Oil Deposition Research Articles

Pre-pilot forward osmosis – Membrane distillation hybrid system for sustainable produced water treatment and reducing volume of hazardous waste in oil and gas industry

This study introduces pre-pilot scale hybrid forward osmosis - membrane distillation (FO-MD) module, designed for the simultaneous treatment of different challenging produced water (PW) streams from Oil &Gas Industry. In this module, hot draw solution simultaneously serves as MD feed solution. The performance of this module was assessed with synthetic and real PW streams for extended operating times. The MD permeate production was doubled and comprised 0.4 L/h for 7:1 MD/FO area ratio (0.105 m2 and 0.015 m2, respectively) compared to permeate production that was observed with equal MD and FO membrane area (0.015 m2 each). The conductivity of the final product water was 364.9 ± 2.7 μS/cm, comparable to the typical potable water conductivity, implying its potential for reuse applications and minimizing volume of hazardous waste. Analysis of MD permeate quality showed that concentration of major ions was reduced by >99 % and chemical oxygen demand was removed by 90.1 %. Continuous operation with real produced streams led to partial pore wetting on the MD active layer. The microscopy showed organic fouling caused by oil and grease deposition and NaCl/CaSO4 scaling was found on both sides of FO membrane. These results suggest that PW pretreatment should be implemented to alleviate membrane fouling and pore wetting. We also observed reverse solute flux of 7.07 g/m2 h in experiments utilizing real DE and WO streams. The results of this study helped to identify challenges arising from the system scale-up and provide grounds for integrating hybrid FO-MD technology to recover water from oil and gas facilities.

Novel hybrid coating material with triple distinct healing bond for fat oil and grease deposition control in the sewer system

Hybrid materials with distinct self-healing bonds are a prominent category of materials, demanding in various modern applications. Developing self-healable hybrid materials with desired self-healing properties at ambient conditions is highly desirable and challenging. Herein, we developed a novel zinc (II)–dimethylglyoxime–urethane-complex-based polyurethane elastomer (Zn-polyurethane hybrid material) with synergetic triple dynamic bonds, which exhibits spontaneous self-healing properties at 30 °C. Moreover, this material shows excellent thermal stability up to approximately 850 °C and is highly stable in water systems. This hybrid material has potential applications in water systems; in this study, we characterized it for fat, oil and grease (FOG) deposition management in sewer systems by applying it as a coating on concrete blocks. The findings indicate that following a 30-day leaching test conducted under controlled pH conditions on uncoated and Zn-polyurethane-coated concrete blocks, a reduction of over 80 % in calcium release was observed in the coated block compared to the uncoated concrete block. Additionally, in FOG deposit formation tests conducted on uncoated and coated concrete blocks for 30 days, a reduction of over 30 % in FOG deposit formation was noted in the coated sample.

Grey correlation analysis of the main influencing factors of wax deposition of waxy crude oil and determination of pigging period based on dynamic analysis

Normal temperature gathering and transportation has significant advantages in reducing energy consumption and cost. Due to the high wax content of crude oil in carbonate reservoirs, obvious wax deposition will occur in the process of gathering and transportation at room temperature. In this paper, according to the component analysis results of crude oil on site, the HEATANALOGY wax deposition model was used to calculate the wax deposition of different gathering pipelines. The main influencing factors of wax deposition were analyzed by grey correlation method. Finally, according to the pigging mechanical balance model, the safe pigging period is derived, and the relationship diagram of different pipe diameters, throughput and ground temperature is drawn. The results show that the wellhead temperature has the greatest influence on the initial wax deposition position and the peak wax deposition position of the pipe section. The flow rate has the greatest influence on the maximum wax deposition thickness of the tube wall. According to the relationship between the working conditions and the pigging cycle, it can be found that with the increase of the throughput, the pigging cycle decreases first and then increases. With the increase of ground temperature, the pigging cycle increases.

