Research

19 pages, 2800 KiB

Open AccessArticle

Maximizing Green Hydrogen Production from Water Electrocatalysis: Modeling and Optimization

by Hegazy Rezk, A. G. Olabi, Mohammad Ali Abdelkareem, Ali Alahmer and Enas Taha Sayed

J. Mar. Sci. Eng. 2023, 11(3), 617; https://doi.org/10.3390/jmse11030617 - 15 Mar 2023

Cited by 15 | Viewed by 3710

The use of green hydrogen as a fuel source for marine applications has the potential to significantly reduce the carbon footprint of the industry. The development of a sustainable and cost-effective method for producing green hydrogen has gained a lot of attention. Water [...] Read more.

The use of green hydrogen as a fuel source for marine applications has the potential to significantly reduce the carbon footprint of the industry. The development of a sustainable and cost-effective method for producing green hydrogen has gained a lot of attention. Water electrolysis is the best and most environmentally friendly method for producing green hydrogen-based renewable energy. Therefore, identifying the ideal operating parameters of the water electrolysis process is critical to hydrogen production. Three controlling factors must be appropriately identified to boost hydrogen generation, namely electrolysis time (min), electric voltage (V), and catalyst amount (μg). The proposed methodology contains the following two phases: modeling and optimization. Initially, a robust model of the water electrolysis process in terms of controlling factors was established using an adaptive neuro-fuzzy inference system (ANFIS) based on the experimental dataset. After that, a modern pelican optimization algorithm (POA) was employed to identify the ideal parameters of electrolysis duration, electric voltage, and catalyst amount to enhance hydrogen production. Compared to the measured datasets and response surface methodology (RSM), the integration of ANFIS and POA improved the generated hydrogen by around 1.3% and 1.7%, respectively. Overall, this study highlights the potential of ANFIS modeling and optimal parameter identification in optimizing the performance of solar-powered water electrocatalysis systems for green hydrogen production in marine applications. This research could pave the way for the more widespread adoption of this technology in the marine industry, which would help to reduce the industry’s carbon footprint and promote sustainability. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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12 pages, 1777 KiB

Open AccessArticle

Adsorptive Treatment of Residues on Macroporous Adsorbent for Marine Fuel Production Scheme on Refinery

by Renata Iuzmukhametova, Roman Boldushevskii, Olga Shmelkova, Yunir Khamzin, Artem Minaev and Pavel Nikulshin

J. Mar. Sci. Eng. 2023, 11(3), 525; https://doi.org/10.3390/jmse11030525 - 28 Feb 2023

Cited by 4 | Viewed by 1055

Abstract

Adsorptive treatment using granulated macroporous Al₂O₃-SiO₂ adsorbent is proposed as a preliminary stage for residue pretreatment in refineries. The study evaluates the adsorptive treatment of atmospheric and visbreaking residue at 485–510 °C and 1 h⁻¹ feed rate, [...] Read more.

Adsorptive treatment using granulated macroporous Al₂O₃-SiO₂ adsorbent is proposed as a preliminary stage for residue pretreatment in refineries. The study evaluates the adsorptive treatment of atmospheric and visbreaking residue at 485–510 °C and 1 h⁻¹ feed rate, resulting in a total liquid product yield of about 73.0–75.0 wt%, coke on the sorbent of 12.6–18.3 wt%, demetallization exceeding 98%, and a reduction in carbon residue of 65–72%. The paper also discusses the role of feed dilution with light gasoil, process temperature, and feed rate in optimizing the adsorptive treatment process. The high coke content on the adsorbent necessitates its regeneration, which is shown to be complete at temperatures up to 750 °C. Regeneration decreases macropore size and volume but does not significantly impact demetallization. The pretreated residual product has low viscosity and is further processed through hydrotreatment in a fixed-bed unit to produce low-sulfur marine fuel. The hydrotreated atmospheric residue meets the requirements for RMA 10 fuel, with a sulfur content lower than 0.1 wt%. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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16 pages, 4286 KiB

Open AccessArticle

Biodiesel as Dispersant to Improve the Stability of Asphaltene in Marine Very-Low-Sulfur Fuel Oil

by Daping Zhou, Haijun Wei, Zhiwen Tan, Shuye Xue, Ye Qiu and Shen Wu

J. Mar. Sci. Eng. 2023, 11(2), 315; https://doi.org/10.3390/jmse11020315 - 02 Feb 2023

Cited by 2 | Viewed by 1559

Abstract

Since the implementation of the sulfur cap legislation in 2020, marine very-low-sulfur fuel oil, often known as VLSFO, has become a crucial source of fuel for the contemporary shipping industry. However, both the production and utilization processes of VLSFO are plagued by the [...] Read more.

