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Power-to-Liquid processes have the potential to decarbonize maritime transport by producing carbon–neutral electro-fuels. One example of a potential implementation of this process is the combined technology of co-electrolysis of carbon dioxide and water, along with Fischer–Tropsch Synthesis. Given the promising prospects of producing electro-fuels to achieve net-zero objectives by 2050, a critical question that arises is whether sufficient resources are available to replace the current demand for fossil marine gas oil (MGO). This study evaluates the requirements and availability of resources necessary for producing marine electro-fuel using the MGO demand at the Port of Barcelona as a case study. The results indicate that current supplies of renewable energy and biogenic CO2 are insufficient to fully replace the total fossil MGO demand. However, by 2050, it is expected that these resource limitations will be overcome, considering the current official projections for the growth of renewable electricity and the biogas industry. The deployment of renewable electricity generation and the rollout of biomethane industrial network as biogenic carbon source is found to be essential for the viability of the future substitution of fossil MGO with its electro-fuel equivalent.

Currently, about 90% of world transport is via water, which means that maritime transport is a decisive factor in the development of civilization. In order for it to effectively continue and compete with other means of transport, it is necessary to use the cheapest marine fuels on ships. The demand for machines generating mechanical energy to propel ships resulted in their dynamic development and, simultaneously, forced the search for primary energy sources (fuels) that enable the production of the working medium. The era of coal and petroleum fuels began in the 19th and 20th centuries, respectively. Today, in the 21st century, we stand at a crossroads – what next? The transition fuel will likely be LNG and biofuels. Ammonia will also occupy a significant share of the fuel market, but the target fuel will be hydrogen. Based on historical and contemporary sources, this article discusses the changes in the use of marine fuels that have occurred since the 19th century [ABSTRACT FROM AUTHOR]

Sulphur Emission Control Areas (SECAs), mandated by the International Maritime Organization (IMO), regulate fuel sulphur content (FSC) to mitigate the environmental and health impact of shipping emissions in coastal areas. Currently, FSC is limited to 0.1% (w/w) within and 0.5% (w/w) outside SECAs, with exceptions for ships employing wet sulphur scrubbers. These scrubbers enable vessels using non-compliant fuels such as high-sulphur heavy fuel oils (HFOs) to enter SECAs. However, while sulphur reduction via scrubbers is effective, their efficiency in capturing other potentially harmful gases remains uncertain. Moreover, emerging compliant fuels like highly aromatic fuels or low-sulphur blends lack characterisation and may pose risks. Over three years, we assessed emissions from an experimental marine engine at 25% and 75% load, representative of manoeuvring and cruising, respectively. First, characterizing emissions from five different compliant and non-compliant fuels (marine gas oil MGO, hydro-treated vegetable oil HVO, high-, low- and ultra-low sulphur HFOs), we calculated emission factors (EF). Then, the wet scrubber gas-phase capture efficiency was measured using compliant and non-compliant HFOs. NO x EF varied among fuels (5200–19700 mg/kWh), with limited scrubber reduction. CO (EF 750–13700 mg/kWh) and hydrocarbons (HC; EF 122–1851 mg/kWh) showed also insufficient abatement. Carcinogenic benzene was notably higher at 25% load and about an order of magnitude higher with HFOs compared to MGO and HVO, with no observed scrubber reduction. In contrast, carbonyls such as carcinogenic formaldehyde and acetaldehyde, acting as ozone precursors, were effectively scrubbed due to their polarity and water solubility. The ozone formation potential (OFP) of all fuels was examined. Significant EF differences between fuels and engine loads were observed, with the wet scrubber providing limited or no reduction of gaseous emissions. We suggest enhanced regulations and emission abatements in the marine sector to mitigate gaseous pollutants harmful to human health and the environment. [Display omitted] • Ship engine gaseous emissions vary widely with fuel type and engine load. • Wet sulphur scrubbers are ineffective in reducing especially water-insoluble gases. • SECA-compliant fuels generally emit less than non-compliant fuels with scrubbers. • Wet scrubbers effectively reduce carbonyls acting as ozone precursors. • Further legislation is required to address non-SO 2 gaseous pollutants. [ABSTRACT FROM AUTHOR]

