Bitumen Extraction Research Articles

Study on the Influence of Surfactant Addition for Bitumen Separation from Asbuton Rocks using Hot Water Process

Indonesia has a bitumen reservoir in a form of rocks located in Buton Island, Southeast Sulawesi. These rocks contain both bitumen and mineral. Bitumen was mostly used for road preparation, hence bitumen had to be separated from its mineral. It was concluded from previous researches that bitumen extraction using the hot water process had a low bitumen recovery. One way to improve its recovery was by adding surfactant. This research aimed to study the effects of anionic and cationic surfactant addition to the percent recovery of bitumen. There were three main processes of bitumen extraction using hot water namely; preparation, mixing-preheating, and digesting. First, asbuton rocks were ground into fine material, then it was sieved using sieve number 30. Then it was continued by mixing asbuton and diesel oil with a ratio of 60:40 at 250 rpm at 60°C for 30 minutes. Then the second process was done by mixing diesel oil-asbuton and wetting agent solution that contains Sodium Dodecyl Benzene Sulfonate (SDBS) as anionic surfactant and NaOH at 1500 rpm for 30 minutes. The other mixture is Dodecyl Trimethyl Ammonium Bromide (DTAB) as a cationic surfactant and NaOH. In this research, the concentrations of surfactant used were 0.125; 0.25; 0.375; 0.5%, the used NaOH concentrations were constant at 0.5% (% mass), while the variation of temperature used were 60, 70, 80, to 90°C. The product of the digestion process was taken into beaker glass for 24 hours to separate into 3 layers by gravitational force. The top layer is a bitumen-diesel oil solution. The result showed that the performance of SDBS is better than DTAB, this could be because DTAB is positively charged, yet the minerals are negatively charged, so they tend to bind. It can be concluded from this study that the highest percent recovery of bitumen was 72.30 % at a temperature of 90°C with SDBS surfactant concentration of 0.125%, which means anionic surfactant had a better result than cationic surfactant.

Condensing Solvent Processes: In Search of the Production Function

Summary The heavy-oil- and bitumen-recovery process by injection of a pure condensing solvent in a solvent vapor chamber provides an alternative to steam-based recovery techniques such as steam-assisted gravity drainage (SAGD). Because of the lower operating temperature between 40 and 80°C, the process uses a much lower energy budget than a steam process and thus results in significantly reduced greenhouse-gas emissions. This paper describes the route to a successful production function with the physical processes at play and using analytical tools. Physical relationships are derived for the solvent/bitumen (S/B) ratio, the bitumen drainage from the roof of the solvent vapor chamber, and for bitumen extraction from both sides of the solvent chamber by the draining condensed solvent. The fast diffusion of bitumen into this narrow liquid solvent zone is likely subtly enhanced by transverse dispersion. The speed of bitumen extraction from the roof of the solvent vapor chamber is constrained by the gas/oil capillary pressure. Extraction from the side of the chamber is approximately three times faster by the action of the thin gravity-draining liquid solvent film. Several equations are provided to enable creation of a heat balance for this condensing solvent process. Laboratory and field observations are matched, including the rates, the heat balance, and the S/B ratio. The model can explain constrained production performance by identifying the rate-limiting steps (e.g., when insufficient solvent condenses). The model predicts high solvent holdup during the rise of the solvent chamber. A method to estimate this solvent liquid saturation is provided. The S/B ratio depends on injector-wellbore heat losses, the (high) liquid saturation in the rising solvent chamber, and the process properties (operating temperature), reservoir properties (heat capacity, porosity, and oil saturation), and solvent properties (density and latent heat). In the existing body of literature, no satisfactory analytical model was available; this new approach helps to constrain production performance and to estimate solvent and heat requirements. The methods in this paper can be used in the future for subsurface project design and performance predictions.

