Heavy fuel oils (HFO) are produced from the refining of crude oils, and have high specific gravities and high viscosities. In recent years, spills of HFO have increased in the environment, and are of great concern because they are difficult to clean up. Spilled HFO is likely to become submerged, and can become stranded if fresh HFO coats benthic substrates or if weathered HFO sinks as tarballs. Conversely, lighter oils float on the surface and their components disperse and become diluted in the water column. There is a research need to assess the unique ecological risks of HFO that can sink and contaminate spawning shoals of fish. Chronic toxicity of HFO to fish embryos is correlated with exposure to polycyclic aromatic hydrocarbon (PAH) that become bioavailable from spilled HFO to identify under which spill conditions fish populations are at greatest risk. The results of this research demonstrate that: (1) Stranded HFO is a significant source of PAH to the receiving environment and causes chronic toxicity to embryonic fish; (2) Tarballs and weathered HFO cause less toxicity than fresh HFO, likely a consequence of physical limitations to PAH release; (3) HFO 7102 samples collected from an HFO spill in Wabamun Lake, Alberta, are less toxic than HFO 6303; (4) HFO is at least 2-fold more toxic than Medium South American (MESA), a well-studied reference crude oil, coincident with 3-fold higher concentrations of alkyl PAH, namely alkyl phenanthrenes. / Thesis (Master, Biology) -- Queen's University, 2011-07-25 10:43:05.759

A rainbow trout liver cell line, RTL-W1, was used to evaluate the toxic potential of a heavy fuel oil (HFO) HFO 7102, and its fractions, which together with the HFO are referred to as the oil samples. The fractions were F2, F3, F3-1, F3-2 and F4 and had been prepared by low-temperature vacuum distillation by collaborators at Queen's University. For presentation to the cells, HFO 7102 and its fractions were made into High Energy-Chemically Enhanced Water Accommodated Fractions (HE-CEWAFs). The procedure for this involved adding Corexit 9500 to the oil samples, mixing them on a vortex, and letting the phases settle. The HE-CEWAFs were added to RTL-W1 cell cultures, and at various times afterwards cell viability and CYP1A induction were monitored. Cell viability was evaluated with two dyes, Alamar Blue, which monitors energy metabolism, and 5-carboxfluorescein diacetate acetoxymethyl ester (CFDA AM), which measures plasma membrane integrity. With both indicator dyes, Corexit 9500 was cytotoxic but the concentrations eliciting cytotoxicity varied with the cell culture media. In Leibovitz's L-15 with fetal bovine serum (FBS), which was the medium used for studying CYP1A induction, Corexit 9500 was only cytotoxic at concentrations of 0.1 % (v/v) and greater. For the oil samples, F3-2 at 1 mg/ml and F4 at 10 mg/ml, which were the highest testable concentrations for each, no loss of cell viability was observed over 24 h. The other oil samples were cytotoxic only at their highest testable concentrations, which ended being between 1 and 10 mg/ml. CYP1A induction was monitored in RTL-W1 as catalytic activity and as the level of CYP1A (P4501A) protein. The catalytic activity was assayed as 7-ethoxyresorufin o-deethylase (EROD) activity; the CYP1A protein level, by western blotting. The positive control was 2, 3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which strongly induced both EROD activity and CYP1A protein. Corexit 9500 by itself neither induced EROD activity nor CYP1A protein. All the oil samples induced both EROD activity and CYP1A protein. With both endpoints, the most potent fraction was F3; the least potent, F3-2. As the induction of CYP1A is associated with the development of blue sac disease (BSD) and mortality in early life stages of fish, the results suggest that HFO 7102 and its fractions have the potential to reduce recruitment of young into adult fish populations. CYP1A induction by F3 was studied further, again through EROD activity and western blotting. As the F3 concentration was increased, EROD activity increased but declined at high concentrations, whereas CYP1A protein continued to increase. This suggests the presence of compounds in F3 that at high concentrations inhibit the catalytic activity of CYP1A. When F3 was presented to RTL-W1 cultures together with TCDD, CYP1A protein was induced but not EROD activity. Again this suggests that F3 contains inhibitor(s) of CYP1A as well as inducers. When cultures were exposed to either F3 or TCDD for 24 h and then followed by western blotting for up to 6 days after F3 or TCDD removal, CYP1A levels declined in F3 cultures but not in TCDD cultures. This suggests that RTL-W1 were able to inactivate CYP1A inducer(s) in F3 through metabolism. Overall the results suggest that the pattern of CYP1A induction by F3, and by extension, HFO involves complex interactions between the many chemical components in these mixtures. Likely the most important chemicals are the polycyclic aromatic hydrocarbons (PAHs).

