Heavy Fuel Oil Research Articles

Seasonal variations, source apportionment and dry deposition of chemical species of total suspended particulate in Pengjia Yu Island, East China Sea

Total of 172 total suspended particulate (TSP) samples and its chemical compositions were collected and analyzed from January to December 2010 in Pengjia Yu Island, an open region in East China Sea (ECS). Despite the predominance of sea-salt major ions (Na+, Cl−), the presence of non-sea-salt SO42− (nss-SO42−) and NO3− as well as combustion-derived trace metals clearly establishes the impact of anthropogenic sources over ECS. The annual contributions of coal, heavy-fuel oil and traffic to the measured chemical species were 21.0 %, 15.0 % and 15.5 %, respectively. Especially in spring, the contributions of crustal minerals to measured chemical species during dust period (33.6 %) were higher than that (13.2 %) during non-dust period. The calculated annual average dry deposition fluxes for trace metals and total inorganic nitrogen were 246.1 ± 345.8 μg/m2/d and 2950.4 ± 2245.0 μg/m2/d, suggesting that atmospheric deposition is an important source of nutrient elements for the south of ECS.

Mixtures of heavy fuel oil and green hydrogen in combustion equipment: Energy analysis, emission estimates, and economic prospects

The high environmental impact of fossil fuels combined with the rise of carbon dioxide in the atmosphere has made the search for renewable fuels imperative. The study assesses the technical and economic viability of replacing heavy fuel oil (HFO) with green hydrogen (H2) in industrial plants for high temperature generation (>1100 K). The study also estimates the emissions generated by the plants after the fuel switch in terms of particulate matter (PM), SO2, NOx and CO2 emissions. To illustrate the feasibility of this replacement, an assessment of a calcination furnace at a pulp plant in Chile in 2022 was carried out, taking into account two electricity generation scenarios for H2 production by water electrolysis. Replacing HFO with a mixture of H2 + HFO was beneficial in terms of emissions. The financial assessment showed that blending H2 with HFO of up to 20 % is the best solution, considering current fuel prices, and that full substitution of HFO with H2 after 2030 is economically viable.

Chemical fingerprints and source resolution of atmospheric fine particles in an industrial harbor based on one-year intermittent field sampling data

This study investigated the spatiotemporal variation, chemical characteristics, and source resolution of PM2.5 in an East Asian seaport adjacent to industrial complex and urban area. Three representative harbor sites were selected to simultaneously sample 24-h PM2.5 once every 13 days in four seasons. A significant seasonal variation was observed with the highest and the lowest PM2.5 concentration in February (winter) and May (summer), respectively. High contribution of secondary inorganic aerosols (SIAs) showed that SO2 and NOx emitted from neighboring combustion sources burning coal and heavy fuel oil (HFO) were the major precursors forming secondary inorganic PM2.5. High ratios of V/Ni and V/Cu were observed in summer (June~August) since the prevailing west and southwest winds from outer port carried ship emissions to inter port. The correlation of chemical fingerprints (V, Ni, V/Ni, Zn, nss-SO42−, OC) and the number of ships were high at the Zhung-He Site and moderate at the Qi-Ho Site. The Cl−, Na+, V, Ni, nss-SO42−, OC, and V/Ni of PM2.5 were co-influenced by ship missions and oceanic spray in the Kaohsiung Harbor. The influences were relatively higher for winds blown from the harbor areas than those blown from the industrial areas. Oppositely, the Fe, Mn, Cr, Cu, Ca, Zn, and Al in PM2.5 were higher for winds blown from the industrial areas than those from the harbor areas. The CMB receptor modelling resolved that the major sources of PM2.5 were industrial missions, secondary aerosols, mobile sources, ship emissions, oceanic spray, fugitive dust, biomass burning, and organic carbon. Similar to Busan (South Korea), Brindisi (Italy), Lampedusa (Italy), and Barcelona (Spain), the contributions of ship emissions in the Kaohsiung Harbor were in the range of 7.4–7.8 %. Meanwhile, Kaohsiung Harbor was highly influenced by emissions from industrial areas and urban areas.