Effect of mineral fillers on ageing of bituminous mastics

Past research has shown that the ageing process of bitumen is not solely a function of the bitumen type itself, but rather, added effects have been identified attributed to the presence of fillers. Nevertheless, contradicting results exist between the various studies with respect to the implications of fillers on the ageing process of bitumen. The present study aims to develop a better understanding regarding the role of the fillers in the ageing process of bitumen. Bitumen-filler blends (mastics) were prepared, according to a single design protocol, and the resulting materials along with pure bitumen were subjected to accelerated laboratory ageing by means of the pressure ageing vessel. The ageing effect was studied by using dynamic shear tests and infrared spectroscopy measurements. The results revealed the ability of fillers to mitigate age-hardening of bitumen, despite the fact that formation of carbonyls in the bitumen matrix was observed. Oxygen diffusion and adsorption mechanisms were found to be responsible for the observed favourable effect of fillers on the ageing of bitumen, while the gradation, the mineralogical/elemental composition and, to some extent, the specific surface area of the fillers where established as the prevailing fillers’ properties regulating the oxidation mechanisms. The investigation of recovered binders from aged mastics did not lead to any further insight regarding the effect of fillers on the ageing of bitumen. Instead, features were revealed which manifest that the extraction and recovery of bitumen may not be a suitable approach to address the research question of this study.

Modeling of Heavy-Oil Flow with Regard to Their Rheological Properties

With the depletion of traditional energy resources, the share of heavy-oil production has been increasing recently. According to some estimates, their reserves account for 80% of the world’s oil resources. Costs for extraction of heavy oil and natural bitumen are 3–4 times higher than the costs of extracting light oil, which is due not only to higher density and viscosity indicators but also to insufficient development of equipment and technologies for the extraction, transportation, and processing of such oils. Currently, a single pipeline system is used to pump both light and heavy oil. Therefore, it is necessary to take into account the features of the heavy-oil pumping mode. This paper presents mathematical models of heavy-oil flow in oil-field pipelines. The rheological properties of several heavy-oil samples were determined by experiments. The dependencies obtained were used as input data for a simulation model using computational fluid dynamics (CFD) methods. The modeling condition investigates the range of shear rates up to 300 s−1. At the same time, results up to 30 s−1 are considered in the developed computational models. The methodology of the research is, thus, based on a CFD approach with experimental confirmation of the results obtained. The proposed rheological flow model for heavy oil reflects the dynamics of the internal structural transformation during petroleum transportation. The validity of the model is confirmed by a comparison between the theoretical and the obtained experimental results. The results of the conducted research can be considered during the selection of heavy-oil treatment techniques for its efficient transportation.

On the ratio of energy produced to energy injected in SAGD: Long-term consequences of early stage operational decisions

Steam-Assisted Gravity Drainage (SAGD) is a recovery process used to extract bitumen from underground reservoirs. The efficiency of SAGD is determined by the volume of steam injected (reflecting cost and greenhouse gas emissions) relative to the volume of oil recovered (revenue). Another way to look at this relationship is as a ratio of cumulative energy produced to energy injected (EPEI). First described in this study, EPEI ratios offer a novel perspective on SAGD because they reduce the inter-well comparison bias caused by operational choices such as steam temperature, steam quality and well length. There are numerous studies on SAGD from an experimental, analytical or numerical simulation perspective, but all require assumptions and constraints specified in advance, and can only return an approximation of field performance. Studies that work exclusively with field data have typically been used for prediction modeling only. In contrast, this study employs a novel methodology by working within the existing constraints and operational choices of SAGD field wells to infer the number of steam-oil performance relationships present, and how long they last. One by one, we eliminate parameters that cannot cause the performance differences seen in the field using only deductive reasoning and multi-parameter sensitivity analysis, and arrive at possible reasons for the performance relationships found. 1520 SAGD well pairs in Alberta, Canada are used, which is more than 90% of the wells in Alberta over the last 20 years, and to the best of our knowledge, the largest field well set of any SAGD study to date. This comprehensive data set ensures that findings are applicable across the industry. Results reveal a new and surprising finding that the EPEI ratio is set during the first few months on production, and is very difficult to change thereafter. Hence, operators have a short, time-limited opportunity to influence each well's recovery ratio (and therefore its profitability and greenhouse gas emissions). This reflects the importance of process start-up and the first few months after start-up when the near well region of the reservoir is conditioned. Finally, the stability of the EPEI ratio permits a simple, new model capable of predicting cumulative recovery months in advance.

