In-situ Burning Research Articles

Air quality impacts in the vicinity of a chemical herder mediated in-situ burn for Arctic oil spill response

Chemical herder augmented in-situ burning (ISB) is one of the most viable oil spill response techniques in partially ice-covered waters. Herein we report on the impacts of herder-mediated ISB tests on ambient air quality by making atmospheric measurements during ISB field tests in partially ice-covered waters in Fairbanks, Alaska. Concentrations of PM2.5, six combustion gases (CO, CO2, NO, NO2, NOx, SO2), volatile organic compounds (VOCs), and herding agent (OP-40) in the airborne plume (6–12 m downwind) were measured during three ISB events. PM2.5 concentrations significantly (p-value = 0.8014) exceeded NAAQS (24 h) exposure limits, while the remaining pollutants were found significantly (p-value <0.05) below the established exposure limits. OP-40 herder was not detected in the collected aerosol samples. To our knowledge, this is the first study on atmospheric emissions in the vicinity of a field-scale herder-augmented oil-spill ISB study in a high-latitude Arctic environment and provides information that is helpful to ensure the safety and well-being of on-site response personnel.

Influence of Immersed Conductive Objects on Quasi-Steady Burning Behavior of Fuel Slick in Turbulent Waters

ABSTRACT In situ burning (ISB) is an effective technique for burning oil spills that occur in oceans. The need for enhancing the burning characteristics and advancing the technique of burning fuels on the water sublayer has been identified. Following this, the study analyzes the steady burning behavior of a fuel layer floating on a turbulent water surface. The turbulent water surface is generated using an experimental platform comprising an axisymmetric upward-pointing submerged jet, an approach used in studies of free-surface turbulence. The turbulence is isotropic in the horizontal plane and bulk-flow free, with a turbulence intensity equal to 1.7 cm/s comparable to water turbulence in a calm ocean. The turbulent boundary condition causes an increase in heat extraction from the bottom of the fuel layer, thereby reducing the mass burning rate by 45% compared to a case with no turbulence. To improve the burning under turbulent water sublayer condition, a 10 mm conductive object is immersed at different depths in the fuel. The copper rod collects the flame’s heat and transmits it into the fuel layer via conduction, thereby increasing the burning rate by more than 1.4 times. A heat transfer model shows that the case with a small rod immersion depth (~10 mm) in a 40 mm fuel layer is best at improving burning because the heat losses from the object to the water sublayer are the lowest. The model also shows that the heat from the flame transmitted by the rod is primarily distributed in a region close to the surface of the fuel, where nucleate boiling is observed around the rod surface. As more of the rod is immersed in the fuel layer, the heat dissipation to the turbulent water increases nearly five times, thereby reducing the bubbling around the rod surface and the burning rate. The implications of burning fuel slicks for fast, slick cleanup during in-situ burning in turbulent water conditions are espoused.

Chemical signatures of polycyclic aromatic hydrocarbons in the emissions from in situ oil burns.

This study characterized the parent and alkylated polycyclic aromatic hydrocarbons (PAHs) in gaseous and particulate emissions from the in situ burning (ISB) of oils. The experimental results indicate that the burning of the heavy oil produced the most PAH emissions because of its longest burning time. In addition, the parent PAHs mainly exist in the particulate phase, while alkylated PAHs mostly accumulate in the gaseous phase. In particular, the diagnostic-ratios of PAHs with great stability in both gaseous and particulate emissions from ISB are identified by comparing the laboratory and field data. The presences of bell-, slope- and V-shaped distribution patterns of alkylated PAHs in the emissions precisely indicate their sources to be petrogenic and pyrogenic processes occurring during ISB. The formation of 2-methylanthracene during ISB is confirmed. The overall findings are expected to provide a prospective protocol to characterize PAH pollution from ISB emissions in case of oil spills.

In Situ Burning for Oil Spill Response in the Arctic: Recovery and Quantification of Chemical Herding Agent OP-40 from Burned Oil Residues.

