Light Oil Research Articles

Benchmark Prices and Iraqi Oil Prices: The Asymmetric Effects of Benchmark Prices on Three Iraqi Oil Blends

This paper examines the asymmetric effects of benchmark oil prices on the prices of the three major Iraqi oil blends (Basrah Light, Basrah Heavy and Kirkuk) using Kilian and Vigfusson's (2011) non-linear VAR specification. The empirical evidence reveals that a decrease in benchmark prices decreases Basrah Light and Kirkuk oil blends more than an increase in the benchmark increases the prices of these two Iraqi blends for the October 2002-October 2019 period. However, the asymmetric behavior of Basrah Heavy is the reverse for the April 2015-October 2019 period. Moreover, as the magnitude of the benchmark oil price shocks increases, the degree of asymmetry increases. This shows that Iraq cannot benefit from oil price increases and market developments for its two most important export blends: Basrah Light and Kirkuk.

Lignin oxidative depolymerization to phenolic compounds in a continuous-flow manufacturing platform

Effective oxidative depolymerization of lignin to phenolic monomers and oligomers is a crucial step in the economic feasibility of biorefinery. To date, most studies on the processing technical of lignin have focused on intermittent treatment, with little attention paid to microreactor. In this research, a novel and efficient process technical of oxidative depolymerization lignin via a continuous manufacturing platform was developed, in which the lignin alkaline solution is the disperse phase and the hydrogen peroxide is the continuous phase (oxidants, 8 wt%). The results show that different products can be obtained through varying the reaction conditions of lignin depolymerization. Under the optimized condition, 93.03 wt% conversion of raw lignin and 22.37 wt% yield of monomer was obtained. Besides, comparative characterizations on the samples of raw lignin and depolymerization products by GC-MS-FID and HSQC NMR analysis illustrated that 84.26 wt% of monomers (the sum of yield of 18.85 wt%) is phenolic compounds, with syringaldehyde (yield of 4.22 wt% and selectivity of 18.86 wt%) and vanillin (yield of 3.49 wt% and selectivity of 15.60 wt%) are the main products and the high yields attributed to the efficient cleavage of C-O linkages (mainly β-O-4 linkages) of lignin. Moreover, GPC and elemental analyses show that the light oil product with an oxygen content of 41.28% was mainly composed of dimers and trimers. This work demonstrating that continuous-flow oxidative depolymerization was an effective strategy on lignin processing technical and will be an interesting field of research on lignin comprehensive utilization.

Synergistic interaction between scrap tyre and plastics for the production of sulphur-free, light oil from fast co-pyrolysis

Fast co-pyrolysis offers a sustainable solution for upcycling polymer waste, including scrap tyre and plastics. Previous studies primarily focused on slow heating rates, neglecting synergistic mechanisms and sulphur transformation in co-pyrolysis with tyre. This research explored fast co-pyrolysis of scrap tyre with polypropylene (PP), low-density polyethylene (LDPE), and polystyrene (PS) to understand synergistic effects and sulphur transformation mechanisms. A pronounced synergy was observed between scrap tyre and plastics, with the nature of the synergy being plastic-type dependent. Remarkably, blending 75 wt% PS or LDPE with tyre effectively eliminated sulphur-bearing compounds in the liquid product. This reduction in sulphur content can substantially mitigate the release of hazardous materials into the environment, emphasizing the environmental significance of co-pyrolysis. The synergy between PP or LDPE and tyre amplified the production of lighter hydrocarbons, while PS's interaction led to the creation of monocyclic aromatics. These findings offer insights into the intricate chemistry of scrap tyre and plastic interactions and highlight the potential of co-pyrolysis in waste management. By converting potential pollutants into valuable products, this method can significantly reduce the release of hazardous materials into the environment.

