Browsing by Author "Nassar, Nashaat N."
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Item Open Access Adsorption Kinetics and Diffusion of Asphaltenes from Dynamic Interfacial Tension Data(2020-03-23) Mohammadi, Mohammadjavad; Hassanzadeh, Hassan; Sarma, Hemanta Kumar; Nassar, Nashaat N.Recently, solvent-aided processes have been implemented to improve oil recovery and reduce greenhouse gas emissions. Most of the research on thermophysical properties has focused on the dilution effect of solvents while their effect on the interfacial tension (IFT) has not been studied in detail. This thesis focuses on three aspects of interfacial phenomena including (i) adsorption kinetics of asphaltenes, (ii) development of a model to improve the estimation of self-diffusion coefficient and adsorption kinetics of asphaltenes, (iii) measurements of dynamic IFT of n-C5/ and n-C7/bitumen. The diffusion and adsorption kinetics of asphaltenes in toluene and various heptol solutions have been studied using IFT data obtained from pendant drop. The dynamic IFT at asphaltenes concentrations of 0.001 to 1 wt % was measured and the Ward-Tordai model is employed to estimate the diffusion of asphaltenes. The results show that while the diffusion coefficient decreases with the concentration of asphaltenes, it increases at a higher volumetric ratio of n-C7. Moreover, higher concentrations of asphaltenes and volumetric ratios of n-C7 improve the adsorption of asphaltenes leading to a further reduction in IFT. To improve the predictions of the Ward-Tordai model, a new analytical model was developed to estimate the self-diffusion coefficient and the adsorption kinetics of asphaltenes. The developed model along with the Frumkin (or Langmuir) isotherm is able to reproduce the experimental dynamic IFT data with acceptable accuracy. The IFT of n-C5/ and n-C7/bitumen at a temperature range between 298.15 and 413.15 K and a pressure of 3.45 MPa at different concentrations of n-C5 and n-C7 was measured. The results reveal that the IFT reduction is non-monotonic and does not follow the common linear trend. It was observed that both systems demonstrate partitioning of surfactants at the oil/water interface at a higher concentration of solvents. The results presented in this thesis improve our understanding of adsorption kinetics of asphaltenes at the oil/water interface and find applications in the design and optimization of oil/water separation and solvent-aided recovery of bitumen. In addition, the developed model finds applications in the estimation of diffusion and adsorption kinetics of surfactants using dynamic IFT data.Item Open Access Behaviour and Interaction of Calcium and Potassium during Catalytic Gasification(2019-04-29) Arnold, Ross Alexander; Hill, Josephine M.; Ponnurangam, Sathish; Nassar, Nashaat N.Gasification is a technique for the conversion of carbon sources such as biomass into syngas. Catalysts reduce the necessary gasification temperature and increase the reaction rate. Potassium is more active than calcium, but calcium addition has been shown to promote the rate of potassium-catalyzed gasification. The mechanism by which this promotion occurs was not well-understood. This thesis used switchgrass and biosolids as carbon feeds, as well as ash-free carbon black to isolate the effects of potassium and calcium. Calcium was found to promote potassium both indirectly and directly. Indirectly, calcium served as a sacrificial species, reacting with aluminosilicates, limiting the sites on which potassium could deactivate by forming catalytically inactive potassium aluminosilicates. X-ray diffraction demonstrated calcium aluminosilicate formation. Directly, calcium carbonate formed a low-melting eutectic phase with potassium carbonate above 820 °C, demonstrated by differential scanning calorimetry and scanning electron microscopy. The eutectic increased the diffusivity of potassium, facilitating the movement of potassium between active carbon sites, increasing the gasification rate below 40% conversion. Above 50% conversion, the eutectic phase inhibited the gasification rate by hindering CO2 diffusion to the carbon. Activation energy calculations showed that diffusion became the rate-determining step at higher conversions. Two mixing methods, hand-mixing and ball-milling, were compared as to their effect on potassium- and calcium-catalyzed gasification. The diffusivity of potassium was high enough that increased dispersion by ball-milling with carbon black did not increase the reaction rate compared to ball-milling the components separately. Ball-milling calcium and carbon black together greatly increased the gasification rate when compared to ball-milling the components separately. The lower diffusivity of calcium compared to potassium explained its lower activity. As the reaction progressed, calcium sintered and hindered CO2 access to the carbon, which reduced the reaction rate even below uncatalyzed carbon black. Reducing the calcium particle size prior to gasification minimized inhibition in addition to increasing catalytic surface area. The experimental results helped to better understand the individual catalytic behaviours of calcium and potassium during gasification, as well as their interactions. The results will help in the design of gasifiers for carbon feeds containing potassium and calcium.Item Open Access Conversion of Petroleum Coke into Valuable Products using Catalytic and Non-Catalytic Oxy-Cracking Reaction(2018-04-20) Manasrah, Abdallah Darweesh; Nassar, Nashaat N.; Chen, Shengnan; Kopyscinski, Jan; Pereira Almao, Pedro; Thurbide, Kevin B.Every year millions of tons petroleum coke (petcoke) is generated as a by-product from bitumen and heavy oil upgrading due to the increasing demand in energy. Petcoke is a carbonaceous solid consisting of polycyclic aromatic hydrocarbons with low hydrogen content, derived from the processing of oil sands and oil refineries. The upgrading and treating of petcoke typically include thermal techniques such as gasification and combustion. However, several challenges limit the effectiveness of these conventional processes such as sulfur and CO2 emissions as well as high energy and costs associated with low efficiency. Therefore, finding an alternative, efficient, environmentally-friendly and cost-effective technology to treat these massive amounts of