A rainbow trout liver cell line, RTL-W1, was used to evaluate the toxic potential of a heavy fuel oil (HFO) HFO 7102, and its fractions, which together with the HFO are referred to as the oil samples. The fractions were F2, F3, F3-1, F3-2 and F4 and had been prepared by low-temperature vacuum distillation by collaborators at Queen's University. For presentation to the cells, HFO 7102 and its fractions were made into High Energy-Chemically Enhanced Water Accommodated Fractions (HE-CEWAFs). The procedure for this involved adding Corexit 9500 to the oil samples, mixing them on a vortex, and letting the phases settle. The HE-CEWAFs were added to RTL-W1 cell cultures, and at various times afterwards cell viability and CYP1A induction were monitored. Cell viability was evaluated with two dyes, Alamar Blue, which monitors energy metabolism, and 5-carboxfluorescein diacetate acetoxymethyl ester (CFDA AM), which measures plasma membrane integrity. With both indicator dyes, Corexit 9500 was cytotoxic but the concentrations eliciting cytotoxicity varied with the cell culture media. In Leibovitz's L-15 with fetal bovine serum (FBS), which was the medium used for studying CYP1A induction, Corexit 9500 was only cytotoxic at concentrations of 0.1 % (v/v) and greater. For the oil samples, F3-2 at 1 mg/ml and F4 at 10 mg/ml, which were the highest testable concentrations for each, no loss of cell viability was observed over 24 h. The other oil samples were cytotoxic only at their highest testable concentrations, which ended being between 1 and 10 mg/ml. CYP1A induction was monitored in RTL-W1 as catalytic activity and as the level of CYP1A (P4501A) protein. The catalytic activity was assayed as 7-ethoxyresorufin o-deethylase (EROD) activity; the CYP1A protein level, by western blotting. The positive control was 2, 3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which strongly induced both EROD activity and CYP1A protein. Corexit 9500 by itself neither induced EROD activity nor CYP1A protein. All the oil samples induced both EROD activity and CYP1A protein. With both endpoints, the most potent fraction was F3; the least potent, F3-2. As the induction of CYP1A is associated with the development of blue sac disease (BSD) and mortality in early life stages of fish, the results suggest that HFO 7102 and its fractions have the potential to reduce recruitment of young into adult fish populations. CYP1A induction by F3 was studied further, again through EROD activity and western blotting. As the F3 concentration was increased, EROD activity increased but declined at high concentrations, whereas CYP1A protein continued to increase. This suggests the presence of compounds in F3 that at high concentrations inhibit the catalytic activity of CYP1A. When F3 was presented to RTL-W1 cultures together with TCDD, CYP1A protein was induced but not EROD activity. Again this suggests that F3 contains inhibitor(s) of CYP1A as well as inducers. When cultures were exposed to either F3 or TCDD for 24 h and then followed by western blotting for up to 6 days after F3 or TCDD removal, CYP1A levels declined in F3 cultures but not in TCDD cultures. This suggests that RTL-W1 were able to inactivate CYP1A inducer(s) in F3 through metabolism. Overall the results suggest that the pattern of CYP1A induction by F3, and by extension, HFO involves complex interactions between the many chemical components in these mixtures. Likely the most important chemicals are the polycyclic aromatic hydrocarbons (PAHs).

