Natural Resources Engineering

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Adaptation of microalgae bioprospected from stressed environments in Northern Ontario for the production of lipids
(2020-12-16) Desjardins, Sabrina Marie
Photosynthetic green microalgae are a promising bio-feedstock that can be used to generate lipids for transesterification into biodiesel and/or various human health products such as polyunsaturated fatty acids. Unfortunately, due to their cultivation requirements, such as high energy requirements and carbon dioxide (CO2) as a carbon source, large-scale biomass production generally remains uneconomical. To address this issue, the use of industrial flue gas as a low-cost source of CO2 and a biorefinery approach to help mend the economic burden of microalgae-based products with an emphasis on creating co-products from lipid-extracted biomass (LEB) are assessed in this thesis. Microalgae’s ability to sequester CO2 through photosynthesis is also advantageous in mitigating harmful industrial emissions. While these flue gases can have high concentrations of CO2, they also can contain numerous contaminants (e.g., heavy metals, particulate matter) that discourage microalgae growth, and therefore their ability to fix CO2. But, the most significant issue can be high nitrous oxide (NOx) and sulphuric dioxide (SO2) concentrations within a flue gas that cause acidification when bubbled through liquid media. It is due to this acidification that finding the productive microalgae species to grow in those systems can be problematic. To address this, bioprospecting acid-tolerant microalgae from low pH environments in active and non-active mining sites was explored and the acidophilic species present identified through DNA sequence analysis. Bioprospected algal species were then grown in acidic conditions similar to those created by bubbling flue gas from a nickel smelter into water (pH 2.5). From this work, it was found that the acid-tolerant green microalgae in the genus Coccomyxa acclimated to the acidic conditions with suitable growth rates (0.136 day-1) and biomass production (25.71 mg L-1day-1). However, anabolic production of target biochemical molecules, such as lipids, is the key step in the bio-product process. It is known that microalgae have the ability to accumulate bioactive compounds when placed in stressed environments, such as high illumination and low nutrient availability, but little is known an about the impact of low pH and in particular the lipid composition of acidophilic microalgae. Research confirmed that the lipid compositions of bioprospected acid-tolerant microalgae was in the target range (13%). However, further work showed that an increased total lipid content (up to 27%), with a desirable rise in the relative level of health beneficial higher polyunsaturated fatty acid, could be achieved by applying dark stress at the end of the exponential growth phase. It is, therefore, proposed that this approach could be an easy, low-cost method to enhance lipid productivity
Adapting methodologies from the forestry industry to measure the productivity of underground hard rock mining equipment
(2017-08-30) Hauta, Rebecca Lynn
The purpose of this dissertation is to develop and apply a framework to characterize the ground support installation component of the mining development cycle in underground hard rock mines for the purposes of comparing equipment. A secondary goal is to identify opportunities to improve the productivity of the ground support installation process. It was found that the forestry industry faces similar challenges as the mining industry when measuring equipment output in a variable environment where equipment productivity is affected by a range of external conditions. Despite this challenge, forestry researchers successfully developed and applied a standardized methodology and nomenclature to measure the productivity of equipment for the purposes of equipment and process comparison in variable external conditions. The methodology used in the forestry industry was modified to measure mechanized and semimechanized ground support installation productivity in three Canadian underground hard rock mines. Furthermore, opportunities to improve the ground support installation process were identified. This framework can be modified to measure and compare other types of mining equipment. By using a standardized methodology to measure, compare and improve mining processes, development and production rates can be increased in underground hard rock mines. In summary, a framework was adapted from the forestry industry to measure and compare the productivity of the ground support installation cycle in three Canadian hard rock mines, and opportunities to improve the process were found.
