Heavy Fuel Oil Combustion Research Articles

Pilot plant for electron beam treatment of flue gases from heavy fuel oil fired boiler

The pilot scale electron beam flue gas treatment (EBFGT) plant was constructed at Saudi Aramco's Refinery in Jiddah, Saudi Arabia. The plant was designed to treat 2000Nm3/h of flue gas emitted from a heavy fuel oil fired boiler. A unique mobile electron accelerator unit (600keV, 20kW) made by EB TECH Co., Ltd., Korea was used as a beam source. The pilot plant operation proved the high potential of the technology for simultaneous control of sulfur dioxide (SO2) and nitrogen oxides (NOx) emissions. The obtained removal efficiencies reached 98.5% for SO2 and 83.1% for NOx. Two types of byproduct collection devices – cartridge bag filter and electrostatic precipitator – were tested. The obtained byproduct was a high quality fertilizer that can be used directly or as a substrate for NPK blends manufacturing. The soluble part of the byproduct was almost pure ammonium sulfate (98% to 99%) with some amount of ammonium nitrate. The content of heavy metals in the byproduct was very low and lower than the allowed standards by two orders of magnitude. The results of the research are the basis for the design of a full industrial scale EBFGT plant for treatment of flue gas from heavy fuel oil combustion.

Cenosphere formation from heavy fuel oil: a numerical analysis accounting for the balance between porous shells and internal pressure

Heavy fuel oil (HFO) as a fuel in industrial and power generation plants ensures the availability of energy at economy. Coke and cenosphere emissions from HFO combustion need to be controlled by particulate control equipment such as electrostatic precipitators, and collection effectiveness is impacted by the properties of these particulates. The cenosphere formation is a function of HFO composition, which varies depending on the source of the HFO. Numerical modelling of the cenosphere formation mechanism presented in this paper is an economical method of characterising cenosphere formation potential for HFO in comparison to experimental analysis of individual HFO samples, leading to better control and collection. In the present work, a novel numerical model is developed for understanding the global cenosphere formation mechanism. The critical diameter of the cenosphere is modelled based on the balance between two pressures developed in an HFO droplet. First is the pressure (Prpf) developed at the interface of the liquid surface and the inner surface of the accumulated coke due to the flow restriction of volatile components from the interior of the droplet. Second is the pressure due to the outer shell strength (PrC) gained from van der Walls energy of the coke layers and surface energy. In this present study it is considered that when PrC ≥ Prpf the outer shell starts to harden. The internal motion in the shell layer ceases and the outer diameter (DSOut) of the shell is then fixed. The entire process of cenosphere formation in this study is analysed in three phases: regression, shell formation and hardening, and post shell hardening. Variations in pressures during shell formation are analysed. Shell (cenosphere) dimensions are evaluated at the completion of droplet evaporation. The rate of fuel evaporation, rate of coke formation and coke accumulation are analysed. The model predicts shell outer diameters of 650, 860 and 1040 µm, and inner diameters are 360, 410 and 430 µm respectively, for 700, 900 and 1100 µm HFO droplets. The present numerical model is validated with experimental results available from the literature. Total variation between computational and experimental results is in the range of 3–7%.

TG/DTG, FT-ICR Mass Spectrometry, and NMR Spectroscopy Study of Heavy Fuel Oil

There is an increasing interest in the comprehensive study of heavy fuel oil (HFO) due to its growing use in furnaces, boilers, marines, and recently in gas turbines. In this work, the thermal combustion characteristics and chemical composition of HFO were investigated using a range of techniques. Thermogravimetric analysis (TGA) was conducted to study the nonisothermal HFO combustion behavior. Chemical characterization of HFO was accomplished using various standard methods in addition to direct infusion atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry (APCI-FTICR MS), high resolution 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional heteronuclear multiple bond correlation (HMBC) spectroscopy. By analyzing thermogravimetry and differential thermogravimetry (TG/DTG) results, three different reaction regions were identified in the combustion of HFO with air, specifically, low temperature oxidation region (LTO), fuel deposition (FD), and hig...