Interactions in co-pyrolysis of Salicornia bigelovii and heavy fuel oil

The interactions in the co-pyrolysis of biomass from Salicornia bigelovii (SB) with heavy fuel oil (HFO) were studied through an investigation of the yields, kinetics, and the quality of bio-oil and biochar produced.

Mechanism of Hydrogen Sulfide Removal from Heavy Fuel Oil by Wave Treatment

Mechanism of Hydrogen Sulfide Removal from Heavy Fuel Oil by Wave Treatment

Optimization of Liner Operations and Fuel Selection considering Emission Control Areas.

The continuous expansion of shipping trade has brought about increasingly serious marine pollution problems. In the context of emission reduction in the global shipping industry, this paper focuses on the operation optimization of container ships inside and outside the emission control area (ECA). From the dual perspectives of shipowners and the general public, models in the annual operating cycle are established to study the economic and environmental benefit differences between traditional fuels, i.e., heavy fuel oil (HFO) and low-sulfur fuel oil (LSFO), and alternative fuels, i.e., liquefied natural gas (LNG) and methanol. Sensitivity analysis was carried out for the proportion of ECA and ship speed. The results show that, in the current situation of high natural gas prices, the use of HFO after the installation of scrubbers is still the most cost-effective option in the short term, followed by the use of LSFO and methanol. LNG is no longer an attractive option, while LSFO and methanol are the best options for both cost and the environment. With the tightening of ECA regulations, methanol will become the optimal choice when the ECA ratio is higher than 47%. By reducing the speed of the ship, the pollutant emission can be effectively reduced, but it will also lead to an overall decrease in profits. Considering the future "zero carbon" emission targets, slow streaming is only suitable as a short-term response measure, while switching to green power energy is a choice that is more in line with the long-term development strategy.

Effects of Synthetic Fuel Co-firing of Heavy Fuel Oil for Marine User

Effects of Synthetic Fuel Co-firing of Heavy Fuel Oil for Marine User

Integrated use of CFD and field data for accurate thermal analyses of oil/gas boilers

In the present study we develop a complete Computational Fluid Dynamics (CFD) modeling procedure suitable for accurate simulations of industrial boilers fed alternatively with gaseous and liquid fuels. The model is developed and validated by means of data from on-site testing.Two different boilers are considered: a 6-burner steam generator of a refinery for the model definition, and a 32-burner thermal power plant boiler for validation, fed by flare-gas/natural-gas or Heavy-Fuel-Oil (HFO). Selected reliable experimental data coming from performance testing are used for both the set-up of the CFD simulations as well as to compute the Flue Exit Gas Temperatures (FEGTs) employed as validation criteria. The flare-gas testing on the 6-burner boiler allows us to accurately determine that a membrane wall emissivity around 0.60 is appropriate as a boundary condition for radiation. By a sensitivity analysis, the relevance of wall emissivity with respect to fouling thermal resistance on the overall heat transfer inside the furnace is established. For boilers alternatively operating with gaseous fuel and HFO a value of 2.8 kW/(m2·K) has been found appropriate. HFO testing on the 6-burner boiler provides data to develop the additional soot modeling, crucial to properly catch oil flame emissivity, based on the model of Khan and Greeves. This allows the matching of a mean soot mass fraction of 1%–3% in the flame zone, a range found by in-flame measurements in the literature and confirmed in the present study by overall heat exchange data in the whole furnace coming from HFO boiler testing. Finally, the 32-burner boiler is considered for validation: using the same procedure and parameters, excellent agreement is found between experimental and CFD results, both on a 100% load natural gas and on a 107% load HFO performance testing.The study demonstrates how field data can be used to validate CFD simulations and confirms that the use of physically meaningful parameters and models exempts from repeated tuning: no change is needed for emissivity and fouling thermal resistance between gaseous and liquid fuel operation, and even a simple soot modeling can be used, just ensuring physically consistent particulate concentration in the oil flame.