Air entrainment and air-water separation in hydraulic air compressors
(2018-08-16) Hutchison, Alex
A hydraulic air compressor (HAC) is an isothermal gas compressor that uses hydropower to compress air, originally developed by Charles Taylor in the 1890s to supply industry with compressed air. In the modern revival of this technology, the hydropower will be provided by pumps rather than natural sources. As such, energy efficiency is an important driver of component design; all of the hydropower is consumed either to overcome irreversibility or to compress air. The compressor relies on the increasing pressure of water flowing downward in a downcomer to compress air in the form of bubbles being dragged along with the flow. The air entrainment process at the top of the downcomer is facilitated by a mixing head. At the bottom of the downcomer, the bubbles are separated from the flow in a separator vessel. The objective of this thesis is to develop the design methodology for the air entrainment and air-water separation components on either end of the downcomer process. Several mixing heads were tested on a small (4.5 m height) prototype HAC. The test without a mixing head successfully entrained air, confirming that air entrainment is a system effect. Two heads with dissimilar geometry were associated with the lowest irreversibility, leading to the conclusion that the best design at that scale is a mixing head incorporating some form of vortex breaker. Air entrainment is driven by a system energy balance and not exclusively by a local Venturi geometry. The fraction of the air successfully captured in the plenum of the separator is called the separator effectiveness. Mechanistic models have been created to characterize both the irreversibility and separator effectiveness of two types of gravity separator (horizontal and vertical orientation) for iv the design of separators for future commercial-scale compressors. The separator effectiveness models require as input the flow field information from computational fluid dynamics analysis and the bubble size distribution at inlet. The bubble size distribution was measured on the small prototype and used to select a bubble size prediction model for testing on a much larger scale (29 m height) demonstrator HAC. The displacement model for horizontal separators matched the actual performance at the prototype scale well, particularly at high flow rate. The vertical velocity model produced a good match for the separator on the demonstrator HAC, but not for the same bubble size model identified on the small prototype.
Application of GenRel for maintainability analysis of underground mining equipment: based on case studies of two hoist systems
(Laurentian University of Sudbury, 2015-01-29) Xu, Chao
With the increasing costs of extracting ores, mines are becoming more mechanized and automated. Mechanization and automation can make considerable contributions to mine productivity, but equipment failures and maintenance have an impact on the profit. Implementing maintenance at suitable time intervals can save money and improve the reliability and maintainability of mining equipment. This thesis focuses on maintainability prediction of mining machinery. For this purpose, a software tool, GenRel, was developed at the Laurentian University Mining Automation Laboratory (LUMAL). GenRel is based on the application of genetic algorithms (GAs) to simulate the failure/repair occurrences during the operational life of equipment. In GenRel it is assumed that failures of mining equipment caused by an array of factors follow the biological evolution theory. GenRel then simulates the failure occurrences during a time period of interest using genetic algorithms (GAs) coupled with a number of statistical techniques. This thesis will show the applicability and limitation of GenRel through case studies, especially in using discrete probability distribution function. One of the objectives of this thesis is to improve GenRel. A discrete probability distribution function named Poisson is added in the pool of available probabilities functions. After improving and enhancing GenRel, the author carries out two groups of case studies. The objectives of the case studies include an assessment of the applicability of GenRel using real-life data and an investigation of the relationship between data size and prediction results. Discrete and continuous distribution functions will be applied on the same input data. The data used in case studies is compiled from failure records of two hoist systems at different iv mine sites from the Sudbury area in Ontario, Canada. The first group of case studies involves maintainability analysis and predictions for a 3-month operating period and a six-month operating period of a hoist system. The second group of case studies investigates the applicability of GenRel as a maintainability analysis tool using historical failure/repair data from another mine hoist system in three different time periods, three months, six months and one year. Both groups apply two different distribution probability functions (discrete and continuous) to investigate the best fit of the applied data sets, and then make a comparative analysis. In each case study, a statistical test is carried out to examine the similarity between the predicted data set with the real-life data set in the same time period. In all case studies, no significant impact of the data size on the applicability of GenRel was observed. In continuous distribution fitting, GenRel demonstrated its capability of predicting future data with data size ranging from 166 to 762. In discrete probability fitting, the case studies indicated to a degree the applicability of GenRel for the hoist systems at Mine A and Mine B. In the discussion and conclusion sections, the author discloses the findings from the case studies and suggests future research direction.
Application of neuroergonomics in the industrial design of mining equipment.