PM10 source apportionment applying PMF and chemical tracer analysis to ship-borne measurements in the Western Mediterranean

Abstract A PM10 sampling campaign was carried out on board the cruise ship Costa Concordia during three weeks in summer 2011. The ship route was Civitavecchia-Savona-Barcelona-Palma de Mallorca-Malta (Valletta)-Palermo-Civitavecchia. The PM10 composition was measured and utilized to identify and characterize the main PM10 sources along the ship route through receptor modelling, making use of the Positive Matrix Factorization (PMF) algorithm. A particular attention was given to the emissions related to heavy fuel oil combustion by ships, which is known to be also an important source of secondary sulphate aerosol. Five aerosol sources were resolved by the PMF analysis. The primary contribution of ship emissions to PM10 turned out to be (12 ± 4)%, while secondary ammonium sulphate contributed by (35 ± 5)%. Approximately, 60% of the total sulphate was identified as secondary aerosol while about 20% was attributed to heavy oil combustion in ship engines. The measured concentrations of methanesulphonic acid (MSA) indicated a relevant contribution to the observed sulphate loading by biogenic sulphate, formed by the atmospheric oxidation of dimethyl sulphide (DMS) emitted by marine phytoplankton.

Physicochemical and optical properties of combustion-generated particles from a coal-fired power plant, automobiles, ship engines, and charcoal kilns

The physicochemical and optical properties of combustion-generated particles from various sources were investigated. Coal-fired power plants, charcoal kilns, automobiles, and ship engines were the major sources, representing combustions of coal, biomass, and two different types of diesel, respectively. Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDX) equipped with both SEM and HRTEM were used for physicochemical analysis. Light-absorbing properties were assessed using a spectrometer equipped with an integrating sphere.Particles generated from different combustion sources and conditions demonstrate great variability in their morphology, structure, and composition. From coal-fired power plants, both fly ash and flue gas were mostly composed of heterogeneously mixed mineral ash spheres, suggesting that complete combustion released carbonaceous species at high temperatures (1200–1300°C). Both automobile and ship exhaust from diesel combustion show the typical features of soot: concentric circles comprising closely packed graphene layers. However, heavy fuel oil (HFO)-combusted particles from ship exhaust demonstrate more complex compositions containing a different morphology of particles than soot; for example, spherically shaped char particles composed of minerals and carbon. Regarding soot aggregates, particles from HFO combustion have different chemical compositions; carbon dominates but Ca (29.8%), S (28.7%), Na (1%), and Mg (1%) are also present, which were not found in particles from automobile emission. This indicates that fuel properties and combustion conditions are important in determining the fate of particles. Finally, from biomass combustion, amorphous and droplet-like carbonaceous particles with no crystalline structure were observed, and are generally formed by the condensation of low-volatile species at low-temperature (∼300–800°C) combustion conditions. Significant differences in optical properties depending on the combustion source were observed. Diesel combustion particles from automobile and ship showed wavelength-independent absorbing properties, whereas the particles from coal and charcoal kiln combustion showed enhanced absorption at shorter wavelengths, which is a characteristic of brown carbon. Main light absorbers at short wavelengths are proposed for organics and minerals (e.g., iron oxide) for biomass and coal combustion, respectively. Our findings suggest that source-dependent properties and distributions across the globe should be considered when their impacts on climate change and air qualities are discussed.

Differential proteomic analysis of mouse macrophages exposed to adsorbate-loaded heavy fuel oil derived combustion particles using an automated sample-preparation workflow.

Ship diesel combustion particles are known to cause broad cytotoxic effects and thereby strongly impact human health. Particles from heavy fuel oil (HFO) operated ships are considered as particularly dangerous. However, little is known about the relevant components of the ship emission particles. In particular, it is interesting to know if the particle cores, consisting of soot and metal oxides, or the adsorbate layers, consisting of semi- and low-volatile organic compounds and salts, are more relevant. We therefore sought to relate the adsorbates and the core composition of HFO combustion particles to the early cellular responses, allowing for the development of measures that counteract their detrimental effects. Hence, the semi-volatile coating of HFO-operated ship diesel engine particles was removed by stepwise thermal stripping using different temperatures. RAW 264.7 macrophages were exposed to native and thermally stripped particles in submersed culture. Proteomic changes were monitored by two different quantitative mass spectrometry approaches, stable isotope labeling by amino acids in cell culture (SILAC) and dimethyl labeling. Our data revealed that cells reacted differently to native or stripped HFO combustion particles. Cells exposed to thermally stripped particles showed a very differential reaction with respect to the composition of the individual chemical load of the particle. The cellular reactions of the HFO particles included reaction to oxidative stress, reorganization of the cytoskeleton and changes in endocytosis. Cells exposed to the 280°C treated particles showed an induction of RNA-related processes, a number of mitochondria-associated processes as well as DNA damage response, while the exposure to 580°C treated HFO particles mainly induced the regulation of intracellular transport. In summary, our analysis based on a highly reproducible automated proteomic sample-preparation procedure shows a diverse cellular response, depending on the soot particle composition. In particular, it was shown that both the molecules of the adsorbate layer as well as particle cores induced strong but different effects in the exposed cells.