With increasing concerns about environmental pollution, the shipping industry has been considering various fuels as alternative power sources. This paper presents a study of the holistic environmental impacts of eco-friendly alternative ship fuels of marine gas oil (MGO), liquefied natural gas (LNG), and hydrogen across each of their life cycles, from their production to the operation of the ship. The environmental impacts of the fuels were estimated by life-cycle assessment (LCA) analysis in the categories of well-to-tank, tank-to-wake, and well-to-wake phases. The LCA analysis was targeted for a 170 gross tonnage (GT) nearshore ferry operating in the ROK, which was conceptually designed in the study to be equipped with the hydrogen fuel cell propulsion system. The environmental impact performance was presented with comparisons for the terms of global warming potential (GWP), acidification potential (AP), photochemical ozone creation potential (POCP), eutrophication potential (EP), and particulate matter (PM). The results showed that the hydrogen showed the highest GWP level during its life cycle due to the large amount of emissions in the hydrogen generation process through the steam methane reforming (SMR) method. The paper concludes with suggestions of an alternative fuel for the nearshore ferry and its production method based on the results of the study. [ABSTRACT FROM AUTHOR]

With increasing concerns about environmental pollution, the shipping industry has been considering various fuels as alternative power sources. This paper presents a study of the holistic environmental impacts of eco-friendly alternative ship fuels of marine gas oil (MGO), liquefied natural gas (LNG), and hydrogen across each of their life cycles, from their production to the operation of the ship. The environmental impacts of the fuels were estimated by life-cycle assessment (LCA) analysis in the categories of well-to-tank, tank-to-wake, and well-to-wake phases. The LCA analysis was targeted for a 170 gross tonnage (GT) nearshore ferry operating in the ROK, which was conceptually designed in the study to be equipped with the hydrogen fuel cell propulsion system. The environmental impact performance was presented with comparisons for the terms of global warming potential (GWP), acidification potential (AP), photochemical ozone creation potential (POCP), eutrophication potential (EP), and particulate matter (PM). The results showed that the hydrogen showed the highest GWP level during its life cycle due to the large amount of emissions in the hydrogen generation process through the steam methane reforming (SMR) method. The paper concludes with suggestions of an alternative fuel for the nearshore ferry and its production method based on the results of the study.

There is a high potential for plant oils as alternative fuel for low and medium speed diesel engines, making petroleum-derived fuels likely to be replaced in these types of engines. Vegetable oils have important advantages over both heavy fuel oil (HFO) and marine gas oil (MGO), the fuels currently used in diesel power plants by large two stroke low-speed diesel engines and by medium speed diesel engines, respectively. The emission of certain pollutants and greenhouse gases like SO x , soot and, mainly, CO 2 can be reduced by using vegetable oils in these types of engines. This work discusses the potential of vegetable oils as fuel for power plant diesel engines and the problems that can be derived from their use. Current experiences with medium speed diesel engines together with the analysis carried out in this paper indicate that vegetable oils can substitute HFO and MGO, without almost any engine modification. • Vegetable oils can be used in current low and medium speed diesel engines. • Soot formation is reduced because vegetable oils do not contain sulphur. • Vegetable oils can reduce the emission of gaseous pollutants except NOx. [ABSTRACT FROM AUTHOR]