A superhydrophobic zirconium‐based metal‐organic framework/cellulose fiber composite material

AbstractCleanup of oil spills has become one of the most challenging tasks in recent years, as marine oil spills have had a great negative impact on human health and the ecological environment. This also urgently requires the development of new materials and methods with superhydrophobic properties for oil–water separation. As new porous materials, metal–organic frameworks (MOFs) have attracted much attention due to their unique structures and fascinating properties. However, powdered MOF materials are difficult to recycle, and therefore, suitable substrates need to be selected to construct superhydrophobic composites. The surface hydroxyl groups of cellulose fibers offer great possibilities for their superhydrophobic preparation. In this paper, HDTMS‐UiO‐66@CFs composites with superhydrophobicity were strategically synthesized by in‐situ growth of Zr(IV)‐based MOFs linked to hexadecyltrimethoxysilane (HDTMS) on cellulosic fibers (cotton fabric) by using a hydrothermal synthesis method. The HDTMS‐UiO‐66@CFs composites have a water contact angle of 172° and the absorption capacity of light oil and heavy oil is more than 1100%, and the oil–water separation efficiency is as high as 96%. Due to the in‐situ growth of the HDTMS‐UiO‐66 material on cotton fibers, which makes the material more resistant and stable, the material can still maintain its superhydrophobic properties in various harsh environments and after repeated use. Therefore, the newly developed HDTMS‐UiO‐66@CFs composites have a high potential as novel adsorbent materials for cleaning up offshore oil spills and other applications.Highlights In‐situ growth of superhydrophobic metal‐organic frameworks (MOF) particles on cellulose fibers. The porous structure of hexadecyltrimethoxysilane (HDTMS)‐UiO66 plays a key role in hydrophobicity. HDTMS‐UiO66@CFs are chemically stable and have long‐term durability.

Special wettable cotton-containing hybrid composite for heavy oil absorption and light oil resistance in underwater atmosphere

By utilizing the gel reaction between dipentaerythritol penta-/hexa-acrylate (5Acl) and branched polyethylenimine (BPEI), the self-made carboxymethylated cotton fibers, chitosan (CTS), and calcium chloride (CaCl2) were simply blended in this reacting system, then only depending on gelation at room temperature, the special wettable cotton-containing hybrid composite was constructed, meanwhile dispensing with any reactive activator. When ambient atmosphere was in underwater condition, heavy oil absorption and light oil resistance of the water-wetted cotton-containing hybrid composite was displayed in the water environment, and which was radically different from the majority of the currently found superwetting phenomena. Based on this, the removal of subaqueous heavy oil was carried out by using this composite product, simultaneously getting rid of water under light oil was also implemented via its water-pretreated state, therefore by just prewetting the mentioned composite, or not, in water, the selective separation for immiscible oil-water mixture could be successfully realized, whether in oil-removing or water-removing filtering separation, its fluxes and efficiencies were higher than 3500 L/m2·h and 96%; from the perspective of difficult or easy degree of such application implementation, simpleness, easiness, adaptability and reliability for the special wettable cotton-containing hybrid composite had advantage over in selective oil-water separation. Beyond that, this unique composite also had a satisfactory capacity to separate of oil-in-water emulsion (flux: 4229.93 L/m2·h, efficiency: 99.71%).

Investigation of the Behavior of Hydrocarbons during Crude Oil Fouling by High-Resolution Electrospray Ionization Mass Spectrometry

Crude oil is probably the most complex natural chemical mixture processed in various ways to make fuel and fine chemicals among a wide range of products in industrial processing. The conditions of those industrial processes often include high temperatures, which often cause undesired chemical reactions. One of those reaction sequences is crude oil fouling, which finally results in the formation of undesired solid deposits of carbon material, a calamity that costs millions of dollars worldwide each year and produces toxic waste. However, the compounds involved in fouling, let alone the underlying reaction mechanisms, are not understood to date. Here, in order to investigate chemical fouling, the process was simulated under laboratory conditions, focusing on hydrocarbons as the main constituents of crude oil. The results demonstrate large differences within the hydrocarbon class of compounds before and after thermal treatment, even for a very light crude oil fraction, which initially does not contain any bigger or heavier compounds. Here, the fouling reaction is simulated and studied on the molecular level using high-resolution mass spectrometry. After thermal treatment, new, higher molecular weight hydrocarbon compounds with high aromaticity were detected. Results indicate that a radical reaction leads to the formation of larger and more aromatic compounds. The findings were verified by the use of a model hydrocarbon compound to study the mechanism.

