Light Oil Research Articles

Development and Application of Certified Reference Materials of Light Crude Oil for Water Content.

The water content of the crude oil needs to be measured accurately. The analytical methods that are used, including distillation and Karl Fischer coulometric titration (KFCT), require verification using certified reference materials (CRMs) of crude oil for the water content. In the present study, five CRMs of light crude oil with large volumes and various certified water contents (1-10 mg/g) were developed using the gravimetric method. Each candidate CRM was prepared individually, including the addition of pure water to the dried blank crude oil and weighing the masses of the added water and the blank crude oil. The water content of the blank crude oil was measured using azeotropic distillation-KFCT (AD-KFCT). The certified water content for the CRM was calculated by using the water content of the blank crude oil, the masses of the added pure water, and the blank crude oil. The certified water content and the expanded uncertainty (U, k = 2) of the five CRMs were 1.12 (0.04), 2.14 (0.06), 3.14 (0.10), 5.14 (0.15), and 10.05 (0.27) mg/g. These CRMs were used to verify the accuracy of analytical methods, including distillation, KFCT, and AD-KFCT methods.

Microbubble-based process for the enhancement of microfine and heavy oil droplets swirl separation in axial inlet hydrocyclone

Because of the pressing demand for environmental governance and resource utilization of pollutants, the separation of oil in oily wastewater has become a research hotspot in water treatment, with swirl de-oiling being one of the most effective separation technologies. However, the current swirl separation technology has significant shortcomings when separating microfine and heavy oil droplets. In this study, a new process based on composite force field enhanced separation was developed to enhance swirl separation of microfine and heavy oils by injecting microbubbles into the axial inlet hydrocyclone. The performance between the standard swirl and the proposed swirl air flotation processes in separating microfine and heavy oil was evaluated for overall separation efficiency, particle grade efficiency, and outlet particle size distribution. The results showed that the swirl air flotation process enhanced the separation efficiency by 24.2 % and 15.9 % for heavy oil (density of 950 kg/m3) and light oil (density of 825 kg/m3) with particle size distribution of EP2, respectively. The main enhancement was in the particle size range of 11.2–58.9 μm, and the largest enhancement in separation capability was achieved for oil droplets with a particle size of 16.4–35.3 μm, with an enhancement of approximately 18 %. Furthermore, the introduction of a swirl-stabilizing tube improved the separation effect and anti-fluctuation of the device. This study provides insights supporting practical applications of swirl air flotation and a provides basis for further studies aimed at broadening the axial inlet hydrocyclone application range.

Geochemical properties, mechanism of formation, and source of solid bitumen in the Ediacaran Dengying Formation from the central to northern Sichuan Basin, China

Several large gas reservoirs, including the Weiyuan and Anyue gas fields, have been discovered in the Ediacaran Dengying Formation in the Sichuan Basin, indicating vast opportunities for deep-petroleum exploration. Understanding the origin and evolution process of these gas reservoirs is crucial for further petroleum exploration and development. Although the burial history of the Sichuan Basin and its surrounding areas is basically dominated by Paleozoic burial and preservation, and Meso-Cenozoic uplift and erosion. However, the source of the Dengying Formation natural gas in the Sichuan Basin is still a subject of controversy between the Ediacaran and Cambrian source rocks due to high thermal maturity, secondary alteration, and multistage tectonic activities. This study aims to examine the investigation on the properties and genetics of Dengying solid bitumens that existed in the central to northern Sichuan Basin, in order to provide insights into the source and evolution history of the Dengying paleo-oil reservoirs. For this purpose, petrologic, elemental, and organic geochemical analyses were used to investigate the properties, origin, and formation mechanism of solid bitumens. The results indicate that these solid bitumens have suffered intense thermal alteration (EqVRo 2.1%–5.3%), and are classified as pyrobitumens. Solid bitumens in the Gaoshiti bulge and the north slope area were subjected to tectonic thermal events (e.g., Emeishan igneous province) and relatively strong thermochemical sulfate reduction (TSR) alteration. These solid bitumens were assumed to be pyrolysis products of light (condensate) oil. In contrast, solid bitumens in the Weiyuan bulge and the Micangshan uplift area were not influenced by tectonic thermal events but experienced weak TSR alteration, and originated from either normal or heavy crude oil. Moreover, a systematic bitumen-source correlation was carried out using δ13Corg values, bound steranes, and trace element distributions. Results reveal that the solid bitumens in the central Sichuan paleo-uplift were mainly derived from the lower Cambrian Maidiping Formation, those in the north slope area originated from the lower Cambrian Qiongzhusi Formation, while those in the Micangshan area were sourced from the Ediacaran Doushantuo Formation. Structural and burial history analysis implies that the differences in the source of the Dengying paleo-oil reservoir (i.e., solid bitumen) between these study areas are attributed to the distribution of source rocks and their contact relationship with reservoirs. This research successfully obtained insights into the source and genetic mechanism of paleo-oil reservoirs by analyzing the properties of high-maturity solid bitumens, which can guide further exploration and development of deep petroleum resources.