In situ burning (ISB) aided by OP-40 is one of the best suited and effective oil spill response techniques for Arctic conditions. However, the fate of OP-40 in the environment after an ISB event is not fully understood, especially the amount of OP-40 remaining within the burned oil residues. Previous studies reported partial accumulation of OP-40 in water, and no OP-40 was measured in the air emissions following the burn. Accumulation of OP-40 in burned oil residues is not appropriately quantified as it is challenging to process and analyze burned oil samples in the laboratory, and there exists no standard method in the literature to measure and quantify OP-40 in burned residues. In this work, we report on the development of an analytical method for the quantification of OP-40 in burned oil residues using column chromatography, followed by gas chromatography-mass spectrometry analysis which was successfully employed to measure more than 90% of the applied OP-40 in the burned residues for controlled bench-scaleburns. Additionally, the robustness of the developed method was further tested by measuring OP-40 in burn residues from ISBs conducted at different oil-water emulsion ratios (60-100% oil) and water temperatures (4-35°C), wherein known amounts of OP-40 were added to the residues. Results indicate that the method is equally effective for different oil-water emulsions, but the OP-40 recoveries (89.2-115.6%) are significantly higher at warmer temperatures than the OP-40 recoveries (87.0-103.3%) at colder temperatures. Overall, the method developed in this work could assist in the understanding of the fate of OP-40 in a potentially important environmental matrix of burned oil residues that are left behind sometimes long (weeks to years) after an ISB event.

Combustion of crude oil during in-situ burning can introduce polycyclic aromatic compounds (PACs) into small-scale freshwater systems

In-situ burning (ISB) is the controlled combustion of an oil slick to remove large quantities of spilled oil from the aquatic environment. Prior to employing ISB as a remediation technique, an oil slick must often be corralled by physical or chemical means to achieve a sufficient thickness (typically >1 mm) for ignition. While ISB is an effective means to remove oil mass, less is known about the potential for ISB to mobilize polycyclic aromatic compounds (PACs) into the aquatic environment. The PACs are primary contaminants of concern in crude oil due to their environmental persistence and toxicity. We examined the potential for ISB to mobilize PACs into underlying waters in a series of small-scale burns conducted across a gradient of oil slick thicknesses (0–7 mm). Concentrations of PACs in underlying waters were evaluated and compared to reference conditions using an equivalent gradient of oil slick thicknesses that were not ignited. At thinner slick thicknesses (i.e. 0 – 4 mm) ISB enhanced the mobilization of total PACs, likely a result of heat transfer to underlying waters; this effect increased as slick thickness increased. Among thicker slicks (i.e. 4 – 7 mm), pyrogenic PACs became more prevalent and greater concentrations of 4-ring PACs were detected in underlying waters. The potential for PAC mobilization needs to be considered in scenarios where ISB may be the only viable oil spill remediation option (e.g. wetlands, marshes, or where oil is entrained) and in shallow systems susceptible to temperature changes.

In situ burning of crude oils using iron oxide nanoparticles as additives

Oil spills in open waters are ongoing threats to the ecosystem, especially marine life. In situ burning (ISB) has been identified as one of the practical responses to these accidents. One of the challenges in applying ISB is the lower efficiency in the burning of heavy oil fractions. This systematic study investigated the feasibility of applying commercially available, inexpensive, and non-toxic iron oxide (Fe2O3) as an additive for ISB of crude oils. Our results showed that Fe2O3 nanoparticles with redox properties generate ionic oxygen species (found in the vicinity of surface defects), which catalyze the combustion reaction. Furthermore, Fe2O3 addition could shorten the gap between the burning of light fractions and the heavy fractions of crude oils (the difference between low-temperature oxidation (LTO) and high-temperature oxidation (HTO) decreased from 88 to 36 degrees upon addition of Fe2O3) and eliminate the endothermic distillation step (involved in the burning process), which in return improved the burning of heavy fractions. This supports the use of Fe2O3 nanoparticles as an effective additive to enhance ISB, especially of light crude oils. This additive resulted in an increase in the burning efficiency of light crude oil by two folds. This study shares the first application of nanoparticles in ISB, revealing its unleashed potential for further developments by the scientific community.