Spilled heavy fuel oil (HFO) sinks within the water column and accumulates in sediments, affecting aquatic organisms that are not typically exposed to oils that float. Previously, the 3-4 ring alkyl substituted polycyclic aromatic hydrocarbons (PAHs) have been identified as the major toxic components in crude oil. Since HFO is comprised of higher concentrations of 3-4 ringed alkyl PAH and an abundance of 5-6 ringed PAH relative to crude oil, it is predicted to be more toxic to the early life stages of fish. An effects-driven chemical fractionation (EDCF) of HFO 7102 was undertaken to establish the toxicity relative to crude oil, and to identify the compounds that are bioavailable and chronically toxic to the early life stages of fish. In this EDCF, the complex HFO 7102 mixture was separated by low temperature vacuum distillation into three distinct fractions, 2, 3 and 4. Each fraction was assessed using a chronic bioassay to determine whether it contained components that caused toxicity to rainbow trout embryos similar to that of the whole oil. Acute bioassays with juvenile trout demonstrated the presence of compounds that induce cytochrome P450 enzymes, an indicator of exposure to PAH. Fraction 3, the fraction more toxic than the parent mixture, was further separated by cold acetone extraction into fraction 3-1 (PAH-rich extract) and fraction 3-2 (wax residue), and assessed with the same bioassays. Simultaneous chemical analysis with bioassays guided the fractionation, and identified compounds abundant and consistently present in toxic fractions. Due to resistance to dispersion of HFO, a chemical dispersant was used with vigorous mixing to drive the maximum amount of oil into solution to minimize the potential for false negatives and the volume of test material used. The potency of HFO 7102 and its fractions were also measured using water accommodated fractions (WAFs) produced by a continuous flow system of water flowing through oil coated gravel. Both exposure methods traced the toxicity from whole oil into fractions containing higher concentrations of 3-4 ring alkyl PAH, similar to crude oil. This research is the first toxicological assessment of HFO 7102, which is essential for determining the risk of spills of HFO to fish, and whether the risk of oils can be predicted from their alkyl PAH composition. / Thesis (Master, Biology) -- Queen's University, 2013-01-24 14:14:16.278

Heavy Fuel Oil (HFO) is a petroleum product and emerging contaminant used as fuel by cargo ships, cruise liners, and oil tankers. As a high-frequency, low volume commodity shipped by pipeline, train, truck, and ship, it is at high risk for small-scale spills in terrestrial, aquatic, and marine environments. There are few reports characterizing HFOs and quantifying the contaminants therein, but previous studies have shown that the most toxic classes of compounds in petroleum products are polycyclic aromatic hydrocarbons (PAHs). This project seeks to address that by analyzing HFO 7102, the specific HFO spilled in Wabamun Lake, Alberta in August 2005. Through an Effects-Driven Fractionation and Analysis, HFO 7102 was successively fractionated by physical and chemical means. First, a low-temperature vacuum distillation separated the oil into three fractions by volatility. The most toxic of these (lowest median toxic concentration, or LC50), F3, underwent a series of solvent extractions to remove asphaltenes and waxes. The remaining PAH-rich extract (F3-1) was further separated using open column chromatography into non-polar, mid-polar, and polar fractions with groupings approximately by number of aromatic rings. At each stage, fractions and sub-fractions were characterized by GC-MS for compositional analysis and bioassays were conducted with rainbow trout embryos. In this fashion, toxicity thresholds were developed for all fractions and the components of HFO 7102 associated with toxicity were identified and quantified. The F3 fraction was six times more toxic than the whole oil. While the wax fraction (F3-2) was shown to be non-toxic, the remaining PAH-rich extract (F3-1) accounted for all of the toxicity in F3. Future work may be done to determine the relative toxicity of the last fractions generated and identify a range of PAH responsible for fish toxicity. It is expected that the F3-1-2 fraction will be most toxic, as it contains nearly all of the three-ring and most of the four-ring PAH. These size classes of PAH have been associated with chronic toxicity to fish embryos in studies of crude oil. Further separations may be attempted to identify a more specific range of toxic compounds, such as by degree of alkylation. / Thesis (Master, Chemistry) -- Queen's University, 2012-07-31 11:31:15.238

Growing environmental concerns, such as global warming, are giving rise to new regulations imposed by the International Maritime Organization (IMO) on sulfur content for marine fuels, thus, constraining refining processes. Oxidative desulfurization (ODS) is an appealing desulfurization method with some advantages over traditional processes like hydrodesulfurization (HDS), such as mild operating conditions and no-hydrogen consumption. ODS could be employed as a complementary or alternative process for HDS. During the oxidative desulfurization, the organo-sulfur compounds are oxidized to polar sulfones. Then, such sulfones are separated from the treated fuel oil using techniques such as liquid-liquid extraction. In the present work, the separation of oxidized sulfur-containing compounds of heavy fuel oil using ultrasound-assisted technology has been investigated and simulated in Aspen Plus. The oxidant selected was hydrogen peroxide, while the catalyst was acetic acid. The chosen solvent for the sulfone separation was acetonitrile. The primary goal of this work is to successfully emulate the operation performed by an oxidative desulfurization pilot plant-scale apparatus designed by Tecnoveritas®, which will later allow the analysis of the parameters on the overall sulfur removal efficiency.