Development of a framework for the assessment of the market penetration of novel in situ bitumen extraction technologies

Greenhouse gas (GHG) mitigation opportunities from emerging in situ mining technologies in oil sands production can play a role in reducing global warming. There is limited research on quantitative assessments of the penetration of emerging oil sands technology in the energy sector. This study addresses this gap by developing a novel framework (MAPL-OET) to assess the market penetration of emerging oil sands extraction technologies. The framework is robust and data-intensive as it combines diffusion models, econometrics models, cost models, and energy-economy equilibrium models. The combined model evaluates the adoption of new energy technologies resulting from carbon price measures and other economic factors, as well as the GHG mitigation potential in the oil sands sector. The accumulated GHG mitigation potential from high carbon and BAU scenarios (i.e., a carbon price of $30/tonne of CO2 in 2030, increasing at a rate of 4%/yr to reach about $105/tonne of CO2) was estimated to be 192.8 Mt of CO2 eq between 2018 and 2050. New extraction technologies also improve average energy intensities by 1.3% annually in the high carbon price scenarios. The developed new framework can help public and private organizations to achieve energy or environmental targets.

Hyperspectral Characteristics of Oil Sand, Part 1: Prediction of Processability and Froth Quality from Measurements of Ore

This study is the first of two companion papers using hyperspectral data to generate predictive models of oil sand ore and froth characteristics as a potential new means for process control. In Alberta, Canada, shallow oil sands deposits are accessed by surface mining and crushed ore is transported to a processing plant for extraction of bitumen using flotation processes. The ore displays considerable variability in clay, bitumen, and fines which affects their behavior in flotation units. Using oil sand ore spanning a range of bitumen and fines characteristics, flotation experiments were performed to generate froth in a batch extractor to determine ore processability (e.g., separation performance) and froth characteristics (color, bitumen, solids). From hyperspectral observations of ore, models can predict the %bitumen content and %fines (particle passing at 44 and 3.9 µm) of ore but the models with highest r2 (>0.96) predict the solids/bitumen of froth and the processability of ore. Spectral observations collected on ore upstream of the separation vessels could therefore offer a first order assessment of froth quality for an ore blend before the ore enters the plant. These models could also potentially be used to monitor and control the performance of the blending process as another means to control the performance of the flotation process.

Heated column experiments: A proxy for investigating the effects of in situ thermal recovery operations on groundwater geochemistry

In situ thermal recovery is utilized extensively for unconventional bitumen extraction in the Cold Lake-Beaver River (CLBR) basin in Alberta, Canada. Public health concerns have been raised over potable groundwater contamination and arsenic release adjacent to these operations within the CLBR basin, which have been linked to subsurface heating of aquifer sediments. Under localized heated conditions, As-bearing aquifer sediments have been shown to undergo water-rock interactions and release constituents at near neutral pH conditions; however, release mechanisms have yet to be conclusively reported. To investigate the hydrogeochemical processes of aquifer heating and solute transport in detail, this study applies a novel heated column design to mimic saturated aquifer materials in contact with a thermal recovery well while constraining flow and geochemical conditions. Two column experiment scenarios were considered using: 1) quartz [SiO2] sand with 0.6 wt% pyrite [FeS2]; and 2) aquifer sediments collected from the CLBR region. Heated temperature gradients between 50 °C and 90 °C were maintained within a 0.6 m section of the 3 m column with a flow rate of one pore volume per week. During heated low oxygen (<3 mg L−1) conditions, results generally show increases in pH, Al, As, B, Mn, Mo, Si and Zn concentrations within and downgradient of the column heating section. Constituent release is primarily attributed to thermal desorption from Fe oxides, clay and silicate mineral dissolution, competitive anion exchange, and increased mixing. Overall results suggest that these mechanisms are responsible for increasing constituent concentrations in groundwater adjacent to in situ thermal recovery operations.