Emission characteristics of particulate matter emitted from 4- and 2-stroke marine diesel engines under the background of sulfur emission reduction.

With the implementation of sulfur emission regulations, influences of particulate matter (PM) emitted by marine diesel engines on nearshore atmospheric environment and human health are of increasingly concern. Whatever measures are chosen to meet sulfur emission regulations, the emission characteristic and influencing factors of PM should also be determined. In this study, number and mass emissions, volatility, main composition, and toxicity of PM from marine 4- and 2-stroke diesel engines were investigated. It was found that the size distribution curves of particle number are multiple peaks. Fuels and engines types influence the modal distribution of particles number concentration. For light diesel oil and low-sulfur heavy fuel oil (HFO), particle number was dominated by nucleation and accumulation mode respectively, and particle mass was dominated by accumulation mode. Reduction of fuel sulfur content (FSC) could reduce the particles mass, number and fraction of volatile substance emissions, and small-size particles had the most volatility. Particulate organic carbon (OC) was the main substance, especially for marine 2-stroke diesel engine burning HFO (high- or low-sulfur), while particulate OC contained a large number of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes. The PAHs also had very high toxicity when the engine was burning HFO. The use of low-sulfur HFO cannot make the marine diesel engine meet the current and upcoming PM regulations, and after-treatment technologies or cleaning fuel should be needed.

Economic-Comparative Study for Carbon Neutrality During Ships Docking and in Port Operations: A Path Towards Maritime Sector Decarbonization

According to the International Energy Agency (IEA) reports, the maritime sector was responsible for around 2% of global energy-related Carbon Dioxide (CO2eq) emissions in 2020 (i.e., 714 Mton). Currently, Heavy Fuel Oil (HFO) is used for supplying main and auxiliary Internal Combustion Engines (ICEs) on board ships, therefore it is responsible for local and global pollution. As matter of fact, HFO is contaminated with several different compounds including aromatics, sulfur, and nitrogen, making emission upon combustion more polluting compared to other fuel oils. In order to reduce pollution in maritime sector, the International Convention for the Prevention of Pollution from Ships (MARPOL) has prohibited ships using of HFO in ports. In this purpose, new solutions involving cleaner fuels as well as new propulsion technologies are needed.This paper is aimed to evaluate the environmental advantages that can be reached by replacing the HFO with low emission fuels and alternative power technologies. In particular, three cases have been investigated: i) ICEs fed by diesel, ii) Fuel Cell Systems fed by “Yellow” hydrogen, iii) Fuel Cell Systems fed by “Green” hydrogen. The analysis has been carried out by applying the Well-to-Waves (WTW) method for estimating and comparing the avoided CO2eq and NOx emissions. Moreover, the economic feasibility has been carried out by estimating the investment and operating costs.

Effect of ambient temperature and water content on emulsified heavy fuel oil droplets evaporation: Evaporation enhancement by droplet puffing and micro-explosion

In this study, the evaporation characteristics of emulsified heavy fuel oil (HFO) with water content from 0 to 30 % at the ambient temperatures of 673, 773, and 873 K are experimentally studied. Three distinguishing phases can be clarified and summarized, including initial heating, fluctuation evaporation, and steady evaporation phases. The fluctuation evaporation phase involves the two sub-phases of heat equilibrium and secondary heating, which are first discovered in the evaporation of emulsified HFO. And the heat equilibrium sub-phase is the distinguishing feature of emulsified HFO from other blended fuels. The duration of the initial heating phase and the fluctuation evaporation phase decreases with the elevated ambient temperature but increases with rising water content. However, the variation of micro-explosion intensity with ambient temperature and water content is the opposite. The time consumed in the fluctuation evaporation phase determines the droplet lifetime. The difference between the evaporation characteristics of HFO and emulsified HFO is that the fluctuation evaporation phase of HFO is not distinct, which is due to the violent and frequent micro-explosion occurring in the emulsified HFO droplet. Consequently, the droplet lifetime of emulsified HFO is significantly shorter than that of HFO. Eventually, a regression formula for the dependences of droplet lifetime from temperature and water content is proposed, which can provide a reference for the practical application of emulsified HFO.