Ship exhausts contain high levels of sulphur oxides, nitrogen oxides, carbon dioxide and particles dueto the heavy fuel oil, HFO, used for combustion and the combustion characteristics of the engine.As a result of upcoming stricter regulations for shipping pollution, as well as growing attentionto greenhouse gas emissions, air pollution and uncertainty of future petroleum oil supply, a shifttowards a cleaner burning fuel is needed.This work explores potential alternative fuels, both conventional and unconventional, and abatementtechnologies, to be used by tankers in the worldwide spot market to comply with upcomingenvironmental regulations in the near and coming future. As a reference the product tanker M/TGotland Marieann is used and recommendations for which fuel that shall be used by the referenceship in 2015 and 2020 are presented.The environmental assessment and evaluation of the fuels are done from a life cycle perspective usingresults from Life Cycle Assessment, LCA, studies.This study illustrates that, of the various alternatives, methanol appears to be the best candidatefor long-term, widespread replacement of petroleum-based fuels within tanker shipping. It does notemit any sulphur oxides nor particles and the nitrogen oxides are shown to be lower than those ofmarine gas oil, MGO. The global warming potential of the natural gas produced methanol is notlower than that of MGO, but when gradually switching to bio-methanol the greenhouse gas emissionsare decreasing and with methanol the vision of a carbon free society can be reached.For 2015 a switch towards methanol is not seen as realistic. Further research and establishment ofregulations and distribution systems are needed, however there are indications that a shift will bepossible sometime between 2015 and 2020. For 2015 a shift towards MGO is suggested as it involveslow investment costs and there is no need for infrastructure changes. As MGO is more expensivethan methanol, a shift is preferable as soon as the market, technology and infrastructure are ready.

Abstract: Global decarbonization requires addressing local challenges and advancing appropriate technologies. In this dissertation, an investigation of appropriate carbon capture technologies for CO2 capture from heavy fuel oil (HFO) fired power plants, common locally, is presented. Two emerging technologies are considered, chemical looping combustion (CLC) and calcium looping (CaL). In a preliminary study, CLC and CaL implementation at an HFO-fired power plant are modeled using Aspen software, and based on the results, CaL is selected for further experimental investigation. Briefly, CaL is a high temperature separation process that utilizes limestone-derived CaO tosimultaneously concentrate CO2 and capture SO2 from flue gas. The solid CaO particles are cycled between carbonation and calcination, CaO + CO2 ⇋ CaCO3, in a dual fluidized bed system and experience capture capacity decay with cycling. Structurally distinct limestones were procured from the two geologic regions where limestone is mined in Saudi Arabia. Using bubbling fluidized bed reactor systems, the capture performance of these two limestones, and a German limestone of known performance, were compared. The combined and individual influence of flue gas H2O and SO2 content, the influence of textural changes caused by sequential calcination/carbonation cycles, and the impact of CaSO4 accumulation on the sorbents’ capture performance were examined. It was discovered that metamorphosed limestone-derived sorbents exhibit atypical capture behavior: flue gas H2O negatively influences CO2 capture performance, while limited sulfation can positively influence CO2 capture. The morphological characteristics influencing sorbent capture behavior were examined using imaging and material characterization tools, and a detailed discussion is presented. Saudi Arabian limestones’ deactivation rates were examined by thermogravimetric analysis. A quantitative correlation describing sulfation deactivation was developed. The validity of amending the conventional semi-empirical sorbent deactivation model with the novel correlation was supported by subsequent pilot scale (20 kWth) experiments. Solving process mass and energy balances, reasonable limits on operating parameters for CaL implementation at HFO-fired power plants were calculated. The influence of power plant configuration, carbonator design, and limestone source on power plant energy efficiency are considered and a discussion is presented. Finally a commentary on the potential of this technology for local implementation and required future work is presented.

