The oilsands industry has made important strides in recent years at cleaning up tailings ponds and reducing its fresh water use. But cutting its greenhouse-gas emissions is proving a harder nut to crack. Most of the improvements in carbon intensity to date have come from efficiencies such as using larger trucks at mine sites, and the returns there are diminishing. But a pilot project at a major producer’s well site aims to suck up as much as 20% of the carbon dioxide produced—using algae.
Last May Canadian Natural Resources teamed up with Markham, Ont.–based Pond Biofuels and the National Research Council to build a $19-million “biorefinery” at its Primrose South project near Bonnyville, Alta. Primrose is an in situ operation, where steam is injected down a well to melt the bitumen so it can be pumped to the surface. The emissions from natural-gas-fired boilers used to generate steam make the well site more carbon-intensive than conventional oil wells.
In the future, those emissions will instead be diverted to the biorefinery, where they, along with waste heat and water from the oilsands operations, will be filtered through vertical fences of glass tubes or “photobioreactors” filled with fast-growing algae. The harvested algae will then be converted into usable products such as biofuels, fertilizer and animal feed. Smaller bioreactors of this kind are already in operation at a cement plant and a steel mill in Ontario. This one will establish whether it can put a dent in the country’s fastest-growing—and widely vilified—source of atmospheric pollution.