(2015-06-26) Mach, Quoc Hao
Neuroergonomics is an interdisciplinary field merging neuroscience and ergonomics to optimize performance. In order to design an optimal user interface, we must understand the cognitive processing involved. Traditional methodology incorporates self-assessment from the user. This dissertation examines the use of neurophysiological techniques in quantifying the cognitive processing involved in allocating cognitive resources. Attentional resources, cognitive processing, memory and visual scanning are examined to test the ecological validity of theoretical laboratory settings and how they translate to real life settings. By incorporating a non-invasive measurement technique, such as the quantitative electroencephalogram (QEEG), we are able to examine connectivity patterns in the brain during operation and discern whether or not a user has obtained expert status. Understanding the activation patterns during each phase of design will allow us to gauge whether our design has balanced the cognitive requirements of the user.
Application of seismic monitoring in caving mines
(Laurentian University of Sudbury, 2013-10-10) Abolfazlzadeh, Yousef
Comprehensive and reliable seismic analysis techniques can aid in achieving successful inference of rockmass behaviour in different stages of the caving process. This case study is based on field data from Telfer sublevel caving mine in Western Australia. A seismic monitoring database was collected during cave progression and breaking into an open pit 550 m above the first caving lift. Five seismic analyses were used for interpreting the seismic events. Interpretation of the seismic data identifies the main effects of the geological features on the rockmass behaviour and the cave evolution. Three spatial zones and four important time periods are defined through seismic data analysis. This thesis also investigates correlations between the seismic event rate, the rate of the seismogenic zone migration, mucking rate, Apparent Stress History, Cumulative Apparent Volume rate and cave behaviour, in order to determine failure mechanisms that control cave evolution at Telfer Gold mine.
Broadband optical wireless communications for the teleoperation of mining equipment
(2017-06-01) Frutuoso Barroso, Alberto Rui
The current level of technological advancement of our civilization serving more than seven billion human population requires new sources of biotic and abiotic natural resources. The depletion and scarcity of high-grade mineral deposits in dry land are forcing the Natural Re- sources industry to look for alternate sources in underwater environments and outer space, requiring the creation of reliable broadband omnidirectional wireless communication systems that allows the teleoperation of exploration and production equipment. Within these ob- jectives, Optical Wireless Communications (OWC) are starting to be used as an alternative or complement to standard radio systems, due to important advantages that optical wave- lengths have to transmit data: potential for Terabit/s bit rates, broadband operation in underwater environments, energy e ciency and better protection against interference and eavesdropping. This research focus in two crucial design aspects required to implement broadband OWC systems for the teleoperation of mining equipment: high bandwidth wide beam photon emission and low noise omnidirectional Free-Space Optical (FSO) receivers. Novel OWC omnidirectional receivers using guided wavelength-shifting photon concentra- tion are experimented in over 100 meters range vehicle teleoperation.
Characterization of seismic sources using sequential spatial clustering and fractal dimension
(2018-07-30) Cortolezzis, Donna Marie
Despite years of research, unexpected seismic events in mines continue to cause damage and loss to people, equipment, infrastructure, and reserves. This research uses novel approaches to characterize the locations, times, and intensity of seismic events for four known seismic sources. The seismic source case studies are the development of a ramp, the abutments around a zone of stopes, a failing stope pillar, and a shear zone adjacent to an orebody. Each seismic source is characterized by sequential spatial clustering, and the fractal dimension of the seismic source parameters of location, time and intensity. The novel application of sequential spatial clustering preserves the sequence of events within a cluster. The method can be used at any point in time which means as a rock mass changes the seismic response is expressed and identified very early on. Once identified, it allows the opportunity for investigation and decision making to take place as the rock mass changes in an unexpected manner. The application of fractal dimension to seismic source parameters revealed that the fractal nature of a parameter is not infinite but exists within a range. The fractal range reflects the character of a seismic source. If some events occur outside the fractal range they also provide important information about the history of the seismic source that occur less often than the fractal range but are still possible. This research has expanded the knowledge of when, where, and how intense seismic events can be expected for four seismic sources using a new sequential spatial clustering method and fractal dimension characterization.