Proof of concept study for in-situ burn application using conventional containment booms – Design of Burning Tongue

In situ burning (ISB) hasn’t been widely used for offshore oil spill response for various reasons. We present a feasibility study for a new ISB method – the Burning Tongue (BT) concept. We conducted scaled experiments in the Ohmsett wave tank to demonstrate its feasibility. We produced a 35-m long “tongue” of burnable oil (average oil thickness 4.2 mm – above the thickness needed for ISB) by towing a conventional boom (with a 12″ (0.3 m) deep skirt) partially filled with crude oil and then released the oil through a 6″ (0.15 m) wide opening at the apex. We found that the boom movement produced a convergence zone just downstream that kept released oil thick and also pulled oil that entrained under the boom skirt into the thick “tongue” of oil. CFD modeling was performed to explain the flow hydrodynamics and the formation of the convergence zone, which indicates the phenomenon is universal. We used small harbor boom only partially filled with oil for this study and believe that a full-scale marine boom filled with oil would achieve an even thicker “burning tongue.” The BT concept could make ISB more widely used for oil spill response in offshore areas.

The fingerprint stability of the biomarker hopanes and steranes in soot emissions from in-situ burning of oil

The behavior of emissions is an important concern of in-situ burning (ISB) of spilled oils. In particular, the heavy soot originated from ISB can negatively impact the atmospheric environment. To track the behavior of ISB soot, the conservative biomarkers, such as hopanes and steranes, can be potentially used. In this study, the stability of chemical fingerprints of hopanes and steranes in the ISB soot were investigated based on the burning of two different types of oils, including one ultra-light condensate (i.e., surrogate Sanchi condensate) and one heavy oil. The results indicate that the chromatographic patterns and diagnostic ratios of hopanes and steranes in the ISB soot emissions almost remain identical to their corresponding source oils, proving the various oil source identification of ISB soot can be realized. This work attempts to provide novel insights into the application of biomarkers in the management of ISB emissions.

Occupational exposure to air pollutants emitted from in situ burning of offshore oil spills: a large-scale field study.

In-situ burning (ISB) could be an effective cleanup method during spills. This study aims to study occupational exposure to pollutants emitted from offshore, large-scale ISB-experiments among personnel on vessels involved in ISB. Six experimental ISBs after release of 4.2-6 m3 crude or refined oils were performed. Air measurements on three vessels were taken of particulate matter (PM) of different size fractions, polycyclic aromatic hydrocarbons (PAH) and volatile organic compounds (VOC). One vessel was located upwind (about 80-140 m) from the burning oil while two work boats were positioned 200-400 m downwind. One of the work boats moved back and forth transverse to the smoke plume while the other followed the edge of the smoke plume downwind. During the burn period (28-63 min) the range of mean concentrations of PM2.5 particles in the closest work boat downwind from the burn (0.068-0.616 mg/m3) was considerably higher than in the upwind vessel (0.0198-0.029 mg/m3) and in the work boat moving downwind at the edge of the visible smoke (0.007-0.078 mg/m3). The particles were mainly in the PM<1 fraction. In the work boat closest to the burn the mean concentration of particulate PAH and VOC was 0.046-0.070 ng/m3 and < limit of detection -17.1 ppm, respectively. The mean PM2.5 levels in the closest vessel varied between 4 and 41 times higher than the 24-hour Norwegian Air Quality Criteria for the general population, indicating that the particulate exposure may impose a health risk for personnel up to 400 m downwind from an ISB. Exposure to VOC and PAH among crew on board vessels both upwind and downwind from the burning was low during these conditions. However, it is recommended that crew on vessels close to and downwind of smoke plumes from oil fires should use half-masks with P3 filters.

Clariant's StyroMax UL3 catalyst demonstrates outstanding productivity at Risun's new styrene monomer plant in China

In situ burning (ISB) is a practical, safe, and economical fire controlled operation widely used in offshore oil spills caused by oil vessels, blowouts from offshore well, and leakage from oil pipelines. Even though ISB technique produces a high amount of smoke and other emissive compounds, it burns oil immediately and prevents further oil spreading to the ocean. However, the ISB technique needs to be deployed meticulously, else, volatile hydrocarbons only will be burnt from oil but, heavier oil molecules will be remaining as residue that becomes difficult to manage. The ISB is also considered as an effective method to eliminate the combustible materials for onshore oil spill. When the right conditions are set on the affected area, it will help to burn a large quantity of oil in a short time and prevent contamination of soil, surface water, vegetation etc. ISB protects the environment by burning oil molecules quickly and effectively while other techniques retain the oil on the surface for a longer duration. This chapter discusses various operational techniques and equipment used for ISB and their impact on the environment.