Real-Time Investigation of Primary Ship Engine Emissions by Vacuum Resonance-Enhanced Multiphoton Ionization High-Resolution Orbitrap Mass Spectrometry.

The comprehensive chemical description of air pollution is a prerequisite for understanding atmospheric transformation processes and effects on climate and environmental health. In this study, a prototype vacuum photoionization Orbitrap mass spectrometer was evaluated for field-suitability by an online on-site investigation of emissions from a ship diesel engine. Despite remote measurements in a challenging environment, the mass spectrometric performance could fully be exploited. Due to the high resolution and mass accuracy in combination with resonance-enhanced multiphoton ionization, the aromatic hydrocarbon profile could selectively and sensitively be analyzed. Limitations from commonly deployed time-of-flight platforms could be overcome, allowing to unraveling the oxygen- and sulfur-containing compounds. Scan-by-scan evaluation of the online data revealed no shift in exact m/z, assignment statistics with root mean square error (RMSE) below 0.2 ppm, continuous high-resolution capabilities, and good isotopic profile matches. Emissions from three different feed fuels were investigated, namely, diesel, heavy fuel oil (HFO), and very low sulfur fuel oil (VLSFO). Regulations mainly concern the fuel sulfur content, and thus, exhaust gas treatment or new emerging fuels, such as the cycle-oil-based VLSFO, can legally be applied. Unfortunately, despite lower CHS-class emissions, a substantial amount of PAHs is emitted by the VLSFO with higher aromaticity compared to the HFO. Hence, legislative measures might need to take further chemical criteria into account.

Theoretical shell formation model for single droplet of heavy fuel oil

Combustion of heavy fuel oil (HFO) involves the complete combustion of volatile components and the emission of pollutants and solid particles. In most cases, solid particles are seen in the form of the cenosphere. Cenosphere is a hollow particle with a thin, brittle porous shell composed of solids leftover from the HFO. Controlling and reducing these polluting particles requires knowing their nature. Therefore, in this article, an innovative numerical model of how the cenosphere is formed has been developed, in which it is possible to accurately measure the mass, diameter, and thickness of the cenosphere, as well as the effect of changes in fuel concentration and temperature on each of the parameters. In this model, it was assumed that due to heat, the fuel turns into two parts, lighter or volatile and heavier. The lighter component evaporates and the heavy component remains as a solid and causes the formation of the cenosphere. The equations used in this approach include the following: the energy conservation and the evaporation equation for the liquid droplet, the kinetic reaction equations to replace the fuel thermal decomposition and calculate the mass of the coke, and the expansion and compression pressure balance equations for obtaining cenosphere diameter. The expansion pressure caused by the fluid flow through the porous shell, and the compression pressure due to the intermolecular force of the Carbon layers, is dissolved. In modeling fuel properties varying with temperature, an ordinary local HFO has been calculated by assuming a transient single-component droplet and using the distillation curve. The results of the model are in acceptable agreement with the experimental data available in the literature. The difference between the experimental and calculated results of the model for a wide range of results was less than 10%.

Aerosol emissions from a marine diesel engine running on different fuels and effects of exhaust gas cleaning measures

