A helping hand from tar sand

TORONTO (CUP) — “I wanted to do something good for the environment, but as an engineer, I am also concerned with producing economically viable processes,” says chemical engineering Professor Charles Jia, about his goal of utilizing “coke,” a waste product of Alberta’s tar sands, to mitigate environmental pollution. Though Canada’s estimated oil reserves are second only to Saudi Arabia’s, much of this black gold is locked up in tar sands, which are made up of sand and a black, tar-like substance called bitumen. “Unfortunately, the bitumen in the tar sand is heavier than crude oil-meaning it has a higher carbon to hydrogen ratio,” says Jia. “This is a bad thing. The carbon to hydrogen ratio needs to be lowered in order to get synthetic crude oil.”

The process for tar sand purification is called “upgrading.” Carbon and hydrogen are removed from bitumen resulting in synthetic crude oil-used for diesel-and coke, a material composed of 90 per cent carbon and six to eight per cent sulphur. Until recently, the Alberta government stockpiled coke, and spent enormous amounts of money to maintain those piles.

Then, Jia had an idea. What if the coke could be used as a starting material in a process that produced two useful products, one of which would be an environmental “cleaning agent”? With funding from Alberta’s government, his research group has come up with a process, called So-Active, that converts coke into elemental sulphur, which is used for fertilizer, and activated carbon, a highly porous form of carbon that absorbs pollutants from air and water.

“Activated carbon, or ‘eco-carbon,’ has a high specific surface area because of its porous internal structure. This high surface area enables it to adsorb lots of pollutants, including sulphur dioxide from flue-gas and mercury from water,” Jia explains. Eco-carbon targets two environmental banes of modern human life. Sulphur dioxide is the agent responsible for acid rain, and mercury is the increasingly prevalent toxin found in fish and other marine life.

Jia sees other uses as well. “High-sulphur coal currently cannot be used as an energy source because of its negative environmental impact. But we are running out of low-sulphur coal. The So-Active technology enables Canada to use high-sulphur coal because the coal can be cleaned up.” Details of the process’ mechanism are unavailable because the patent on the process is still pending, but Jia hopes that it will be commercialized within the next two or three years.