2018 Winner: Outstanding Achievement in Science & Engineering sponsored by Alberta Economic Development and Trade
Improving oil sands recovery has significant impact
Dr. Xu is a world leader and Canada’s foremost expert in the development of state-of-the-art interfacial science to advance mineral processing and improve bitumen recovery from oil sands. Dr. Xu pioneered the use of modern scientific methods to understand underlying theory to optimize and revolutionize the processing of natural resources while reducing the environmental impact.
What problem did you see a need to solve and how did you solve this real-world problem?
My research is mainly in oil sands engineering with an emphasis on the fundamentals of extraction.
In the oil sands extraction process, to extract the bitumen from oil sands, you must detach the bitumen from the sand and solids. The challenge comes from the presence of lots of fine clay, which has a detrimental impact on the bitumen recovery. When you separate the bitumen from the sand in slurry, you must enrich the bitumen oil and use flotation. In the flotation, the challenge is to attach bitumen effectively onto the air bubbles to improve the recovery. If you can improve the recovery from the same amount of resource with the same operating costs, with less energy usage, this will have a positive environment impact and economical incentive.
What has been the impact?
The coarse sand is easy to remove, but the issue is in the fine clays that settle to 30 percent, which is like a gel, and will not consolidate any more. As you produce more oil and mine more oil sands, you accumulate a lot of this sludge, which is an environmental liability for the industry. In oil research, the focus is on improving all aspects, from the flotation and bitumen liberation to the challenge of using warm water.
Originally hot water was used, but now with slurry pipelines they use warm water to heat up the slurry to increase separation. Our research is to find a way to do the extraction process at the minimum temperature required. We developed a hybrid oil sands flotation and extraction process, which uses less heat and better aerates the slurry so that the bitumen more effectively attaches to the air bubbles.
We did lots of interfacial phenomenon research to understand why the water droplets are so stable in the oil. Then we developed new ways to break the interface oil in the water so the water droplets coalesce.
On the tailing side, to reduce the liability, we developed a new inorganic hybrid polymer, which can effectively flocculate clays and enhance the solid and the liquid separation to produce stackable solids. This process can release the maximum amount of water so you don’t have to use as much fresh water and you don’t have to contain as much tailings water.
Has being in Alberta helped you find success?
I started my academic career at McGill University in Montreal. I worked mainly with the mining industry with sulphides and base metals. When I was exposed to the oil sands, I saw that this was a very good opportunity for me to grow in my academic career.
I moved from Montreal to Edmonton in 1997. I’m so happy I made the move because I accomplished so much working with great people at the University of Alberta and from the oil sands industry. The industry is very supportive of fundamental research to reduce the environmental footprint for oil sands extraction and development.
Who have been your major supporters?
Our research has been supported by most of the oil sands operators, including Syncrude, Suncor, Canadian Natural Resources Limited, Shell and companies like Total S.A. from France, Statoil from Norway, Outotec from Finland, and Nalco Champion and Baker Hughes from the US. Our research is very well supported and our research is very visible in terms of extraction.
What are the plans for the future?
Our research strength is really in trying to develop the oil sands to be more competitive, but leave a minimal environmental footprint.
The hybrid processes we’re developing will be one of the new directions down the road that industry will consider seriously because we can perform extraction at the ambient temperature. Of course, you have to resolve tailings issues. There is so much waste produced like coke, sulphur and clays. If we can find new ways to utilize those by-products, there will be no waste and that would be a very good direction for the industry.
How does it feel to be an ASTech Finalist?
I’m excited to be selected as people are recognizing the work we have been doing here. It is another way to drive us for the further development of oil sands, to utilize more effectively the resources we have in Alberta, to make them more competitive and with less environmental issues.