Three-dimensional porous carbon materials as catalysts for upgrading coal pyrolysis volatiles to boost light tar

The large proportion of heavy components in volatiles from coal pyrolysis is liable to entrain dust and form coke, resulting in the difficulty of separating oil from dust, which thus causes the blocking of technical pipelines. Carbon-based catalysts (BC and BHC) and metal-modified carbon-based catalysts (Fe-BC, Ni-BC, Fe-BHC and Ni-BHC) were prepared for the upgrading of volatiles from coal pyrolysis. This three-dimensional interconnected macroporous carbon material is primarily derived from the pyrolysis of the blend of a biochar and a caking coal. The results show that the metal-modified carbon-based catalysts aid in activating small molecules, such as CH4, CO2, and H2O, increasing in-situ hydrogen donation while cracking polycyclic aromatics, macromolecular oxygen-containing compounds, and N, S-containing heterocyclic compounds. This thus increases the selective catalysis of benzene, naphthalene, biphenyl, and anthracene and improves tar quality. The unactivated Fe-BC and Ni-BC catalysts exhibit high selectivity for light oil with a boiling point below 170 °C. In contrast, the activated Fe-BHC and Ni-BHC catalysts have a stronger ability to crack heavy tar due to the synergistic effect of metal and carbon defect structures. However, the micropores within the catalysts prevent mass transfer of macromolecular compounds, drastically lowering the tar yield with coke formation. Overall, the unactivated metal modified catalyst with three-dimensional porous structure allows for the synergistic effect of dust removal and upgrading of volatiles while maintaining the tar yield, especially the Fe-BC catalyst with a lower price.

Catalytic hydrotreating of crude bio-oil from straw and its distillates obtained by molecular distillation: A comparative study

In this study, the crude bio-oil (CBO) obtained from hydrothermal liquefaction of peanut straw was separated into light oil (LO) and heavy oil (HO) by molecular distillation at 130 ℃ and different pressures (0.5, 1 and 3 kPa). With process variables fixed, the CBO and its distillates were subjected to catalytic hydrotreating to probe the behavior characteristics of CBO from straws during this process. The LO yield fluctuated between 29.8 and 34.8 wt% with the change of distillation pressure. LO presented lower C content and higher H and O content than the corresponding HO. The LO obtained at 1 kPa showed a significant content difference between ketones (34.50%) and phenolic compounds (5.84%), indicating the differential distribution of these chemical components in CBO and the possibility of component separation by molecular distillation. Hydrotreating of LO gained obviously higher yield of upgraded oil (82.1–89.7 wt%) and lower yield of solid (6.1–9.1 wt%) than the corresponding HO (61.2–69.4 wt% and 21.3–24.6 wt%, respectively). The addition of n-hexane in the hydrotreating of HO led to an increase in hydrocarbon content and a decrease in content of phenolic compounds in the upgraded oil, although it did not contribute to increasing the upgraded oil yield.