Ship auxiliary engines contribute large amounts of air pollutants when at berth. Biodiesel, including that from waste cooking oil (WCO), can favor a reduction in the emission of primary pollutant when used with internal combustion engines. This study investigated the emissions of gaseous intermediate-volatile organic compounds (IVOCs) between WCO biodiesel and marine gas oil (MGO) to further understand the differences in secondary organic aerosol (SOA) production of exhausts. Results revealed that WCO exhaust exhibited similar IVOC composition and volatility distribution to MGO exhaust, despite the differences between fuel contents. While WCO biodiesel could reduce IVOC emissions by 50% as compared to MGO, and thus reduced the SOA production from IVOCs. The compositions and volatility distributions of exhaust IVOCs varied to those of their fuels, implying that fuel-component-based SOA predicting model should be used with more cautions when assessing SOA production of WCO and MGO exhausts. WCO biodiesel is a cleaner fuel comparing to conventional MGO on ship auxiliary engines with regard to the reductions in gaseous IVOC emissions and corresponding SOA productions. Although the tests were conducted on test bench, the results could be considered as representative due to the widely applications of the test engine and MGO fuel on real-world ships. Image 1 [ABSTRACT FROM AUTHOR]

Marine lubricating oil (LO) is deteriorated by contaminants—especially marine gas oil (MGO), which is invariably mixed during its usage—that can damage engine performance. This study investigates a method for determining the content of MGO in lubricating oil. Weight loss from MGO-containing lubricant was evaluated through thermogravimetric analysis (TGA), and a standard calibration curve was plotted to establish a correlation with MGO content. A comparison of the commonly used ASTM–based gas chromatography (GC) analysis, and this TGA approach revealed that the former was more accurate when the lubricant contained ≤1% MGO; however, TGA afforded higher accuracy when the MGO content was between 0.5% and 15%. Hence, TGA can be used as a simple, reliable, and rapid method to analyze the contents of a lubricant contaminant such as MGO.

In this study, the environmental impacts of various alternative ship fuels for a coastal ferry were assessed by the life cycle assessment (LCA) analysis. The comparative study was performed with marine gas oil (MGO), natural gas, and hydrogen with various energy sources for a 12,000 gross tonne (GT) coastal ferry operating in the Republic of Korea (ROK). Considering the energy imports of ROK, i.e., MGO from Saudi Arabia and natural gas from Qatar, these countries were chosen to provide the MGO and the natural gas for the LCA. The hydrogen is considered to be produced by steam methane reforming (SMR) from natural gas with hard coal, nuclear energy, renewable energy, and electricity in the ROK model. The lifecycles of the fuels were analyzed in classifications of Well-to- Tank, Tank-to-Wake, and Well-to-Wake phases. The environmental impacts were provided in terms of global warming potential (GWP), acidification potential (AP), photochemical potential (POCP), eutrophication potential (EP), and particulate matter (PM). The results showed that MGO and natural gas cannot be used for ships to meet the International Maritime Organization’s (IMO) 2050 GHG regulation. Moreover, it was pointed out that the energy sources in SMR are important contributing factors to emission levels. The paper concludes with suggestions for a hydrogen application plan for ships from small, nearshore ships in order to truly achieve a ship with zero emissions based on the results of this study.

Several sustainable liquid fuel alternatives are needed for different compression ignition (CI) engine applications. In the present study, five different fuel blends were investigated. Rapeseed methyl ester (RME) was used as the basic renewable fuel, and it was blended with low-sulfur light fuel oil (LFO), kerosene, marine gas oil (MGO), and naphtha. Of these fuels, MGO is a circulation economy fuel, manufactured from used lubricants. Naphtha is renewable as it is a by-product of renewable diesel production process using tall oil as feedstock. In addition to RME, naphtha was also blended with LFO. The aim of the current study was to determine the most important properties of the five fuel blends in order to gather fundamental knowledge about their suitability for medium-speed CI engines. The share of renewables within these five blends varied from 20 to 100 vol.%. The properties that were investigated and compared were the cetane number, distillation, density, viscosity, cold properties, and lubricity. According to the results, all the studied blends may be operable in medium-speed engines. Blending of new, renewable fuels with more conventional ones will help ease the technical transitional period as long as the availability of renewable fuels is limited.

