Guest Columnist: Nashaat N. Nassar
Nanotechnology could help in reducing the environmental footprints of Alberta oilsands industry
Nanoscrubbers for air emission capture, nanoadsorbents for adsorptive removal of waste and hydrocarbons, and nanocatalysts for catalytic steam gasification of asphaltenes and naphthenic acid for improving oil quality and water recyclability.
The oilsands recovery and upgrading with the current processes are more water and energy intensive; as a result more pollution is created, such as heavier residue, wastewater, solids waste, and air emissions. This has resulted in opportunities for development of new technologies that improve heavy oil recovery, minimize the use of energy and water-based processes and reduce the air emissions with lower cost services. Nanotechnology, which is relatively a new area of science, presents new opportunities for reducing the environmental footprints of oilsands industry. The name nano comes from the size of molecules which is measured in nanometers or one billionth of a meter (1 10-9 meter). Nanoparticles are one of the important examples on nanotechnology applications. Due to their unique properties, nanoparticles can be used to sustain oilsands industry through the development of greener processes with cost-effective approach.
Nanoparticles (NPs) have unique properties; including exceptionally high surface area to volume ratios, high dispersive properties, and functionalizable surface that maintains high adsorption affinity and catalytic activity. Also, NPs are easily to prepare in-situ compare to conventional adsorbent/catalysts, and overcome pore plugging experienced in supported catalysts as they are highly mobile in porous media because they are much smaller than the relevant pore spaces, leading to effective transport. Our research and development at the Alberta Ingenuity Centre for In Situ Energy at U of C focuses on in-situ formed NPs, in which metallic and multi-metallic oxide NPs are prepared within the heavy oil matrix or water contaminated zone, and their application for reducing the environmental footprints of oil sands industry. A few key points of our research are as follows:
- Produced water treatment: employing in-situ, in place, prepared metallic or multi-metallic oxide nanoparticles (nanoabsorbents/nanocatalysts) with different surface functionality for removal of organic contaminants, such as naphthenic acid (which is the most prevalent toxin), from produced water and subsequent treatment of the precipitate (gasification or oxidation). These NPs are also magnetic, allowing for their magnetic separation and removal from the process stream.
- Air emission control: Applying the in-situ prepared nanoscrubbers for the removal of gaseous pollutants during oilsands recovery and upgrading. All toxic gases before they seep into an aquifer and the atmosphere are securely captured upon reaction with nanoparticles. In this work, we investigated the development of novel metal oxide absorbents prepared in-situ within the heavy oil matrix and examined for the first time the online removal of H2S(g) from the matrix under the upgrading conditions. Current work focuses on CO2 capture by in-situ prepared nanoscrubbers.
- Heavy oil upgrading: Adoption of ultradispersed nanoparticles for in-situ heavy oil upgrading reduces the need to transport oilsands ore by haul trucks to the upgrader. This enhances oil production and helps save operating costs related to surface facilities. This process also reduces emissions of greenhouse gases and oxides of nitrogen, eliminates the solid waste product and minimizes the consumption of fresh water. The process can be achieved by the following two-fold technique:
- Asphaltenes are removed by adsorption onto nanoparticles (nanoadsorbents): With a particular affinity towards asphaltenes, these NPs are also magnetic, allowing for their magnetic separation and removal from the process stream
- Nanocatalysts: The in-situ prepared nanoparticles are employed as catalysts for upgrading asphaltenes into light utilizable distillates, within the reservoir environment, this helps increase the upgrading efficiency with a substantial decrease in project environmental footprints.
By adopting our cleaner technology we can improve the efficiency of oilsands upgrading, reduce costs, avoid air emissions, reduce fresh water usage and even create new income streams (such as carbon credits). Our next steps are to design pilot plants which are needed to validate laboratory results for future field-scale application. Our work on synthesis and application of nanoparticles has been recognized and published in more than 10 prestigious journals (for the last year only); including: Energy and Fuels, Fuel, Journal of Colloids and Interface Science, Journal of Hazardous Materials, Colloids and Surfaces, A, etc. These findings could help oilsands industry to upgrade heavy oil more effectively, with less environmental impact. This research may also have applications in other areas such as treatment of municipal wastewater, textile wastewater, etc, which are areas that we are currently exploring.
Dr. Nashaat N. Nassar is a research scientist in the Alberta Ingenuity Centre for In-Situ Energy and an instructor at the Schulich School of Engineering at the University of Calgary. He is a professional member of APEGA