Integrated isotopic and organic geochemical constraints on the depositional controls and source rock quality of the Neogene Kalamaki sedimentary successions (Zakynthos Island, Ionian Sea)

This study investigates the oxygen and carbon (δ18O, δ13C) stable isotope ratios, as well as the organic geochemical features of the 146-m-thick composite Kalamaki section located in the southwest margin of the Hellenic Fold and Thrust Belt (Zakynthos Island). The section includes Late Miocene–Pliocene pre-evaporitic, evaporitic, and post-evaporitic deposits. The obtained bulk geochemical data (Rock–Eval II, bitumen extraction, and fractionation) and biomarker compositions indicate poor–fair source-rock potential predominantly promising for gas production. TOC values indicate the presence of samples that might be of slight interest (0.50–0.95%) in the evaporitic interval and samples that are worthy of further investigation (up to 1.31%) in the pre-evaporitic sequence. The organic matter type (type III kerogen), along with the presence of plant remains (leaves) in the studied deposits reflect the mainly terrestrial origin of the organic material. Tmax and Production Index values further indicate that most of the sediments (138 out of 195 samples) are immature for oil generation and were not under high temperature conditions during burial, whereas 29 of them correspond to the mature oil stage. Oil generation requires deeper burial, which may have occurred offshore in the Ionian Sea. A marine paleoenvironment is indicated that received organic material from both marine and terrigenous sources. Isotopic values imply influence of continental fresh-water inputs in a high salinity, evaporative depositional setting. Furthermore, our findings provide evidence that the climate has favored the development of these source rocks by triggering relative sea-level fall, which in turn enhanced the preservation of organic matter by increasing sea-water salinity and suppressing carbonate deposition.

Structure and Mineralogy of Hydrophilic and Biwettable Sub-2 µm Clay Aggregates in Oil Sands Bitumen Froth

A primary concern of commercial mined oil sands operations is the extent to which one can minimize the content of water and solids contaminants in the solvent-diluted bitumen products resulting from the bitumen production processes. During bitumen production, particles of about 2 µm or less may be responsible for the stabilization of water-in-bitumen emulsions that form during aqueous extraction of bitumen and purification of bitumen froth subsequently during the froth treatment processes, thus leading to the presence of those contaminants in solvent-diluted bitumen products. In this study, we separate and analyze sub-2 µm clay solids isolated from typical bitumen froth fed to a froth treatment plant at a commercial mined oil sands operation. Analytical transmission electron microscopy (TEM) with spatially-resolved energy-dispersive X-ray spectroscopy (EDX) and electron energy-loss spectroscopy (EELS) demonstrate key differences in morphology and composition between sub-2 µm clay aggregates with two distinct wettability characteristics: hydrophilic vs. biwettable particle surfaces. In particular, clay platelets with &lt;200 nm lateral dimensions and thicknesses of a few atomic layers, which are intermixed within coarser sub-2 µm clay aggregates, are found to confer clear differences in morphological characteristics and wettability behaviors to the sub-2 µm clay aggregates. The &lt;200 nm clay platelets found within sub-2 µm biwettable clays tend to arrange themselves with random orientations, whereas &lt;200 nm clay platelets within sub-2 µm hydrophilic clays typically form well-ordered face-to-face stacks. Moreover, in biwettable sub-2 µm clay aggregates, &lt;200 nm clay platelets often cover the surfaces of ~1–2 µm sized mineral particles, whereas similarly sized mineral particles in hydrophilic sub-2 µm clay aggregates, in contrast, generally have exposed surfaces without clay platelet coverage. These biwettable vs. hydrophilic behaviors are attributed to a difference in the surface characteristics of the &lt;200 nm clay platelets caused by toluene-unextractable organic carbon coatings. Nanometer-scale carbon mapping reveals an inhomogeneous toluene-unextractable organic carbon coating on the surfaces of &lt;200 nm platelets in biwettable clays. In contrast, hydrophilic clays have a significantly lower amount of toluene-unextractable organic carbon, which tends to be concentrated at steps or near metal oxide nanoparticles on clay particle surfaces. Mixing surface-active organic species, such as asphaltene, resin, or carboxylic organic acids of various types with inorganic solids can lead to a dramatically enhanced emulsion stability. Consequently, understanding the origin and characteristics of sub-2 µm clay solids in bitumen froth is important to (i) clarify their potential role in the formation of stable water-in-oil emulsions during bitumen production and (ii) improve froth treatment process performance to further reduce contaminant solids in solvent-diluted bitumen products. We discuss the implications of our results from these two perspectives.