petcoke is needed. In this study, an oxy-cracking technique, which is a combination of oxidation and cracking reactions, is introduced as an alternative approach for petcoke utilization. This oxy-cracking takes place in basic aqueous media, at mild operation temperatures (170-230 oC) and pressures (500-600 psi). The oxy-cracking reaction mechanism was investigated using Quinolin-65 (Q-65) as a model molecule mimicking the residual feedstocks. Theoretical calaculations along with experimental reaction were carried out on Q-65 to explore the reaction pathways. Consequently, several operating conditions on petcoke oxy-cracking were investigated, such as temperature, oxygen pressure, reaction time, particle size and mixing rate to optimize the solubility and selectivity of oxy-cracked products. To enhance the oxy-cracking reaction conversion, an in-house prepared copper-silicate catalyst was introduced and characterized using BET, SEM, FTIR and XRD techniques. The oxy-cracking technique successfully converted the petcoke into valuable products, particularly humic acids analogs with other functional groups such as carboxylic, carbonyl, and sulfonic acids, as confirmed by FTIR, XPS and NMR analyses, in addition to minimal emission of CO2. Interestingly, based on the experimental findings, the metal contents in the obtained oxy-cracked products are significantly lower than that in the virgin petcoke. Consequently, the heating value and oxidation behaviour of the oxy-cracked products was investigated using TGA. These results showed that the oxy-cracked petcoke is easier and faster to oxidize compared to the virgin petcoke, suggesting that the oxy-cracked petcoke could be an alternative-clean fuel for power generation.Item Open Access Development of Sustainable Nanosorbcats Based Technology for Hydrocarbons and Organic Pollutants Recovery from Industrial Wastewater(2017) El-Qanni, Amjad; Nassar, Nashaat N.; De Visscher, Alex; Hassanzadeh, Hassan; Thurbide, Kevin; Hussien, Muataz A.The worldwide shortage of fresh water and the huge competing demands from a variety of users stimulate an urgent need for finding innovative wastewater treatment processes. For instance, oil sand process-affected waters pose a critical energy issue and an environmental alert since these effluents are toxic to many aquatic and non-aquatic living organisms. In addition, some of these pollutants are non-biodegradable and, thus they will exist for a long time in the environment, which may cause a real challenge to the conventional wastewater treatment processes. Accordingly, economically viable and environmentally sound techniques are needed. The application of nanoparticle technology as adsorbents and catalysts (nanosorbcats), whether as a standalone or as an enabling technology, in cleaning up wastewater has recently received great attention. This is because of the unique chemical and physical properties of nanoparticles in comparison with their counterparts, which make them superior to the conventional adsorbent/catalysts. Hence, in the present study, the employment of newly in-house prepared silica-embedded nanosorbcats functionalized with active species of NiO and MgO for cleaning up produced water was investigated. A facile co-precipitation synthesis route was used to prepare those nanosorbcats, which were characterized by different characterization techniques like XRD, BET, HRTEM, CO2-TPD, and IR spectroscopy. The prepared nanosorbcats were then employed for the adsorptive removal of cationic, anionic, and organic acid model molecules. Computational modeling, DFT calculations, and MD simulations of the interaction between the model molecules and the surfaces of prepared nanoparticles were carried out to get more mechanistic insights into their adsorptive behaviors. Eventually, these nanosorbcats were successfully used to treat real SAGD produced waters within an experimental scheme including three processes, namely; oxy-cracking, packed-bed adsorption, and catalytic steam gasification.Item Open Access Development of Upflow Aerobic Granular Sludge Bioreactor (UAGSBR) for Treatment of High-strength Organic Wastewater(2019-04-02) Hamza, Rania Ahmed Sayed Eid; Tay, Joohwa; Hettiaratchi, Joseph Patrick A.; Koshnazar, Rahil; Nassar, Nashaat N.; Liu, YangIndustrial wastewater, typically referred to as high-strength wastewater, is a major source of water pollution due to its elevated organic content. High-strength organic wastewaters are characterized by chemical oxygen demand (COD) concentrations greater than 4000 mg/L. The effluents of these industries need to undergo biological treatment to remove the organic matter. However, conventional biological treatment processes fail to stabilize high-strength wastewater to regulatory limits. Aerobic treatment processes are not economically feasible for the treatment of high-strength organic wastewater. Anaerobic processes suffer from low growth rate of the microorganisms, high sensitivity to toxic loadings, fluctuations in environmental conditions, and require post-treatment to bring the water quality within regulations. This work aimed at developing an upflow aerobic granular sludge bioreactor (UAGSBR) to provide a downstream effective treatment process in order to combine the benefit of anaerobic digestion (i.e., biogas production) with the benefit of aerobic treatment (i.e., better removal of organics). Moreover, it is hypothesized that effluent of anaerobic treatment provides a solubilized organic matter suitable for subsequent aerobic treatment because of its reduced organic strength and enhanced amounts of nitrogen and phosphorus. The combined system will overcome the limitations of both anaerobic and aerobic systems, such as long treatment duration and low stability due to rapid bacterial growth, respectively. In this project, biogranulation, formed by the self-immobilization of microorganisms, was employed as a novel technology in an upflow semi-pilot-scale bioreactor. These granules are dense microbial communities packed with different bacterial species, which can achieve rapid treatment for high volumes of wastewater in a smaller footprint when compared to conventional biomass. Mechanisms of granule formation and stability considering influential factors such as system start-up, organic loading rate, food-to-microorganisms ratio, and nutrients addition were