Ship emissions are known to cause severe impacts on human health, but are less restricted than land-based emissions. A regulation to improve air quality in coastal regions and frequented waterways is the limitation of fuel sulphur content to 0.1% in sulphur emission control areas (SECAs), which has caused a switch from heavy fuel oil (HFO) towards diesel-like marine gas oil (MGO) or marine diesel oil (MDO). The fraction of aromatic organic vapours in the exhaust from a marine engine, operating on HFO and MGO, was investigated by resonance-enhanced multi-photon ionisation time-of-flight mass spectrometry (REMPI-TOFMS). MGO with fuel sulphur content (FSC) below 0.1% and HFO with an average FSC of 2.7% denote representative marine fuels inside and outside SECAs, respectively. The obtained emission spectra were combined with data of previous REMPI-TOFMS studies of combustion engines and wood combustion in statistical analyses to derive marker substances for ship emissions inside and outside SECAs. A diagnostic ratio of C2-naphthalenes to methyl-naphthalenes was found to hold for a good discriminator between ship emissions on the one hand and road traffic and wood combustion on the other hand. Furthermore, random REMPI spectra from all emission sources were mixed with different proportions in a simulation to create a model based on partial least square (PLS) regression for the prediction of ship contribution to aromatic organic vapours. We point out that in particular PAHs with higher degree of alkylation are significant markers for primary ship emissions which may support source apportionment studies inside and outside SECAs to assess the benefits of fuel sulphur content regulation on air quality. [ABSTRACT FROM AUTHOR]

In this study, seven mixtures of diisopropanolamides that were synthesized from various vegetable oils (sunflower oil, soybean oil, cotton seed oil, olive oil, tobacco seed oil, coconut oil, used frying oil) were used as lubricating additives in a low-sulfur marine gas oil. All tribological measurements were carried out by using the high-frequency reciprocating ring (HFRR) test procedure, according to EN ISO 12156-1. The obtained wear results showed that all mixtures of diisopropanolamides used provide satisfactory a mean wear scar diameter (WS 1.4) of less than 520 μm, at concentration levels of 60-120 ppm. The concentrations below 60 ppm had no effect on the fuel lubricity. An increase in the concentration of the diisopropanolamide mixtures led to an insignificant increase of the lubrication effectiveness. [ABSTRACT FROM AUTHOR]

The main driver for the investigation of fast pyrolysis oil marine fuel blends is EU directive 2012/33/EU which aims to cut the sulphur content of marine fuel and thereby reduce air pollution caused by marine vessels. The aim of this study was to investigate the miscibility of three- and four- component blends containing pyrolysis oil, 1-butanol, biodiesel (RME) and/or marine gas oil (MGO). The ideal blend would be a stable homogenous product with a minimum amount of butanol, whilst maximising the amount of pyrolysis oil. A successful blend would have properties suitable for use in marine engines. In order to successfully utilise a marine fuel blend in commercial vessels it should meet minimum specification requirements such as a flash point ≥60°C. Blends of pyrolysis oil, RME, MGO and 1-butanol were evaluated and characterised. The mixed blends were inspected after 48 hours for homogeneity and the results plotted on a tri-plot phase diagram. Homogenous samples were tested for water content, pH, acid number, viscosity and flash point as these indicate a blend's suitability for engine testing. The work forms part of the ReShip Project which is funded by Norwegian industry partners and the Research Council of Norway (The ENERGIX programme). © 2016 American Institute of Chemical Engineers Environ Prog, 36: 677-684, 2017 [ABSTRACT FROM AUTHOR]

Humic-like substances (HULIS), known for their substantial impact on the atmosphere, are identified in marine diesel engine emissions obtained from five different fuels at two engine loads simulating real world scenarios as well as the application of wet sulfur scrubbers. The HULIS chemical composition is characterized by electrospray ionization (ESI) ultrahigh resolution mass spectrometry and shown to contain partially oxidized alkylated polycyclic aromatic compounds as well as partially oxidized aliphatic compounds, both including abundant nitrogen- and sulfur-containing species, and clearly different to HULIS emitted from biomass burning. Fuel properties such as sulfur content and aromaticity as well as the fuel combustion efficiency and engine mode are reflected in the observed HULIS composition. When the marine diesel engine is operated below the optimum engine settings, e.g., during maneuvering in harbors, HULIS-C emission factors are increased (262-893 mg kg -1 ), and a higher number of HULIS with a shift toward lower degree of oxidation and higher aromaticity is detected. Additionally, more aromatic and aliphatic CHOS compounds in HULIS were detected, especially for high-sulfur fuel combustion. The application of wet sulfur scrubbers decreased the HULIS-C emission factors by 4-49% but also led to the formation of new HULIS compounds. Overall, our results suggest the consideration of marine diesel engines as a relevant regional source of HULIS emissions.

