Paraffin Content Research Articles

Novel adsorption-based upgradation of end-of-life polypropylene pyrolysis oil using carbonised rice husk

Plastic waste management is a global issue, with end-of-life polypropylene (EoL PP) having significant contribution. Polypropylene degradation forms undesirable compounds in pyrolysis oil, reducing its quality and limiting its fuel usability. Pyrolysis offers a promising solution for converting plastic waste into valuable fuels; however, the presence of degraded materials necessitates an effective upgrading process to enhance the fuel quality. This study introduces an innovative ex-situ adsorption-based upgradation technique using carbonised rice husk (CRH), an abundantly available, sustainable and cost-effective biomass residue, to significantly improve the quality of pyrolysis oil derived from EoL PP. The upgradation process reduced sulphur content in polypropylene pyrolysis oil from 0.19 % to 0.02 %. The cetane index, a key fuel quality metric, rose from 43.83 to 55.25, enhancing combustion properties. Proton nuclear magnetic resonance showed an increase in paraffin content from 53.15 vol% to 60.81 vol%, improving energy content and combustion efficiency. Olefins and aromatics decreased, improving fuel stability and reducing emissions. GCxGC TOF-MS analysis revealed a decrease in oxygenates and an increase in diesel-range hydrocarbons, improving fuel quality and stability. This comprehensive study highlights the dual benefits of CRH in enhancing fuel quality and supporting circular economy practices, making a significant contribution to the development of sustainable fuel alternatives in the waste-to-energy conversion sector.

From pandemic protection to fuel production: Conversion of waste personal protective equipment-kits to high-quality hydro-processed fuels

The advent of COVID-19 has heightened apprehensions within the plastic waste management sector, particularly due to the increased adoption of single-use personal protective equipment (PPE)-kits at the domestic level and hospitals for protection against contagious diseases. This study addresses the issue by focusing on the hydro-processing of pyrolytic oil derived from thermally catalysed cracking of sterilized waste PPE kits. Employing an indigenously prepared FCC-supported Ni catalyst, the investigation delves into the effects of hydrogenation process parameters-temperature, catalyst composition, and catalyst loadings—maintaining a constant pressure of 70 bar H2 on fuel quality. Experimental results indicate that oil upgraded at a higher temperature of 240 °C with a 10% Ni/FCC catalyst at a 20 wt% loading demonstrates a remarkable selectivity of 76.51 wt% compounds in the C5-12 range, signifying a substantial gasoline fraction. The hydrogenated oil exhibits 57.05 wt% paraffinic content and a desirable 24.5 wt% yield of aromatics. GC-MS analysis reveals the presence of 25 wt% C5-7 iso-alkanes, 9.33 wt% toluene, and 12.35 wt% benzene, closely resembling the composition of commercial gasoline. Moreover, the physicochemical properties of the hydrogenated oil meet specifications for commercial gasoline suitable for automobile applications, making it a viable substitute or complement for blending with commercial gasoline.

A novel paraffin/graphite PCM backfill for PHC energy pile: Numerical and experimental analysis on thermal performance

A novel paraffin/graphite phase change material was proposed as backfills for prestressed high-performance concrete piles. An experimental device for high-performance concrete energy pile was established to access the thermal performance of paraffin/graphite phase change material backfill and a finite element method numerical simulation based on the experiment was conducted. Two theoretical models, Multiphase-Effective Medium Theory and Maxwell-Eucken with parallel, were proposed to calculate the thermophysical parameters of paraffin/graphite phase change material. The results show that Multiphase-Effective Medium Theory achieves enhanced reliability than Maxwell-Eucken with parallel in the thermophysical parameters calculation of multi-phase composites. Paraffin/graphite phase change material can enhance the heat storage capacity of paraffin/graphite phase change material and reduce the temperature fluctuation of the piles, while graphite can accelerate the heat transfer within the pile system. A “transition point” in dynamic competition between the graphite and paraffin of paraffin/graphite phase change material was first discovered during the heat transfer process, which can be employed as an indicator for the operational patterns of the prestressed high-performance concrete energy pile. The thermal performance of prestressed high-performance concrete energy piles can be improved by reasonably controlling the graphite and paraffin contents in paraffin/graphite phase change material backfills.

