Albian Sands is exploring a way to improve oil sands process water treatment. With project support and funding from Alberta Innovates, Albian has been working with a variety of research institutions to develop membranes for different water treatment applications. The challenge is finding a membrane technology that can withstand the wide range of water quality conditions that oil sands operations encounter—temperature, pressure, organics, clay, sand—while allowing mining operators to recycle more water. Titania (TiO2 Ceramic) membranes may do just that and Albian is investigating with its Titania Membrane De-risking Pilot Project at its oil sands mining facility.
Membranes are a key component of the water treatment process and in the oil sands industry, ceramic membranes are often used as a first point of filtration to remove suspended solids from process water. These ceramic membranes are prone to contamination after prolonged exposure to bitumen and saline whereas titania membranes are more resistant to fouling, allowing for easier maintenance and a longer lifespan. Titania membranes are also more than just a filtration system. With a 0.9 nanometre (nm) pore size—substantially smaller than the 40 nm pore size of a ceramic membrane—titania membranes allow for the filtration of some dissolved ions as well as the suspended solids. (For comparison, a water molecule is less than 1 nm and a strand of human hair is 100,000 nm in diameter.) This enhances the overall water quality earlier in the treatment process, reducing time and energy outputs.
Titania membrane technology could be used in two main applications:
- To treat recycled oil sands process water for reuse.
- To recycle warm thickener overflow water for reuse.
Starting in 2015, the Titania Membrane De-risking Pilot Project has been carried out at Albian to test titania membranes with a surface area of 0.25 m2. Initial testing demonstrated the versatility of the titania technology to operate effectively in a wide range of water quality conditions.
If successful, this technology has the potential to be applied to both mining and in situ oil sands operations. Current testing of titania membranes is being performed on mining operations.
There are two key environmental benefits to adopting titania membrane technology.
- Recovering heat from process water or waste streams could improve energy efficiency and recycling rates in oil sands processing plants. Water temperatures in a mining facility are between 80 and 100 degrees Celsius; water is over 300 degrees Celsius in an in situ facility.
“Titania membranes have been shown to operate efficiently under high-temperature conditions,” explains Gavin Freeman, Technology Development at Canadian Natural. “Treating produced water without first having to cool the water down, and thereby conserving its heat value, will have a dramatic impact for in situ operations by reducing the complexity of the water treatment process and reducing the need for additional energy inputs.”
In addition to operators storing less process-affected water on account of higher recycle rates, reduced energy inputs mean less greenhouse gas emissions and overall cost-savings.
- Installing the membranes as pre-treatment for existing water processing plants could reduce river water intake. For Albian, it could represent a 40 percent reduction in water withdrawal at current rates.
The Titania Membrane De-risking Pilot Project was made possible by project support and a significant financial contribution by Alberta Innovates. The development of TiO2 ceramic membranes has been done in collaboration with Frauenhofer IKTS and is a contributed technology from Shell Canada to COSIA member companies.
Titania membrane technology will be tested in a high-pressure commercial oil sands facility and will include membranes of different sizes.
In 2017, Canadian Natural acquired 70 percent ownership of the Athabasca Oil Sands Project and is the operator of Albian and all of its technology. Testing continues at Albian to evaluate the performance, lifespan and maintenance of the membrane in commercial conditions. It is scheduled for completion at the end of 2017. A full-scale design, process and economic evaluation will be completed based on the test results.