Since the implementation of the sulfur cap legislation in 2020, marine very-low-sulfur fuel oil, often known as VLSFO, has become a crucial source of fuel for the contemporary shipping industry. However, both the production and utilization processes of VLSFO are plagued by the poor miscibility of the cutter fraction and the residual fraction, which can result in the precipitation of asphaltene. In this study, biodiesel was chosen as a cutter fraction to improve the stability and compatibility of asphaltene in VLSFO because of its environmental benefit and strong solubility. The average chemical structure of asphaltene derived from the marine low-sulfur fuel oil sample was analyzed using element analysis, FTIR, ¹HNMR, and time-flight spectroscopy. The composition of biodiesel was analyzed using GC-MS. It was found that the asphaltene had a feature of a short side chain, low H/C ratio, high aromaticity, and a high proportion of heteroatoms. Both laboratory experiments and molecular dynamic simulations were applied to investigate the dispersion effect and mechanism compared with other dispersants. The dispersion effect of biodiesel was studied using measurements of the initial precipitation point (IPP), dispersion improvement rate, and morphology of asphaltene in the model oil. Experimental results revealed that biodiesel was fully compatible with heavy fuel oil and that it can postpone the IPP from 46% to 54% and increase the dispersion improvement rate to 35%. Molecular dynamics (MDs) simulation results show that biodiesel can form strong interactions with the fused aromatics structures and heteroatoms in the asphaltene; such interactions can increase the solubility of asphaltene and acts as a “connection bridge” to promote the dispersion effect of asphaltene molecules. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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26 pages, 9688 KiB

Open AccessArticle

A Techno-Economic Analysis of a Cargo Ship Using Flettner Rotors

by Gianluca Angelini, Sara Muggiasca and Marco Belloli

J. Mar. Sci. Eng. 2023, 11(1), 229; https://doi.org/10.3390/jmse11010229 - 16 Jan 2023

Cited by 4 | Viewed by 1981

Abstract

In the last twenty years, the global shipping transport demand has strongly increased (around 4% per year since the 1990s), together with the request for new green propulsion technologies to break down carbon emissions and face the costs deriving from the usage of [...] Read more.

In the last twenty years, the global shipping transport demand has strongly increased (around 4% per year since the 1990s), together with the request for new green propulsion technologies to break down carbon emissions and face the costs deriving from the usage of conventional diesel fuels. Flettner rotors (hereafter: FRs) have been identified by several researchers as a promising solution to exploit wind energy on commercial ships, reducing fuel consumption. The present work presents a six-degree-of-freedom (6DOF) ship performance model set up to evaluate the best way of using a pair of Flettner rotors. The study analyses the performance of this propulsion system in consideration of weather and sea conditions, evaluating the related reduction in fuel consumption. A discussion about the economic and environmental advantages of the usage of FRs is provided, considering the costs linked to their installation and the new emission restrictions. Relevant results have been obtained for different routes, speed ranges and rotor dimensions while investigating the best Flettner rotor arrangement to minimise both the emissions and the installation cost payback period. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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17 pages, 2551 KiB

Open AccessArticle

Impact of Biofuel on the Environmental and Economic Performance of Marine Diesel Engines

by Sergii Sagin, Sergey Karianskyi, Volodymyr Madey, Arsenii Sagin, Tymur Stoliaryk and Ivan Tkachenko

J. Mar. Sci. Eng. 2023, 11(1), 120; https://doi.org/10.3390/jmse11010120 - 05 Jan 2023

Cited by 8 | Viewed by 1954

Abstract

The results of the research work on biofuel’s impact on the environmental and economic performance of marine diesel engines are presented. During the research, a fuel mixture was used that consisted of the diesel fuel RMA10 and FAME biofuel. The objective of the [...] Read more.