Chemical and toxicological characterisation of residues from offshore in-situ burning of spilled fuel oils

Burn residues collected after large scale experimental in situ burns performed in the North Sea were characterised with emphasis on chemistry and acute toxicity. Low-energy water accommodated fractions (WAFs) of three marine fuels (Ultra Low Sulphur Fuel Oil (ULSFO), bunker oil (IFO180), and marine gas oil (MGO) and their field-generated residues from in situ burning (ISB). were prepared to evaluate the potential impact of ISB residue to the environment. The toxicity effects on primary consumers were assessed by testing on early life stage (nauplii) of the marine copepod Calanus finmarchicus. Toxicity studies showed that ISB decreased the acute toxicity of the WAFs compared to the initial oils. WAF of MGO had highest toxicity, and ISB residue of MGO seems to be more toxic than WAFs of fresh ULSFO and IFO180. Additive toxicity expressed as toxic unit (TU) based on the chemical composition also indicated that the toxicity of WAFs from ISB residues were lower than for the initial oils. The 2−3 ring PAHs seem to contribute most to the TU. Overall, the three offshore burns reduced the total mass of PAHs in the water accommodated fractions by >90 % compared to the released unburned oils and caused a reduction of the acute toxicity to copepod nauplii.

Biodegradation Potential of Residue Generated During the In-Situ Burning of Oil in the Marine Environment

Biodegradation Potential of Residue Generated During the In-Situ Burning of Oil in the Marine Environment

Experimental investigation on flame morphology and improved flame radiation model of rectangular heptane pool fire

AbstractThe safety process and effectiveness of in situ burning (ISB) method dealing with spilling liquids depend on flame morphology, mass burning rate and flame radiation. In this work, eight rectangular pools with a fixed area of 400 cm2 but different aspect ratios (length–width ratio, n = 1, 2, 4, 6, 8, 10, 12, and 16, respectively) are used. As the aspect ratio increases from n = 1 to n = 16, the flame height decreases from 105.6 to 72.9 cm, whereas the incident heat flux increases from 0.283 to 0.562 kW/m2. The mass burning rate decreases initially at n ≤ 6 and increases afterwards at n &gt; 6. The traditional flame radiation model overestimates experimental measurement because the radiation model assumes that the flame surface is rectangular, but the actual flame shape shows a trapezoidal surface due to air entrainment. The mathematical linear interpolation method is proposed to make an improvement of rectangular radiation model. The new‐proposed flame radiation model is validated by experimental measurements with the relative error &lt; 5%. The current work provides a good method to evaluate the magnitude of loss prevention of oil leakage.

Coastline in-situ burning of oil spills in the Arctic. Studies of the environmental impacts on the littoral zone community

In-situ burning (ISB) has been an oil combat technique studied since the 1950s. However, burning of the oil on the sea surface along the coastline, coastline ISB (cISB), is novel and was tested for the first time in the Arctic along a rocky coast in the summer 2017. A light crude oil was burned and effects of the cISB operation on the littoral zone communities investigated. The impact on macroalgal vegetation and associated fauna was analysed in three littoral zone levels. The analyses revealed limited effects on the littoral community, and that variation between sample plots and years in macroalgal biomass and coverage, as well as fauna biomass and abundance was higher than the impact from cISB. Therefore, it is concluded that cISB in the Arctic along a rocky shore may be an oil spill response option with relatively low environmental side effects for the specific oil type used.

Offshore field experiments with in-situ burning of oil: Emissions and burn efficiency