Prediction of the Viscosity-Temperature Dependence of a Mixture of Oils Based on Information about the Density, Content of Paraffin, Resins, Asphaltenes and Fractional Composition

Prediction of the Viscosity-Temperature Dependence of a Mixture of Oils Based on Information about the Density, Content of Paraffin, Resins, Asphaltenes and Fractional Composition

Adsorption behavior of asphaltene aggregates generated by self-association at the oil/water interface

The formation of emulsions is undesirable yet unavoidable in petroleum production. Researchers suggest that asphaltenes adsorb at the oil/water interface, forming a protective film that stabilizes emulsions. This study investigates how asphaltene aggregates, formed through intermolecular interactions, affect emulsion stability and the properties of the oil/water interface. First, the effects of asphaltene concentrations, components, and temperatures on emulsion stability and the association state of asphaltenes were explored using the bottle test method and dynamic light scattering, respectively. The promotion of asphaltene aggregation by higher asphaltene concentrations and liquid paraffin content was confirmed by comparing the average size of aggregates, while higher temperatures were found to inhibit aggregation. Higher temperatures destabilize emulsions containing asphaltenes by increasing water droplet collisions, whereas higher asphaltene concentrations and liquid paraffin content stabilize emulsions. Subsequently, the effects of these conditions on expansion modulus were thoroughly investigated using the pendant drop technology. Pendant drop experiments demonstrate that increasing asphaltene concentration, along with the introduction of liquid paraffin, enhances asphaltene aggregation, thereby reinforcing the structural stability of the interfacial film. Spinning drop experiments were conducted to obtain dynamic interfacial tension (IFT) and analyze the adsorption behavior of aggregates at the oil/water interface. The adsorption process of asphaltenes driven by intermolecular interactions, occurs in three regimes: a short-term diffusion-controlled process, a transition process, and a long-term low-speed descent process, referred to as Regimes I, II, and III. The diffusion coefficient in Regime I increases with temperature, while the equilibrium IFT in Regime III decreases with temperature. In Regime II, adsorbed asphaltene aggregates from Regime I tend to prevent further adsorption, reducing the rate of dynamic IFT decrease. In Regime III, dynamic IFT decreases slowly, primarily due to the continued adsorption of asphaltene aggregates into the sublayer and their subsequent reconfiguration. These findings have significant implications for improving the understanding of oil/water interface properties and emulsion behavior in oil production, transportation, and refining systems.

Efficiency analysis of the application of thermal methods at the Pirallahi and Darwin bank fields

The efficiency of oil and gas field development is associated with the correct choice of appropriate measures to be implemented. This research considers the Pirallahi and Darwin Bank fields with hard-to-recover oil reserves. The Pirallahi field is located in the eastern part of the Absheron Peninsula. The initial balance reserve for the facility is 4 million tons, and the level of reserve utilization is 19%. Among the notable features, the Pirallahi deposit represents the southern fold of the PK (Pre-Kirma- ki) horizon. Across the horizon, the initial balance reserve is approximately one million tons, and the utilization rate is 17%. In other groups, the level of utilization exceeds 20%. Accordingly, the volume of initial balance reserves ranges between 8-35 million tons. Industrially important objects here are KSv (Kirmaki suite, fifth horizon), KSn (Kirmaki suite, n horizon), and PKS (Post-Kirmaki suite). To develop oil reserves, more than 1000 production wells were drilled at different stages of the development process. The southern fold consists of a brachyanticline extending from northwest to southeast. The main tectonic element of the southern fold is its thrust nature and its very complex tectonic structure. The fold is heavily watered. Therefore, to increase the efficiency of developing these fields, it is necessary to use appropriate methods of influencing the formations. To enhance the efficiency of the development process in the northern part, the in-situ combustion method was applied. The Darwin Bank field belongs to the Absheron archipelago and has a tectonic brachyanticlinal structure. The structure is complicated by numerous longitudinal and transverse faults. It is divided into six tectonic zones by several transverse and one longitudinal fault passing through the crest. Darwin Bank oils are heavy oils with low sulfur content. In addition, low paraffin and high resin content are observed in the composition of field oil. For both fields, the recovery rate of geological reserves fluctuates around 30%. The article, primarily, examines the selection of objects and the use of enhanced oil recovery methods in these fields. The in-situ combustion method was used in the northern part of the Pirallahi field and Darwin Bank.