The results of the research work on biofuel’s impact on the environmental and economic performance of marine diesel engines are presented. During the research, a fuel mixture was used that consisted of the diesel fuel RMA10 and FAME biofuel. The objective of the research was to determine the optimal concentration of biofuel mixed with diesel fuel. The research work was carried out on three of the same type of marine medium-speed diesel engine, 6N165LW Yanmar. One of the diesel engines only operated on diesel fuel, and the other two operated on a mixture of diesel fuel and 5–20% biofuel. During the experiment, the diesel engines operated at a load of 50–80% of the rated value. Experimentally, it was found that using biofuel improved the environmental friendliness of diesel engines: the emission of nitrogen oxides in exhaust gases was reduced by 8.7–23.4%, and the emission of carbon oxides in exhaust gases was reduced by 3.1–24%. However, when using biofuel, the economic efficiency of diesel operation decreased as the specific effective fuel consumption increased by 0.5–9.3%. The highest environmental efficiency was achieved when using a fuel mixture that included 10–15% biofuel in an 80% diesel load. In this case, the emission of nitrogen oxides was reduced by 21–23.5%, the emission of carbon oxides was reduced by 16.5–19.2%, and the magnification of the specific useful consumption of the diesel engine was 1–1.55%. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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39 pages, 14922 KiB

Open AccessEditor’s ChoiceArticle

Technological Potential Analysis and Vacant Technology Forecasting in Properties and Composition of Low-Sulfur Marine Fuel Oil (VLSFO and ULSFO) Bunkered in Key World Ports

by Mikhail A. Ershov, Vsevolod D. Savelenko, Alisa E. Makhmudova, Ekaterina S. Rekhletskaya, Ulyana A. Makhova, Vladimir M. Kapustin, Daria Y. Mukhina and Tamer M. M. Abdellatief

J. Mar. Sci. Eng. 2022, 10(12), 1828; https://doi.org/10.3390/jmse10121828 - 28 Nov 2022

Cited by 18 | Viewed by 3269

Abstract

Analysis of the very-low-sulfur fuel oil (VLSFO) and ultra-low-sulfur fuel oil (ULSFO) bunkered in key ports in Asia, the Middle East, North America, Western Europe, and Russia is presented. The characteristics of said fuels, including density, sulfur content, kinematic viscosity, aluminum and silicon [...] Read more.

Analysis of the very-low-sulfur fuel oil (VLSFO) and ultra-low-sulfur fuel oil (ULSFO) bunkered in key ports in Asia, the Middle East, North America, Western Europe, and Russia is presented. The characteristics of said fuels, including density, sulfur content, kinematic viscosity, aluminum and silicon content, vanadium and nickel content, as well as pour point are investigated. Furthermore, the main trends and correlations are also discussed. Based on the graphical and mathematical analysis of the properties, the composition of the fuels is predicted. The key fuel components in Asian ports, the most important of which is Singapore, are hydrodesulfurized atmospheric residues (AR) (50–70%) and catalytic cracker heavy cycle oil (HCO) (15–35%) with the addition of other components, which is explained by the presence of a number of large oil refining centers in the area. In the Middle East ports, the most used VLSFO compositions are based on available resources of low-sulfur components, namely hydrodesulfurized AR, the production facilities of which were recently built in the region. In European ports, due to the relatively low sulfur content in processed oils, straight-run AR is widely used as a component of low-sulfur marine fuels. In addition, fuels in Western European ports contain on average significantly more hydrotreated vacuum gas oil (21%) than in the rest of the world (4–5%). Finally, a mixture of hydrotreated (80–90%) and straight-run fuel oil (10–15%) with a sulfur content of no more than 2.0–2.5% is used as the base low-sulfur component of marine fuels in the ports of Singapore and the Middle East. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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17 pages, 5079 KiB

Open AccessArticle

Reduction of Sulphur in Marine Residual Fuels by Deasphalting to Produce VLSFO

by Radel Sultanbekov, Kirill Denisov, Aleksei Zhurkevich and Shamil Islamov

J. Mar. Sci. Eng. 2022, 10(11), 1765; https://doi.org/10.3390/jmse10111765 - 16 Nov 2022

Cited by 13 | Viewed by 1999

Abstract

This paper presents the results of the controlled sedimentation process for deasphalting, caused by targeted formation of the fuel dispersed system components incompatibility (proportion of the paraffins with normal structure increase) experimental investigations. The main purpose was to decrease the contained amount of [...] Read more.