In situ burning (ISB) is an oil spill response technique including ignition and burning to remove oil on the water surface. The technique rapidly and effectively removes large portions of the oil. However, the combustion process causes a large smoke plume and leaves a viscous residue in the water. During six large-scale experimental burns in the North Sea in 2018 and 2019, the smoke plume, released oil and contained residues were analysed. The objectives were to document the content of particles and gases in the smoke plume, properties of both the released oils and residues, and the effectiveness of the burns. Oseberg crude oil, Ultra Low Sulphur Fuel Oil (ULSFO), Intermediate Fuel Oil (IFO180) and Marine Gas Oil (MGO) were released into a fire-boom and ignited. Particles and gases in the smoke plume were monitored using drones with several sensors. Soot particle monitoring indicated that more than 90% of the particles produced during the burns were <1 μm. Soot fallout was mainly limited to visible smoke, and the particle concentration was highest directly under the smoke plume and declined with distance from the burn. Gas monitoring in the smoke indicated low concentrations of SO2 and NOX (<2 ppm), and the concentrations of CO2 and CO were within air quality standards. Black Carbon produced relative to the amount of oil burned was 10–18%. The burn efficiency varied and were estimated to 80–91% for Oseberg, >90% for MGO, and <60% for both ULSFO and IFO180. The present paper addresses the results of the smoke plume monitoring, properties of the ISB residues and the burn efficiency.

Dissolved organic matter production from herder application and in-situ burning of crude oil at high latitudes: Bioavailable molecular composition patterns and microbial community diversity effects

Chemical herders and in-situ burning (ISB) are designed to mitigate the effects that oil spills may have on the high latitude marine environment. Little information exists on the water solubilization of petroleum residues stemming from chemically herded ISB and whether these bioavailable compounds have measurable impacts on marine biota. In this experiment, we investigated the effects of Siltech OP40 and crude oil ISB on a) petroleum-derived dissolved organic matter (DOMHC) composition and b) seawater microbial community diversity over 28 days at 4 °C in aquarium-scale mesocosms. Ultra-high resolution mass spectrometry and fluorescence spectroscopy revealed increases in aromaticity over time, with ISB and ISB+OP40 samples having higher % aromatic classes in the initial incubation periods. ISB+OP40 contained a nearly 12-fold increase in the number of DOMHC formulae relative to those before ISB. 16S rRNA gene sequencing identified differences in microbial alpha diversity between seawater, ISB, OP40, and ISB+OP40. Microbial betadiversity shifts were observed that correlated strongly with aromatic/condensed relative abundance and incubation time. Proteobacteria, specifically from the genera Marinomonas and Perlucidibaca experienced −22 and +24 log2-fold changes in ISB+OP40 vs. seawater, respectively. These findings provide an important opportunity to advance our understanding of chemical herders and ISB in the high latitude marine environment.

Characterization, fate and impact of ISB products from different types of crude oils: Literature review and experimental study for ISB predictive modelling and SIMA process

In situ burning (ISB) is an OSR (Oil Spill Response) technique generally not accepted as a “standard” response by most regulators. Main reluctance generally comes from the occurrence of large and dark smokes plumes as well as possible heavy burn residues likely to sink and reach the seafloor. However, ISB has been widely used during the Macondo oil spill in 2010 and highlighted as a promising operational technique. Additionally, standard OSR modeling tools do not consider ISB, as there is a lack of knowledge in the capacity to predict accurately the physico-chemical characteristics, fate and ecotoxicity, of the burn products from large varieties of crude oils. In order to provide dispassionate arguments, we have conducted a study to gain knowledge and try to develop predictive capabilities to infer composition and fate of burn products from characteristics of starting crude oils. The study comprises both large literature review and experimental work where six crude oils of different types (along with corresponding weathered oils) were burnt, and all products quantified and analyzed (physico-chemistry), at both laboratory scale (burning bench) and pilot scale (fire platform). Additionally, ecotoxicity testing on Vibrio fischeri bacteria and Phaeodactylum tricornutum algae were conducted on crude and weathered oils, burn residues, water and soot. The fate of burn residues was also investigated through dispersibility, emulsification and biodegradability testing. The experimental work led to a very large set of data which was subject to multivariate regression statistical treatments to build predictive models. Main data investigated were burn efficiency, density, viscosity, SARA (Saturates, Aromatics, Resins, Asphaltenes) composition, n-alkanes and PAHs (polycyclic aromatic hydrocarbons) distributions in burn residues, gas emissions composition, soot' PAHs distribution in the smokes, and ecotoxicity data of burn residues, soot and water. The paper describes the main results of this study, with promising outcomes to develop predictive ISB modeling and help addressing objectively the relative impact of ISB within the SIMA process in comparison with other cleaning responses.