The trend of changes in soil organic carbon content in Poland over recent years

The article analyzes soil organic carbon (SOC) content of in Poland from 2015 to 2021. The research aims to determine SOC levels and their dependence on soil agronomic categories and drought intensity. Soil samples from 1011 farms across 8 Polish voivodships were collected for analysis, all from the same agricultural plots. SOC determination was conducted using the Tiurin method. The results indicate a low SOC content nationwide (0.85-2.35%). Heavy soils exhibited higher SOC accumulation compared to light soils. Moreover, significant drought impact led to decreased SOC content in affected regions. Scientific evidence underscores a declining trend in organic carbon stock within agricultural soils, attributed to natural soil changes and unsustainable management practices. This decline is concerning given the crucial role of SOC in soil health, quality, and crop productivity. Therefore, it is imperative to monitor and address areas with low SOC levels to enhance SOC abundance. Furthermore, when used as a whole-cell biocatalyst in a low-cost upflow MFC, the Morganella morganii-rich SF11 consortium demonstrated the highest voltage and power density of 964.93±1.86 mV and 0.56±0.00 W/m3, respectively. These results suggest that the SF11 bacterial consortium has the potential for use in ceramic separator MFCs for the removal of penicillin and electricity generation.

Assessing anaerobic microbial degradation rates of crude light oil with reverse stable isotope labelling and community analysis

Oil reservoirs represent extreme environments where anaerobic degradation profoundly influences oil composition and quality. Despite the common observation of biodegraded oil, the microbial degradation rates remain largely unknown. To address this knowledge gap, we conducted microcosm incubations with light oil as carbon source, original formation water and sulfate as electron acceptor, closely mimicking in situ conditions to assess oil degradation rates. Samples were taken from a newly drilled oil well to exclude contamination with injection water and allochthonous microorganisms. At the end of the incubations, microbial community analyses with 16S rRNA gene amplicon sequencing revealed the most prominent phyla as Desulfobacterota, Thermotogota, Bacteroidota, Bacillota (formerly Firmicutes), and Synergistota, collectively accounting for up to 44% of relative abundance. Ion chromatography and reverse stable isotope labeling were used to monitor sulfate reduction and CO2 evolution respectively. We calculated an average degradation rate of 0.35 mmol CO2 per year corresponding to 15.2 mmol CO2/mol CH2(oil) per year. This resembles to approximately 200 years to degrade one gram of oil under the applied, presumably ideal conditions. Factoring in the available oil-water-contact (OWC) zone within the incubations yielded a degradation rate of 120 g CH2 m−2 OWC per year, closely aligning with the modeled degradation rates typically observed in oil reservoirs. Moreover, our study highlighted the utility of the reverse stable isotope labeling (RSIL) approach for measuring complex substrate degradation at minute rates.

Azolla Pinnata: Sustainable Floating Oil Cleaner of Water Bodies.

Various plant-based materials effectively absorb oil contaminants at the water/air interface. These materials showcase unparalleled efficiency in purging oil contaminants, encompassing rivers, lakes, and boundless oceans, positioning them as integral components of environmental restoration endeavors. In addition, they are biodegradable, readily available, and eco-friendly, thus making them a preferable choice over traditional oil cleaning materials. This study explores the phenomenal properties of the floating Azolla fern (Azolla pinnata), focusing on its unique hierarchical leaf surface design at both the microscale and nanoscale levels. These intricate structures endow the fern with exceptional characteristics, including superhydrophobicity, high water adhesion, and remarkable oil or organic solvent absorption capabilities. Azolla's leaf surface exhibits a rare combination of dual wettability, where hydrophilic spots on a superhydrophobic base enable the pinning of water droplets, even when positioned upside-down. This extraordinary property, known as the parahydrophobic state, is rare in floating plants, akin to the renowned Salvinia molesta, setting Azolla apart as a natural wonder. Submerged in water, Azolla leaves excel at absorbing light oils at the air-water interface, demonstrating a notable ability to extract high-density organic solvents. Moreover, Azolla's rapid growth, doubling in the area every 4-5 days, especially in flowing waters, positions it as a sustainable alternative to traditional synthetic oil-cleaning materials with long-term environmental repercussions. This scientific lead could pave the way for more environmentally friendly approaches to mitigate the negative impacts of oil spills and promote a cleaner water ecosystem.