Novel hydrogen-bonded organic frameworks-based coating for fat oil and grease deposition control in the sewer system

Hydrogen-bonded organic frameworks (HOFs) represent an emerging class of porous materials characterized by crystalline frame structures, self-assembled from organic molecules through hydrogen bonding. This study demonstrates that HOFs fragment into small particles while preserving their original structure when dispersed in a polymeric epoxy solution. The intermolecular hydrogen bond structural and electronic properties of the LH4-HOF complex as well as the mechanism of HOF incorporated epoxy were extensively studied using density functional theory. LH4-HOF has a high Langmuir surface area of 2758.3 m2/g and nonlocal density functional theory pore size distributions of 3 A°. This unique solution processability enables the fabrication of coatings with high stability in aqueous systems. Results from a 30-day leaching test under controlled conditions (pH 7, temperature 20 ± 2 °C) indicate that LH4-HOF incorporated epoxy-coated concrete samples exhibited an over 85 % reduction in calcium release compared to uncoated samples, with epoxy-coated samples alone showing a 60 % reduction in calcium leaching. Additionally, the LH4-HOF-incorporated epoxy coating reduced the formation of fats, oils and grease deposits by more than 73 % on the concrete samples. Thus, this novel coating approach offers a sustainable solution with significant potential applications in sewer management.

Comparative analysis of transcriptome in oil biosynthesis between seeds and non-seed tissues of Symplocos paniculata fruit.

The Symplocos paniculata, a woody oil plant, has garnered attention for its oil-rich fruit, which exhibits potential for both oil production and ecological restoration endeavors, thereby presenting substantial developmental value. However, the comprehension of the distinctive oil biosynthesis and deposition strategies within the fruit's various compartments, coupled with the tissue-specific biosynthetic pathways yielding optimal fatty acid profiles, remains in its infancy. This investigation was designed to delineate the tissue specificity of oil biosynthetic disparities and to elucidate the molecular underpinnings within the fruit mesocarp and seeds of S. paniculata, employing lipidomic and transcriptomic analyses. The results revealed that oil biosynthesis within the fruit mesocarp commences approximately 40 days prior to that within the seeds, with a concomitant higher lipid content observed in the mesocarp, reaching 43% as opposed to 30% in the seeds. The fruit mesocarp was found to be enriched with palmitic acid (C16:0) and exhibited a harmonious ratio of saturated, monounsaturated, to polyunsaturated fatty acids (SFA: MUFA: PUFA=1:1:1), in stark contrast to the seed oil, which is predominantly composed of unsaturated fatty acids, accounting for 90% of its total FA content. Microstructural assessments have unveiled divergent oil deposition modalities; the fruit mesocarp oils are predominantly sequestered within oil cells (OC) and a spectrum of lipid droplets (LD), whereas the seeds predominantly harbor uniformly-sized LD. The expression patterns of pivotal genes implicated in oil biosynthesis were observed to be markedly contingent upon the tissue type and developmental stage. Notably, the light-responsive fatty acid synthase (FAS) gene demonstrated preferential transcription within the fruit mesocarp. In contrast, genes pivotal for carbon chain elongation, such as 3-ketoacyl-ACP synthase II (KASII) and fatty acyl-ACP thioesterase A (FATA), and desaturation, typified by Stearoyl-ACP desaturase (SAD) and Fatty Acid Desaturase (FAD), were noted to be more robustly transcribed within the seeds. Furthermore, isoenzyme gene families integral to the assembly of triacylglycerol (TAG), including long-chain acyl-CoA synthetases (LACSs), glycerol-3-phosphate acyltransferases (GPATs), and lysophosphatidic acid acyltransferases (LPATs), exhibited pronounced tissue specificity. This research endeavors to clarify the molecular regulatory mechanisms that oversee oil biosynthesis within both seed and non-seed tissues of oilseed-bearing plants with entire fruits. Collectively, these findings lay the groundwork and offer technical scaffolding for future targeted cultivation of woody oil plants, with the ultimate aim of augmenting fruit oil yield and refining FA compositions.