Bitumen spreading over an air bubble in water

The spreading of bitumen over an air bubble is one important sub step in the surface mining method of bitumen extraction from oil sands. In this study, the spreading process of the whole bitumen and deasphalted bitumen (maltene) over an air bubble in an aqueous phase was investigated at a macroscopic scale using a high-speed camera. It was observed that in pure water at 50 °C, bitumen spread onto the air bubble while maltene did not. While in simulated process water, both bitumen and maltene spread in a similar pattern. Bitumen spreading had a shorter induction time but a slightly slower spreading rate compared to maltene spreading. It was suggested that the role asphaltene played in bitumen spreading might be to reduce the magnitude of the zeta-potential at the bitumen-water interface and thus the electrostatic repulsion between the bitumen-water and air-water interfaces. Further, the influence of the temperature on the spreading kinetics was studied at a temperature range of 22–73 °C. The results showed that the spreading kinetics increased with increasing temperature and the areal spreading velocity decreased with time for all temperatures. The activation energy for the bitumen spreading was calculated to be 94.7 and 107.9 kJ/mol for 1 and 2 mm2 coverage, respectively. In addition, it was found that the spreading kinetics increased with increasing the toluene amount added into the bitumen. The findings in this work will help better understand the mechanisms involved in the spreading of bitumen over an air bubble in water.

Thermoresponsive Starch for the Flocculation of Oil Sands Mature Fine Tailings.

The reclamation of land and recovery of water from tailing ponds created during bitumen extraction from oil sands is a major technical and environmental challenge. In the current study, thermoresponsive hydroxybutylated (HB) corn starch (HB-CS) and potato starch (HB-PS), with lower critical solution temperatures (LCSTs) ranging from 36 to 45 °C, were examined as flocculants for oil sands mature fine tailings (MFT). The ability of different doses of the HB-CS and HB-PS to flocculate 2 and 10 wt % MFT, prepared by diluting 35 wt % MFT in tap water, in terms of the initial settling rate (ISR), supernatant turbidity (ST), sediment solids content (SSC), and water recovery (WR), was examined at temperatures below and above their LCSTs. The thermoresponsive HB-CS and HB-PS were good flocculants of MFT, and their thermoresponsive behavior was essential for optimal results in that they were considerably more effective in several aspects at temperatures above their LCSTs than below. In terms of ISRs, the HB-PS was a considerably better flocculant than the HB-CS, and this was especially so with the 10 wt % MFT. With the HB-PS, the ISR was lower when using diluted MFT prepared with tap water as opposed to simulated oil sands process water.

Superior Performance of Electrochemical Double Layer Supercapacitor Made with Asphaltene Derived Activated Carbon Fibers

High energy and power values are obtained from fabricated electrochemical double layer supercapacitor (EDLS) cells derived from asphaltene precursors, which are a solid by‐product of bitumen extraction in pentane solvents. Chemical activation, using dry KOH, is used to activate carbon fibers. Chemical activation introduces high specific surface areas (SSAs) into the fiber microstructure by partially etching the carbon. The electrodes are prepared by mixing activated fibers, polytetrafluoroethylene (PTFE), and acetylene black to form flexible electrode films. The unique bimodal pore size distribution with large micropore and mesopore volumes (micropore volume as high as 0.88 cm3 g−1), from chemical activation, generate high‐performance EDLS symmetric cells with capacitance values exceeding 310 F g−1 in aqueous electrolytes and 210 F g−1 in ionic liquid electrolytes (at a specific current of 40 mA g−1). A specific energy of 36 Wh kg−1 at a specific power of 525 W kg−1 is reached in ionic liquid electrolytes.

