically for super-heavy oil. By integrating mineral catalytic effects and individual gas evolution pathways, the model offers superior predictive accuracy over traditional frameworks. These results enhance understanding of gas formation during SAGD and provide practical guidance for improving gas control and oil recovery in super-heavy oil reservoirs.

Based on observational data from a coastal city in East China, this study integrates meteorological measurements and numerical modeling to identify key drivers and spatiotemporal patterns of regional atmospheric pollution. The findings indicated that the annual 90th percentile concentration of daily maximum 8-h average O3 in Beilun District reached 143.69 μg/m3 in 2022, exceeding the national Class I limit for O3. Seasonal ozone pollution peaked in spring and summer, exhibiting a distinct single-peak diurnal profile. High temperature and low humidity favored photochemical O3 formation, while wind conditions influenced O3 through both local accumulation under weak winds and regional transport under low-to-moderate sea-breeze conditions. Application of the empirical kinetic modelling approach demonstrated that ozone formation was predominantly volatile organic compound (VOC)-limited, with alkenes exhibiting the highest ozone formation potential, followed by alkanes and aromatics. Source apportionment via positive matrix factorization model identified vehicle exhaust (28.7%), solvent usage (24.3%), and oil gas evaporation (24.1%) as the principal sources of ambient VOCs. Backward trajectory analysis indicated that air masses in May were predominantly influenced by eastern marine pathways (38.71%), whereas air masses in July were characterized by transport from inland sources in southwestern Zhejiang Province (62.23%). Potential source contribution function analysis further designated port areas as high-contribution zones for ozone precursors (contribution factors > 0.8), underscoring the significant role of coastal industrial operations and shipping emissions in exacerbating local air pollution.

In this study, four FCC catalysts were synthesized by varying both the zeolite Y content (30 wt% and 40 wt%) and the degree of structural modification through alkaline desilication, aiming to evaluate their resistance to nitrogen-induced catalytic deactivation during the cracking of Colombian vacuum gas oil (VGO). The generation of hierarchical zeolites with intracrystalline mesoporosity enabled their subsequent incorporation into catalyst formulations with different active phase loadings. To simulate severe deactivation conditions, quinoline and indole were added to the VGO as model ni-trogen-containing compounds with distinct basicity. Catalytic performance was assessed in a fixed-bed MAT reactor, analyzing conversion, product distribution and quality, coke deposition, as well as the evolution of textural and acidic properties. The results revealed a synergistic effect between zeolite hierarchization and its loading in the catalyst, leading to enhanced nitrogen tolerance, improved structural stability, and increased resistance to coke-induced deactivation. Specifically, systems containing hierarchical zeolite with higher active phase content exhibited better preservation of Brønsted acidity and reduced coke formation, underscoring the importance of multiscale pore design in mitigating inhibitory effects from nitrogen species. This study provides experimental evidence of the critical role of intracrystalline mesoporosity and zeolite content in determining FCC catalyst performance under severe chemical deactivation scenariosstract text goes here.

Polycyclic aromatic hydrocarbons in surface seawater at the southern Okhotsk Sea, 2017-2022.

Toxic effects of diesel oil on Arbacia dufresnii gametes during early developmental stages.