Cobalt-doped zinc oxide thin films as model Fischer-Tropsch nano-catalysts grown by pulsed electron beam ablation
(2017-12-05) Ali, Asghar
The production of materials in thin film form with unique properties is of growing scientific and technological interest. Zinc oxide is a low cost, and environmentally benign wide band gap semiconductor, which makes it an excellent supporting material for nanoparticles with a plethora of potential applications. Upon doping with Co and other transition metals, ZnO exhibits room temperature ferromagnetic properties with enhanced performance and new functionalities when used in thin film devices. Zinc oxide-supported cobalt nano-composites are promising materials with desirable catalytic properties making it an interesting material for use as an efficient nano-catalyst in many important reactive processes such as Fischer-Tropsch synthesis (FTS), photocatalysis, hydrogen production and steam reforming. Pulsed electron beam ablation (PEBA) has recently emerged as a potential technique for the fabrication of superior quality thin films. The production of well controlled nano-sized particulates is a characteristic feature of PEBA, which has a strong bearing on the surface morphology of the deposited films. In the current work, the potential of PEBA in the deposition of Co-doped ZnO thin films has been assessed and the critical process conditions that affect the growth of the thin films on different substrates have been thoroughly investigated. The main objective of the current work is to deposit Co-doped ZnO thin films via PEBA, and assess the potential of the deposited films as model nano-structured catalysts for the synthesis of green liquid fuels from syngas. PEBA has several advantages including modest requirements for vacuum, control of film thickness, easy set-up, low capital cost, reduced operation and maintenance costs, small footprint, enhanced efficiency, and relative safety (no toxic gases as in pulsed laser ablation or potential noxious by-products as in solvo-thermal routes) over other film preparation techniques. In this project, Co:ZnO thin films have been synthesized from a single target on various substrates. Numerous process parameters have been assessed such as substrate material, deposition temperature, electron beam voltage, beam pulse frequency. Targets of varying cobalt loads viz., 5 w%, 10 w%, and 20 w% have been investigated as well. The effects of pre and post annealing on the physico-chemical properties of the thin films have also been studied. The deposited films have been characterized using complementary analytical techniques such as xray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive x-ray (EDX), visible reflectance spectroscopy (VRS), and atomic force microscopy (AFM). Such comprehensive analyses have helped in assessing the quality of the films and in guiding the experimental strategy in the quest to find the optimal process conditions. Finally, the films have been evaluated for their potential as model nano-catalysts for FischerTropsch synthesis in a 3-phase continuously-stirred tank slurry reactor (3-φ-CSTSR) using a Robinson-Mahoney stationary basket (RMSB). The results have been described in terms of activity and selectivity of the thin film nano-catalysts.
Commissioning and verification of compressed air yield on the hydraulic air compressor demonstrator
(2018-03-28) Sivret, Justin
The completion of the hydraulic air compressor (HAC) demonstrator at Dynamic Earth in Sudbury, Ontario marks the beginning of a series of research activities to increase the efficiency of compressed air production and build confidence in future commercial applications. Before any proper experiments could be conducted on the HAC Demonstrator a series of commissioning activities and testing was completed to i) calibrate the instruments, ii) check and understand losses, and iii) verify, or otherwise, some of the assumptions made during the system design. The practical work associated with this master’s thesis included the development of a human machine interface (HMI) to allow for automated control of the HAC. Instrumentation and control equipment was installed and routed to a control panel providing conditioned power and routes for signals. Within the control panel, these are digitised and transmitted using TCP/ IP/ MODBUS protocol, operating over a TopServer (Software toolbox, 2009) OPC backbone. The OPC Client toolbox in MATLAB was adopted to interface with the OPC Server, and MATLAB’s App Designer adopted for authoring the HMI. All I/O functionality is thus routed to MATLAB in which a PID control loop was established between the HAC separator water level and the HAC’s compressed air motorized globe valve. Thus, a reliable, flexible, scientific control interface and data storage infrastructure was established for this novel compression plant as part of the master’s work. The HAC Demonstrator can now effectively run a variety of experiments while recording a wide range of data for analysis. To date, a series of 90 benchmark tests for compressor performance have been completed in a systematic manner on the demonstrator to create a database of real HAC operating conditions. This thesis thus represents the first formal publication of the HAC Demonstrator’s complete performance under the baseline operating conditions. Previous predictions of the compressed air yield and efficiency of a HAC of this size have been made by Millar (2014), upgraded to weakly couple solubility loss by Pavese et al. (2016) and refined using Young’s (2017) detailed coupling of solubility and psychrometric phenomena. The predictions made by these models have been tested. The 1D hydrodynamic solubility models also predicted a small beneficial ‘airlift’ effect on compressor performance, due to exsolution of formerly dissolved compressed gas, that has also been reported upon. One unexpectedly important factor that has been found to affect HAC performance that was not anticipated in any of the models included the absolute surface roughness of rubber lined pipe, in comparison to that of bare steel pipe. High precision experiments are reported upon that have produced reliable values for absolute surface roughness for rubber lining materials, that have now been adopted in the HAC models, and may be adopted more widely too. The occurrence of detrainment, water jet-free fall and air re-entrainment is speculated upon as the source of previously unreported loss in the air-water mixing process, based on pressure profiling observations undertaken over the complete performance envelope of the Dynamic Earth HAC Demonstrator.