Designing a superhydrophobic cotton fiber coating exploiting TiO2@g-C3N4 layered structure for augmented photocatalysis and efficient water-oil separation

This study introduces a novel approach to develop a multifunctional coating on cotton fabric, emphasizing the utilization of cotton fiber as a biological macromolecule, by integrating a TiO2@g-C3N4 layered structure to confer superhydrophobic properties and multiple functionalities. The engineered structure not only enhances fabric roughness but also incorporates non-fluoro hydrophobic agents, thereby imparting diverse capabilities such as photocatalysis, oil-water separation, and self-cleaning to the cotton substrate. Fabrication of the TiO2@g-C3N4 layered structure involved ultrasonic dispersion of TiO2 and g-C3N4, subsequently deposited onto cotton fabric. Sequential hydrophobic treatment with polydimethylsiloxane (PDMS) and isophorone diisocyanate (IPDI) achieved superhydrophobicity, exhibiting an exceptional water contact angle (WCA) of 157.9°. Comprehensive characterization via scanning electron microscopy (SEM), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric validated the composite's structural and chemical properties. The introduced TiO2@g-C3N4 structure significantly enhanced fabric roughness, while PDMS treatment lowered surface energy and IPDI hydrolysis facilitated cross-linking, ensuring durability. The resultant TiO2@g-C3N4/PDMS cotton exhibited outstanding self-cleaning properties and demonstrated oil adsorption capacity, accommodating both heavy and light oils. Notably, this superhydrophobic cotton efficiently separated water-oil mixtures, achieving 96.8 % efficiency even after 10 cycles. Moreover, under simulated light, it displayed outstanding photocatalytic degradation (93.2 %) of methylene blue while maintaining a WCA of 150° post-degradation, highlighting sustained functionality. This innovation holds promise for sustainable applications, offering robust physical and chemical durability within the realm of biological macromolecules. The amalgamation of TiO2@g-C3N4 layered structure and PDMS treatment on cotton fabric underscores a sustainable approach to address water-oil separation challenges and enable efficient self-cleaning. This research demonstrates a significant step towards sustainable material applications and addresses pertinent real-world challenges in diverse technological domains.

PENGARUH POLIMER PC DENGAN ADDITIF TWEEN-80 TERHADAP KARAKTERISTIK POLIMER DAN RECOVERY FACTOR PADA MINYAK 39 °API DI BATUAN SANDSTONE

Background: The increasing demand for petroleum and the depletion of oil reserves in oil fields require the development of more efficient oil recovery techniques to enhance oil production. One method that can be employed is Enhanced Oil Recovery (EOR), where chemical injection becomes a viable approach. One chemical injection method that can be used is polymer injection. One suitable polymer for this purpose is cellulose polymer (PC). Cellulose polymer (PC) is the most abundant polymer in nature, a renewable material that is degradable, biocompatible, cost-effective, and non-toxic. Cellulose can be derived from plants and certain types of bacteria.Objective: This research aims to investigate the influence of temperature variations on cellulose polymer (PC) with Tween-80 additive on the Recovery Factor.Methodology: Laboratory experiments were conducted using the core flooding technique with a core holder, applying the slug method with various °API variations on light crude oil with an API gravity value of 39. Sandstone rock samples were used in the experiments, prepared by saturating with brine and oil.Result: The laboratory results showed a recovery percentage of 7.89% at a temperature of 60 °C and 17.86% at a temperature of 80 °C. The highest increase in oil recovery was observed at a temperature of 80 °C, with a recovery factor of 17.86%. In conclusion:, based on the conducted core flooding experiments, the best recovery factor was found in polymer injection using PC with Tween-80 additive at a temperature of 80 °C.