Molecular dynamics simulation of deposition of high waxy crude oil on different pipeline walls

ABSTRACT Wax deposition occurs in the process of waxy crude oil pipeline transportation, which seriously affects the normal operation of crude oil pipeline. At present, non-metallic pipes have been proved to be effective in delaying the occurrence of wax deposition. Therefore, based on the pipeline walls of 20 G steel, glass fiber reinforced plastic (FRP), and polyethylene (PE), the microscopic mechanism of wax deposition during the pipeline transportation of waxy crude oil was studied by molecular dynamics simulation. The simulation results show that the waxy crude oil clusters undergo diffusion, deposition, reverse diffusion processes, and finally a wax deposition layer is formed on the pipeline surface. On the pipe walls of different materials, the surface free energy affects the interface energy of the solid-liquid contact surface between the waxy crude oil and the pipe wall, which is the main factor for the low surface free energy pipe to have the anti-wax effect. At the same time, according to the analysis of the contact angle on different materials in the simulation results, the difference in pipeline materials can only delay the formation speed of the wax deposition layer and cannot completely prevent the occurrence of wax deposition..

Research on the Compounding Scheme of High-Efficiency and Environmentally Friendly Water-Based Well Cleaning Fluid and Analysis of Its Application Effect

In the process of oil well production, the deposition and enrichment of heavy oil and wax are common phenomena. The deposition of these high-viscosity organic substances will not only seriously affect the normal production of oil wells but also cause certain pollution to the environment. Traditional well-washing operations usually rely on high temperatures and strong cleaning chemicals, which have the problems of low cleaning efficiency at low temperatures and poor environmental protection. Therefore, it is particularly important to study a more efficient and environmentally friendly water-based well-washing fluid. At present, most oilfields in China use diesel or organic cleaning agents to clean oil wells, which not only increases the cost of well-washing operations but also may cause pollution to the environment. In response to this problem, the core of this study lies in its innovative compounding scheme. The scheme includes preferred alkaline components, surfactants, emulsifiers, and solubilizers, and introduces glass fiber cutting and erosion technology. This well-washing fluid can effectively remove wax and heavy oil attached to the well wall at a lower temperature, which not only improves cleaning ability but also greatly reduces the dependence on high temperature. The water-based well-washing fluid provided in this study is composed of water, alkaline substances, surfactants, emulsifiers, and glass fibers. Emulsifiers such as Tween 80, OP-20, and polyethers form a stable emulsification system to help disperse and encapsulate oil and grease particles.

Wax Deposition of Diesel Oil and Consequent Contamination of Gasoline in Sequential Transportation of Product Oil Pipeline

Wax deposition of diesel oil and contamination of gasoline by diesel wax deposit is a severe problem in sequential transportation of product oil in pipes. However, it has long been neglected by the pipeline transportation industry. In response, this work aims to present a unique perspective on wax deposition of diesel oil and consequent contamination of gasoline. A cold finger apparatus was designed and constructed. Model oil composed of diesel and refined wax was prepared for wax deposition. Shear dispersion was excluded for wax deposition of diesel oil. Moreover, dissolution experiments of diesel wax deposit in gasoline were conducted. It was found that the dissolution rate increases with oil temperature and decreases with cold finger temperature and shear stress. Analysis on gasoline quality after diesel wax deposit dissolution indicated that contamination of gasoline caused by diesel wax deposit severely deteriorates its distillation range, but the octane number remains acceptable. This work features an interesting investigation on the wax-deposition mechanism of diesel oil, dissolution characteristics of diesel wax deposit, as well as quality deterioration of subsequent gasoline. It would be helpful in scheduling a product oil-transportation program.

Oil uptake via marine snow: Effects on blue mussels (Mytilus sp.)