Computer-based application to assess gross motor skills using Microsoft Kinect sensor
(2018-03-07) Bragança Moraes, Arina
The performance of a fundamental motor skill in early childhood can be investigated using diverse assessment tools. Although the classical tests are reliable and useful for motor skills assessment, they have some limitations. The launch of the Microsoft Kinect marked a revolutionary advancement for developers thanks to the depth camera and its affordable price. This work aims to develop a reliable computer-based application using the Microsoft Kinect sensor to implement the third version of the Test of Gross Motor Development (TGMD-3). The assessment consists of customized algorithms that verify if the 3D position of the most relevant joints for each subtest varies along time according to the respective performance criteria. The proposed system returns an immediate feedback to the participant, indicating if s/he passes or fails the selected subtest. The results revealed the computer-based application for assessing gross motor skills is accurate, although it is limited by the space requirements.
Cross-linked polymers of phenylacetylene and 1,3-diethynylbenzene: new polymer precursors for nanoporous carbon materials for supercapacitors and gas storage
(Laurentian University of Sudbury, 2015-01-09) Grundy, Mark
The increasing threats of global warming, rapid depletion of fossil fuels, and increasing energy demands are driving an enormous amount of research into clean renewable sources of energy, flue gas capture technologies, and environmentally friendly energy storage devices, to name a few. Activated carbons present a multipurpose material commonly used in many of these increasingly popular green technologies. A wide range of cross-linked acetylenic polymers of phenylacetylene and 1,3- diethynylbenzene were synthesized and investigated in this thesis to generate materials for electrochemical double layer capacitors, CO2 capture, and hydrogen storage. Chemical activation of the copolymers in the presence of KOH was shown to produce highly microporous carbons with various textural properties. The specific cross-linking densities of the polymer precursors prior to carbonization were shown to greatly affect the carbon yield, surface area, pore volumes and pore sizes of the carbons produced. Electrochemical measurements of the activated carbons showed their impressive performances as capacitor materials, with high specific capacitances (up to 446 F g−1 at 0.5 A g−1 in 3-electrode cell) and long cycle life. Gas sorption studies also demonstrated impressive H2 and CO2 adsorption capacities (up to 2.66 wt% or 13.3 mmol g−1 for H2 adsorption at 77 K and 1 atm, and up to 30.6 wt% or 6.95 mmol g−1 for CO2 adsorption at 273 K and 1 atm). Owing to the high content of pendent alkyne groups in these polymers, complexation reactions with metallic carbonyl ligands are able to provide an effective iv way of dispersing metallic and metal oxide nanoparticles within the synthesized copolymers, which could provide additional pseudocapacitive properties. An appropriate copolymer with high alkyne content was subjected to complexation with Co2(CO)8, and subsequently carbonized and oxidized to yield carbon-supported CoxOy/Co nanoparticles (CoxOy@C-CPD76%). In addition to pseudocapacitive contributions, the cobalt species also effectively catalyzed the production of graphitic networks within the carbon support, improving their conductive properties. Electrochemical measurements demonstrated impressive specific capacitance (310 F g−1 at 0.1 A g−1) compared with non-activated carbons (160 – 177 F g−1 at 0.1 A g−1) synthesized at identical conditions, and provided a large stable potential window (1.4 V) in an aqueous KOH solution. The combined electrochemical double layer capacitance and pseudocapactiance behaviour of the carbon and CoxOy/Co also provided improved energy densities (21 W h kg−1), and uncompromised power densities (2017 W kg−1) compared with the pristine carbons (~2034 W kg−1).