examined. Treatment efficiency, assessed in terms of organics and nutrients (nitrogen and phosphorus) removal, was above 90%. The UAGSBR provides a compact system for high-strength organics wastewater treatment (at 20-30% spatial footprint of a conventional plant). Item Open Access Effects of Nanoparticles on Thermal Conductivity Enhancement in Different Oils(2018-12-11) Mustafin, Robert; Nassar, Nashaat N.; Hejazi, Seyed Hossein; Hassanzadeh, Hassan; Chen, ShengnanIn recent years, depleting amount of energy extracted from conventional oil reservoirs, together with an industrial shift towards heavy oil/bitumen recovery has become more pronounced. Today, steam injection heating methods are primary used by industry for heavy oil/bitumen recovery. However, these methods have a detrimental effect on the environment, high-energy consumption and limited application, especially for the deep reservoirs. Therefore, there is a high priority to investigate alternative approaches. To date, the most progressive alternative technique that has proven its potential during pilot-plant tests is “Nanocatalytic in-situ heavy oil/bitumen upgrading via hot-fluid injection,” developed by Catalysis and Adsorption for Fuels and Energy (CAFE) research group at the University of Calgary. Nevertheless, continual improvement of the technique is of utmost importance. Therefore, this study is intended for proposal of new nanofluid system suitable for high-temperature injection into the reservoir with consecutive heavy oil/bitumen upgrading. New nanofluid system posses enhanced thermal properties represented by thermal conductivity, which is one of the critical parameters that affects the performance of oil recovery. Experimental studies on the thermal conductivity of oil-based medias were conducted and the effects of particle type, solid mass fraction, particle size distribution and temperature augmentation were evaluated. The results showed that the thermal conductivity values of nanofluid systems is substantially higher than that of the base fluids. Thermal conductivity enhancement trend was found to increase with increase in particle dosage. The highest thermal conductivity enhancement was determined for nanofluids with smaller average hydrodynamic particle size. Moreover, presence of chemo-physical interactions between nanoparticles and base fluid led to additional intensification of thermal conductivity. Also, the temperature augmentation in a range from 80 to 110°C exhibited a positive effect on thermal conductivity enhancement of vacuum residue-based nanofluid system. The present study holds great promise for the application of nanoparticle technology in enhancing heavy oil upgrading and recovery.Item Open Access Enhancing Tribological Properties of Metallic Sliding Surfaces through Micro Multi-texturing Techniques(2019-07-10) Reséndiz-Pérez, Jaime De Jesús; Park, Simon S.; Egberts, Philip; Park, Simon S.; Egberts, Philip; Cheng, Yufeng Frank; Ramírez Serrano, Alejandro; Nassar, Nashaat N.; Dunn, Alison C.Friction reduction is important for minimizing energy loss and improving the life of sliding components. Surface texturing is considered an effective way to control the wear and friction on these components. In this research, textured surfaces were created on aluminium workpieces using the tilted micro end milling technique. A flat end mill was used to generate asymmetric dimples. A different series of symmetric dimpled surfaces were also machined using a single crystal diamond cutter. Cutting forces were modelled and compared with the experimental results. On the symmetric dimpled surface, a multi-scale texture process was carried out on the dimples to create a smaller scale roughness through a High-Velocity Abrasive Machining process. A reciprocating tribometer, based on a piezoelectric table dynamometer and a hemispherical ruby counter surface, was used to evaluate friction coefficients under both dry and lubricated sliding conditions. Asymmetric dimples exhibited directional friction effects. For multi-scale textured surfaces, it has been observed a greater reduction in the friction coefficient under lubricated conditions when compared with symmetrical dimples. To gain insight into the mechanism of friction reduction for these surfaces, a series of 2D simulations were performed. These simulations showed that the mechanism of friction reduction is attributed to the ability of dimples to increase the pressure of the lubricant in the contact region resulting from the fluid flow between the sliding surfaces. Moreover, a substantial decrease in the depth of the dimples on worn surfaces was observed, suggesting that entrapment of wear particles within the surface texture features may also influence the measured friction coefficient. Analysis of the wear track depth showed that surface texturing also has a beneficial influence on the calculated Archard wear coefficient.Item Open Access Influence of Dual Surface Functionalized Nanoparticles on Flocculation and Dewatering of Kaolinite Suspensions(2022-04-25) Karaki, Taha; Nassar, Nashaat N.; Lu, Qingye (Gemma); Hu, JinguangMature fine tailings (MFT) generated from oil sands extraction processes in Alberta are the most challenging mine tailings to settle and dewater. MFT typically contains almost 35 wt% of fine clays covered by a layer of residual bitumen. These clays are essentially composed of kaolinite mineral (<2 microns in size), which represents over a third of the solid composition of MFT. This thesis investigates the effect of nanoparticle grafted with dual polymer (i.e., hydrophobic and hydrophilic species), termed as nano-flocculants, on enhancing the flocculation and consolidation of kaolinite suspensions. Four different types of eco-friendly nanoparticles were initially synthesised, using the hydrothermal method, and subsequently functionalized with polyacrylamide (PAM) and sodium lauryl sulfate (SLS) at room conditions. The flocculation and dewatering performance for each nano-flocculent was evaluated by measuring the initial settling rate (ISR), supernatant turbidity, capillary suction time (CST) and specific resistance to filtration (SRF).Results showed that the initial settling rate of kaolinite increased from 0.45 m/h to 20.4 m/h after introducing the dual surface functionalized nanoparticles. It appears that ISR is nanoparticle specific, where