Numerical simulation on gas-solid separation characteristics of in-situ pyrolysis products of tar-rich coal

ABSTRACT Tar-rich coal holds the potential to substitute the supply of oil-gas resources. The in-situ pyrolysis contributes to efficient resource utilization and can potentially achieve net-zero CO2 emissions. However, it is challenging to efficiently separate oil-gas resources, which are predominated by tar, from multiphase products of in-situ pyrolysis of tar-rich coal. Additionally, the difference in fluid properties yields significant influences on separation performance, while the understanding of the separation characteristics of high-viscosity fluid remains insufficient. In this study, the separation process of pyrolysis products from tar-rich coal was investigated using the computational fluid dynamics simulation approach. The flow field, pressure drop, separation efficiency and distribution characteristics were analyzed. The simulation results indicate that the volute cyclone separator exhibits commendable separation efficiency, exceeding 98%. Meanwhile, in handling tars containing a high concentration of light oil, the separator demonstrates remarkable adaptability. The separation efficiency of solid particles decreases from 89% to 83% when the system contains a high content of pitch. The particle diameter exerts great influence on the flow field. The separation efficiencies are 99% and 0.37%, respectively, when the particle sizes are selected as 0.1 mm and 0.001 mm. In the scope of this study, the optimal working conditions of the cyclone separator were determined, which provides data support for improving the separation efficiency and recovery rate of the oil-gas resources.

Scaling up in situ combustion process for enhanced oil recovery in water-flooded light oil reservoirs from laboratory to field implementation

Aiming at low permeability, high water content light reservoir with a recovery rate higher than 20%, an improved air injection enhanced heat flooding technology is applied by combining the combustion reaction flow and flue gas flooding mechanism. The method involves the injection of air into the reservoir, which reacts with the crude oil at temperatures ranging from 220 to 300 °C. This reaction consumes part of the oil, enabling effective evaporation and flow of the remaining oil. This process combines combustion reaction flow with flue gas flooding, using high-temperature oxidation reactions to mobilize residual oil. Experimental results from combustion tube tests demonstrate stable reaction fronts, peak temperatures reaching up to 550 °C, and a significant increase in recovery rates, reaching 73.8% in some cases. Field applications of this technology require maintaining high air flux and burning rates in low-permeability zones to ensure effective heat-driven evaporation. The geological model of the well group shows that the recovery factor of the target block can be increased by more than 20% by air injection based on the water drive recovery factor of 28%–30%. The oil exchange ratio can be less than 4000 sm3/m3 by optimizing the air injection rate and oxygen content. The research results provide technical feasibility for heat flooding to significantly improve oil flow and recovery in low-permeability light oil reservoirs.

Effect of fast heating rate and alkaline catalyst on composition and characteristic of volatile products during catalytic upgrading of oil sand bitumen