In this study, seven mixtures of diisopropanolamides that were synthesized from various vegetable oils (sunflower oil, soybean oil, cotton seed oil, olive oil, tobacco seed oil, coconut oil, used frying oil) were used as lubricating additives in a low-sulfur marine gas oil. All tribological measurements were carried out by using the high-frequency reciprocating ring (HFRR) test procedure, according to EN ISO 12156-1. The obtained wear results showed that all mixtures of diisopropanolamides used provide satisfactory a mean wear scar diameter (WS 1.4) of less than 520 μm, at concentration levels of 60–120 ppm. The concentrations below 60 ppm had no effect on the fuel lubricity. An increase in the concentration of the diisopropanolamide mixtures led to an insignificant increase of the lubrication effectiveness.

This paper examines the costs and benefits of reduction measures for the shipping industry to comply with the forthcoming sulphur emission regulations. Sulphur scrubbers and marine gas oil are two promising alternatives for ship owners. However, their economic comparisons are primarily based on a private perspective. This paper provides a wider viewpoint by integrating the private abatement costs of ship owners and the social environmental benefits from emission reduction. The results showed that the price spread between marine gas oil and heavy fuel oil is a determining factor in making this choice. Marine gas oil tends to have higher net present values than scrubbers when the price spread of fuel is less than 231 Euros per tonne. Furthermore, it is more beneficial to install a scrubber on new ships than retrofits. An old ship is not suitable for a scrubber installation when its remaining lifespan is less than 4 years. [ABSTRACT FROM AUTHOR]

Abstract: Particle emission characteristics were studied from heavy-duty diesel engine operating on fuels with sulfur levels relevant to marine operation, i.e. 0.05% S and 3% S respectively. Effects of primary dilution temperature (PDT) and primary dilution ratio (PDR) were investigated together with effect of filter media and time of filter conditioning. PDT increase was found slowing down nucleation rate due to increase of saturation vapor pressures of volatile species. In turn, increasing PDR reduces partial pressure of exhaust species and hence weakens both homogeneous and heterogeneous nucleation. All these effects are amplified by high sulfur content in marine fuels which increases available amount of nucleation-prone vapor-phase semivolatile compounds. At the same time, water condensation artifact was observed at PDR=3. No filter type was found to be overwhelmingly superior as certain positive and/or negative measurement artifacts are inherently associated with all filter materials. The filter conditioning time was also found to cause substantial PM mass variation, as control over VOC take up from (or lost to) laboratory air and hydration of sulfuric acid is required. The standard 24hour conditioning time was found insufficient to reach complete PM mass equilibrium, so longer time is required when measuring from high-sulfur fuels. [Copyright &y& Elsevier]

Air emissions from shipping have received attention in recent years and the shipping industry is striving for solutions to reduce their emissions and to comply with stricter regulations. Strategies to reduce emissions can consist of a fuel switch, engine changes, or end-of-pipe technologies, but they do not necessarily imply reduced life cycle emissions. The present paper assesses the environmental performance of marine fuels from well-to-propeller using life cycle assessment (LCA). Four fossil fuels are compared: heavy fuel oil (HFO), marine gas oil, gas-to-liquid (GTL) fuel, and liquefied natural gas (LNG), combined with two exhaust abatement techniques: open-loop scrubber and selective catalytic reduction. LNG and other alternatives that comply with the SECA 2015 and Tier III NOx requirements give decreased acidification and eutrophication potentials with 78–90 per cent in a life cycle perspective compared with HFO. In contrast, the use of LNG does not decrease the global warming potential by more than 8–20 per cent, the amount depending mainly on the magnitude of the methane slip from the gas engine. None of the fossil fuels scrutinized here would decrease the greenhouse gas emissions significantly from a life cycle perspective. The study supports the need for LCA when evaluating the environmental impact of a fuel change, e.g. it is found that the highest global warming potential during the whole life cycle is connected to the alternatives with GTL fuel. [ABSTRACT FROM PUBLISHER]