iron-based nanoparticles showed the highest ISR owing to their higher density and the capability of grafting significant amounts of PAM and SLS compared with other types of nanoparticles. It appears that surface activity of these nanoparticles allowed grafting more segments of PAM/SLS, which provided additional bridging and capturing sites of the suspended kaolinite particles. The effect of coexisting pollutants, e.g., bitumen and cations, on kaolinite settling and interactions with nano-flocculants were comprehensively addressed. As for the dewatering study, results showed that adding 3000 mg/L of nano-flocculants reduced the CST value to as low as 17 s and SRF to as low as 0.16×10^10 m/kg, compared with 90 s and 1.4×10^11 m/kg for conventional flocculants, respectively. It appears that the presence of hydrophobic agent (SLS) bonded to the PAM backbones greatly enhanced the dewatering performance of nano-flocculants. Settling and consolidation model (S-model) was modified and successfully used to describe the flocculation and dewatering behavior of the applied nano-flocculants using phenomenological model parameters. The proposed model presented a straightforward approach to predict and capture all characteristics of the settling and consolidation performance for each nano-flocculants.Experimental and modeling results obtained from this study provide clear insights into the phenomenon that governs the synergistic effects of nanoparticle grafted with dual polymer on flocculation and subsequent dewatering of kaolinite-based suspensions.Item Open Access Integrating Direct Air Carbon Capture and Microalgae-Based Bioenergy Production(2020-01-31) Caceres Falla, Maria Camila; De La Hoz Siegler, H.; Kibria, Md Golam; Nassar, Nashaat N.Carbon dioxide (CO2) emissions are one of the main causes of air pollution and global climate change; consequently, current research focuses on finding ways to reduce CO2 emissions or reusing them. Additionally, the increasing energy demand has provided the impetus for developing alternative energy sources; with an emphasis on renewables. Bioenergy from microalgae has captured the attention of researchers given that they efficiently convert CO2 directly captured from the air into energy. Extrapolating the concept of how algae obtain the carbon source to produce energy, this thesis main goal is to examine the feasibility of using direct air capture as a mean for replenishing CO2 supply in the medium used for microalgal cultivation, converting the CO2 harvested from the atmosphere into biomass at high pH and high alkalinity conditions. The proposed capture unit is a packed absorption column, and was studied both from an experimental and modeling point of view. The laboratory-scale unit was able to capture ~50% of the CO2 in the inlet stream using the spent algal cultivation medium. Experimental results were used to adjust model parameters and to further validate model predictions. After the experimental validation, this model was successfully used to design a unit that can meet the desired CO2 requirements for microalgal cultivation. The column specifications include design parameters, such as packing, and the overall column dimensions to fulfill the specified demand. The model is able to predict, with a 98% reliability, the column’s performance for variations in process conditions which include pH level, air temperature, humidity, and CO2 concentration in the inlet. This model considers the actual rates of multicomponent mass transfer, heat transfer and chemical reactions which are taken into account simultaneously. Pressure drop along the absorption column was ~1% of the inlet pressure, which translates in reduced energy consumption. Water losses in the air capture unit were estimated to be under 1% of the water circulating in the system, which is significantly less than the water losses estimated for traditional open pond cultivation systems.Item Open Access Investigation of friction reduction in high turbulent flows by different polymer additives(2021-09) Bakir, Mohammed; Nassar, Nashaat N.; Natale, Giovanniantonio; Hugo, Ronald JIndustrial applications such as hydraulic fracturing require large flowrates and pressure resulting in high energy consumption and costs. To mitigate these concerns, dilute concentrations of friction reducers (i.e., polymers, and surfactants) are used to reduce the pressure drop (therefore friction) in the solvent operating under turbulent flow conditions resulting in lower energy consumption, and costs. These applications are also present in other industrial applications such as marine transportation, firefighting, and heating & cooling systems, where friction reducers have been employed to reduce the friction by over 80% in these industrial processes. In this study, the friction reducing performance of a commonly used friction reducer, Partially Hydrolyzed Polyacrylamide (HPAM), was investigated in a friction flow loop. While HPAM is inexpensive, environmentally friendly and an effective friction reducer in fresh water, HPAM degrades irreversibly due to high flow rates (shear), and salts present in brine. As a result, HPAM was mixed with polyethylene oxide (PEO), and xanthan gum (XG) to improve the friction reduction (FR) peak performance, shear stability and salt-tolerance of HPAM., The novelty of this work is to analyze the effects and mechanisms of friction reducing polymer mixtures in brine solutions and high turbulent flows similar to what is present in the field. The interesting finding was that HPAM-PEO and HPAM-XG mixtures improved the FR performance of HPAM in brine at a greater rate than in tap water. It was investigated that brine solutions enhance the likelihood of intermolecular interactions of the polymer mixtures than in tap water resulting in the improved FR performance; the correlation between the FR and the intermolecular associations between HPAM with PEO and XG has not been reported in literature. Evidence of intermolecular interactions between HPAM with PEO and XG was found using Fourier transform infrared spectroscopy (FTIR). In addition, two degradation models were used confirming that XG improves the degradation resistance of HPAM. Lastly, it was shown that PEO, and XG reduce the consumption of HPAM required achieve an optimal FR performance, thus transitioning towards alternate, eco-friendly FR