The emissions of marine diesel engines have gained both global and regional attentions because of their impact on human health and climate change. To reduce ship emissions, the International Maritime Organization capped the fuel sulfur content of marine fuels. Consequently, either low-sulfur fuels or additional exhaust gas cleaning devices for the reduction in sulfur dioxide (SO2) emissions became mandatory. Although a wet scrubber reduces the amount of SO2 significantly, there is still a need to consider the reduction in particle emissions directly.We present data on the particle removal efficiency of a scrubber regarding particle number and mass concentration with different marine fuel types, marine gas oil, and two heavy fuel oils (HFOs). An open-loop sulfur scrubber was installed in the exhaust line of a marine diesel test engine. Fine particulate matter was comprehensively characterized in terms of its physical and chemical properties. The wet scrubber led up to a 40% reduction in particle number, whereas a reduction in particle mass emissions was not generally determined. We observed a shift in the size distribution by the scrubber to larger particle diameters when the engine was operated on conventional HFOs.The reduction in particle number concentrations and shift in particle size were caused by the coagulation of soot particles and formation/growing of sulfur-containing particles. Combining the scrubber with a wet electrostatic precipitator as an additional abatement system showed a reduction in particle number and mass emission factors by >98%.Therefore, the application of a wet scrubber for the after-treatment of marine fuel oil combustion will reduce SO2 emissions, but it does not substantially affect the number and mass concentration of respirable particulate matters. To reduce particle emission, the scrubber should be combined with additional abatement systems.

Hybrid Diesel/PV Multi-Megawatt Plant Seasonal Behavioral Model to Analyze Microgrid Effectiveness: Case Study of a Mining Site Electrification

Mining sites that combine energy-intensive operations with community living in areas remote from the electricity grid are increasingly developing dedicated micro-grids. Fossil oil gensets hybridization with renewable energy resources has gained momentum. Difficulties in assessing performance are experienced by operators who wish to benefit from improved performances. The designers of such systems also need additional knowledge to anticipate the solutions of the particular problems related to the power plant’s implementation area characteristics. The proposed approach gives more suitable tools on the effectiveness evaluation of hybridized microgrid, combining a Heavy Fuel Oil (HFO) thermal power station with photovoltaic generator powering mine activities in the Sahelian area. The authors provide key analyses and improvement factors by seasonal behavioral modelling (SBM) of the fuel consumption of the gensets related to the overall irradiance dynamics of the PV array. Several years of data analysis results have been integrated for sharper considerations on the transient interactions impact of the PV/Diesel Hybrid Power Plant operation. The results of simulations carried out using the proposed new models, including the case of an extended system with storage unit, have been used to evaluate the levelized cost of energy, and to discuss competitiveness. This very relevant approach provides additional knowledge for designers and energetic effectiveness analysts.

Selective characterization of petroporphyrins in shipping fuels and their corresponding emissions using electron-transfer matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry

In the context of the global transportation of goods, shipping emissions account for a significant proportion of air pollution. Indeed, a focus has been made over recent years on this primary emission source, leading to several regulations with respect to the chemical composition of shipping fuels. However, these regulations mainly concern the fuel sulfur content (FSC) and do not consider other compound classes such as polycyclic aromatic hydrocarbons (PAHs) or metal-containing aromatics, i.e., petroporphyrins, known to be present in bunker fuels. Petroporphyrins are tetrapyrrole-based metal complexes derived from the transformation of chlorophylls through geological time scales. In contrast to PAHs, their fate in the combustion process and effects on environmental health are widely unknown. In this study, we present electron-transfer ionization in matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (ET-MALDI FTICR MS) for the characterization of vanadyl and nickel porphyrins in shipping feed fuels and primary particulate matter emissions. For the first time, these petroporphyrins could successfully be described in the heavy fuel oil (HFO) feeds but also in the particles emitted by the combustion of the respective fuel on a molecular level. Three main alkylated series of porphyrins were observed; these series can be qualified by their double bond equivalent, i.e., 17, 18, and 20, and correspond to various core structures. Our results highlight the molecular fate of the petroporphyrins through combustion and show that a significant amount of petroporphyrins is released unburned or partially dealkylated to the atmosphere. Furthermore, our results suggest that a higher amount of petroporphyrins might be released in harbors than in open sea, due to a less efficient combustion at lower engine load. This last observation motivates a future specific study on porphyrins’ health and environmental effects.