The influence of the design features of the fuel injector atomizer on the process of diesel fuel injection

Abstract. Problem. Increasing the demands for the technical and economic characteristics and the resource of modern augmented diesel engines requires finding ways and approaches to improve their design and systems, in particular, their fuel supply system. Changing the design parameters of the fuel injector atomizer allows to influence the conditions of fuel injection, its atomization in the combustion chamber, and the efficiency of the engine. The number and mutual arrangement of the nozzle holes of the fuel injector atomizer and their diameter are chosen by manufacturers based on the design features of the engine, in particular, the configuration of the combustion chamber and the conditions for filling the cylinder with fresh air. Goal. The purpose of the work was to carry out comparative numerical modelling to assess the influence of the number and diameter of the nozzle holes of the fuel injector atomizer on the diesel fuel injection process. Methodology. The problem is considered in a three-dimensional non-stationary setting. For numerical modelling, the geometry of the flow part of the fuel injector atomizer was formed, taking into account its design features (standard and modernized versions). The standard version has 7 nozzle holes with a diameter of 0.25 mm (evenly arranged relative to the axis of the atomizer, and the modernized version has 4 holes with a diameter of 0.3 mm in the standard place, evenly arranged relative to the axis of the atomizer and, additionally, 4 holes with a diameter of 0.2 mm from above (in the area of the closing cone) evenly arranged relative to the axis of the atomizer, but with a rotation around the axis of the atomizer by 45 degrees relative to the lower holes. To describe the process of the diesel fuel flow in the flow part of the fuel injector atomizer, the k - ε turbulence model is used, and to describe the process of phase transition from a liquid state to a vapour state – a mixture model is used. Results. The obtained results showed that the use of two rows of nozzle holes of different diameters for the atomizer of the fuel injector of the transport diesel engine allows to effectively organize the fuel injection process. For the atomizer nozzle of the modernized design, the volumetric fuel consumption is 30% for the upper holes and 70% for the lower ones. Originality. The scientific novelty of the work lies in determining the influence of the number and diameter of the nozzle holes of the fuel injector nozzle on the conditions of diesel fuel injection, taking into account cavitation effects. Practical value. The total area of the nozzle holes in the modernized version was increased by 20%, which makes it possible to increase the cycle supply of diesel fuel. It is especially important when using new types of fuel with a lower paraffin content and, accordingly, lower caloric content

Green building material with superior thermal insulation and energy storage properties fabricated by Paraffin and foam cement composite

In the field of architecture and construction, foam cement has been gradually gaining popularity due to its outstanding attributes of reduced weight, carbon footprint, and potential thermal insulation effects. However, relying solely on the thermal insulation provided by the foam in foam cement lacks the capability to store and release heat. In this paper, a novel approach is proposed by directly incorporating paraffin into foam cement with non-continuous pores, creating a phase change foam cement. The addition of paraffin to foam cement, facilitated by the presence of surfactants in foam, allows the paraffin to disperse. In contrast, if paraffin is directly added to cement without the foam, it tends to aggregate. The internal pore structure, thermal performance, phase change temperature, and relaxation distributions were investigated through equipment such as scanning electron microscope (SEM), thermal conductivity meter, differential scanning calorimetry (DSC), and H1 nuclear magnetic resonance (NMR). Results indicate that paraffin/foam cement plays a dual function, effectively storing and releasing energy, significantly enhancing its thermal insulation performance. Particularly, the incorporation of 10 vol% paraffin content results in a notable 21.8 % reduction in the thermal conductivity, for foam cement with a density of 600 kg/m3. This is attributed to the heat storage capability of the phase-change paraffin, which absorbs heat as the surrounding temperature rises, synergistically collaborating with the foam. This presents a novel perspective for the development of green and energy-efficient building materials, contributing to the realization of sustainable energy utilization in the construction industry.