additives.Item Open Access Investigation of the Interaction between Nanoparticles, Asphaltenes, and Silica Surfaces for Inhibition and Remediation of Formation Damage(2021-07-19) Montoya, Leidy Tatiana; Nassar, Nashaat N.; Chen, Shengnan (Nancy); Hassanzadeh, Hassan; Moore, Robert Gordon; Khoshnazar, Rahil; Dejam, MortezaWorld population growth, increment in industrialization and motorization of the world, increment in technical development and living standards are some factors that keep contributing to the increasing of the global energy demand. Therefore, it is necessary to find alternative sources to meet these demands. Considering renewable and non-renewable energies, there is still an interest in enhancing the oil and gas recovery, because its reserves are considerable in terms of the energy supply. Nevertheless, there are several challenges facing the oil production related with asphaltenes, and it requires a knowledge on the deposition mechanism of this fraction of oil and the factors influencing it, since they are important in many parts of the production processes, and refinery catalyst deactivation, causing significant production losses. Accordingly, appropriate mitigation techniques, for surfaces exposed to asphaltenes or operating conditions, can be identified. It has been demonstrated that the use of nanoparticles may improve the mobility of oil. This is because nanoparticles may enhance wettability alteration or disaggregation of asphaltene aggregates. Accordingly, this study will help to understand the interactions between asphaltenes and nanoparticles, at the beginning using computational modeling and model molecules for resins and asphaltenes. It is important to consider that asphaltenes are not the only component in the oil and the adsorbent affinity is affected for it. Then, naturally derived silicate-based nanoparticles were used to investigate their performance on wettability alteration and what is the mechanism involved in continuous flow over pre-adsorbed/deposited asphaltene SiO2 sensors; this was achieved using a QCM-D, contact angle measurements and AFM images. The results showed that depending on the asphaltenes aggregation stage, the nanoparticles interact differently with them. Finally, basic silicate-based nanofluids were tested at reservoir conditions. The main results indicated that low salinity was the most promising formulation for inhibiting/remediating formation damage caused by asphaltene precipitation/deposition. Relative permeability curves showed a shift to right after the injection of nanoparticles, confirming the role of nanoparticles on wettability alteration. Oil recovery factor was also increased when using nanoparticles to inhibit/remediate the damage. Therefore, silicate-based nanoparticles are good candidates to use as treatment for asphaltene formation damage.Item Open Access Life Cycle Greenhouse Gas Emissions of Western Canadian Natural Gas and a Proposed Method for Upstream Life Cycle Emissions Tracking(2019-05-28) Liu, Ryan Edward; Bergerson, Joule A.; De La Hoz Siegler, H.; Nassar, Nashaat N.Natural gas (NG) produced in Western Canada is a major source of Canada’s energy and emissions portfolio. However, there is only limited understanding of the sources and drivers of greenhouse gas (GHG) emissions. To assess the climate impact of NG in Western Canada, a life cycle assessment (LCA) of a hypothetical 1 billion cubic feet per day LNG production facility with upstream operations based on Seven Generation Energy Ltd.’s (the ‘company’) operations is performed using a model available through the National Energy Technology Laboratory (NETL) which has been modified to adjust for provided company data. Using this case study as an example, the completeness of publicly available GHG emissions data on oil and gas operations in Western Canada to estimate their upstream GHG footprint is examined. The LCA of company-sourced natural gas resulted in a GHG emissions intensity of 410-477 gCO2e/kWh for electricity production (domestic use and LNG to China) and 87 gCO2e/MJ heat for district heating in China. These results indicate that the company’s natural gas produces lower life cycle GHG emissions than the average emissions from natural gas production in the US, AB, and BC, and emit 370-640 gCO2e/kWh fewer emissions compared to coal. The low emissions intensity is achieved through mitigation methods implemented by the company including but not limited to utilizing air-driven pneumatic devices, regular leak detection and repair (LDAR), inherent reservoir characteristics. The upstream GHG emission intensity of the company’s NG production is estimated to be 3.1 - 4.0 gCO2e/MJ compared to current estimates of BC emissions intensities of 6.2 - 12 gCO2e/MJ NG and the US average of 15 gCO2e/MJ. The analysis reveals that compared to US studies, public GHG emissions data for Western Canada have significant data aggregation and/or missing data (gaps) and satisfy only 50% of the modified NETL model inputs. Company provided data close a majority of these gaps, satisfying all data inputs for pre-production, production, and processing (~80% of model inputs) but not transmission as the Company does not operate NG transmission pipelines. To better inform the public of GHG emissions in Alberta and BC, the thesis recommends that the provinces reduce its reliance on aggregate data reporting and develop a data collection and for public release template based on the modified NETL model. In this context, the thesis proposes a data collection template to facilitate better GHG emissions estimates and provide insight to potential mitigation strategies.Item Open Access Naturally Derived Silicate-based Nanoparticles for Enhanced Oil Recovery in Sandstone Reservoirs(2020-11-16) Sagala, Farad; Nassar, Nashaat N.; Hassanzadeh, Hassan; Maini, B. B.; Dong, Mingzhe; Tutolo, Benjamin M.; Poitzsch, Martin E.Chemical enhanced oil recovery (C-EOR) is a commonplace method used extensively to extract trapped oil with reasonable recovery percentages during the tertiary stage of oil production. Besides, new technologies have emerged and have been tested for their efficiency to increase oil recovery after the conventional primary and secondary recovery techniques. Nanoparticles as a branch of nanotechnology are emerging as a new alternative technology for C-EOR and recovery processes of