Accidental oil spills into the ocean can lead to downward transport and settling of oil onto the seafloor as part of marine snow, as seen during the Deepwater Horizon incident in 2010 in the Gulf of Mexico. The arctic and subarctic regions may favor conditions leading to this benthic oil deposition, prompting questions about the potential impacts on benthic communities. This study investigated the effects of oil-contaminated marine snow uptake on the blue mussel (Mytilus sp.). We exposed mussels for four days to 1) oil-contaminated marine snow (MOS treatment), or to 2) chemically-enhanced water-accommodated fraction (CEWAF) of oil plus unaggregated food particles (CEWAF treatment). Both oil treatments received the same nominal concentration of oil and food. Two controls were included: 1) Clean seawater plus unaggregated food (agg-free control) and 2) clean seawater plus marine snow (marine snow control). After the exposure, mussels were allowed to recover for ten days under clean, running seawater. Samples were taken right before and after the exposure period, and after the recovery phase for the following endpoints: distribution (partitioning) of oil compounds between seawater and MOS, and between seawater and mussel tissue; DNA damage (assessed via the comet assay); clearance rate; and condition index [tissue dry weight (g) divided by shell length (mm)]. Some discernable patterns were found in the partitioning of oil compounds between seawater and MOS. However, these patterns did not translate to any significant differences in the partitioning of oil compounds into mussel tissue between the two oil treatments. DNA damage did not exceed background levels (10% tail DNA or less; to be expected in healthy, viable cells) at any sampling time point, but significantly higher DNA damage was observed in CEWAF-T compared to MOS-T mussels after the recovery phase. After the exposure, a significant difference emerged in the clearance rate between the CEWAF treatment and the agg-free control, but not between the MOS treatment and the marine snow control. All mussels except those from the CEWAF treatment exhibited an increased condition index after the exposure time. Together, these results suggest that aggregates could moderate the effects of oil exposure on blue mussels, possibly by providing better, more concentrated nutrition than unaggregated food particles.

Impact of mustard biodiesel and clove oil additives on particulate matter emission and carbon deposition in diesel engines

Recent studies suggest that the world is facing an energy crisis due to the depletion of fossil fuel reserves. To combat this issue, researchers have turned to biodiesel, a renewable bioenergy source made from vegetable oils, microalgae, and animal fats. A recent study analysed engine parts’ particulate matter emissions and carbon deposition during the long-term use of mustard biodiesel and clove oil as antioxidants in a compression ignition engine. Three samples of fuels: DF (diesel fuel), B30 (30% mustard biodiesel and 70% DF), and biodiesel blended fuel with 3000 PPM in a single-cylinder CI engine. The use of 30% biodiesel in diesel fuel (B30) for the endurance test was based on a good mix. The engine was run for 100 h to investigate the particulate matter emissions and carbon deposition. The particulate matter emission data was collected every 25 h, and for carbon deposition, the engine’s fuel injector was turned off after 100 h of engine running. The results showed a reduction in particulate matter emissions of about 9.97%, 13.367%, 7.24%, 14.64%, 5.3%, 12.32%, 1.88%, and 7.99% for PM1, PM2.5, PM7, and PM10 in biodiesel blended fuel and biodiesel blended fuel with clove oil, respectively. The deposition of clove oil added to biodiesel blended fuel in the fuel injector has been reduced compared with the other fuels. Carbon deposition of the fuel injector was analysed through SEM and EDX tests, and the results showed that the carbon content in biodiesel blended fuel was lower than in diesel fuel. The deposition of clove oil added to biodiesel blended fuel in the fuel injector has been reduced compared with biodiesel blended fuel.

Consideration of geomechanic effects during hydrodynamic model of weakly-cemented reservoir setting

The article offers an approach to tuning of heavy oil deposition model from weakly-cemented reservoir with geomechanic effects. This effects appear as changing permeability at the downhole zone near the injection well. Researchers think that the nature of low-density zones occurrence related to increasing of the resistance factor which is influenced with increasing of filtration velocity. High filtration velocity is caused by polymer flooding increasing. This work was made with basis on hydrodynamic model of the pilot area where are the experiments of displacement of heavy oil during polymer flooding. There are not only well history-matching but assessment of hydrodynamic model prediction ability. Keeping of geomechanic effects allows to achieve the adequate reproduction dynamic of fact bottom-hole pressure during polymer solution injection. Application of the given approach leads to uncertainty reduction and improved prediction reliability.