The purpose of this work was to investigate the impact of marine gas oil (MGO)/biodiesel blends on the exhaust emissions and fuel consumption in a single cylinder, stationary, diesel engine. Three different origins of biodiesel were used as the blending feedstock with the reference MGO, at proportions of 5 and 10% by volume. Methyl esters were examined according to the automotive FAME standard EN 14214. The baseline MGO and biodiesel blends were examined according to ISO 8217:2005 specifications for the DMA category. Independently of the biodiesel used, a decrease of PM, HC, CO and CO2 emissions was observed. Emissions of NOx were also lower with respect to MGO. This reduction in NOx may be attributed to some physicochemical properties of the fuels applied, such as the higher cetane number and the lower volatility of methyl esters. Reductions in PM for biodiesel blends were lower in the exhaust than those of the reference fuel which was attributed to the oxygen content and the near absence of sulphur and aromatics compounds in biodiesel. However, a slight increase in fuel consumption was observed for the biodiesel blends that may be tolerated due to the exhaust emissions benefits. Brake thermal efficiency was also determined. Unregulated emissions were characterized by determining the soluble organic fraction content of the particulate matter. [ABSTRACT FROM AUTHOR]

• Methane has a positive effect on desulfurization of low-sulfur fuel oil. • 50% sulfur removal is achieved for marine gas oil and marine diesel oil. • Less than 0.1% sulfur content is reached for both oils. • Methane presence suppresses the over-cracking and coking formation. The desulfurization of marine gas oil (MGO) and marine diesel oil (MDO) is crucial for the bunker fuel industry due to the new regulation on SO x emission imposed by the International Maritime Organization. The catalytic desulfurization of such feedstock is conducted under methane environment in this study. Using a ZSM-5 with uniform cylindrical morphology (UZSM-5) as the catalyst support material, the over-cracking of oil molecules is inhibited. The incorporation of Ga and Mo enhances the activation of methane, aromatization of the feedstock and conversion of sulfur containing groups, particularly when marine diesel oil with a higher sulfur content is charged as the feed. Under CH 4 environment, 58.8% sulfur content in the feedstock is converted comparing with that of 42.8% under N 2 environment when Ga-Mo/UZSM-5 is employed as the catalyst. The participation of methane not only improves the desulfurization performance, but also suppresses coking and over-cracking of the feedstock as well as increasing the liquid product yield probably through methane incorporation to the product molecules. [ABSTRACT FROM AUTHOR]

Marine lubricating oil (LO) is deteriorated by contaminants—especially marine gas oil (MGO), which is invariably mixed during its usage—that can damage engine performance. This study investigates a method for determining the content of MGO in lubricating oil. Weight loss from MGO-containing lubricant was evaluated through thermogravimetric analysis (TGA), and a standard calibration curve was plotted to establish a correlation with MGO content. A comparison of the commonly used ASTM–based gas chromatography (GC) analysis, and this TGA approach revealed that the former was more accurate when the lubricant contained ≤1% MGO; however, TGA afforded higher accuracy when the MGO content was between 0.5% and 15%. Hence, TGA can be used as a simple, reliable, and rapid method to analyze the contents of a lubricant contaminant such as MGO. [ABSTRACT FROM AUTHOR]