trapped oil. Tunable silicate-based nanoparticles as nanofluids can be injected into the reservoir at the secondary/tertiary stage as a standalone or when coupled with some other existing conventional techniques to enhance the recovery of the remaining trapped oil. Nanofluids can be introduced into the reservoir at a typical chemical flood configuration to produce more oil by changing the geochemical properties of the reservoir such as wettability, disjoining pressure, IFT etc. In the first phase of this study, silicate-based nanoparticles were synthesized, then partially altered their functionality by anchoring various agents such as silanes and polymers, generating various forms of functionalized silicate-based nanoparticles. Characterization techniques, such as scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), dynamic light scattering (DLS), and zeta potential were conducted for the produced nanoparticles to confirm their surface identity, functionality, stability, and morphology. The EOR performance was investigated by mainly interfacial tension (IFT), contact angle, spontaneous imbibition, relative permeability measurements, conducting aggregation experiments and displacement tests using Berea sandstone cores at reservoir conditions. Results showed that the synthesized nanoparticles either alone or when integrated with existing conventional techniques can recover substantial trapped oil at the tertiary stage. Furthermore, a considerable improvement of oil recovery was achieved by combining silicate-based nanoparticles with low salinity water flooding. Subsequently, using silicate-based nanoparticles as EOR agents provides a prospect of being applied in EOR.Item Open Access Novel Combination of Cerium and Nickel in Ce-Ni-MFI Catalysts in Low-Temperature Water Gas Shift Reaction(2019-01-19) Alamolhoda, Sarah; Pereira-Almao, Pedro R.; Nassar, Nashaat N.; Maini, B. B.; Moore, Robert Gordon Gord; Salahub, Dennis R.; De Lasa, Hugo I.Increasing demand for clean fuel has raised interest in the water gas shift reaction (WGSR), a well-established industrial technology that produces hydrogen as a clean, highly-efficient and recyclable fuel. This reaction is exothermic and reversible; therefore, catalysts are used to reduce the operating temperature and improve the performance of the process. The synergistic effect between nickel (Ni) and cerium (Ce) as catalysts in the WGSR is well-known. The cost of these metals is continuously increasing, as they are widely-used in industry, hence making the advent of novel low percentage and well dispersed nickel-cerium catalysts a necessity. In this research, novel and highly-efficient nickel-cerium catalysts were synthesized exhibiting several important features. First, low percentages of nickel and cerium (less than 3%) were incorporated in a crystalline silica framework (MFI). Second, the catalysts showed a high yield in the low-temperature WGSR (453 K – 593 K). Third, the catalysts showed high selectivity, hence the undesired produced methane was negligible. Last but not least, the catalysts benefit from simpler preparation, in which impregnation of metals, drying, and further calcination were not necessary. The produced solids were characterised by several techniques including x-ray diffraction (XRD), temperature-programmed reduction or oxidation (TPR-TPO), temperature-programmed desorption (TPD), scanning electron microscopy and energy dispersive X-ray analyzer (SEM/EDX), inductively-coupled plasma mass spectrometry (ICP-MS), and N2 physisorption. Ce-MFI solids were inactive at lower temperatures. However, Ni-MFI solids catalyzed the reaction, and more nickel led to higher activity. The synthesized Ce-Ni-MFI catalysts synergistically accelerated WGSR, and catalysts with similar mass percentage of cerium and nickel outperformed others. Furthermore, the maximum reduction temperature of these solids was reduced, confirming their higher performance in the WGSR. Moreover, the O-exchange capability of the solids was investigated using isotopic water H218O. Cerium was more active than nickel in water splitting. However, their combination outperformed the single metal solids in water splitting. Finally, to design a proper reactor for the WGSR using the proposed catalysts, kinetic expressions were determined to predict the reaction rate. Toward this goal, first, mass transfer limitations were eliminated. Then, several experiments were performed at different temperatures, and with different molar ratios of the reactants (CO and H2O). The effects of these changes on the reaction rate were analyzed, and the kinetic expression was obtained using an empirical approach, a microkinetic method, and an artificial neural networks technique. The calculated reaction rate was in good agreement with experimental results and the microkinetic study confirmed the cooperation of Ce and Ni for the dissociation of water.Item Open Access Novel mature fine tailings treatment using colloidal silica particles(2018-12-17) Shamim, Shahrukh; Trifkovic, Milana; Hill, Josephine M.; Nassar, Nashaat N.The oil sands tailings industry currently employs a vast array of technologies ranging from flocculation/coagulation to traditional mechanical techniques such as filtration or centrifugation. The performance of the treatment options, alone or in combination, have proven to be challenging for practical implementation with reliable results in terms of sediment compactness levels, water release, and strength development due to unpredictable tailings composition, solids content, and clay activity levels. As a new and promising treatment route, the application of silica particles for tailings clay densification has not been studied in depth and governing treatment mechanisms are unknown. The study presented here focused on understanding the effects of addition of monodisperse bare colloidal silica particles on the structural and rheological properties of highly stable mature fine tailings (MFT) with the end goal of colloidal suspension destabilization and subsequent water release. A simple mixing regime involving addition of CSPs and NaOH to the MFT at different stages was developed. Controlled experiments showed synergistic effect of CSPs and NaOH in the destabilization and flocculation of MFT over the course of a day whereas the addition of CSPs or NaOH alone did not cause the