Design and optimization of a novel top-lit gas-lift bioreactor for industrial CO2 mitigation and microalgae-sourced biodiesel production
(2017-03-24) Seyed Hosseini, Nekoo
Mitigation of CO2 in industrial off-gasses by sparging the gas through photosynthetic microalgae bioreactors is an attractive concept. The goal is for the CO2 to be consumed by the microalgae as a nutrient, which in turn produces lipids suitable for conversion into biodiesel, as well as other value-added bioproducts such as Omega-3 fatty acids and antioxidants. Open systems are considered the most economic outdoor, large-scale cultivation option but have large land space requirements due to their shallow depths (15-35 cm). Consequently, finding sufficient space to locate them close to off-gas sources on industrial sites can be a significant challenge. Shallow depths are also likely to result in low uptake of CO2 and consequently reduced biomass productivity due to short gas residence times in the culture medium. In order to obtain longer gas/liquid transfer times, as well as greater per area productivity, the tanks through which the off-gas is sparged must be as deep as possible. However, to make the tanks deeper and avoid the costs associated with sub-surface artificial lighting, the issue is how to ensure the microalgae receive adequate light exposure. We have, therefore, looked for a novel method for increasing the depth of the tanks through which the off-gas is sparged. To achieve this, we have investigated the use of a gas-lift circulating system in a deep top-lit open bioreactor. In addition to providing CO2, the sparged gas also provides continual vertical circulation of the microalgae to ensure good mixing and an adequate light/dark cycle. Compared to existing shallow open systems, the results obtained showed comparable biomass productivity per unit volume, but importantly around three-times higher biomass productivity per unit area occupied by the bioreactor. The lipid productivity was also increased due to light and hydrodynamic stresses. In order to enhance further light utilization efficiency in the deep cultivation bioreactor, the use of a novel non-energy-consuming light column was also evaluated. The results of using the light column showed a 33% increase in areal biomass productivity and a 16% increase in areal lipid production. The proposed design and developed models can be easily translated into larger scale, onsite production facilities in industrial sectors emitting off-gas. The carbon capturing properties of microalgae can, therefore, help reduce industrial carbon dioxide emissions, whilst at the same time producing biodiesel from the resulting lipids.
Design and verification of a Hydraulic Air Compressor as a CO2 capture and sequestration system.
(2023-08-17) Mahdavi, Maryam
As a result of human activities, the level of atmospheric carbon dioxide (CO2) has increased. Carbon capture and sequestration (CCS) technologies offer an effective approach for mitigating CO2 from various industrial process to reduce the global climate change effect. These technologies can be integrated into existing infrastructure with minimal disruption. This study reviews on post- combustion CO2 capture and sequestration techniques, with a specific focus on mineral carbonation process routes and their potential feedstocks. Mineral carbonation is an approach that mimics the natural weathering of rock, in which metal oxide-bearing materials, for instance natural silicate minerals (serpentinite, olivine) react with gaseous CO2 to form solid carbonates. This process takes place on geological time scales, but it can be accelerated by increasing the concentration of CO2 in a reactor through pressurization of the system. The purpose of this study was investigation of technical feasibility of a CCS process by means of a hydraulic air compressor (HAC). A series of experiments were conducted on the HAC pilot plant to investigate the potential of the system as a post-combustion CO2 capture system. Those experiences experimentally verified a one-dimensional steady-state model for two-phase bubbly flow. The verified bubbly flow model was used to compare the hydrodynamics and mass transfer characteristics of HAC downcomers and upward co-current flow bubble column reactors and to predict gas liquid mass transfer coefficients. The experimental results showed that the HAC is an effective technology for intensification of CCS processes due to its improved mass transfer performance compared to other mass transfer devices. While the high capital cost of HAC construction, following a general Millar (2014) design paradigm, limits applicability, the horizontal injector loop (HIL), developed in this thesis offers a new apparatus with similar gas compressor performance and reduced height, which would make the concept more accessible for capital restricted projects. A mathematical dynamic kinetic model is developed to simulate the kinetics of CO2 absorption into an alkaline solution in the HIL. This model makes a significant contribution in predicting the absorption rate under operating conditions beyond those achievable in experimental tests undertaken. In addition, this model can be used to guide the design of a new reactor and future experiments, making it a valuable tool for CO2 capture and sequestration activity. Carbon dioxide capture and sequestration by means of a HIL as a pressurized, continuous chemical reactor was also investigated experimentally. The experimental results demonstrated that the HIL has a credible potential for this purpose. These experiments were also simulated using the dynamic kinetic model, which showed good agreement with the experimental findings. However, some potential improvements to the dynamic kinetic model have been identified to enhance its compatibility with experimental conditions.