Hydrothermal liquefaction of plastic marine debris from the North Pacific Garbage Patch

Ocean plastic waste poses a growing environmental threat, efforts are now underway to help clean the ocean surface or to prevent plastic streams entering. Repurposing these highly mixed polymers presents a great challenge due to their inherent complexity, intertanglement, and the presence of contaminants. Herein, we process real samples of ocean-floating plastics from the North Pacific Garage Patch through supercritical hydrothermal liquefaction (HTL), targeting their chemical recycling into synthetic crude oil. Investigating key process parameters (temperature, pressure, time, and plastic load), we found that plastic load and temperature are crucial parameters influencing oil yield and that moderate conditions maximized hydrocarbon yield, reaching 90 wt%. Overall, longer residence times and higher temperatures favored aromatic-rich oils. We suggest a reaction pathway to account for hydrogen release from aromatization reactions, influencing paraffin, olefin, and aromatic contents. Supercritical HTL offers an effective, tailored approach for recycling complex plastic mixtures to produce synthetic crude oil.

Nickel and cobalt incorporated mesoporous HZSM-5 catalysts for biofuel production from bio-oil model compounds

Bio-oil obtained through the gasification or pyrolysis of biomass is a renewable energy source with the potential to be used in motor vehicles. However, when the properties of bio-oil are compared to crude oil, bio-oil is observed to have high oxygen content and acidity. The aim of this study is to enhance the physical properties of bio-oil and produce new alternative fuels to crude oil. For this purpose, nickel and cobalt-incorporated mesoporous HZSM-5 catalysts have been synthesized. The synthesized catalysts were characterized by X-ray diffraction, N2 adsorption–desorption, Scanning electron microscopy energy dispersive spectroscopy, Inductively coupled plasma optical emission spectroscopy, Fourier-transformed infrared spectroscopy, and thermogravimetric/differential thermal analysis. In the study, formic acid, furfural, and hydroxypropanone were used as model components. To enhance catalyst activity, nickel was loaded onto the HZSM-5 catalyst. However, during biofuel production, a significant amount of coke was formed as a by-product. Therefore, cobalt was impregnated to reduce coke formation. In the activity test studies, a conversion in the range of 77–84% was achieved with HZSM-5 catalysts. Nickel addition increased the paraffin and olefin content in the biofuel along with bio-oil conversion. The maximum paraffin selectivity (97%) was provided with the 5Ni@HZSM-5 catalyst. However, the highest biofuel selectivity (77.5%) with the minimum coke formation (4%) was observed with the 5Co-5Ni@HZSM-5. In the study, the regeneration and long-term catalytic activity were also investigated, and the results showed that 5Co-5Ni@HZSM is an attractive catalyst for biofuel production from bio-oil.

APPROACH TO MATHEMATICAL MODELING OF THE COST OF APPLYING COATINGS TO PREVENT THE FORMATION OF ARPD

The authors explore the topic of operation of main oil pipelines, complicated by the formation and settling of asphalt, resin, and paraffin deposits (wax deposits). It is known that the fallout of paraffin deteriorates the technological characteristics of the pipeline, which has a number of negative consequences from an economic point of view: a decrease in income due to a narrowing of the flow area and the volume of pumped oil, an increase in costs due to the increased load on main pumps. Today, there are many different ways to combat wax deposits, primarily aimed at preventing the fallout or removing formed deposits from the internal surface of an oil pipeline, the effectiveness of which is determined individually for each pipeline due to the complexity in assessing the influence of the rheological characteristics of oil and the geological conditions of the pipeline on the effectiveness of the methods. One of the additional and universal options for combating wax deposits is the use of internal and external protective coatings.The authors have developed a number of models of oil pipelines that use oils from various oil and gas basins, differing in paraffin content, and considering the presence of insulation of various protective coatings (paint and varnish, highly reinforced protective coating (VUS), bitumen-mastic VUS, polyurethane foam) and their combinations. For these models, the Schlumberger OLGA program simulated the operation of the pipeline for 180 days, on the basis of which the maximum thickness of the formed paraffin was estimated, and the specific energy costs for pumping through the pipeline without coating and various types of coating were calculated, after which the calculation was performed main economic indicators of pipeline operation for each option. Based on the calculation results, it was concluded that it is advisable to use one or another coating based on the shortest payback period. This comprehensive assessment demonstrates a methodology for assessing the effectiveness of the use of protective coatings from both a technological and economic point of view and allows us to draw conclusions about the possibility of using one or another option based on the results of the study, depending on the composition of the oil.