same effect. Final pH of the suspension was fixed at 10 which triggered the dissolution of ionic species from the CSPs and clay particles thereby causing polycondensation reaction and produced strong aggregates. The characterization by confocal microscopy and SEM as well as rheometry confirmed the presence of three different layers having varying compaction levels and strength with the bottom layer being the strongest and readily reclaimable. Higher dosage of CSPs in the MFT resulted in the formation of a bi-layered structure in the sediment sludge. The specific way in which the destabilization was induced and its governing mechanisms resulted in the liberation of residual bitumen from the MFT which can potentially minimize the GHG emissions from the tailings ponds. The results reported in this thesis give significant new insights into the mechanism and efficiency of MFT flocculation using CSPs that applied alone or in combination with other techniques could lead to better tailings management.Item Open Access pH-responsive Pickering emulsion using magnetic nanoparticles(2020-03-02) Rai, Ajay Kumar; Natale, Giovanniantonio; Trifkovic, Milana; Nassar, Nashaat N.; Hu, Jinguang; Natale, Giovanniantonio; Trifkovic, MilanaMagnetic nanoparticle engineering, characterization and their use as an emulsion stabilizer is the focal point of this research and dissertation. Their magnetic properties enable remote manipulation of particle’s motion. In this research pH-responsive Fe3O4 nanoparticles were synthesized using a chemical co-precipitation method and consequently used to stabilize Pickering emulsions. Oleic acid was used to modify the nanoparticle surface to tailor their wettability as well as pH responsiveness as a consequence of deprotonation/protonation of carboxylic group. It was found that the oleic acid arranges in bilayer structure at pH higher than 8 but remains as a monolayer at pH lower than 7. This change in structure alters the wettability of particle with a change in pH. The nanoparticles were characterized in terms of particle morphology, size distribution by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometer, thermo-gravimetric analysis (TGA) and zeta potential. Bilayer stabilized magnetic nanoparticles were suitable for preparing Pickering emulsions. The stability of emulsion was dependent on pH with stable emulsions forming at pH higher than 10. The rheological studies were done to understand the flow behavior of emulsions. Emulsions with higher weight percentage of nanoparticles were found to be the least stable due to decrease in pH of aqueous phase. The decrease in pH and consequent lower stability of emulsions was due to oxidation of bare Fe3O4 nanoparticle in alkaline medium. These findings are applicable in applications such as enhanced oil recovery, liquid phase heterogeneous catalysis, emulsion polymerization, and biomedicine where control destabilization of Pickering emulsion is required. Emulsion droplets can be directed using an external magnetic field and emulsions can also be destabilize by changing the pH of the aqueous phase. Since the particle are magnetic, they can be recovered in presence of external magnetic field after the separation of phases of emulsion.Item Open Access Poly(ethylenimine)-Functionalized Pyroxene Nanoparticles Embedded on Diatomite for Removal of Total Organic Carbon from Industrial Wastewater: Batch and Fixed-bed studies(2017) Hethnawi, Afif; Nassar, Nashaat N.; Lu, Qingye; Hejazi, HosseinAbstract Providing clean and affordable water to meet the human needs is a big challenge in this century. Globally, the water supply for many industries struggles to keep up with the strong demand. This demand issue is exacerbated by industrialization, which led to water quality deterioration, forming polluted wastewater. Existence of treatment processes to overcome wastewater problems are not efficient and appropriate to maintaining the industrial effluent composition within the standard limits. Specifically, presence of dissolved organic compounds not properly eliminated during the wastewater treatment has a negative impact on human health and the environment. As a novel solution, nanotechnology holds great potential in water and wastewater treatment to improve water quality efficiently. Here, we introduce an innovative technique using environmentally friendly, multifunctional, and effective poly(ethylenimine)-functionalized pyroxene nanoparticles to provide an efficient removal of the dissolved total organic carbon from industrial wastewater in batch and contenuious fixed-bed column studies under various conditions. Our study includes arrays of characterization techniques for the prepared nanoparticles and for Diatomite (commonly used filter aid) before and after embedding it with the nanoparticles at a very low mass ratio (<5 wt%). Diatomite, on its own, has a very low adsorption capacity for the dissolved organic contaminants in field applications. Among these applications is the employment of Diatomite with a rotary drum filter (RDF). Therefore, we embedded the nanoparticles to improve the performance of the Diatomite employed with a rotary drum filter used for the removal of dissolved organic pollutants. This followed our bench scale adsorption experiment using a continuous fixed-bed column that is considered to be the best lab scale model for the rotary drum filter. The experimental results showed that, compared to using activated carbon and magnetic nanoparticles, the prepared nanoparticles were very effective in the removal of dissolved organic contaminants in batch and continuous fixed-bed column experiments. In continuous fixed-bed column experiments, the breakthrough behavior was described using a convection-axial dispersion model that had a good fit with the obtained experimental data. Interestingly, this innovative technique was successfully applied at Executive Mat Ltd, here in Calgary in their rotary drum filter after optimizing some operational conditions.Item Open Access Preparation and Application of Amorphous Silica-Alumina for the Removal of Pharmaceutical Compounds from Water(2018-12-13) Alnajjar, Maysam; Nassar, Nashaat N.; Jackson, Leland J.; De La Hoz Siegler, H.Pharmaceuticals are found in surface waters as emerging contaminants. The anti-diabetic agent metformin (MF) is one of the most prescribed pharmaceutical