The study was devoted to exploring the fundamental study on the upgrading of Buton oil sand bitumen (OSB) via fast alkaline catalytic pyrolysis based on the fluid pyrolysis technology. The effect of fast heating rate on the composition and molecular distribution of volatile products from the high-temperature fast pyrolysis of OSB was investigated by Py-GC/TOF-MS that could simulate the fast heating rate of industrial fluid pyrolysis process. The results showed that the volatile products of OSB under heating rates ranging from 10 to 1000 °C/s had the similar species composition. It was found that there were the highest relative content of low-carbon alkenes (C2-C4) and light aromatics (C6-C8) in volatile products under the 1000 °C/s, indicating that the fast heating rate favored the production of light alkenes and aromatics. Subsequently, a laboratory-scale fluidized bed apparatus was employed to further gain insight into fast alkaline catalytic pyrolysis behaviors of OSB. The investigation on the yield distribution, fractional- and molecular-level chemical characteristic of volatile products obtained from the fast alkaline catalytic upgrading of OSB over calcium aluminate was carried out with the aid of the comparison with that over Y zeolite-based FCC catalyst and silica sand. The results revealed that three-phase products over calcium aluminate possessed the larger selectivity of C2−C4 alkenes, larger yield of light oil and the lower coke output, which were 51.88%, 45.49% and 7.96%, respectively. On basis of the chemical structure analysis of liquid products, the alkaline catalytic upgrading of OSB over calcium aluminate could heighten the content of chain alkyl structures as well as alkyl-substituents attached to aromatic ring in liquid products. This indicated that the fast heating rate and alkaline catalyst that adopted in catalytic upgrading process of OSB could play an energetic role in optimizing the composition of volatile products. The alkaline catalytic upgrading of OSB based on fluid pyrolysis technology with the fast heating rate could heighten the yield of low-carbon olefins and light oil and lessen coke yield, meanwhile modify the chemical structure characteristics of liquid products that were conducive to the generation of valuable chemicals (light alkanes and BTX) during secondary processing of liquid products.

Impact of Metal Impregnation of Commercial Zeolites in the Catalytic Pyrolysis of Real Mixture of Post-Consumer Plastic Waste

This work reports the study of the catalytic pyrolysis of rejected plastic fractions collected from municipal solid waste whose mechanical recovery is not plausible due to technical or poor conservation issues. The chemical recycling using catalytic pyrolysis was carried out over commercial zeolites formulas, i.e., HY and HZSM-5, in which Ni or Co metals were deposited at two different loadings (1 and 5%, wt.). The presence of these transition metals on the zeolitic supports impacted the total production of compounds existing in the liquid oil. The samples were characterized in terms of structural, chemical, and morphologic properties, and the production of different fuel fractions (gasoline, light cycle oil, and heavy cycle oil) was correlated with a combined parameter defined as a ratio of Acidity/BET area.

Identifying risks in temporal supernetworks: an IO-SuperPageRank algorithm

Complex systems pose risks characterized by factors such as uncertainty, nonlinearity, and diversity, making traditional risk measurement methods based on a probabilistic framework inadequate. Supernetworks can effectively model complex systems, and temporal supernetworks can capture the dynamic evolution of these systems. From the perspective of network stability, supernetworks can aid in risk identification for complex systems. In this paper, an IO-SuperPageRank algorithm is proposed based on the supernetwork topological structure. This algorithm reveals network instability by calculating changes in node importance, thereby helping to identify risks in complex systems. To validate the effectiveness of this algorithm, a four-layer supernetwork composed of scale-free networks is constructed. Simulated experiments are conducted to assess the impact of changes in intralayer edge numbers, intralayer node numbers, and interlayer superedge numbers on the risk indicator IO value. Linear regression and multiple tests were used to validate these relationships. The experiments show that changes in the three network topological indicators all bring about risks, with changes in intralayer node numbers having the most significant correlation with the risk indicator IO value. Compared to traditional measures of network node centrality and connectivity, this algorithm can more accurately predict the impact of node updates on network stability. Additionally, this paper collected trade data for crude oil, chemical light oil, man-made filaments and man-made staple fibers from the UN Comtrade Database. We constructed a man-made filaments and fibers supply chain temporal supernetwork, utilizing the algorithm to identify supply chain risks from December 2020 to October 2023. The study revealed that the algorithm effectively identified risks brought about by changes in international situations such as the Russia-Ukraine war, Israel–Hamas conflict, and the COVID-19 pandemic. This demonstrated the algorithm’s effectiveness in empirical analysis. In the future, we plan to further expand its application based on different scenarios, assess risks by analyzing changes in specific system elements, and implement effective risk intervention measures.