Liquefaction of polystyrene(PS) waste plastics in supercritical ethanol and reaction pathway exploration

The correlation between the liquefaction efficiency of polystyrene (PS) with different process parameters was studied using an autoclave. In addition, we also analyze the reaction path of PS liquefaction based on the composition of functional groups and compounds in the liquefied oil. The results showed that the products were dominated by 2–4 cyclic benzenes. PS favored liquefaction to oil at mild temperatures, long residence times, and low solid-to-liquid ratios, with the highest liquefaction efficiency (63.86%) when liquefied at 340 °C for 90 min at a 10% solid-to-liquid ratio. The 1H NMR spectrum found that 6.0–8.5 ppm is the main resonance peak of chemical shift, indicating that the liquefied oil contains a large amount of aromatic/hetero-aromatic ring functional group-like compounds. The GC-MS analysis results were consistent with the 1H NMR results. The highest content of compounds in the liquefied oil were benzene derivatives. TG and DTG analysis showed that the pyrolysis of liquefied oil was divided into two stages: light oil and heavy oil, and the boiling range was 60 °C ∼ 400 °C. Analyzed by carbon chain length, the percentage of C1∼C22 in the oil can reach up to 86.51%. Therefore, PS liquefied oil has the potential as a liquid fuel.

Research on the Timing of WAG Intervention in Low Permeability Reservoir CO2 Flooding Process to Improve CO2 Performance and Enhance Recovery

In low permeability reservoirs, CO2 flooding usually leads to gas channeling, whereby a significant amount of CO2 bypasses the oil-bearing formation and fails to effectively displace oil. Introducing water-alternating-gas (WAG) flooding, utilizing water phase stability-driven processes, serves to suppress gas channeling and enhance oil recovery rates. Implementing WAG flooding, which utilizes water phase stability-driven processes, helps suppress gas channeling and improve oil recovery rates. The timing of implementing WAG flooding is crucial. Initiating WAG flooding prematurely can limit the efficiency of CO2 displacement, while initiating it with delays may result in severe gas channeling, resulting in decreased production and increased environmental risks. Finding the balance point is the challenge. The balance point can effectively control gas channeling without reducing the efficiency of CO2 flooding. In this paper, the timing of WAG flooding in low permeability reservoirs is studied in detail. Firstly, this study conducted experimental research to investigate the CO2 displacement process in both homogeneous and heterogeneous cores. Furthermore, it validated the correlation between the timing of WAG injection and the heterogeneity of the cores. The experimental results indicated the existence of an optimal timing for WAG injection, which is correlated with the degree of heterogeneity. Numerical simulation studies were performed to simulate the characteristics of the light oil–CO2 system using the Peng–Robinson (PR) equation. Furthermore, a history matching analysis was performed to validate the experimental results and investigate the correlation between WAG injection and the degree of heterogeneity. The study concluded that as the degree of heterogeneity increases, initiating WAG injection earlier leads to a more significant suppression of gas channeling, increased water–gas interaction, improved gas–oil contact, and enhanced the synergistic effect of increasing the resistance and pressure of WAG flooding and controlling gas channeling. This finding has significant practical implications, as the optimization of WAG injection timing can enhance oilfield production efficiency.