This paper presents the results of the controlled sedimentation process for deasphalting, caused by targeted formation of the fuel dispersed system components incompatibility (proportion of the paraffins with normal structure increase) experimental investigations. The main purpose was to decrease the contained amount of sulphur in sedentary marine fuel and procure VLSFO. Developed and given account of the laboratorial method of instituting the sediment which modifies standard TSP and allows to control the deasphalting with the take-off of sediment and deasphaltisate for future analysis. In this case, 5 components of marine fuels, their basic physical and chemical properties, and chemical group composition were used as an object of study. Based on the data obtained and via use of worked out software package, 6 compositions of marine fuels were specified. Furthermore, they were then produced and their quality attributes were defined. The results show that the deasphalting caused by the components targeted incompatibility is accompanied by the desulphurization. Sulphur concentration took place in the sediment where its content was 4.5 times higher than in composite fuel. At the same time, sediment content fell from 0.9% to 1.02% by weight according to the fuel composition. The sulphur content in the resulting deasphaltisate declined by approximately 15% in relation to original fuel mix, moreover, other quality indicators improved. In order to find out whether the usage of sediment obtained is possible, its composition and structure were assessed. The results of the interpretation showed, that sediments were inclined to bitumens, which allows them to be mixed with sediments as a way to cut process waste. Targeted deasphalting makes it possible for the expenses on reducing sulphur containment in marine residual fuels to be decreased, which expands the opportunities of fuels application according to ISO 8217:2017. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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11 pages, 3549 KiB

Open AccessArticle

Mixing Properties of Emulsified Fuel Oil from Mixing Marine Bunker-C Fuel Oil and Water

by Taeho Lee, Jinho Cho and Jeekeun Lee

J. Mar. Sci. Eng. 2022, 10(11), 1610; https://doi.org/10.3390/jmse10111610 - 01 Nov 2022

Cited by 6 | Viewed by 3500

Abstract

Alternative marine fuels are needed to help reduce the exhaust emissions of ships. In this study, we performed an analysis to verify the potential applicability of a fuel based on Bunker-C oil, a low-grade marine heavy oil, as a novel alternative marine fuel. [...] Read more.

Alternative marine fuels are needed to help reduce the exhaust emissions of ships. In this study, we performed an analysis to verify the potential applicability of a fuel based on Bunker-C oil, a low-grade marine heavy oil, as a novel alternative marine fuel. Bunker-C oil and water were mixed in the presence of a 0.8–1.2% emulsifier in four steps from 0% to 25% to produce a special type of emulsified fuel oil. Confocal microscopy images of samples after stabilization for approximately three days at room temperature showed no variation in the pattern at the 0% condition with no water, but a relatively homogenous mixed state of water droplets was found across all domains at the 5–25% conditions. The open-source software Image-J indicated the extraction of 166, 3438, and 5636 water droplets with mean diameters of 1.57, 1.79, and 2.08 μm, as well as maximum diameters of 7.31, 21.41, and 25.91 μm, at the 5%, 15%, and 25% conditions, respectively. For all three conditions, the mean particle diameter was approximately 2 μm, below the 20 μm reported in previous studies, with uniform distributions. This suggests that the mixed state was adequately homogenous. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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22 pages, 3907 KiB

Open AccessArticle

Techno-Economic Analysis of NH₃ Fuel Supply and Onboard Re-Liquefaction System for an NH₃-Fueled Ocean-Going Large Container Ship

by Jinkwang Lee, Younseok Choi and Jungho Choi

J. Mar. Sci. Eng. 2022, 10(10), 1500; https://doi.org/10.3390/jmse10101500 - 15 Oct 2022

Cited by 7 | Viewed by 2227

Abstract

This study proposed the integrated design of an NH₃ fuel supply system and a re-liquefaction system for an ocean-going NH₃-fueled ship. The target ship was a 14,000 TEU large container ship traveling from Asia to Europe. The NH₃ fuel [...] Read more.