Analysis of the Processes of Paraffin Deposition of Oil from the Kumkol Group of Fields in Kazakhstan

The oil pipeline transportation of highly waxy oils when it is cold is accompanied by the deposition of paraffins in the inner surface of the pipeline. This study of the initial properties of the oil; the composition, structure, and nature of the components of normal alkanes in oil; and their influence on the aggregative stability of the resulting system makes it possible to find the best solutions to optimize the conditions of oil transportation with the lowest energy costs. This study shows that, according to the content of solid paraffin (14.0–16.2%), the oils of the Kumkol group of fields in Kazakhstan are highly waxy. They are characterized by high yield loss temperature values (+9–+12 °C), which also correlate with the values of the rheological parameters (τ0 1.389 Pa, 3.564 Pa). The influence of the temperature and shear rate on the shear stress and effective viscosity of the initial oils was studied. At temperatures below 20 °C, depending on the shear rate, there is an increase in the effective viscosity values (0.020 Pa∙s, 0.351 Pa∙s). The influence of the nature of solid hydrocarbons on the parameters of the paraffinization process and of the intensity of the paraffinization of the metal surfaces was studied. Our study shows that the main share of n-alkanes in the Kumkol and Akshabulak oils falls on paraffins of the C15–C44 group. The greater the temperature difference between the oil and the cold steel surface (≤40 °C), the lesser the amount of asphalt–resin–paraffin deposits (ARPDs) that fall out on the surface of the rod, although the content of long-chain paraffins prevails in these ARPDs. At the same time, the consistency of the released asphalt–resin–paraffin deposits (ARPDs) becomes denser, which makes their mechanical removal more difficult. Furthermore, the results of this study of the cooling rate shows that the rapid cooling of oils leads to the formation of a large number of crystallization centers, which leads to an increase in the values of the yield loss temperature and kinematic viscosity of the oils.

Preparation of superhydrophobic charcoal using in-situ combustion and chemical vapor deposition of silicone oil for oil-spill cleanup

A simple one-step strategy for the preparation of superhydrophobic charcoal with water contact angle of 155° and sliding angle of about 3° is presented. The procedure includes the chemical vapor deposition of smoke from silicone oil combustion onto the charcoal. The prepared sample was characterized with FE-SEM, microtopography, contact angle measurement, FT-IR spectroscopy, XRD and N2 adsorption/desorption analysis. Deposited network of spherical silica nanoparticles coated with silicone oil fragments onto the charcoal provides a surface with high porosity (nanoscale) and low surface energy which are essential for superhydrophobicity. Thanks to the high porosity, low density and superhydrophobic/superoleophilic character of the prepared charcoal it shows excellent performance in separating various oils and organic solvents from water. Oil-water separation with various methods and using superhydrophobic charcoal was studied.

A gentle conditioning agent consisted of oppositely-charged-induced cellulose nanocrystal and cationic cellulose: Stability, conditioning and delivery

The concerns about the health and environmental effects of the conditioning agent in current hair care products have attracted attention to seeking out a gentle and biosafe alternative, especially from nature. Cationic cellulose is a gentle conditioning agent from natural resource, but is rarely used in emulsion due to its hydrophilicity. In this study, cellulose-based complexes were prepared by opposite-charged-induced cellulose nanocrystals and cationic cellulose to replace cationic surfactants as conditioning agent. We demonstrated that the presence of cellulose nanocrystals effectively improved the emulsifying property of cationic cellulose, thereby could be used to prepare stable silicone oil emulsion. More importantly, by analyzing the relationship between emulsion morphology and the deposition of silicone oil, it was proposed for the first time that emulsion flocculation was positively correlated with deposition of silicone oil. Based on this, a method for rapid comparison of deposition of silicone oil was creatively proposed using ultraviolet absorbance of emulsion. Besides, we found that the resulting emulsion could be used as platform for delivery of essential oil to control the release of essential oil. In summary, this study has developed a gentle and clean cellulose-based complexes for personal care, which is expected to produce safer and cleaner emulsion to reduce potential health risks.