중질 잔사유의 연소성 분석과 보조 분사에 의한 연소성 향상에 관한 검토

Due to the development of the petroleum refining technology and continuously increased demand from markets, a quantity of gasoline and diesel oil produced from a restricted quantity of crude oil has been increasing, and residual fuel to be used at marine diesel engines has been gradually becoming low quality. As a result, it was recently reported that trouble oils which cause abnormal combustion such as knocking with extreme noise and misfire from internal combustion engines were increasing throughout the world. In this study, an author investigated ignitability and combustion quality by using combustion analyzer with constant volume(FCA, Fuel Combustion Analyzer) and middle speed diesel engine about MDO(Marine Diesel Oil), HFO(Heavy Fuel Oil), LCO(Light Cycle Oil) and Blend-HFO which was blended LCO of 1000 liters with HFO of 600 liters. Moreover, for betterment of ignitability and combustion quality of injected fuels, multi-injection experiment was carried out in the diesel engine using Blend-HFO. According to the results of FCA analysis, ignitability and combustion quality was bad in the order of MDO<HFO<Blend-HFO<LCO. And combustion of blended HFO caused extreme knocking in experiments of the diesel engine. However, sub-injection with injection timing of BTDC 20 CA(Crack Angle) defused the knocking that was caused from drop of fuel quality.

Correction to Optical and Chemical Characterization of Aerosols Emitted from Coal, Heavy and Light Fuel Oil and Small-Scale Wood Combustion

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to Optical and Chemical Characterization of Aerosols Emitted from Coal, Heavy and Light Fuel Oil and Small-Scale Wood CombustionAnna K. Frey*, Karri Saarnio, Heikki Lamberg, Fanni Mylläri, Panu Karjalainen, Kimmo Teinilä, Samara Carbone, Jarkko Tissari, Ville Niemelä, Anna Häyrinen, Jani Rautiainen, Jorma Kytömäki, Paulo Artaxo, Aki Virkkula, Liisa Pirjola, Topi Rönkkö, Jorma Keskinen, Jorma Jokiniemi, and Risto HillamoCite this: Environ. Sci. Technol. 2014, 48, 14, 8283Publication Date (Web):June 20, 2014Publication History Published online20 June 2014Published inissue 15 July 2014https://doi.org/10.1021/es502892yCopyright © 2014 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views316Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (119 KB) Get e-Alerts Get e-Alerts

Investigating SO3 Formation from the Combustion of Heavy Fuel Oil in a Four-Stroke Medium-Speed Test Engine

The validation of detailed models, in terms of SO3 formation in large marine engines operating on sulfur-containing heavy fuel oils (HFOs), relies on experimental work. The requisite is addressed i...

Deposit Formation in a Grate-Kiln Plant for Iron-Ore Pellet Production. Part 1: Characterization of Process Gas Particles

Slag formation in the grate-kiln process is a major problem for iron-ore pellet producers. It is therefore important to understand the slag formation mechanism in the grate-kiln production plant. This study initiated the investigation by in situ sampling and identifying particles in the flue gas from a full-scale 40 MW grate-kiln production plant for iron-ore pelletizing. Particles were sampled from two cases of combustion with pulverized coal and heavy fuel oil. The sampling location was at the transfer chute that was situated between the traveling grate and the rotary kiln. The particle-sampling system was set up with a water-cooled particle probe equipped with nitrogen gas dilution, cyclone, and low-pressure impactor. Sub-micrometer and fine particles were size-segregated in the impactor, while coarse particles (>6 μm) were separated with a cyclone before the impactor. Characterization of these particles was carried out with environmental scanning electron microscopy (ESEM), and the morphology of sub-micrometer particles was studied with transmission electron microscopy (TEM). The results showed that particles in the flue gas consisted principally of fragments from iron-ore pellets and secondarily of ashes from pulverized coal and heavy fuel oil combustions. Three categories of particle modes were identified: (1) sub-micrometer mode, (2) first fragmentation mode, and (3) second fragmentation mode. The sub-micrometer mode consisted of vaporized and condensed species; relatively high concentrations of Na and K were observed for both combustion cases, with higher concentrations of Cl and S from heavy fuel oil combustion but higher concentrations of Si and Fe and minor P, Ca, and Al from coal combustion. The first fragmentation mode consisted of both iron-ore pellet fines and fly ash particles; a significant increment of Fe (>65 wt %) was observed, with higher concentrations of Ca and Si during heavy fuel oil combustion but higher concentrations of Si and Al during coal combustion. The second fragmentation mode consisted almost entirely of coarse iron-ore pellet fines, predominantly of Fe (∼90 wt %). The particles in the flue gas were dominantly iron-ore fines because the second fragmentation mode contributed >96 wt % of the total mass of collected particles.