This study proposed the integrated design of an NH₃ fuel supply system and a re-liquefaction system for an ocean-going NH₃-fueled ship. The target ship was a 14,000 TEU large container ship traveling from Asia to Europe. The NH₃ fuel supply system was developed to feed the liquid fuel at 40 °C and 80 bar and cope with the re-circulated fuel with the sealing oil. Its power consumptions and SECs ranged from 56.4 to 157.5 kW and from 0.0063 to 0.009 kWh/kg, respectively. An onboard re-liquefaction system with a vapor compression refrigeration cycle was also designed to liquefy the BOG from the fuel tank. The re-liquefaction system’s exergy efficiency and SEC were 34.71% and 0.224 kWh/kg, respectively. The equipment with the most exergy destruction was the heat exchangers, accounting for 60% of the total exergy destruction. NPV analysis found that it is recommended to introduce the re-liquefaction system to the target ship. At the NH₃ price of USD 250/ton, the reasonable cost of the re-liquefaction system is less than USD 1 million. According to LCC, NH₃ fuel is economically feasible if the carbon tax is more than USD 80/ton and the NH₃ price is around USD 250/ton. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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16 pages, 4028 KiB

Open AccessArticle

Study on the Cumulative Effects of Using a High-Efficiency Turbocharger and Biodiesel B20 Fuelling on Performance and Emissions of a Large Marine Diesel Engine

by Nicolae Adrian Visan, Razvan Carlanescu, Dan Catalin Niculescu and Radu Chiriac

J. Mar. Sci. Eng. 2022, 10(10), 1403; https://doi.org/10.3390/jmse10101403 - 01 Oct 2022

Cited by 4 | Viewed by 1236

Abstract

The marine sector represents probably the most powerful segment of international transport. Most ships use diesel engines for propulsion. Pollutant emission regulations with their continuous decline of acceptable limits put huge pressure on engine manufacturers. The use of low-quality fuels makes the marine [...] Read more.

The marine sector represents probably the most powerful segment of international transport. Most ships use diesel engines for propulsion. Pollutant emission regulations with their continuous decline of acceptable limits put huge pressure on engine manufacturers. The use of low-quality fuels makes the marine sector a significant contributor to global pollution. The present study shows how turbocharger operating parameters and replacing diesel fuel with biodiesel B20 (20% oil and 80% diesel volumetric fractions) affect the performance, efficiency and pollutant emissions of a four-stroke diesel engine ALCO V16 251F for marine application. A combustion model developed with the AVL BOOST software was used to perform calculations using diesel fuel and biodiesel B20 for different turbocharger characteristics and injection timings. The model was calibrated against experimental data measured on a tested engine at the application site using diesel fuel and operating in a stationary condition of full load at 600, 700 and 800 rpm engine speeds. The results show that the cumulative effects of using an improved turbocharger associated with B20 fuelling under optimized injection timings could provide reductions of 45% for soot and 5% for NO_x, while maintaining the same engine performance obtained with diesel fuel operation. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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12 pages, 2094 KiB

Open AccessArticle

Analysis of Characteristic Changes of Blended Very Low Sulfur Fuel Oil on Ultrasonic Frequency for Marine Fuel

by Hae-ji Ju and Soo-kyung Jeon

J. Mar. Sci. Eng. 2022, 10(9), 1254; https://doi.org/10.3390/jmse10091254 - 05 Sep 2022

Cited by 6 | Viewed by 2058

Abstract

The demand for very low sulfur fuel oil (VLSFO) with a sulfur content of less than 0.5% has increased since the IMO2020 regulations were published. However, most VLSFOs for marine fuel are produced by blending two fuel oils with different sulfur contents, which [...] Read more.

The demand for very low sulfur fuel oil (VLSFO) with a sulfur content of less than 0.5% has increased since the IMO2020 regulations were published. However, most VLSFOs for marine fuel are produced by blending two fuel oils with different sulfur contents, which causes some problems, such as sludge formation. This study investigates the effect of ultrasonic irradiation frequency (25 and 72 kHz), ultrasonic irradiation time (0, 12, and 24 h), and the blending ratio (marine gas oil (MGO) and bunker-A (B-A) with weight ratios of 25:75, 50:50, and 75:25 on the characteristics of blended VLSFO. After 12 h of irradiation time and a frequency of 25 kHz, the amount of carbon residue decreases with increasing MGO content; it decreases by 33% for 75% MGO. However, at 72 kHz, the carbon residue increases with increasing MGO content, implying that the change in carbon residue depends on the ultrasonic frequency. After 24 h, the carbon residue does not decrease in any scenario; however, it does increase in some cases due to asphaltene reaggregation caused by excessive ultrasonic irritation. The sulfur content decreases by approximately 4% for the 100% B-A condition. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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13 pages, 1221 KiB