Electrophoretic deposition of tea tree oil containing chitosan/gelatin/whitlockite composite coatings for biofilm protection and bone tissue regeneration

This work presents a design of experiment (DoE) approach to optimize the electrophoretic deposition (EPD) parameters for chitosan (CS), gelatin (Gel), and whitlockite (WH) composite coatings on titanium substrate. The suspension for EPD was prepared by dissolving CS and Gel in acetic acid and WH nanoparticles (NPs) were dispersed in ethanol. Afterward, both (CS, Gel solution, and WH suspension) were mixed and the suspension stability was evaluated using zeta potential. Deposition parameters like voltage, concentration of WH, and time were optimized using Taguchi L16 orthogonal array with four control factors. The statistical data obtained confirmed that a higher time with average voltage and WH concentration is ideal to achieve deposits with maximum yield and minimum signal-to-noise ratio. Tea tree oil (TTO) in different concentrations was added to these optimized conditions. Different physiochemical characterization like x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), in-vitro degradation, surface adhesion, and wettability tests were done to evaluate the coating stability, adhesion, surface and chemical properties. The obtained data confirmed that coatings were mechanically strong, chemically stable, and possessed good adhesion strength to the substrate. To further confirm the bone tissue regeneration potential of the coatings, in-vitro bioactivity, cell viability, and cell proliferation tests were done. The obtained data confirmed that CS/Gel/WH composite is highly bioactive and promotes osseointegration. TTO at lower concentrations facilitates cell proliferation but it is toxic at higher concentrations. TTO interacted with the coating matrix via non-covalent interactions that resulted in its slow and sustained release over 28 days. TTO showed antibacterial effect when tested with E. coli bacteria. Hence, in this work, experimental, statistical, physiochemical, and biological analyses are discussed in detail based on the current knowledge of WH coatings and the effect of TTO on cytocompatibility as well as biofilm prevention.

Friction Performance of Rubber Sealing Disc Inside Pipe Robots for the Production of High-Paraffin Oil

The in-pipe robot is the most commonly used technique in offshore pipelines. The use of rubber sealing discs is important for in-pipe robots to ensure that the robots are moved by fluid pressures inside offshore pipelines. This paper focuses on the measuring and modeling of the wax–oil gel-breaking process at the soft frictional area between sealing discs and the pipe wall. In this study, a detailed characterization of the gel-scraping process and in situ probing portable microscopy are performed. Two contributions are made in this study. First, a direct observation of wax–oil deposition breaking is employed to detect the minute changes at the in-pipe robot. Second, we find that a simple function is possible to describe the relationship between the wax contents and dewaxing efficiency, in which the debris material removal ratio (DRR) is discussed. Thus, the gel deposition-breaking phenomena are quite different under the influence of rubber sealing discs. This result is further confirmed by the real contact ratio measurements. It is important to research the sealing disc further and apply it more in the petroleum industry, especially in in-pipe robots for deepwater pipeline systems.

Effective regeneration of deactivated Raney-Ni catalyst during multiphase hydrogenation of vegetable oil

Raney nickel is extensively used as a catalyst in the hydrogenation of vegetable oils. However, it deactivates over time and is known as a spent nickel catalyst, which is potentially hazardous to the environment. By contrasting different approaches, a straightforward and original strategy for regenerating spent nickel catalyst was developed by comparing various methods. The fresh, spent nickel catalyst, and treated catalyst samples were characterized using X-ray diffraction, Fourier transform infrared, atomic absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and color scheme analyses. The results showed that the catalyst deactivation was primarily due to oil deposition over the active sites, agglomeration of catalyst, and entrainment of nickel during hydrogenation. Using n-hexane as the solvent with a spent nickel catalyst-to-solvent ratio of 1:12 (g/mL), a 65 °C temperature, and a two-hour extraction time, ultrasonication-assisted solvent extraction of spent nickel catalyst proved to be the most effective and efficient process for regeneration.

The Essential Oils Obtained from (Lonicerae japonicae Flos) Flower Buds Could Affect the Deposition of Sunflower Oil under Common High Temperature Conditions and the Traditional Frying Process in Maye.