Role of mineral flotation technology in improving bitumen extraction from mined Athabasca oil sands III. Next generation of water‐based oil sands extraction

AbstractCurrent water‐based oil sands extraction operations are unsustainable, due to their consumption of large quantities of water and energy, generation of large volumes of fluid fine tailings, and rapid expansion of tailing ponds. From a brief analysis of the historical evolution of water‐based oil sands extraction, it has been identified that the use of conventional dispersed air flotation to recover liberated bitumen from oil sand slurries is mainly responsible for the high consumption of water required and the fluid fine tailings generated. Based on mineral flotation principles, a new concept is proposed, whereby water‐based oil sands extraction is simplified as a process of transferring hydrophobic bitumen from hydrophilic surfaces (sands) to hydrophobic surfaces (bitumen carriers). Compared to existing bitumen extraction technologies, bitumen liberation from sands is accelerated by attrition/scrubbing, and the liberated bitumen is recovered from the oil sand slurry by hydrophobic coagulation and heavy media separation. This concept is verified from preliminary laboratory tests for processing (above) average grade oil sands. The water required is significantly reduced from 100 to 150 wt% of the ores processed (as seen in current commercial operations) to 30‐40 wt% of the ores. Virtually no fluid fine tailings are generated, with the potential of eliminating tailing ponds. The tailings produced after bitumen extraction are paste‐like, containing &gt;60 wt% solids, which can be directly disposed of in the mining pit, with little or no further treatment. Future research is needed to justify and refine the concept in large‐scale tests and engineer it into commercial operations.

Determination of optimum polymer dosage for dewatering of oil sands tailings using torque rheology

The slow settlement of fine clay particles in oil sands tailings, the by-product from the process of bitumen extraction from the oil sands ores takes many years, leading to the build-up of an enormous volume of fluid fine tailings in tailings ponds over time, which also gives rise to the biggest challenge in tailings management – poor dewatering rate and long consolidation time. Adding polymers can promote the flocculation of clay particles, and thus, can improve the dewaterability of tailings. However, choosing an ideal polymer dosage for a particular tailings composition or fine-tuning the polymer dosage based on the changes in tailings composition has always been a challenge for the oil sands industry. This study examined the potential of two rheological methods, which are based on torque rheology and measure the rheological parameters (i.e., peak torque and totalized torque) to determine the optimum polymer dosage. When the tailings sample was subjected to a shearing force in a torque rheometer and a polymer solution was injected into that sample simultaneously, the rheometer measured the torque on the impeller. The peak torque and the totalized torque were determined from the torque-time rheogram and their interpretations provided useful information on the strength of the elastic floc network, which was formed after adding the polymer, and also on the degree of flocculation. When the polymer dosage was increased in a stepwise manner and the resulting peak torques and totalized torques were plotted against the corresponding polymer dosages (six polymer dosages in total: 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 g/kg of dry solids), a local decrease was observed in both plots at the dosage of 0.8 g/kg of dry solids, which also corresponded to the shortest suction time determined from the capillary suction time tests and the highest solids settlement obtained from the settling tests at the same dosage. Hence, the results suggested that the measurement of peak torque and totalized torque could be used as a reliable control parameter for the optimization of polymer dosage for the dewatering of tailings.

Comparative Evaluation of Methods for Removing Residual Mineral Fillers during Bitumen Extraction and Recovery Based on FTIR

AbstractAsphalt extraction and recovery are essential steps before characterizing components and properties of aged asphalt binders for recycling the reclaimed asphalt pavement (RAP). To accurately...

Accelerated consolidation of oil sands tailings using an anaerobic bioreactor

Bitumen extraction from oil sands ores generates enormous volumes of fluid tailings in on-site repositories where slow consolidation of suspended solids and porewater recovery hamper tailings reclamation. Here, we demonstrate proof-of-concept where mature fine tailings (MFT) amended with hydrolyzed canola meal incubated in an anaerobic stirred tank reactor (STR) for 8 weeks stimulated indigenous microbes and subsequently accelerated consolidation and porewater recovery in columns and methane (CH4) production in sealed microcosms. Compared to untreated MFT, 5 weeks of STR treatment enhanced consolidation (solids increased from 23.2 to 39.4 wt%) and expression of porewater (four-fold more porewater in one-third the time), and up to 30-fold more CH4. The microbial community shifted towards diverse fermentative taxa and different methanogens. This approach suggests a potential technology to reduce tailings pond volumes and increase water use efficiency, decreasing freshwater demand in the bitumen extraction process while converting low-value substrate to CH4 for on-site utilization.