Catalytic pyrolysis of tar-rich coal for coal tar to light oil with catalysts of modified granulated blast furnace slag

Catalytic pyrolysis of tar-rich coal for coal tar to light oil with catalysts of modified granulated blast furnace slag

Co-processing of organic fraction from groundnut shell biocrude with VGO in FCC unit to produce petrochemical products

This research work explores the transformative potential of biomass leading to sustainable production of biocrude and its utilization in refinery and petrochemical sector for reducing reliance on fossil fuels. In this study, groundnut shell biomass was thermally converted in a customized continuous semi pilot auger reactor in temperature range of 400–700 °C. The optimum temperature for maximizing biocrude was studied, and detailed chemical analysis revealed that biocrude contains hydrocarbons and alcohols with a calorific value of 29 MJ/kg. Furthermore, this study demonstrates the performance of the FCC (Fluid Catalytic Cracking) catalyst and feedstock (H-T- VGO (Hydrothermal vacuum gasoline oil) & Biocrude) in a laboratory-scale utilizing ACE R + MM (Advanced Cracking Evaluation - Residue and Metals Management) unit under predetermined temperatures (515 °C, 525 °C) and a fixed cat-to-oil weight ratio (CTO = 6 w/w). The organic phase and FCC feedstock in different weight ratios from 5 to 20 wt % were blended. There are marginal changes in the yields of dry gas, LCO (light cycle oil) and HCO (heavy cycle oil), with significant increase in the yields of LPG (liquified petroleum gas) and gasoline. Bottoms have been reduced, and coke formation has been adjusted. However, this process requires prudent blending and temperature choices, with future recommendations including improvement in the quality of biocrude to enhance the yields of both LPG and gasoline along with reduced coke formation.

Molecular insights into the adsorption and penetration of oil droplets on hydrophobic membrane in membrane distillation

Membrane fouling induced by oily substances significantly constrains membrane distillation performance in treating hypersaline oily wastewater. Overcoming this challenge necessitates a heightened fundamental understanding of the oil fouling phenomenon. Herein, the adsorption and penetration mechanism of oil droplets on hydrophobic membranes in membrane distillation process was investigated at the molecular level. Our results demonstrated that the adsorption and penetration of oil droplets were divided into four stages, including the free stage, contact stage, spreading stage, and equilibrium stage. Due to the extensive non-polar surface distribution of the polytetrafluoroethylene (PTFE) membrane (comprising 95.41 %), the interaction between oil molecules and PTFE was primarily governed by van der Waals interaction. Continuous oil droplet membrane fouling model revealed that the new oil droplet molecules preferred to penetrate into membrane pores where oil droplets already existed. The penetration of resin (a component of medium-quality oil droplets) onto PTFE membrane pores required the “pre-paving” of light crude oil. Finally, the ΔE quantitative structure-activity relationships (QSAR) models were developed to evaluate the penetration mechanism of pollutant molecules on the PTFE membrane. This research provides new insights for improving sustainable membrane distillation technologies in treating saline oily wastewater.

Semantic segmentation model for concrete cracks based on parallel Swin-CNNs framework

In recent years, crack detection has been the focus of relevant research since concrete fractures are the most dangerous damage to structures. Computer vision-based approaches are frequently employed for their distinct benefits. However, the crack segmentation model based only on convolutional neural networks (CNNs) is still inadequate in generalization because of its inherent bias produced by its low contextual understanding capacity. This research provides a framework PSC (Parallel Swin-CNNs) that employs a multi-scale feature fusion pyramid decoder to partition concrete cracks semantically using Swin Transformer and CNNs. This research evaluates classic CNN models U-Net, U-Net++, DeepLabV3, PSPNet, Feature Pyramid Network (FPN), and DeepCrack on two datasets. The proposed PSC model achieves the best crack segmentation results, with a maximum improvement of 36.57% in F1-score and 62.38% in Intersection over Union value on both datasets, a reduction in parameters of 2.95%–40.89% except for PSPNet. The proposed PSC model demonstrates versatile applicability across various scenarios, effectively overcoming interferences such as light shadows, oil stains, potholes, and textured surfaces while maintaining high computational efficiency.