may 2009 issue
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The Keyser File
An Answer at Hand?
Since the dawn of oilsands mining, the search has been on for a better way to deal with tailings. One answer could prove to be bipolymer beads small enough to hold in your palm
by Tom Keyser
Freelance Columnist
They roll lightly across your palm, these featherweight beads that one writer aptly compared to Kellogg’s Corn Pops. Technically, they’re known as re-useable hydrocarbon sorbent technology, or RHST, and their owners believe they represent an answer to one of the most urgent questions in the energy industry: how to neutralize the negative effects of oilsands tailings.
Fine tailings are a water-and-clay-based mixture about the consistency of thin yogurt. Created as a byproduct of the warm-water process in oilsand extraction at the rate of about one cubic metre for every four barrels of oil produced, fine tailings contain residual bitumen, naphthenic acids and naturally occurring salts.
“I’m not in favour of extreme environmental positions against commercial interests. I’d much rather see a well-grounded, middle road with a progression to success,” says Keith McCrae, P.Eng., Gradek Energy’s chief operating officer and point man in Western Canada. Gradek Energy is the Montreal company that developed RHST.
But neither is Mr. McCrae one to understate the situation. He points out: “Tailings ponds exist because industry has so far been unable to remove bitumen from the fine particles such as clays and metallic oxides during the extraction process. And as bitumen in the ponds biodegrades, it forms methane and stable, long-life toxic acids, which may eventually leach into groundwater.”
Syncrude Supports Pilot
During a series of small-scale tests, the RHST process has already proven itself by working every time, Mr. McCrae says. Now, after eight years of preparatory testing and discussions, the Calgary-based engineer and his team have convinced Syncrude Canada Ltd. to participate in a major pilot project to demonstrate the process under continuous flow conditions.
To be completed by year’s end, the treatment pilot will be on a neutral test site with a steady tailings feed of 3.5 tonnes an hour. Syncrude will supply feedstock and monitor results. If things go well, a larger-scale test will follow.
“Scalability is the primary question,” notes Mr. McCrae. “I have complete confidence in the technology and its commercial viability, but there will be many engineering challenges in achieving the necessary scale-up to between 2,000 and 4,000 tonnes per hour of tailings feed, per train.”
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LITTLE BEADS, BIG JOB |
It’s an intriguing enough tech-nology, in fact, that RHST drew Mr. McCrae’s sights away from retirement.
He’s an APEGGA life member who spent much of his career on oilpatch-related process facilities projects. At one point, he was based in Kazakhstan with Hurricane Hydrocarbons Ltd. of Calgary, later renamed Petro-Kazakhstan. There, he was president of the operating company, Hurricane Kumkol Munai.
Meeting the Genius
By 2000, he was still involved in challenging international projects located in Yemen and Colombia. But then a colleague introduced him to a Montreal-based scientist named Thomas Gradek, ing., who invented and developed RHST.
“Tom is an insatiable reader and researcher,” says Mr. McCrae. “I consider him a genius.”
As Mr. McCrae tells it, Mr. Gradek was profoundly upset by the Exxon Valdez disaster of 1989 and set out to find a new way to deal with major oil spills. This was the genesis of RHST.
The remarkable affinity of the bipolymer for hydrocarbons led him to the oilsands industry and his research switched gears. He redesigned the RHST bead with a hard surface to withstand the abrasive qualities of the silicon sand environment.
During experiments, Mr. Gradek mixed oilsands ore with water heated to 40 C. Drawn from the slurry by the bipolymer beads, residual bitumen hugged them like dew on a blade of grass.
Left behind were residual tailings solids and a reservoir of surprisingly clean water. Mr. McCrae says the water can be successfully treated by conventional means and re-used for further bitumen extraction.
It all added up to just the sort of technology a major oilsands company would like to look at.
Mr. McCrae’s experience with oilsands mining projects and the operating companies provided the context for introducing Gradek Energy to Syncrude, which has already spent millions of its own dollars in the search for a solution to the tailings problem.
Although clearly hoping for the best, the oilsands consortium is taking a wait-and-see position.
“We want to support (external) ideas we think have some merit,” says Dr. Jim Kresta, P.Eng., a senior member of Syncrude’s research team. “Gradek will run the pilot and we will provide feedstock, along with advice on what the company needs to prove to say it makes sense to move one step closer to a finished product.”
Obviously, Mr. McCrae also hopes for the best. Yet he is confident that RHST will hit a home run.
One thing is certain. No matter where this adventure leads, Mr. McCrae nurses no regrets about his decision to put retirement on hold.
“Tom Gradek and I share a passion to create an industry-wide solution to the complex problems rooted in the proliferation of tailings ponds in Alberta. The tag ‘dirty oil’ is simply not acceptable to Canadians and humanity in general.
“This technology offers the prospect for solving many problems at the interface between preservation of our environment and the world’s dependence on oil supply.
“As for myself, I don’t see retirement happening anytime soon.”
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