Characteristics of bound biomarkers released from pyrobitumens generated from the cracking of different types of crude oils

Pyrobitumen has attracted significant attention from petroleum geologists and geochemists due to its close relationship with crude oil and natural gas. Generally, the analysis of free biomarkers in pyrobitumen is of limited use, because these biomarkers can be easily modified by biodegradation and thermal alteration. The utilization of bound biomarkers in pyrobitumen appears to be a viable solution to address these issues. However, the compositions and concentrations of bound biomarker moieties in pyrobitumen can also be influenced by external factors such as thermal stress during its formation and the original abundance of asphaltenes in oil. The goal of this study is to examine the evolutionary history of free and bound biomarkers during the formation process of pyrobitumen from different types of crude oil. This is beneficial for the interpretation of covalently bound biomarkers released from natural pyrobitumens in applications such as oil/gas–solid bitumen-source correlation and oil/gas migration studies. Anhydrous and hydrous pyrolysis experiments were conducted on three types of crude oil (condensate, black oil, and heavy oil) to simulate the formation process of pyrobitumen. The comparison of free biomarkers in the liquid residuals of the oil pyrolysis and the bound biomarkers released by the hydropyrolysis of the corresponding pyrobitumen products indicated that the differences between free and bound biomarkers vary with the types of original oils. At elevated thermal maturity (Easy %Ro ≥ ca. 1.0%), the higher the absolute abundance of the asphaltene fraction within a particular oil, the greater the similarity between the distribution of bound biomarkers (especially for steroids) released from pyrobitumen and the corresponding original oil. Thus, the use of pyrobitumen-bound biomarkers formed by heavy oil (asphaltene-rich) can obtain relatively accurate biogenic information on paleo-reservoirs. However, caution should be exercised when employing pyrobitumen-bound biomarkers in paleo-reservoirs formed by light oil (asphaltene-depleted).

Study on lightening of coal tar with metal oxide supported γ-Al2O3 catalyst

In this experiment, a fixed bed of pyrolysis was used to conduct pyrolysis with coal and a mixture of coal and catalyst, and the distribution and composition of tar products were studied. The pyrolysis of raw coal was carried out at different temperatures and at different constant temperature times, and the effects of pyrolysis temperature and constant temperature pyrolysis time on tar product formation from raw coal pyrolysis were studied. γ-Al2O3 was used as the carrier, and 4 kinds of alkaline earth metal oxides (MgO, CaO, SrO, BaO), 3 kinds of subgroup metal oxides (Fe2O3, Co2O3, NiO) and 5 kinds of VIII metal oxides (Cr2O3, MnO2, CuO, ZnO, MnO2) were selected as active components. The supported γ-Al2O3 catalyst was prepared by the method of equal volume impregnation and roasting in a muffle furnace. The γ-Al2O3 catalyst was characterized by means of XPS, BET and SEM, and the mechanism of the mixed pyrolysis of coal with different metal oxide supported catalysts to generate tar was studied. The results showed that: (1) under the conditions of 450 °C, 500 °C, 550 °C and 600 °C, the maximum tar yield was 0.32 g at 600 °C, and the tar yield was higher at constant temperature for 15 min than at final temperature of 600 °C, with an increase of 15.63%. (2) Fe2O3/γ-Al2O3 catalyst resulted in the highest tar yield of 0.75 g, which was 134.38% higher than that of coal pyrolysis. (3) From the increase of light oil and phenol oil and the decrease of anthracene oil and asphalt, Co2O3/γ-Al2O3, Fe2O3/γ-Al2O3 and Cr2O3/γ-Al2O3 can improve the tar quality better.

Exploration of Oil/Water/Gas Occurrence State in Shale Reservoir by Molecular Dynamics Simulation