Assessment of Low Engine Order Excitation of a Contaminated Turbocharger Radial Turbine Stage Using a Nozzle Ring Only Computational Model

Abstract The use of critical fuels such as heavy fuel oil (HFO) usually leads to deposits of combustion residues in the turbocharger turbine stage, foremost in the nozzle ring where flow channels can get partially or completely clogged. The resulting change in geometry is heavily asymmetrical and therefore induces low engine order (LEO) excitation, which may lead to resonant excitation of rotor blades and potentially to high cycle fatigue (HCF) failure. The accurate prediction of LEO excitation is computationally intensive especially, in the context of a probabilistic analysis. The current study investigates the suitability of using a simplified model that only contains the nozzle ring in the assessment of LEO excitation to reduce computational costs. The aerodynamic excitation is assessed from the circumferential variation of the nozzle ring outflow. The results obtained with this simplified model are compared to results of validated forced response analyses. Two deteriorated nozzle rings are used for validation purposes, a generic one having one passage blocked by 90%, and a digital replica of a real contaminated nozzle ring. It is shown that the simplified model is suitable for the qualitative prediction of the aerodynamic excitation if the contamination patterns feature sufficiently large differences and that the computational costs can be greatly reduced.

Comparison of Heavy Fuel-Oil Fractions Produced by Semicoking of Kukersite Shale in Kiviter and Petroter Systems

Comparison of Heavy Fuel-Oil Fractions Produced by Semicoking of Kukersite Shale in Kiviter and Petroter Systems

Challenges of oxidative/extractive desulphurization of heavy fuel oil

AbstractOxidative desulphurization (ODS) of heavy fuel oil (HFO) has some challenges such as gum formation and a high level of waste hydrocarbons. Simple calculations show that, assuming dibenzothiophene (DBT) as a representative component of sulphur‐containing components in the cut, about 20% of hydrocarbons are lost within the extraction process. An experimental investigation has been conducted in a three‐neck glass flask with a mechanical stirrer to obtain more insight about the gum formation during ODS of HFO. The gum formation process was investigated in diluted forms of fuel oil. It was observed that the fuel oil converted to the gum increases by decreasing the hydrogen/carbon (H/C) content of the diluting solvents. The main reason for gum formation during ODS is some polymer formation reactions induced by peroxide radicals. At an oxidant to sulphur ratio (O/S) ratio of 0.25, no gum was formed, while at O/S = 5.0, all of the fuel oil was converted to gum. Finally, a simple and efficient extractive desulphurization procedure has been proposed as an alternative method. At the best condition, about 84% desulphurization was obtained with dimethylformamide (DMF) solvent extraction of HFO. It can be assumed as a potential method to use mild mixing conditions with low contact time for extractive desulphurization of HFO on an industrial scale.

Experimental evaluation of DPF performance loaded over Pt and sulfur-resisting material for marine diesel engines.

Different from vehicle engines, Diesel Particulate Filter (DPF) inactivation is an unavoidable issue for low-speed marine diesel engines fueled with Heavy Fuel Oil (HFO). This paper introduced a sulfur resisting material in Silicon Carbide (SiC)-DPF to improve DPF performance. The results of bench-scale experiments showed that the Balance Point Temperature of the modified DPF module was 300°C and DPF modules had a good filtration performance, with Particulate Matters (PMs) residual being less than 0.6 g per cycle. In pilot-scale tests, PMs emissions of unit power decreased with engine load going up, filtration efficiency of nucleation mode PMs being only 36% under 100% load, while DPF still had a good performance in accumulation mode PMs control, being 94.2% under the same load. DPF modules showed excellent regeneration durability in the 205h endurance test, with a regeneration period of 1.5-2h under 380°C. There was no obvious degeneration in the DPF module structure, with no cracks or breakage. Besides, the DPF module could also control gaseous emissions, total emissions decreased by 10.53% for NO and 57.19% for CO, respectively. The results suggested that introducing sulfur-resisting material in DPF could greatly improve the DPF performance of low-speed marine diesel engines fueled with HFO.