Open AccessArticle

Application of the UNIFAC Model for the Low-Sulfur Residue Marine Fuel Asphaltenes Solubility Calculation

by Vladimir G. Povarov, Ignaty Efimov, Ksenia I. Smyshlyaeva and Viacheslav A. Rudko

J. Mar. Sci. Eng. 2022, 10(8), 1017; https://doi.org/10.3390/jmse10081017 - 25 Jul 2022

Cited by 15 | Viewed by 1557

Abstract

Since 2020, 0.5% limits on the sulfur content of marine fuels have been in effect worldwide. One way to achieve this value is to mix the residual sulfur and distillate low sulfur components. The main problem with this method is the possibility of [...] Read more.

Since 2020, 0.5% limits on the sulfur content of marine fuels have been in effect worldwide. One way to achieve this value is to mix the residual sulfur and distillate low sulfur components. The main problem with this method is the possibility of sedimentation instability of the compounded residual marine fuel due to sedimentation of asphaltenes. In this paper, the application of the UNIFAC group solution model for calculating the solubility of asphaltenes in hydrocarbons is considered. This model makes it possible to represent organic compounds as a set of functional groups (ACH, AC, CH₂, CH₃), the qualitative and quantitative composition of which determines the thermodynamic properties of the solution. According to the asphaltene composition, average molecular weight (450–2500 mol/L) and group theories of solutions, a method for predicting the sedimentation stability of compounded residual marine fuels was proposed. The effect of the heat of fusion, temperature of fusion, molecular weight, and group composition on the solubility of asphaltenes in marine fuel has been evaluated. The comparison of the model approach with the data obtained experimentally is carried out. The results obtained make it possible to predict the sedimentation stability of the fuel system depending on the structure and composition of asphaltenes. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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13 pages, 3005 KiB

Open AccessArticle

Effect of Ultrasound Irradiation on the Properties and Sulfur Contents of Blended Very Low-Sulfur Fuel Oil (VLSFO)

by Hae-ji Ju and Soo-kyung Jeon

J. Mar. Sci. Eng. 2022, 10(7), 980; https://doi.org/10.3390/jmse10070980 - 17 Jul 2022

Cited by 6 | Viewed by 1713

Abstract

Quality issues concerning very low-sulfur fuel oil (VLSFO) have increased significantly since the IMO sulfur-limit regulation became mandatory in 2020, as most VLSFO is produced by blending high-sulfur fuel oil (HSFO) with VLSFO. For instance, the conversion of VLSFO paraffins (C₁₉ or [...] Read more.

Quality issues concerning very low-sulfur fuel oil (VLSFO) have increased significantly since the IMO sulfur-limit regulation became mandatory in 2020, as most VLSFO is produced by blending high-sulfur fuel oil (HSFO) with VLSFO. For instance, the conversion of VLSFO paraffins (C₁₉ or higher alkanes) into waxes at low temperatures adversely affects cold flow properties. This study investigates the effects of ultrasonication on the chemical composition, dispersion stability, and sulfur content of samples prepared by blending ISO-F-DMA-grade marine gas oil (i.e., VLSFO) and ISO-F-RMG-grade marine heavy oil (i.e., HSFO) in volumetric ratios of 25:75 (BFO1), 50:50 (BFO2), and 75:25 (BFO3). The paraffin content decreased by 19.2% after 120 min of ultrasonic irradiation for BFO1 by 16.8% after 30 min for BFO3. The decrease in the content of high-molecular-weight compounds was faster at higher HSFO content; however, ultrasonication for longer-than-optimal times induced reaggregation, and thus, increased the content of high-molecular-weight compounds and decreased dispersion stability. In addition, ultrasonication did not significantly affect the sulfur content of BFO1 but decreased those of BFO2 (by 19% after 60 min) and BFO3 (by 25% after 30 min). Desulfurization efficiency increased with the increasing content of HSFO, as water present therein acted as an oxidant for oxidative desulfurization. Full article

(This article belongs to the Special Issue Marine Fuels and Green Energy)

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