The occurrence state of oil, gas, and water plays a crucial role in exploring shale reservoirs. In this study, molecular dynamics simulations were used to investigate the occurrence states of these fluids in shale nanopores. The results showed that when the alkane is light oil, in narrow pores with a width less than 3 nm, oil molecules exist only in an adsorbed state, whereas both adsorbed and free states exist in larger pores. Due to the stronger interaction of water with the rock surface, the adsorption of oil molecules near the rock is severely prohibited. Oil/water/gas occurrence characteristics in the water-containing pore study indicate that CO2 gas can drive free oil molecules out of the pore, break water bridges, and change the occurrence state of water. During displacement, the gas type affects the oil/gas occurrence state. CO2 has strong adsorption capacity, forming a 1.45 g/cm3 adsorption layer on the rock surface, higher than oil’s density peak of 1.29 g/cm3. Octane solubility in injected gases is CO2 (88.1%) > CH4 (76.8%) > N2 (75.4%), with N2 and CH4 having weak competitive adsorption on the rock. The investigation of different shale reservoir conditions suggests that at high temperature or low pressure, oil/gas molecules are more easily displaced, while at low temperature or high pressure, they are tightly adsorbed to the reservoir rock. These findings contribute to the understanding of fundamental mechanisms governing fluid behavior in shale reservoirs, which could help to develop proper hydrocarbon recovery methods from different oil reservoirs.

Enhanced micro-explosion to improve the yield of light oil in catalytic cracking of water-in-heavy oil emulsion prepared by continuous membrane emulsification

Membrane emulsification provides new ideas for improving the atomization performance of high viscosity heavy oil in catalytic cracking process, thereby improving the distribution of catalytic cracking products. A comprehensive understanding of the micro-explosion characteristics and catalytic cracking of low water content heavy oil emulsion is the key to the application of membrane emulsification technology in heavy oil catalytic cracking process. Therefore, different water droplet sizes and water content of heavy oil emulsion were controllably prepared by continuous membrane emulsification, and their micro-explosion characteristics and catalytic cracking performance were investigated. The evaporation of heavy oil emulsion droplets (water content over 3 vol%) only underwent the heat transfer stage and the fluctuating evaporation stage due to the strong micro-explosion. The micro-explosion delay time of emulsion droplets decreased from 2.631 to 0.434 s/mm2 with increased temperature (300–600 ℃), increased from 0.645 to 1.042 s/mm2 with increased water content (1–5 vol%), and increased from 0.642 to 1.237 s/mm2 with increased average droplet size (1.80–14.6 μm). The child droplets generated after micro-explosion were characterized, and the different heating behaviors were quantitatively distinguished by the average size of the child droplets. Additionally, the micro-explosion performance (i.e. child droplets size and strong micro-explosion probability) of emulsion droplets improved with increasing water content and average water droplet size, while it initially decreased and then increased when the temperature increased. Furthermore, the improvement of micro-explosion performance by membrane emulsification can increase the yield of light oil (up to a maximum increase of 10.82 %) and reduce the yield of coke (up to a maximum decrease of 5.99 %) in the heavy oil emulsion catalytic cracking.

Selective Single‐step Co‐hydroprocessing of Light Cycle Oil and Waste Cooking Oil Mixtures for Diesel Fuel Production

AbstractThis study investigates the co‐hydroprocessing of light cycle oil (LCO) with waste cooking oil (WCO) as a potential strategy to enhance LCO′s qualities and overall performance. The study involves the integration of LCO with WCO in three different ratios, facilitating a combined hydrotreatment process within a fixed bed continuous down‐flow reactor. The findings reveal that incorporating WCO into LCO hydrotreatment enhances LCO′s properties, albeit with a minor reduction in hydrodesulfurization efficacy. WCO demonstrates approximately 10.7 % density and 26 % cetane number improvements compared to the LCO/WCO (70/30) blend at 380 °C. The most significant reduction in di and poly‐aromatic compounds is observed at 340 °C for pure LCO, while WCO inclusion has minimal impact on poly‐aromatic saturation. The yield range for medium distillates across all products is between 87 % and 93 %. The time‐on‐stream study suggests excellent catalyst stability and activity up to 456 h, which is one of the highest lifetimes reported so far. TGA study of the spent catalyst indicates 22 wt % coke deposition complemented by TEM results. FTIR analysis revealed absorptions of alicyclic hydrocarbons‐type compounds deposited over the catalyst surface. This research contributes to the development of innovative catalysts for selectively converting LCO and WCO into diesel‐range hydrocarbons through single‐step process.