Destabilization of bitumen-coated fine solids in oil through water-assisted flocculation using biomolecules extracted from guar beans

Non-aqueous extraction (NAE) of bitumen from oil sands has been gaining great attention from both the industry and academia as an alternative to the water-based extraction. A fine solids removal step is important for a NAE process in order to obtain high-quality bitumen product, which, however, remains a great challenge to reduce the fine solids content to the desired level. Here, we introduce a strategy of destabilizing the bitumen-coated silica particles in toluene with the addition of water and biomolecules extracted from Cyamopsiste tragonolobuosr L. Taup., i.e., high molecular weight guar gum (HGG) and low molecular weight guar gum (LGG), respectively. By virtue of sedimentation tests and focused beam reflectance measurement analysis, we demonstrate that the introduced water droplets modified with these biomolecules can facilitate the settling of the solid particles in toluene although the underlying mechanisms differ between these two biomolecule cases. Specifically, in the case of LGG, the added water droplets with the interfacial amphiphilic LGG can strengthen the attachment of solid particles from bulk toluene to the LGG surface. This research work provides useful insight into the development of effective approaches for destabilization and removal of bitumen-coated fine solids from NAE bitumen.

Of pipe dreams and fossil fools: Advancing Canadian fossil fuel hegemony through the Trans Mountain pipeline

This article uses the Trans Mountain pipeline expansion project as a Canadian case study to critically examine and showcase one instance of the hegemony of fossil fuels in the era of global heating. The present Canadian federal government, under the leadership of Liberal Prime Minister Justin Trudeau, is seeking to simultaneously position itself as a global climate leader while supporting the exploitation of Canada’s extensive bitumen oil reserves. We apply a critical discourse analysis to seven speeches given between 2016 and 2019 by two members of the Canadian federal government on the Trans Mountain pipeline expansion project to interrogate how the government discursively reconciles these two contradicting stances. Our analysis yields three main results: 1) the government naturalizes bitumen as a substance, culturally and politically hindering the capacity for Canada to move beyond it, 2) the extraction of bitumen is portrayed as an imperative, implicating the overall economic and social health of Canada and justifying the government’s use of coercion and 3) appeals to climate change and action are paradoxically subsumed into the argument for bitumen extraction. Overall, we argue, this discourse depoliticizes the social and environmental struggles surrounding bitumen extraction. It functions to maintain the hegemony of fossil fuels in the era of global heating, thus foreclosing on possibilities of leaving the fuels in the ground while reinforcing Canadian bitumen’s multi-dimensional carbon lock-in.

Waste Containment Ponds Are a Major Source of Secondary Organic Aerosol Precursors from Oil Sands Operations.

The surface mining and bitumen extraction of oil sands (OS) generates over one million barrels of heavy oil each day in the Alberta Oil Sands Region of Canada. Recent observations suggest that emissions from OS development contribute to secondary organic aerosol (SOA) formation, but the chemical composition, mass fluxes, and sources of those emissions are poorly delineated. Here, we simulated OS extraction and used comprehensive two-dimensional gas chromatography to quantify and characterize direct air emissions, bitumen froth, residual wastewater, and tailings components, ultimately enabling fate modeling of over 1500 chromatographic features simultaneously. During the non-ice cover season, tailings ponds emissions contributed 15 000-72 000 metric tonnes of hydrocarbon SOA precursors, translating to 3000-13 000 tonnes of SOA, whereas direct emissions during the extraction process itself were notably smaller (960 ± 500 tonnes SOA yr-1). These results suggest that tailings pond waste management practices should be targeted to reduce environmental emissions.