Effects of Switching to Lower Sulfur Marine Fuel Oil on Air Quality in the San Francisco Bay Area

Ocean-going vessels burning high-sulfur heavy fuel oil are an important source of air pollutants, such as sulfur dioxide and particulate matter. Beginning in July 2009, an emission control area was put into effect at ports and along the California coastline, requiring use of lower sulfur fuels in place of heavy fuel oil in main engines of ships. To assess impacts of the fuel changes on air quality at the Port of Oakland and in the surrounding San Francisco Bay area, we analyzed speciated fine particle concentration data from four urban sites and two more remote sites. Measured changes in concentrations of vanadium, a specific marker for heavy fuel oil combustion, are related to overall changes in aerosol emissions from ships. We found a substantial reduction in vanadium concentrations after the fuel change and a 28-72% decrease in SO2 concentrations, with the SO2 decrease varying depending on proximity to shipping lanes. We estimate that the changes in ship fuel reduced ambient PM2.5 mass concentrations at urban sites in the Bay area by about 3.1 ± 0.6% or 0.28 ± 0.05 μg/m(3). The largest contributing factor to lower PM mass concentrations was reductions in particulate sulfate. Absolute sulfate reductions were fairly consistent across sites, whereas trace metal reductions were largest at a monitoring site in West Oakland near the port.

A two-component heavy fuel oil evaporation model for CFD studies in marine Diesel engines

The paper presents an evaporation model for Heavy Fuel Oil (HFO) combustion studies. In the present work, HFO is considered as a mixture of a heavy and a light fuel component, with the thermophysical properties of the heavy component calculated from the recently introduced model of Kyriakides et al. (2009) [1]. The model proposes a proper treatment of convective heat transfer to the evaporating fuel droplets. Computational Fluid Dynamics (CFD) simulations of HFO spray combustion in constant volume chambers are performed, utilizing a modified characteristic time combustion model. The results are in good agreement with literature experimental data. Computational results for a two-stroke marine Diesel engine also compare favorably against experiments. The present development yields a basis for detailed CFD studies of HFO combustion in large marine Diesel engines.

Comparison of emissions and toxicological properties of fine particles from wood and oil boilers in small (20–25 kW) and medium (5–10 MW) scale

The aim of this study was to compare four alternatives for providing decentralized energy production in small communities in terms of their flue gas emissions and toxicological properties of the emissions. In this study, two different size classes of boilers were examined and the use of fossil fuel oils was compared against wood fuels. The lowest PM1 emission, 0.1 mg MJ−1, was observed from small-scale light fuel oil combustion. In medium-scale wood combustion, PM1 emission values from a grate fired wood combustion boiler (10 MW) without particulate filtration were the highest (264 mg MJ−1) but were substantially reduced down to 0.6 mg MJ−1 due to the usage of an electrostatic precipitator (ESP). The wood combustion particles were mainly formed of potassium salts. In light fuel oil combustion, one of the main components in the particles was sulphate whereas in heavy fuel oil combustion also significant amounts of V and Ni were emitted. Pellet combustion produced the lowest PAH emissions. Overall, oil combustion produced higher amount of PAHs than wood combustion. This was indicated also as a higher cytotoxicity of the oil combustion samples when compared to those from wood combustion in the corresponding scale of boilers. However, when calculated on an equal mass basis, the particles collected after ESP were even more cytotoxic which can be explained by the altered chemical characteristics of the emissions in the ESP. Due to the variation in the emissions and in the toxicity of the emissions, we propose that in the long term, not only the emission levels but also the toxicity of the emissions should be taken into account in the regulations of the emission limits of the combustion plants.