Azerbaijan—The Land of Unquenchable Fire

_ For millennia, Zoroastrian fire worshippers traveled on pilgrimage to pray at temples built where methane seeping from deep underground caused flames to burst from the earth on the Absheron Peninsula near Baku, the capital of today’s Azerbaijan. The Venetian merchant Marco Polo observed such mysterious fires and puddles of oil that bubbled or even gushed as fountains to the surface as he trekked along the Silk Road through the Caucasus Mountains in the 13th century. In a travelogue written in 1298, The Travels of Marco Polo, he is said to have described: “Near the Georgian border there is a spring from which gushes a stream of oil in such abundance that a hundred ships may load here at once. This oil is not good to eat, but it is good for burning and as a salve for men and camels affected with itch or scab.” He was referring to the Khanates of Azerbaijan, a part of the Persian Empire in Marco Polo’s time but absorbed in 1806 into the Russian Empire whose czars took an interest in financing early oil production—hand dug and exported on camel back. Its high paraffin content was valued for producing kerosene lamp oil and lubricants including cannon grease. World’s First Mechanically Drilled Oil Well As the Industrial Revolution swept from West to East in the mid-19th century, many of the innovations and business systems around which the modern oil and gas industry were soon to coalesce were tested in the ancient “Land of Fire.” Czar Nicholas I (1825–1855) financed the world’s first mechanically drilled oil well in 1846 using a cable-tool percussion drilling method. A 21-m-deep (69 ft) exploration well was the result. This happened a decade before Edwin Drake added steam-engine power to a mechanical drill to put Titusville, Pennsylvania, on the map in 1859, as described in the Branobel History archives. By 1871, with Nicholas’ son, the reformer Alexander II now on the Russian throne, boreholes had replaced buckets across the Bibi-Heybat and Balakhani oil fields. The arrival from Sweden in the 1870s of Alfred Nobel’s brothers, Ludvig and Robert, brought a step change to Azerbaijan in terms of industrial innovation, construction, and logistics such that by 1900 Azerbaijan was producing 50% of the world’s oil, historical sources agree. Alexander II had abolished the state monopoly on oil production in 1869, opening the door to foreign industrialists and their capital. Robert Nobel obliged and opened the joint stock Branobel Co. in 1878 with a partner from a weapons plant in the Russian town of Izhevsk. He put down share capital of 3 million rubles ($30,000 in today’s money) to register Tovarishestvo Neftyanogo Proizvodstva Bratyev Nobel—in English, The Brothers Nobel Paraffin Production Company (aka Branobel). The transformation of Baku’s oil fields into a capitalist production sector had begun in 1872 with the auction of 15 blocks in the Balakhani oil field and two blocks in Bibi-Heybat, according to a history prepared by Azerbaijan’s Ministry of Energy in 2020. This drove a 340% growth in oil production between 1876 and 1882, from 24,000 to 816,000 tons, respectively, between those years. By 1894 Azerbaijan’s production equaled that of the US (5.55 million tons per year) though Baku’s fields were 20 times less productive, according to Branobel archivists.

Development of a new reagent for the prevention of asphaltene-resin-paraffin deposits

Asphaltene-Resin-Paraffin deposits (ARPD) form a certain proportion of the crude oil mass, separating as temperature and pressure decrease and adsorbing to the surfaces of the reservoir wellbore zone, downhole equipment and tubulars. These deposits precipitate in the wellbore zone, oilfield equipment and pipes,resulting in reduced system productivity, reduced pumping efficiency of the pumping equipment and other negative consequences. Asphalt-resin and paraffin deposits (ARPD) are a complex mixture of solid paraffin hydrocarbons, asphalt-resin substances (ARS), water and mechanical impurities. The strength and composition of ARPD depend on the composition and properties of oil, geological, physical and technological conditions of field development. Chemical methods for removing deposits are currently the most widely used, as they are highly effective and technologically advanced. To this end, new reagents have been developed and their physico-chemical properties have been studied. Subsequently, the selected reagents were tested on oil samples from Oil and Gas Production Department (OGPD) with a paraffin content of more than 6 %. It was also shown that paraffin inhibitors have individual effects; a reagent that is effective on oil from one field may not have the same effect on oil from other fields. The research includes studies of selected reagents for paraffinic oils from different fields. Using the «cold finger» method, the efficacy of the selected reagents against paraffin deposition was investigated and their optimum doses were determined. Keywords: reagent; sendiment; paraffin; asphaltene; resin; well bottom zone; viscosity; depressor.