Good Practices for In-situ Burning of Marshes Based on Two Decades of Responses in Louisiana

ABSTRACT Spills that result in oiled marshes provide unique challenges for responders because intensive removal methods can cause additional harm and slow overall recovery of the habitat. These issues are of particular concern for spills that affect the marsh interior, where access is limited, often resulting in extensive damage from foot and vessel traffic. In Louisiana, extensive marshes are crossed by numerous pipelines and oil wells, and spills can result in heavy oiling of interior habitats in remote locations. Thus, in-situ burning (ISB) is often considered as the best response option. Monitoring of in-situ burns in marshes has provided the scientific basis for evaluating the conditions under which a burn can speed recovery. The lessons learned from multiple burns in Louisiana over the period 2000–2019 include: the burned area can be much greater than oiled area, so the potential for a larger burn should be explicitly considered and planned for; a water layer over the marsh soil is preferred but not required under all conditions; water-saturated soils are required; ISB can be used weeks post-spill to remove oil, but it will not prevent vegetation mortality from oil exposure prior to the burn; oil that penetrates into the substrates or is released below the marsh surface may persist after burning; select ISB as an option early, to prevent damage from foot traffic, etc.; vegetative recovery usually occurs within 1–2 growing seasons; burning can result in a change in dominant plant species; and ISB is very appropriate for small spills in the marsh interior where access for manual removal can cause extensive damage.

Effects of crude oil and field-generated burned oil residue on Northern shrimp (Pandalus borealis) larvae

In situ burning (ISB) is an oil spill clean-up option used by oil spill responders to mitigate impacts on the marine environment. Despite advantages such as high efficiency and potential applicability for challenging areas such as the Arctic, the actual environmental side effects are still uncertain. Acute and sublethal effects of the water accommodated fractions (WAFs from 25 g oil/L seawater) of a pre-weathered North Sea crude (Oseberg Blend 200 °C+) and field generated ISB residue were evaluated on Northern shrimp (Pandalus borealis) larvae. The larvae were first exposed for 96 h to a serial dilution of seven concentrations, and then maintained for two weeks in clean seawater post-exposure. No acute (mortality) or sublethal effects (feeding, development, or growth) were detected in any of the ISB residue concentrations. Significant larvae mortality was found in the three highest concentrations of crude oil (96-h LC50:469 μg/L total petroleum hydrocarbon) but no sublethal effects were found in the surviving larvae post-exposure. This study indicates that applying ISB could mitigate acute impacts of spilled oil on shrimp larvae.

Comparison of particulate-matter emissions from liquid-fueled pool fires and fire whirls

Abstract In-situ burning (ISB) is one of the most effective means of removing oil spilled over open water. While current ISB practices can eliminate a large fraction of the spilled oil, they still result in significant airborne emissions of particulate matter. ISBs are classified as large, free-buoyant pool fires, from which black smoke consisting of particulate matter (PM, soot) emanates as a plume. An experimental investigation of soot emissions from pool fires (PF) and fire whirls (FW) was conducted using liquid hydrocarbon fuels, n-heptane and Alaska North Slope (ANS) crude oil, in fuel pools 10 − 70 cm in diameter. Burning attributes such as burning rate, fuel-consumption efficiency, and emissions of PM, unburned hydrocarbons, carbon dioxide, and oxygen consumption were measured. For both fuels and all pool diameters, compared to PFs, FWs consumed fuel at a higher rate, had lower post-combustion residual mass and PM emission rates. Collectively, these resulted in consistently lower PM emission factors (EF PM ) for FWs at all scales. For FWs, EF PM decreased linearly with a nondimensional quantity defined as the ratio of inverse Rossby number to nondimensional heat-release rate. These results show that the addition of ambient circulation to free-burning PFs to form FWs can increase burning efficiency, reducing both burning duration and EF PM across length scales. The reduction in EF PM with increasing influence of circulation is attributed to a feedback loop of higher temperatures, heat feedback, burning rate and air-entrainment velocity, which in turn contributes to maintaining the structure of a FW. Boilover was observed for fires formed with ANS crude oil at the 70 cm scale, although the overall EF PM was not affected significantly. This investigation presents a foundation to evaluate the detailed mechanisms further, such that appropriate configurations can be developed help minimize the environmental impact of ISBs.