Evidence for heavy fuel oil combustion aerosols from chemical analyses at the island of Lampedusa: a possible large role of ships emissions in the Mediterranean

Abstract. Measurements of aerosol chemical composition made on the island of Lampedusa, south of the Sicily channel, during years 2004–2008, are used to identify the influence of heavy fuel oil (HFO) combustion emissions on aerosol particles in the Central Mediterranean. Aerosol samples influenced by HFO are characterized by elevated Ni and V soluble fraction (about 80% for aerosol from HFO combustion, versus about 40% for crustal particles), high V and Ni to Si ratios, and values of Vsol&gt;6 ng m−3. Evidence of HFO combustion influence is found in 17% of the daily samples. Back trajectories analysis on the selected events show that air masses prevalently come from the Sicily channel region, where an intense ship traffic occurs. This behavior suggests that single fixed sources like refineries are not the main responsible for the elevated V and Ni events, which are probably mainly due to ships emissions. Vsol, Nisol, and non-sea salt SO42− (nssSO42−) show a marked seasonal behaviour, with an evident summer maximum. Such a pattern can be explained by several processes: (i) increased photochemical activity in summer, leading to a faster production of secondary aerosols, mainly nssSO42−, from the oxidation of SO2 (ii) stronger marine boundary layer (MBL) stability in summer, leading to higher concentration of emitted compounds in the lowest atmospheric layers. A very intense event in spring 2008 was studied in detail, also using size segregated chemical measurements. These data show that elements arising from heavy oil combustion (V, Ni, Al, Fe) are distributed in the sub-micrometric fraction of the aerosol, and the metals are present as free metals, carbonates, oxides hydrates or labile complex with organic ligands, so that they are dissolved in mild condition (HNO3, pH1.5). Data suggest a characteristic nssSO42−/V ratio in the range 200–400 for HFO combustion aerosols in summer at Lampedusa. By using the value of 200 a lower limit for the HFO contribution to total sulphates is estimated. HFO combustion emissions account, as a summer average, at least for 1.2 μg m−3, representing about 30% of the total nssSO42−, 3.9% of PM10, 8% of PM2.5, and 11% of PM1. Within the used dataset, sulphate from HFO combustion emissions reached the peak value of 6.1 μg m−3 on 26 June 2008, when it contributed by 47% to nssSO42−, and by 15% to PM10.

Heavy Fuel Oil Combustion Modelling Using Continuous Thermodynamics

Global shipping uses Heavy Fuel Oil (HFO) as the primary fuel. HFO is a mixture of oil refinery residue and cutter stock, hence it contains large numbers of hydrocarbons with a wide range of molecular weights and dissimilar structures. Conventional thermodynamics modelling techniques are inadequate for HFO vaporisation modelling. The present article summarises continuous thermodynamics vaporization models along with chemical kinetics models for decomposition and polymerisation, and soot burnout models, employed to study the behaviour of HFO spray combustion. A sample of HFO is also characterised in the laboratory using chemical characterisation procedures including sequential elution solvent chromatography, gas-chromatography mass spectrometry and elemental analysis, to obtain the composition and mean molecular weights of HFO fractions required for continuous thermodynamics modelling. Models are implemented via subroutines in a diesel spray simulation in the CFD package STAR-CD. The simulation is applied to a constant volume spray combustion chamber. The present model accounts for the formation and burnout of liquid phase soot in diesel engines. This soot will be emitted as Black Carbon if unburnt. The models are examined for two representative fuel samples; one with the good combustion quality and the other with poor. Good qualitative agreement is shown between the simulations and published experimental data.

NO&lt;SUB&gt;X&lt;/SUB&gt; reduction in oil fired glass tanks: experiments and simulations

The paper presents atomisation measurements, semi-industrial scale experiments and computational fluid dynamics computations of heavy fuel oil combustion in a glass tank simulator. The study has demonstrated the pronounced effect of discrete fuel injection on NOX emissions in glass tank conditions. Injecting and dispersing the oil droplets into the recirculation zone appeared to be a very successful method for NOX emission reduction due to the delayed mixing between oil droplets and combustion air. The method takes advantage of both the high process temperatures and the strong recirculation zone of the glass tank system so that a substantial NOX emission reduction is achievable without excessive CO emissions.