• The hybrid fuel was more toxic to marine zooplankton than the Marine Gas Oil. • The hybrid fuel contained more PAHs than the Marie Gas Oil. • Exposure to hybrid fuel changed zooplankton community structure. • Low levels of hybrid fuel increase the feeding rate. International shipping is responsible for the release of numerous contaminants to the air and the marine environment. In order to reduce airborne emissions, a global 0.5 % sulphur limit for marine fuels was implemented in January 2020. Recently, a new generation of so-called hybrid fuels that meet these new requirements have appeared on the market. Studies have shown that these fuels have physical properties that make conventional clean-up methods difficult, but few have studied their effects on marine life. We conducted short and long-term microcosm experiments with natural mesozooplankton communities exposed to the water accommodated fractions (WAFs) of the hybrid fuel RMD80 (0.1 % sulphur) and a Marine Gas Oil (MGO). We compared the toxicity of both fuel types in 48h short-term exposures, and studied the effects of the hybrid fuel on community structure over two generations in a 28-day experiment. The F0 generation was exposed for eight days and the F1 generation was raised for 22 days without exposure. GC–MS and GC–FID analysis of the WAFs revealed that the hybrid fuel was dominated by a mixture of volatile organic compounds (VOCs) and poly aromatic hydrocarbons (PAHs), whereas the MGO was mainly composed of VOCs. We observed significant short-term effects on copepod egg production from exposure to 25 % hybrid fuel WAF, but no effects from the MGO WAF at equivalent WAF dilution. In the long-term experiment with RMD80, the feeding rate was initially increased after exposure to 0.5–1.1 % hybrid fuel WAF, but this did not increase the copepod egg production. Significant change in community structure was observed after eight days in the F0 community at 0.5–3.3 % WAF. Indications of further alterations in species abundances was observed in the F1 community. Our results demonstrate that the MGO is a less toxic low-sulphur alternative to the hybrid fuel for marine zooplankton, and that a hybrid fuel spill could result in altered diversity of future generations of copepod communities. [ABSTRACT FROM AUTHOR]

In this study, the environmental impacts of various alternative ship fuels for a coastal ferry were assessed by the life cycle assessment (LCA) analysis. The comparative study was performed with marine gas oil (MGO), natural gas, and hydrogen with various energy sources for a 12,000 gross tonne (GT) coastal ferry operating in the Republic of Korea (ROK). Considering the energy imports of ROK, i.e., MGO from Saudi Arabia and natural gas from Qatar, these countries were chosen to provide the MGO and the natural gas for the LCA. The hydrogen is considered to be produced by steam methane reforming (SMR) from natural gas with hard coal, nuclear energy, renewable energy, and electricity in the ROK model. The lifecycles of the fuels were analyzed in classifications of Well-to- Tank, Tank-to-Wake, and Well-to-Wake phases. The environmental impacts were provided in terms of global warming potential (GWP), acidification potential (AP), photochemical potential (POCP), eutrophication potential (EP), and particulate matter (PM). The results showed that MGO and natural gas cannot be used for ships to meet the International Maritime Organization's (IMO) 2050 GHG regulation. Moreover, it was pointed out that the energy sources in SMR are important contributing factors to emission levels. The paper concludes with suggestions for a hydrogen application plan for ships from small, nearshore ships in order to truly achieve a ship with zero emissions based on the results of this study. [ABSTRACT FROM AUTHOR]

Several sustainable liquid fuel alternatives are needed for different compression ignition (CI) engine applications. In the present study, five different fuel blends were investigated. Rapeseed methyl ester (RME) was used as the basic renewable fuel, and it was blended with low-sulfur light fuel oil (LFO), kerosene, marine gas oil (MGO), and naphtha. Of these fuels, MGO is a circulation economy fuel, manufactured from used lubricants. Naphtha is renewable as it is a by-product of renewable diesel production process using tall oil as feedstock. In addition to RME, naphtha was also blended with LFO. The aim of the current study was to determine the most important properties of the five fuel blends in order to gather fundamental knowledge about their suitability for medium-speed CI engines. The share of renewables within these five blends varied from 20 to 100 vol.%. The properties that were investigated and compared were the cetane number, distillation, density, viscosity, cold properties, and lubricity. According to the results, all the studied blends may be operable in medium-speed engines. Blending of new, renewable fuels with more conventional ones will help ease the technical transitional period as long as the availability of renewable fuels is limited. [ABSTRACT FROM AUTHOR]