compounds by mass. When administered, 52% of MF is excreted unmetabolized in urine, making it one of the most ubiquitous pharmaceutical pollutants in wastewater. The widespread occurrence of this pollutant in water highlights the importance of implementing a new technology in wastewater treatment plants for the removal of MF and other pharmaceutical pollutants from wastewater. Herein, amorphous silica-alumina (SA) composite was synthesized for an environmentally-friendly and efficient adsorptive removal of MF from pharmaceutical water. An array of characterization techniques was employed to study the morphology, textural properties, porosity, surface acidity, and surface charge on adsorption using SEM, BET, TGA, NH3-TPD-MS, zeta potential, and FTIR. The crystallinity, polymorphism, and stability of the adsorbate MF were studied using XRD followed by FTIR analysis. The adsorption process was investigated in batch and continuous modes under various conditions. Batch adsorption isotherms were well-fitted with Sips model, and the rate-limiting steps were investigated using Boyd’s and Weber’s models. The behavior of continuous adsorption breakthrough profiles was investigated under different dynamic conditions, and experimental data were described using convection-axial dispersion model with a good fit. The adsorbent showed very high affinity to adsorb MF molecules by an electrostatic interaction between the positively-charged MF ions and the negatively-charged Brønsted acid sites on the surface of SA. Thermal regeneration of the exhausted SA was successfully utilized for the reusability of the adsorbent over three adsorption-regeneration cycles. These results show a consistent removal of around 95% of MF in the feed.Item Open Access Preparation and Application of Polymer Grafted Nanopyroxene for the Removal of Naphthenic Acids from Wastewater(2017) Nafie, Ghada Hamdy; Nassar, Nashaat N.; De Visscher, Alex; Natale, GiovanniantonioPyroxene nanoparticles were prepared and grafted with an environmentally friendly monomer for the removal of naphthenic acids from oil sand process-affected water (OSPW) which contributes to its toxicity. Grafting was utilized to achieve high affinity towards the removal of naphthenic acids (NA) in the OSPW. The prepared grafted nanopyroxenes were fully characterized using FTIR, TGA, BET, XRD, HRTEM and AFM to study and confirm their textural surface properties and morphology. Computational modeling was conducted to provide deep insight on the grafting technique as well as the NA removal mechanism. An OSPW sample was characterized using FTIR, NMR, TGA, XRD, SimDist and GC-MS to understand the nature of the contaminants in the wastewater. This was followed by the preparation of a synthetic wastewater solution by dissolving two model molecules and commercial NA in water. Macroscopic batch adsorption experiments were conducted to carefully study the removal mechanism analyzed using GC-MS and compare it with the computational modeling study. The prepared grafted nanopyroxenes were found to interact with the contaminants in the water removing essentially all the two model molecules and about 50% of the commercial NA. The size, shape and structure of the contaminant played a key role in the interaction. The bigger molecules were found to have a stronger interaction with the grafted nanopyroxenes over the smaller ones. The present work holds great promise for the OSPW remediation and the thesis falls within our efforts to reduce the environmental impact of the oil and gas industry in Alberta.Item Open Access Stabilization of Carbon Dioxide Foam by Low Concentration of CTAB-grafted Nano-Faujasite Zeolite(2022-04-26) Mheibesh, Yazan; Nassar, Nashaat N.; Hassanzazadeh, Hassan; Hugo, Ron J.Nanoparticles received great attention as one of the most effective additives proposed to mitigate the destabilizing mechanisms of CO2 foams targeted for enhanced oil recovery (EOR) applications. The irreversible adsorption of nanoparticles at the gas/liquid interface assists the CO2 foam stability via three distinct but intimately connected mechanisms, namely: it enhances the foam liquid film dilatational viscoelasticity, which increases the ability of foam lamellas to withstand rupture against distortion; it retards film thinning and bubbles coalescence, and it minimizes the Ostwald ripening effect. While extensive studies investigated the synergistic effect between several types of surfactants and nanoparticles in enhancing CO2 foam stability, none of the previous studies proved to generate a stable CO2 foam at surfactant concentration below the critical micelle concentration (CMC). Furthermore, previous research relied on ultra-high nanoparticle concentrations which is non-economical. This thesis introduces an innovative technique of CO2 foam stabilization using environmentally friendly faujasite (FAU) zeolite nanoparticles grafted with effective cationic surfactant (CTAB) to enhance CO2 foam stability at surfactant concentrations below the CMC. The study involves arrays of characterization and stability evaluation techniques for the synthesized nanoparticles before and after surface grafting. Furthermore, the foamability and foam stabilization properties of the developed CTAB-FAU, both grafted and the physically mixed CTAB/FAU, dispersion in CO2 foam stabilization were assessed by studying the decay of foam volume, liquid holdup, and bubbles evolution in an in-house constructed foam evaluation setup developed using foam optical properties and machine learning. Moreover, the synergy between CTAB and FAU nanoparticles in enhancing the CO2 foam interfacial dilatational properties and surface shear viscosity was investigated under room conditions. The experimental findings were validated using the population balance model to evaluate the effectiveness of the nanoparticle dispersion in retarding foam bubbles' coalescence and liquid discharge destabilization mechanisms. The experimental and modeling results verified that CTAB-grafted nanoparticles were able to significantly optimize CO2 foam stability at a bulk concentration of ~150 ppm, whereas the physically mixed surfactant and nanoparticles dispersions require a bulk concentration of 1,000 ppm. Hence, the developed technique of surfactant grafted nanoparticles can provide an economical alternative to conventional gas EOR methods.