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.

Performance analysis of solar thermal storage systems with packed bed utilizing form-stable phase change materials and heat pump integration

Solar energy, a pivotal renewable resource, faces operational challenges due to its intermittent and unstable power output. Thermal energy storage systems emerge as a promising solution, with phase change materials (PCMs) packed beds attracting attention for their compactness and stable temperature transitions. This paper details a laboratory-scale solar thermal storage PCM packed bed integrated with a heat pump, utilizing a novel form-stable PCM. A numerical model was established to assess the thermal storage characteristics and heat extraction performance of the solar PCM packed bed coupled with a heat pump. Simulation results show that increasing solar irradiance significantly reduces storage duration, achieving full thermal storage in 3.4 h at 900 W/m2 irradiance. Optimal starting times were identified as 9:00 a.m. or 11:00 a.m., with later starts resulting in incomplete storage due to the PCM not reaching its phase change temperature. Additionally, packed bed parameters influenced storage conditions; increasing the paraffin content in the PCM extended the phase change duration, while graphene nanoparticles slightly reduced it. Lower porosity (0.49) beds, with higher PCM content, reached 70 °C quicker than higher porosity (0.61) beds due to higher pressure drops promoting more uniform flow and temperature distribution. During heat extraction, coupling the heat pump at 2 liters/min achieved temperatures below 45 °C in 4.1 h, while at 6 liters/min, the time reduced to 1.6 h, demonstrating adaptability to different extraction rates. These findings provide insight into the thermal performance of solar PCM packed beds coupled with heat pumps, contributing to efficient and stable thermal utilization of solar energy.

Oil/Brine Screening for Improved Fluid/Fluid Interactions during Low-Salinity Water Flooding

Low-salinity water flooding/smart water flooding (LSWF/SWF) are used for enhanced oil recovery (EOR) because of the improved extraction efficiency. These methods are more environmentally friendly and in many scenarios more economical for oil recovery. They are proven to increase recovery factors (RFs) by between 6 and 20%, making LSWF/SWF technologies that should be further evaluated to replace conventional water flooding or other EOR methods. Fluid/fluid interaction improvements include interfacial tension (IFT) reduction, viscoelastic behavior (elastic properties modification), and microemulsion generation, which could complement the main mechanisms, such as wettability alteration. In this research, we evaluate the importance of fluid/fluid mechanisms during LSWF/SWF operations. Our study showed that a substantial decrease in IFT occurs when the oil asphaltene content is in the range of 0% to 3 wt.%. An IFT reduction was observed at low salinity (0–10,000 ppm) and a specific oil composition condition. Optimal IFT occurs at higher divalent ion concentrations when oil has low asphaltene content. For the oil with high asphaltene content, the sulfates concentration controls the IFT alteration. At high asphaltene concentrations, the formation of micro-dispersion is not effective to recover oil, and only a 5% recovery factor improvement was observed. The presence of asphaltene at the oil/low-salinity brine interface increases the energy required to disrupt it, inducing significant changes in the elastic moduli. In cases of low asphaltene content, the storage modulus demonstrates optimal performance at higher divalent concentrations. Conversely, at high asphaltene concentrations, the dominant factors to control the interface are paraffin content and temperature.

Recovery of oil viscosity values according to its additive parameters

Considering the complexity of mixtures formed within extensive and intricate pipeline networks, determining the viscosity of mixtures through a computational method that utilizes parameters conducive to additivity is advantageous. These parameters may include the density and component composition, as well as corresponding derivatives, such as the content of paraffins, resins, asphaltenes, and fractional composition. This study explored the relationship between the viscosity and these parameters. A linear regression model for estimating the logarithm of the viscosity was developed, where significant regression coefficients were identified, and the prediction error was assessed through cross-validation. A similar approach was adopted for the second-order regression analysis. This analysis incorporated linear regression including parameters pertaining to the fractional composition. Formulas for calculating the viscosity based on the identified properties were derived and the respective errors were evaluated. Keywords: oil; viscosity; Arrhenius formula; cross-validation; paraffin; resins; asphaltenes; database.