Design, construction and testing of a Tesla Turbine
(2016-02-26) Holland, Kris
This thesis presents the design, construction and testing of a boundary layer turbine, also known as a Tesla Turbine. A turbine, with discs of 92mm in diameter, central exhaust, plenum chamber, and swappable nozzles was constructed. The setup included instrumentation and a simple torque sensor with which to sense the relatively low torques given the low testing pressures. After construction, the setup was tested with various angles of nozzles ranging from 2.5° to 45° from tangential. The testing resulted in an estimated maximum efficiency of 8.5%, while running the rig at 3 bar, which is comparable to the literature. Unexpectedly, this maximum was achieved with a nozzle pointed at 45° from tangential, which may have been caused by the disc pack variant used in the tests.
The distance analysis of a mine scale event
(2022-02-25) Ollila, Benjamin
Mining induced seismic events greater then Nuttli Magnitude 3.0 are difficult to understand, have high potential consequences and are becoming increasingly common in Canada. The term mine scale event (MSE) is used to describe a seismic event in which the mechanisms and processes involved take place on a scale similar to that of the mine. A MSE from Nickel Rim South Mine was investigated using seismic data to explain its time, location and large magnitude. A novel tool, Time Distance Analysis was developed to identify spatial-temporal trends in seismicity around the MSE. Guidelines were developed to account for the unknown spatial and temporal extent of the processes that led to and were affected by the MSE. The results showed that preceding seismicity tended to coalesce around the eventual hypocenter of the MSE while subsequent seismicity migrated away. The coalescence was interpreted to represent the deterioration of a fault asperity, leading to an eventual rupture. After the MSE occurred, the dispersion of seismicity was interpreted to represent an unloading of the source region.
Dynamic modelling of catalytic SO2 converter in a sulfuric acid plant of an industrial smelter
(2018-04-16) He, Jianjun
In industrial nickel and copper production, sulfur dioxide (SO2) is generated from the combustion of sulfide ores. With increasingly tightened regulations on SO2 emissions, a sulfuric acid plant has become a crucial part of industrial smelters. It converts environmentally harmful SO2, which is generated in smelter furnaces, roasters, and Cu-reactors, into commercially beneficial sulfuric acid. This method is recognized as one of the most effective ways to ensure that smelters are able to satisfy the SO2 emission regulations. A sulfuric acid plant is primarily comprised of a central catalytic SO2 converter, SO3 (sulfur trioxide) absorption towers and a series of interconnected heat exchangers. The catalytic SO2 converter is the key component and the focus of this research. Both steady-state and dynamic models of the converter are developed in this thesis. A steady-state model of the converter is established in accordance with steady-state mass and energy balances. The developed model provides an explicit relation between SO2 conversion ratio and gas temperature, which is denoted as the heat-up path of the converter. By combining the heat-up path with the equilibrium curve of the SO2 oxidation reaction, an equilibrium state for every converter stage can be obtained. Using the developed steady-state model, simulations are performed to investigate the effect of inlet SO2 molar fraction and gas temperature on the equilibrium conversion ratio. In an industrial SO2 converter, the SO2 concentration and conversion ratio out of each bed are important variables but are not measured in real time. To monitor these unmeasured variables in industrial operations, a soft sensor is proposed by combining the derived steadystate model with dynamic data analysis. The obtained soft sensor provides a real-time estimation of outlet SO2 concentration and the conversion ratio from measured temperatures. For synchronization between the inlet SO2 concentration and outlet temperature, a first-order exponential data filter is applied to the feed SO2 data. With the filtered signal being used, the proposed soft sensors give a satisfactory estimation of both outlet SO2 concentration and conversion ratio in the converter stages. Dynamic modelling is carried out using two different model forms: ordinary differential equation (ODE) and partial differential equation (PDE) models. The ODE model is obtained by applying dynamic mass and energy conservation to the SO2 converter. The resulting model can be used in industrial applications and describes the converter performance even if information of reaction kinetics is not available. A good fit with collected industrial data verifies the validity of the developed ODE model. The effect of process input variables is studied using simulations with the ODE model. Dynamic modelling is performed by implementing mass and energy balances on both fluid and solid-phase gas flows. The proposed two-phase dynamic model, which takes the PDE form, is able to generate detailed profiles of the SO2 converter within time and space. With the estimated parameters, this two-phase dynamic model generates a good fit between the simulated and measured outlet temperatures. Based on the PDE model, simulations are run to investigate the detailed mechanistic performance of the converter. The detailed PDE model provides useful explanation of, and prediction for the converter behaviour.