Selective cracking of light cycle oil to monoaromatics over non-noble bifunctional zeolite-supported Ni and NiW catalysts

The utilization of light cycle oil (LCO) for producing monoaromatics is investigated using bifunctional Ni and NiW catalysts supported on four different zeolites at atmospheric pressure without using external H2. The order of BTX yield for various feed compositions (2-methylnaphthalene, 2-methylnaphthalene + 9-methylanthracene, LCO) is: NiW/Beta > NiW/Y > Ni/Beta > NiW/Mordenite > Ni/Y > NiW/Mix > Ni/Mordenite > Ni/Mix, whereas the coke yield exhibits the reverse trend. The better performance of NiW-based catalysts is explained by the formation of NiW oxide species and their strong interactions with the support, as ascertained through H2-TPR, XPS, and UV-DRS. The higher moderate acidity, optimal balance between medium-strength Brønsted acid sites (BAS) and strong Lewis acid sites (LAS), and the higher hydrogen transfer index (HTI) in NiW-based catalysts, facilitate the selective cracking of LCO, resulting in the desired product yield. This study also establishes a strong correlation between the structural properties of various catalysts (pore diameter, surface area, pore volume, crystallite size) and the performance parameters, thus explaining the superior performance of Beta zeolite-supported catalysts for BTX production. Experiments with NiW/Beta and a physical mixture of W/Beta and Ni/Beta show the synergistic effect due to the co-presence of Ni and W. It is inferred that triaromatics are rapidly transformed to diaromatics, and the conversion of monoaromatics having two rings determines the BTX yield. LCO compounds are found to be the primary source for the formation of monoaromatics, while n-hexadecane (n-HD) is the hydrogen source. Reaction pathways for 2-methylnaphthalene and 9-methylanthracene conversion are presented based on detailed product characterization.

On the influence of low octane gasoline and biodiesel on diesel engine operating characteristics

Biodiesel is a promising alternative fuel, but it has drawbacks. This research aims to diminish the NOx dilemma for diesel and biodiesel by utilizing straight-run naphtha as an additive. It has a low carbon footprint of production from light distilled crude oil without any requirement for the thermal cracking process. The diesel was blended with naphtha at percentages of 5%, 10%, and 15% that abbreviated by N5, N10, and N15, respectively. The biodiesel/diesel blend was mixed with the same naphtha concentrations forming the blends B30N5, B30N10, and B30N15, respectively. Experiments were applied on a single-cylinder engine at 2,000 rpm and different loads. The findings revealed that N15 declined the brake specific fuel consumption (bsfc) at most loads relative to neat diesel. Contrarily, biodiesel blends reflected a spiking trend of bsfc at tested loads. Notably, the NOx emissions declined with N15 blend at high loads relative to neat diesel. The blends B30N15 and B30N10 reduced NOx at high loads compared to the diesel/biodiesel blend. The straight-run naphtha was found to be a promising additive because the balanced composition of the iso-paraffins and n-paraffins. Hence, it dominated the ignition tendency and reduced NOx emissions due to its cooling effect.

Organic Matter Source, Fluid Migration, and Geological Significance of Stylolites in Organic-Lean Carbonate Rocks: A Case from the Sichuan Basin