Experimental measurement of fuel properties are expensive, require sophisticated instrumentation and are time consuming. Mathematical models and approaches for predicting fuel properties can help reduce time and costs. A new approach for characterizing petroleum fuels called the functional group approach was developed by disassembling the innumerable fuel molecules into a finite number of molecular fragments or ‘functional groups’. This thesis proposes and tests the following hypothesis, Can a fuels functional groups be used to predict its combustion properties? Analytical techniques like NMR spectroscopy that are ideally suited to identify and quantify the various functional groups present in the fuels was used. Branching index (BI), a new parameter that quantifies the degree and quality of branching in a molecule was defined. The proposed hypothesis was tested on three classes of fuels namely gasolines, diesel and heavy fuel oil. Five key functional groups namely paraffinic CH3, paraffinic CH2, paraffinic CH, naphthenic CH-CH2 and aromatic C-CH groups along with BI were used as matching targets to formulate simple surrogates of one or two molecules that reproduce the combustion characteristics. Using this approach, termed as the minimalist functional group (MFG) approach surrogates were formulated for a number of standard gasoline, diesel and jet fuels. The surrogates were experimentally validated using measurements from Ignition quality tester (IQT), Rapid compression machine (RCM) and smoke point (SP) apparatus. The functional group approach was also employed to predict research octane number (RON) and motor octane number (MON) of fuels blended with ethanol using artificial neural networks (ANN). A multiple linear regression (MLR) based model for predicting derived cetane number (DCN) of hydrocarbon fuels was also developed. The functional group approach was also extended to study heavy fuel oil (HFO), a viscous residual fuel that contains heteroatoms like S, N and O. It is used in ships as marine fuel and also in boilers for electricity generation. 1H NMR and 13C NMR measurements were made to analyze the average molecular parameters (AMP) of HFO molecules. The fuel was divided into 19 different functional groups and their concentrations were calculated from the AMP values. A surrogate molecule that represents the average structure of HFO was then formulated and its properties were predicted using QSPR approaches.

Land-based turbine engines are currently used to burn heavy fuel oil (HFO), which is a lower cost fuel. HFO contains inorganic material that forms deposits on turbine blades reducing output and efficiency. Magnesium based additives are used to inhibit vanadium pentoxide deposition and reduce the corrosive nature of the gas and deposits in the hot gas path of the gas turbine. The focus of this study was to determine particle morphology and elemental composition of ash when firing HFO in an atmospheric combustor at various fuel injector atomization pressures. Prior to firing, the HFO was washed with water to remove sodium and potassium. A commercially available magnesium based additive was used to inhibit the vanadium in the HFO. Fuel was injected using an air-blast atomizer at air blast atomization gage pressures of 117, 186, and 255 kPa. Ash was collected from three locations downstream of combustion: immediately following combustion (pre-cyclone), from a cyclone separator (cyclone), and finally from a position located after the cyclone separator (post-cyclone). A Philips XL30 Scanning Electron Microscope (SEM) provided images, weight percent of elements of the ash, and element maps. Images taken from the SEM clearly show two particle types: 1) hollow spherical particles, or cenospheres, and 2) submicron agglomerated spherical particles. The cenospheres contained high carbon concentrations and were found primarily in the cyclone and probe bag filter. Element maps show that cenospheres, regardless of size, predominately contain carbon, oxygen, and sulfur with lesser amounts of sodium, magnesium, aluminum, and silicon. Particles collected downstream of the cyclone were primarily sub-micron in size and inorganic in composition. It is postulated that the cenospheres are the result of incomplete combustion of fuel oil droplets while the submicron spheres are nucleated inorganic material that initially evaporated from the liquid droplets. Particle size analysis was performed for each sample location. As the injection pressure was increased; the pre-cyclone and cyclone locations had similar number mean diameters that would decrease with increasing pressure. The diameter of the post-cyclone location did not change significantly with increasing air atomization. While increasing atomization pressure decreased the carbon content of the ash at all measurement locations, the atomization had little influence on the inorganic composition of the particles. The fine condensed phase particles and the larger cenosphere particles both produced similar compositions of inorganic material.