The effects of automation on the environmental impact of deep underground metal ore mining operations
(2020-10-27) Moreau, Kyle Steven
The growing demand for increased production has resulted in the need to develop deeper underground mines to extract more resources. However, the mining process becomes less economically attractive as the ventilation and ore transportation costs drastically increase when operating at large depths. This has led to the industry investigating automated battery-electric and biodiesel fueled machinery instead of diesel machines to reduce emissions, and hence ventilation costs, as well improve productivity and thereby, the economic viability of deep mine projects. A life cycle assessment (LCA) approach has been developed to evaluate the environmental impact from introducing automated equipment in underground copper mines. This is a novel application for an LCA, and as a gauge of model accuracy, it was found that calculated greenhouse gas (GHG) emissions for an underground mine site in Canada were within 5.6% of their reported emissions. The model was then expanded using data collected from automation trials at a Canadian mine to predict changes due to the introduction of various levels of automation with regards to the impact potentials of global warming, acidification, eutrophication and human toxicity. All impact levels were quantified and found to decrease due to automation. Data from this site study was then used to further develop the LCA model to predict changes in environmental impacts for underground copper mine sites in Australia, Canada, Poland, USA and Zambia. Site specific parameters and processes that contribute to their overall environmental impacts were identified, and the calculated CO2 emissions were within 4.2-5.6% of the reported values. The mining industry is moving toward introducing significantly more technology to enhance both productivity and safety. This thesis investigates using an LCA approach to add a third dimension; improved environmental impacts that contribute to more sustainable mining
Electrolytic destruction of cyanide on bare and MNO2 coated 304 stainless steel electrodes
(2021-09-15) Schmidt, Jacob
MnO2 coated lead and ANSI-304 stainless steel anodes were evaluated for use in electrolytic cyanide waste effluent treatment. Cyclic voltametry experiments revealed that MnO2 on lead was too resistive to be a feasible substrate. Cyclic voltammetry on bare and MnO2 coated steel shows evidence of cyanide destruction just prior to the onset of massive oxygen evolution, suggesting a reaction mechanism in which cyanide is oxidized via reaction with hydroxide radical species on the electrode surface. Galvanostatic experiments showed little difference in cyanide oxidation performance behaviour between bare steel and the MnO2 coating. However, copper ion were found to catalyse cyanide oxidation for bare steel, but had no observed effect for MnO2 coated steel. A cost analysis was done comparing electrolytic cyanide destruction using bare steel anodes to the INCO SO2/Air process. Electrolytic cyanide oxidation was concluded to have significantly lower operating costs, but is infeasible due to prohibitive capital costs.
Employing heat pumps to recover low grade industrial thermal resources for space heating and cooling
(2016-05-16) Ross, Ian Michiel
The use of heat pumps to upgrade and recover low grade industrial thermal resources is an opportunity for industry to deliver low cost space heating at a reduced carbon footprint. Heat pumps also offer the potential to provide space heating and space cooling from a single unit. To facilitate rapid determination of the potential for low grade heat recovery using ground source heat pumps, a rapid scoping method was developed capable of establishing critical temperatures to help elucidate which resources are most likely to be recovered economically. To demonstrate the applicability of the rapid scoping method, an analysis of various process cooling waters present at a smelter site was undertaken. The implications for cost and carbon dioxide emissions, were both analyzed for this facility, although the concepts developed can be employed to any site that generates large quantities of thermally low-grade heat.

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