Carbonate rocks exhibit significant heterogeneity as both a source rock and reservoir. Stylolite formation plays a crucial role in the enrichment of organic matter and the migration of geofluids within carbonate rocks. In order to study the enrichment mechanism of organic matter and the geofluid migration mode in the stylolites developed in carbonate rocks, stylolite-bearing core samples from the Dachigan structural belt in the eastern Sichuan Basin were collected. The stylolites and matrix were subjected to the total organic carbon (TOC) test and Rock-Eval pyrolysis, thin-section observation under fluorescent light, whole-rock X-ray diffraction, carbon and oxygen isotope analysis, and scanning electron microscopy. The organic matter occurring in the stylolites is mainly in the form of three types: soluble organic matter, pyrobitumen, and bitumen. This suggests that the organic matter within the stylolites mainly consists of secondary migrated organic matter. The stylolites also exhibit well-developed secondary dolomite and pyrite resulting from late-diagenetic recrystallization. These minerals contribute to the preservation of intercrystalline pore spaces and fractures, providing favorable conditions for oil and gas accumulation and migration. The strong cementation observed at the contact between the stylolites and matrix, along with the presence of secondary minerals nearby, may be attributed to the fractionation of light and heavy oil components during the migration of hydrocarbon fluids from the matrix to the stylolites. The thicknesses of the stylolites vary within the bulk, indicating severe diagenesis in thinner areas. Consequently, this leads to significant fractionation effects. The fractionation of crude oil components by stylolites poses challenges for the study of definitive oil–source correlations. To overcome these challenges, future research could investigate biomarker compounds to attempt oil–source correlations. Additionally, future efforts should take into consideration the spatial variation in the crude oil properties. Understanding the role of stylolites in organic matter enrichment and geofluid migration is crucial for optimizing exploration strategies in the Sichuan Basin, a region of growing importance in the energy industry. Moreover, our findings shed light on the complex interactions within stylolite-bearing rocks, which are not limited to this specific basin. These insights offer valuable contributions to the broader field of geology and reservoir characterization, enhancing our ability to predict and interpret similar geological formations globally.

Effect of Sowing Method on Yield of Different Plants Grown as a Catch Crop

Currently, the most important task of stubble catch crops, as an element of sustainable agriculture, is to provide the soil with organic matter. The basic problem in the implementation of this task is the shortage of precipitation during the sowing period, which, combined with high temperatures in Europe in August, results in the loss of soil water and, consequently, weakening of germination and delay in plant emergence. The development of agrotechnics to increase the reliability of germination of seeds of plants grown as a catch crops is very important for the use of this valuable source of organic matter in regions with low and irregular rainfall, especially in the case of light soils with low water retention capacity. The aim of the study was to evaluate the response to furrow sowing of plants from various botanical groups grown as a stubble catch crop. Field studies were carried out on lessive soil in 2013–2015 at the Research Station in Mochełek near Bydgoszcz. The subject of the research was the sowing method (factor I): furrow sowing versus traditional (row) sowing. Sowing methods were tested for four crops (factor II): white mustard, tansy phacelia, common buckwheat, and common vetch. Certain plants reacted differently to the use of furrow sowing, and this reaction was different in various years of the study. In years with average soil moisture during the sowing period, furrow sowing made it possible to increase the yield of green mass and post-harvest residues of catch crop. In a year with very low soil moisture in this period, the desired effect of this method was not obtained. Furrow sowing allows seeds to be placed in a deeper, more moist soil layer, which can contribute to the acceleration of plant emergence. However, it requires refinement in terms of the precision of covering the sown seeds with soil.

Recycled waste masks as oil absorbent based on stable SiO2 coating for efficient separation of oil-water mixtures and oil-in-water emulsions

Due to the COVID-19 pandemic, mask contamination has become a global concern, and proper disposal of used masks is crucial. In this study, Waste Masks (WM) were modified into a highly efficient oil adsorption material by in-situ growth of SiO2 and subsequent grafting with Octadecyl trichlorosilane (OTS). The modified masks had a water contact angle of 153.2°, showed attractive adsorption capacity (27.33, 31.84, and 32.81 g·g−1) for soybean oil, lubricating oil and engine oil. The modified WM can adsorb not only the light oil on the water surface but also the heavy oil under water. Furthermore, the modified WM was able to separate oil-in-water emulsions of n-hexane and toluene by adsorbing the oil emulsion droplets. Molecular dynamic (MD) simulation was used to investigate the oil-water separation mechanism and calculate the adsorption energy of oil molecules on the OTS-grafted surface. This study provides an interesting solution to the environmental problems caused by discarded masks and the production of low-cost, reusable, and eco-friendly oil-absorbing materials.