Comparison of particle emissions from small heavy fuel oil and wood-fired boilers

Flue gas emissions of wood and heavy fuel oil (HFO) fired district heating units of size range 4–15 MW were studied. The emission measurements included analyses of particle mass, number and size distributions, particle chemical compositions and gaseous emissions. Thermodynamic equilibrium calculations were carried out to interpret the experimental findings. In wood combustion, PM1 (fine particle emission) was mainly formed of K, S and Cl, released from the fuel. In addition PM1 contained small amounts of organic material, CO 3, Na and different metals of which Zn was the most abundant. The fine particles from HFO combustion contained varying transient metals and Na that originate from the fuel, sulphuric acid, elemental carbon (soot) and organic material. The majority of particles were formed at high temperature (>800 °C) from V, Ni, Fe and Na. At the flue gas dew point (125 °C in undiluted flue gas) sulphuric acid condensed forming a liquid layer on the particles. This increases the PM1 substantially and may lead to partial dissolution of the metallic cores. Wood-fired grate boilers had 6–21-fold PM1 and 2–23-fold total suspended particle (TSP) concentrations upstream of the particle filters when compared to those of HFO-fired boilers. However, the use of single field electrostatic precipitators (ESP) in wood-fired grate boilers decreased particle emissions to same level or even lower as in HFO combustion. On the other hand, particles released from the HFO boilers were clearly smaller and higher in number concentration than those of wood boilers with ESPs. In addition, in contrast to wood combustion, HFO boilers produce notable SO 2 emissions that contribute to secondary particle formation in the atmosphere. Due to vast differences in concentrations of gaseous and particle emissions and in the physical and chemical properties of the particles, HFO and wood fuel based energy production units are likely to have very different effects on health and climate.

Ship particulate pollutants: Characterization in terms of environmental implication

A major aspect of monitoring the atmosphere is the quantification of man-made pollution and their interactions with the environment. Key physico-chemical characteristics of diesel exhaust particulates of sea-going ship emissions are presented with respect to morphology, microstructure, and chemical composition. Heavy fuel oil (HFO)-derived particles exhibit extremely complex chemistry. They demonstrate three distinct morphological structures with different chemical composition, namely soot, char and mineral/ash. The composition analysis investigates the content of environmentally-dangerous pollutants: metals, inorganic/mineral species, and soluble, volatile organic and ionic compounds. It is found that hazardous constituents from HFO combustion, such as transitional and alkali earth metals (V, Ni, Ca, Fe) and their soluble or insoluble chemical forms (sulfides, sulfates, oxides, carbides), are released together with particles into the atmosphere. The water soluble fraction, more than 27 wt%, is dominated by sulfates and calcium cations. They cause the high hygroscopicity of ship exhaust particles and their possible ability to act as cloud nuclei in humid marine environment.

On the Role of Devolatilization in Fossil Fuel Combustion

At the initial stage of liquid or solid fuel combustion volatiles are released, then tar decomposes, and finally carbonic residue burns out. In connection with this, vaporization and burning of a fuel oil droplet on the hot surface and the processes of volatile release and carbonic residue burning are analyzed. Most part of fuel caloricity is related to volatiles, and this is the initial combustion stage on which further fuel combustion depends. On the basis of the experience of heavy fuel oil combustion in different boilers, we summarize how to use the initial volatile combustion in order to reduce the residue of soot, nitrogen oxides, and CO. Wider use of biofuel is related to gasification of this fuel. Manufacturing of synthetic gas differs for wood, which is comprised of aliphatic spirits, from that of fuel oil or tires, where there are plenty of aromatic hydrocarbons and their conglomerates, such as naphtenes. The pyrolysis process depends on temperature, the amount of oxygen existent in the environment, and chemical composition of fuel, and all this will be revealed by research of used tires and glycerol gasification. The theoretical combustion process and numerical modeling of volatile assessment are discussed in general.

On the Role of Devolatilization in Fossil Fuel Combustion

At the initial stage of liquid or solid fuel combustion volatiles are released, then tar decomposes, and finally carbonic residue burns out. In connection with this, vaporization and burning of a fuel oil droplet on the hot surface and the processes of volatile release and carbonic residue burning are analyzed. Most part of fuel caloricity is related to volatiles, and this is the initial combustion stage on which further fuel combustion depends. On the basis of the experience of heavy fuel oil combustion in different boilers, we summarize how to use the initial volatile combustion in order to reduce the residue of soot, nitrogen oxides, and CO. Wider use of biofuel is related to gasification of this fuel. Manufacturing of synthetic gas differs for wood, which is comprised of aliphatic spirits, from that of fuel oil or tires, where there are plenty of aromatic hydrocarbons and their conglomerates, such as naphtenes. The pyrolysis process depends on temperature, the amount of oxygen existent in the environment, and chemical composition of fuel, and all this will be revealed by research of used tires and glycerol gasification. The theoretical combustion process and numerical modeling of volatile assessment are discussed in general.