Khammar M.,CANMET Energy |
Xu Y.,CANMET Energy
Energy and Fuels | Year: 2017
A model for flow through a porous medium with variable saturation is presented in this work to predict the volume and flow rate of extracted solvent-diluted bitumen from mineral solids during centrifugal filtration. The numerical method used for solving the flow equation is based on the mass-conservative-modified Picard iteration scheme and the Anderson acceleration algorithm. It is found that bitumen extraction involves filtration and desaturation phases, and the transition between them can be identified from the evolution with time of extracted liquid volume and flow rate. An analytical description of the filtration phase is developed to predict the evolution of the liquid layer thickness above the cake during centrifugation. Numerical and analytical models presented in this work can be used in a fitting procedure to determine hydraulic properties of oil sand cake. Effects of centrifugal force and solvent mass fraction on the predicted fraction of extracted diluted bitumen are investigated. © Published 2017 by the American Chemical Society.
Czerwinski F.,CANMET Energy
Corrosion Science | Year: 2014
The perceived easy ignition and flammability of magnesium alloys create a detrimental safety feature that overshadows their high strength-to-weight ratio and hinders the aerospace application opportunities. To overcome the existing barriers a progress in understanding and controlling the reactivity of magnesium at high temperatures is required. This report describes fundamentals of magnesium ignition and flammability along with laboratory testing procedures and correlations with full scale fire scenarios, related in particular to the aircraft cabin. The influence of alloying elements on high temperature reactivity of magnesium and global efforts to develop ignition resistant and non-flammable magnesium alloys are reviewed. Although ignition and flammability represent quite different quantities, both are controlled by an oxidation resistance of the alloy and its capability to form a dense and protective surface oxide after exposures to an open flame or other heat source. Since surface oxide, composed of pure MgO, does not offer a sufficient protection, the research strategy is focused on modification of its chemistry and microstructure by micro-alloying the substrate with rare earths and other elements having high affinity to oxygen. © 2014.
Ben Anthony E.J.,CANMET Energy
Greenhouse Gases: Science and Technology | Year: 2011
Calcium looping technology is a promising new technique for high-temperature scrubbing of CO 2 from fl ue gas and syngases. Current economic projections suggest it might be able to capture CO 2 at costs of ∼$20/ton of avoided CO 2. Nonetheless there are questions about the long-term behavior of natural sorbents in such systems, and there is substantial R&D being done on this technology worldwide to answer questions about whether the performance of natural sorbents can be improved, or whether it would be better to use synthetic ones. The current period is particularly interesting as the first pilot plants and demonstration units capable of operating continuously are now coming on stream, and if successful these will lead to large-scale industrial demonstrations of the technology in the next 10 to 15 years. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd.
Manovic V.,CANMET Energy |
Anthony E.J.,CANMET Energy
Fuel | Year: 2011
CaO-based pellets supported with aluminate cements show superior performance in carbonation/calcination cycles for high-temperature CO 2 capture. However, like other CaO-based sorbents, their CO 2 carrying activity is reduced after increasing numbers of cycles under high-temperature, high-CO2 concentration conditions. In this work the feasibility of their reactivation by steam or water and remaking (reshaping) was investigated. The pellets, prepared from three limestones, Cadomin and Havelock (Canada) and Katowice (Poland, Upper Silesia), were tested in a thermogravimetric analyzer (TGA). The cycles were performed under realistic CO2 capture conditions, which included calcination in 100% CO 2 at temperatures up to 950 °C. Typically, after 30 cycles, samples were hydrated for 5 min with saturated steam at 100 °C in a laboratory steam reactor (SR). Moreover, larger amounts of pellets were cycled in a tube furnace (TF), hydrated with water and reshaped, and tested to determine their CO2 capture activity in the TGA. It was found that, after the hydration stage, pellets recovered their activity, and more interestingly, pellets that had experienced a longer series of cycles responded more favorably to reactivation. Moreover, it was found that conversion of pellets increased after about 70 cycles (23%), reaching 33% by about cycle 210, with no reactivation step. Scanning electron microscope (SEM) analyses showed that the morphology of the low-porosity shell formed at the pellet surface during cycles, which limits conversion, was eliminated after a short period (5 min) of steam hydration. The nitrogen physisorption analyses (BET, BJH) of reshaped spent pellets from cycles in the TF confirmed that sorbent surface area and pore size distribution were similar to those of the original pellets. The main alumina compound in remade pellets as determined by XRD was mayenite (Ca12Al14O33). These results showed that, with periodic hydration/remaking steps, pellets can be used for extended times in CO2 looping cycles, regardless of capture/regeneration conditions. © 2010 Elsevier Ltd. All rights reserved.