Study of aromatic extraction from light cycle oil from the viewpoint of industrial applications

Light cycle oil (LCO) is a significant products of fluid catalytic cracking (FCC) process in refineries. Increasing the output of high-value chemicals from LCO is an important step towards achieving ‘dual carbon’ targets. Separating aromatic and non-aromatic components in LCO is crucial to producing valuable products. Extraction is a promising process for separating these components based on the principle of “polar similarity and solubility”. From the perspective of industrial applications, this study explores the development and application of novel functionalized extractants to produce valuable products. Ionic liquids (ILs) with alkyl-substituted imidazoles [CnMIM]+ and alkyl-substituted pyridines [CnMPy]+ as cations and tetrafluoroborate [BF4]− and hexafluorophosphate [PF6]− as anions were used. The effects of extraction temperature, IL-oil ratio, number of extraction stages, and reusability were systematically investigated. In addition, the basic physical properties data of ILs and residues in oil were studied in detail. The suitability of ionic liquids for industrial applications was evaluated based on their solubility with hydrocarbons, physical and chemical properties, selectivity for aromatics, and residues in oil. Following a thorough examination of the performance of ionic liquids for the extraction of aromatics from LCO, [C6MIM][PF6] was identified as the most suitable extractant. A multi-stage countercurrent extraction process was established and the conditions systematically studied. The results demonstrate that the aromatic content of the extracted oil is greater than 95 wt%, which can be utilized for producing BTX products. Meanwhile, the aromatic content of the raffinate oil is less than 10 wt%, which can function as a clean diesel blending component or as steam cracking feedstocks. This study has successfully promoted the industrial application of functionalized ionic liquids for the LCO dearomatization process and provided an essential reference for developing new functionalized extraction solvents.

Catalytic Activation of Ammonium Nitrate and Sodium Nitrite: Experimental, Modeling and Prediction of the Fracking Envelope in Low-Permeability Reservoirs with Light and Heavy Oils

Catalytic Activation of Ammonium Nitrate and Sodium Nitrite: Experimental, Modeling and Prediction of the Fracking Envelope in Low-Permeability Reservoirs with Light and Heavy Oils

Fodder Galega—Persistence as a Special Asset in Sustainable Agriculture

Perennial crops, especially legumes, have a crucial role in the development of sustainable agriculture. One such species may be fodder galega (Galega orientalis Lam.), whose utility values, including persistence and multi-directional use, are still not sufficiently known and appreciated. The aim of this study was to evaluate fodder galega yield dynamics, taking into account some indices of fodder value and the accumulation of mineral components in long-term use in light soil under moderate climate conditions with periodic shortages of precipitation. The results of six long-term experiments conducted at the Mochełek Research Station (53°120′ N, 17°510′ E) were evaluated. The dynamics of dry matter, total protein yield, and accumulation of minerals were best reflected by trend lines in the form of logarithmic functions, where during the first 4–5 years of use, a significant increase in the assessed values was noted, and in subsequent years, the increase continued but at a lower rate. The advancement in plant development in the establishment year had a significant impact on yields in the first production year. On average, during 10 production years, the dry matter yield obtained was 936 g m2, and the total protein yield was 177 g m2. Between 50% and 60% of the yield was determined by herbage accumulation in the first cut. Among minerals, the highest accumulation level was achieved for potassium. The height of shoots and the content of crude fiber in the plants increased linearly in the following years. The shoot density, leafiness, and content of minerals did not depend on the age of the galega stand, and their values were different among growth periods within a season. The number of shoots per 1 m2 in successive cuts was 170, 139, and 92, and their height was 79, 67, and 31 cm, respectively. The share of leaves in the first cut yield was 50%, and in the second and third cuts, it was 65% on average. In these conditions, over 10 years of use, galega turned out to be a valuable, persistent, and reliably yielding fodder crop.