The essential oil extracted from the flower buds of Lonicerae japonicae (LJEO) was employed in the high-temperature (65℃) accelerated preservation of sunflower oil. In the present investigation, the addition of the essential oil at a concentration of 800 ppm significantly inhibited the decrease in the oxidative stability of sunflower oil. This positive effect was achieved by significantly hindering the reduction in acidity value (AV), peroxide value (PV), p-anisidine value (AnV), the total oxidation value (TOTOX) (p < 0.01), and the levels of thiobarbituric acid reactive substance (TBARS), the absorbance at 232/268 nm (K232/K268) and total polar compounds (TPC) (p < 0.01). Besides, it also significantly enhances the sensory attributes of Maye, including taste, flavor, and appearance, improving its overall acceptability through the addition of certain potential fragrance molecules (p < 0.01). Furthermore, one of the primary chemical compounds in LJEO, eugenol, has demonstrated significant natural antioxidant properties in the traditional deep-frying procedure for the product, Maye. Consequently, together with eugenol, the essential oil LJEO could be employed as a possible effective antioxidant for the typical long-term preservation and even the traditional deep-frying procedures, and developed as effective antioxidant extracted from plants for the whole food industry.

An experimental apparatus for the study of high-temperature degradation and solid-deposit formation of lubricants.

When exposed to high surface temperatures, engine lubricating oils degrade and may form solid deposits, which cause operational issues and increase shutdown time and maintenance costs. Despite its being a common issue in engine operation, the information available on the mechanics of this phenomenon is still lacking, and the experimental data and conditions must be updated to match the improvements in both lubricant stability and engine efficiency. To this end, an experimental apparatus has been developed to study the mechanisms that lead to the degradation and deposit formation of lubricants at high temperatures. The apparatus is designed to operate at pressures up to 69 bar, surface temperatures up to 650 °C, oil bulk temperatures up to 550 °C, and flow rates of <14 mL/min. In this apparatus, the oil is cycled through a heated test section, and deposits accumulate on the heated surface. The time required for deposits to start accumulating under the test conditions is determined based on the recorded temperature traces, and collected oil and deposit samples may be analyzed to determine changes in composition over time due to high-temperature exposure. The removable test section can be modified to accommodate different geometries, surface materials, and flow paths to adapt the instrument to a range of potential research directions. This paper presents the technical details of the new apparatus and the steps taken to characterize the experimental conditions. In addition, sample data are provided to show the unique capabilities of the new instrument, and an Arrhenius plot for Castrol Perfecto X 32 in the surface temperature range of 445-475 °C is presented as a demonstration of its use for quantifying the coking delay time. The new instrument detailed herein is the first such device to demonstrate a reliable, lab-scale technique for studying lube oil coke formation and deposition at temperatures and pressures of interest to power generation gas turbines.

Effectiveness of grease interceptors in food service establishments for controlling fat, oil and grease deposition in the sewer system

The water industry worldwide experiences numerous sewer blockages each year, partially attributed to the accumulation of fat, oil and grease (FOG). Managing this issue involves various strategies, including the requirement for installation of grease interceptors (GIs) installation. However, the claimed efficacy of commercial GIs of eliminating 99 % of FOG has been questioned for many years because FOG deposit formation occurs despite food service establishments (FSEs) using GIs, therefore detailed understanding of FOG wastewater compositions and its removal by GIs is required. This study provides an insight into the key FOG components such as FOG particle size, metals and fatty acid (FA) profile in GI influent and effluent, and within the GI, at three different FSEs. Analysis of FAs identified substantial proportions of extra-long-chain FAs in the effluents, including arachidic (C20:0), behenic (C22:0), mead (C20:3), lignoceric (C24:0), and nervonic (C24:1) acids. In contrast, the household kitchen released palmitic (C16:0), oleic (C18:1) and linoleic (C18:2) acids. It was further observed that scums effectively remove the larger FOG particles, leaving only 10 % below 75.4 μm. Notably, FSEs which employed automatic dishwashers produced up to 80.4 % of particles ≤45 μm, whereas FSEs and household kitchen which used handwash sinks generated only 36.9 % and 26.3 % of particles ≤45 μm, respectively. This study demonstrated that the commercial GIs do not remove FOG entirely but clearly demonstrated that they discharge high concentrations of FOG with extra-long FFAs which were attributed to the occurrence of microbial activity and hydrolysis of triglycerides within the GI, potentially contributing to FOG deposition.