Investigation on Fuel Properties of Synthetic Gasoline-like Fuels

Article Investigation on Fuel Properties of Synthetic Gasoline-like Fuels Weidi Huang 1,2, Koichi Kinoshita 1,*, Yohko Abe 1, Mitsuharu Oguma 1, and Kotaro Tanaka 2,3 1 Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology, 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564, Japan 2 Carbon Recycling Energy Research Centre, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511, Japan 3 Graduate School of Science and Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511, Japan * Correspondence: koichi-kinoshita@aist.go.jp Received: 8 November 2023 Accepted: 25 March 2024 Published: 27 March 2024 Abstract: Synthetic fuels have gained considerable attention due to their promising characteristics. A comprehensive survey was undertaken to assess the availability of synthetic fuels in the global market, followed by an investigation to evaluate their potential in engines. This report presents the initial findings regarding the physical and chemical properties of synthetic gasoline-like fuels, specifically DMC (dimethyl carbonate), bioethanol, EtG (ethanol-to-gasoline), G40, and bio-naphtha. A comparison was conducted between these synthetic fuels and conventional gasoline. Furthermore, discussions were provided to enhance the understanding of the potential influence of fuel properties on spray and combustion characteristics. EtG and G40 are specifically designed to emulate conventional gasoline. Results indicate that EtG and gasoline should be directly interchangeable in the engine or blended in any proportion because they have almost identical Research Octane Number (RON)/Motor Octane Number (MON), fuel density, and higher heating value (HHV). G40 has a higher RON (105) compared with that of gasoline (92.2), likely resulting from the high content of iso-paraffin in G40. Bio-naphtha exhibits the high fraction of paraffin and naphthene content relative to other fuels. The feature of chemical compositions results in a lower RON (55.9), lower HHV and smaller fuel density compared to other fuels. DMC and bioethanol blends in gasoline were investigated. Regardless of whether DMC or bioethanol is incorporated, under a 60% blend ratio, gasoline distillation accelerates initially, until DMC or bioethanol completely evaporates, after which gasoline distillation returns to its normal rate. With increasing the volumetric fraction of the ethanol in the blends, either chemical compositions or the RON/HHV basically change linearly.

Assessment of Performance and Deactivation Resistance of Catalysts in the Pyrolysis of Polyethylene and Post‐Consumer Polyolefin Waste

AbstractIn the present work, the catalyst performances of USY and REY zeolites and MgO, ZnO, and MgxAlOy oxides are investigated in the pyrolysis of virgin high‐density polyethylene (HDPE) and of post‐consumer polyolefin waste. The influence of operation parameters and catalyst deactivation resistance over four reaction cycles are evaluated. The results indicate that basic oxides do not show relevant cracking activity, so that the only identified effect for these catalysts is the production of liquid products with higher contents of paraffins when compared to thermal pyrolysis. Among the evaluated oxides, MgxAlOy is the most active and resistant to deactivation. The zeolites promote cracking and secondary reactions of isomerization, cyclization, and aromatization. Particularly, USY promotes the production of higher‐quality oils and shows higher deactivation resistance, when compared to REY. Additionally, a significant loss of catalyst activity is identified in reactions conducted with post‐consumer polyolefin wastes. However, increase in rates of coke formation and the presence of contaminants (such as halogens and metals) are not detected in the catalysts after the reactions.

Preparation of cellulose-paraffin composite foams by an emulsion–gelation method using aqueous inorganic salt solution for thermal energy regulation

Leakage of paraffin phase-change materials during phase transitions limits their application. Cellulose is an environment-friendly material that has the potential to resolve leakage problems. In this study, large-scale, firm, and no leakage cellulose-paraffin composite foams were fabricated via an emulsion–gelation method using a cellulose/LiBr solution. Spherical paraffin particles were embedded into the three-dimensional nanofibrillar network structure of the regenerated cellulose, with no chemical interaction between the paraffin and cellulose. This cellulose-paraffin foam exhibited excellent mechanical properties, with a maximum elastic modulus value of 7.08 MPa. No leakage was observed at 80 °C even when the paraffin content was 80 %. During phase change, the maximum latent heat was 173.2 J g−1. The thermal conductivity was relatively low (46.5–77.2 mW m−1); this represented 23–38 % of the thermal conductivity of pure paraffin. Therefore, foams are promising materials for efficient and reliable thermal energy storage applications.