Riveros P.A.,CANMET Energy
Hydrometallurgy | Year: 2010
An effective method is presented to elute Sb(V) from the amino-phosphonic resins that are used industrially to control the antimony concentration in copper electrolytes. Unlike Sb(III), which is amenable to elution with HCl and other reagents, Sb(V) is extremely difficult to elute from amino-phosphonic resins. Consequently, in industrial practice, a gradual build-up of Sb(V) often takes place on the resin beads, and this reduces the resin capacity and useful life. In this project, it was found that solutions containing 0.5-1.0 g/L of thiourea in 5-7 M HCl are effective eluting agents for Sb(V). It is postulated that thiourea reduces Sb(V) to Sb(III), a reaction that can only take place in concentrated HCl. The main parameters influencing the elution of Sb(V) with thiourea and HCl are presented and discussed.
Kudra T.,CANMET Energy
Drying Technology | Year: 2012
Following background information on energy efficiency measures, this paper presents the methodology and calculation results for energy performance of several industrial dryers quantified in terms of the specific energy consumption and compared to the results obtained from the Baker and McKenzie's adiabatic dryer model for convective dryers. Examples of performance assessment are given for an indirectly heated spouted bed dryer with inert particles and a spray dryer with integrated fluidized bed. Because the energy performance determination is based on temperature and humidity of the ambient and exhaust air, the calculation method is also given for gas-fired direct dryers represented by a natural-gas heated pneumatic dryer for which combustion air and generated water vapor have to be accounted. © 2012 Copyright Taylor and Francis Group, LLC.
Lee S.W.,CANMET Energy
Fuel | Year: 2010
This paper describes a number of global regulations dealing with very fine ambient particulate matter, PM2.5 and PM10 and the measurements aspects of PM2.5 emission measurement methods for stationary sources, particularly of dilution techniques that promote simulation of atmospheric transformation of stack gases allowing for the use of the resulting near-ambient emission data in source apportionment and health risk studies, along with the current progress on international standardization of source PM2.5 measurement methods. Crown Copyright © 2009.
Thevenard D.,Numerical Logics Inc. |
Pelland S.,CANMET Energy
Solar Energy | Year: 2013
The uncertainty in long-term photovoltaic (PV) system yield predictions was examined by statistical modeling of a hypothetical 10. MW AC, c-Si photovoltaic system in Toronto, Canada. The goal of this research was to develop a methodology for estimating the uncertainty in PV yield predictions and to identify avenues for reducing this uncertainty. In this case study, uncertainties were estimated to be about 3.9% for year-to-year climate variability, 5% for long-term average horizontal insolation, 3% for estimation of radiation in the plane of the array, 3% for power rating of modules, 2% for losses due to dirt and soiling, 1.5% for losses due to snow and 5% for other sources of error. Uncertainties due to ageing and system availability were also considered. By performing statistical simulations with the Solar Advisor Model software, it was found that the combined uncertainty (standard deviation) is approximately 8.7% for the first year of operation, and 7.9% for the average yield over the PV system lifetime. While these numbers could vary significantly from one system to the next, the methodology developed is widely applicable. Moreover, a simpler methodology was also explored which should yield quick and fairly reliable estimates of uncertainty. Finally, avenues for reducing yield uncertainties were identified, including: increasing the reliability and resolution of solar radiation estimates, including measurements of irradiance in non-horizontal planes at high quality ground stations, reducing the uncertainty in module ratings and investigating losses that have not been well documented such as those due to dirt, soiling and snow. © 2011 Crown © 2013 and Elsevier Ltd.
Qiu K.,CANMET Energy |
Hayden A.C.S.,CANMET Energy
Applied Energy | Year: 2012
Interest in micro-combined heat and power (micro-CHP) for residential homes is growing. Stirling engines, internal combustion engines and organic Rankine cycles (ORC) could be applied for micro-CHP. However, the electrical efficiency of these micro-CHP systems is relatively low. The present paper discusses an integrated system of thermoelectric power cycle and ORC which forms an advanced dual-cycle power system. The integration scheme and the dual-cycle system thermodynamics were studied and a mathematic model was established. Dual-cycle system performance was simulated under various conditions. Overall power output and energy conversion efficiency were calculated using the established model. Experiments were conducted in an experimental setup to investigate the performance of power generation under conditions representative of the dual-cycle system. The thermoelectric modules or converters were found to be well suited for integration with the micro-CHP system. © 2011.
Qiu K.,CANMET Energy |
Hayden A.C.S.,CANMET Energy
Applied Energy | Year: 2012
Thermophotovoltaic (TPV) cells can convert infrared radiation into electricity. They open up possibilities for silent and stand-alone power production in fuel-fired heating equipment. Similarly, thermoelectric (TE) devices convert thermal energy directly into electricity with no moving parts. However, TE devices have relatively low efficiency for electric power generation. In this study, the concept of cascading TPV and TE power generation was developed where the used heat stream is taken from the TPV and applied to the input of a TE converter. A prototype cascading TPV and TE generation system was built and tested. GaSb TPV cells and an integrated semiconductor TE converter were used in the cascading power system. The electric output characteristics of the TPV cells and the TE converter have been investigated in the power generation system at various operating conditions. Experimental results show that the cascading power generation is feasible and has the potential for certain applications. © 2011 .