Wednesday, July 20, 2011

A Lesson on Tar Sands

This article was written by MN GreenCorps resident, John van der Linden.

Question: Where does the oil for most of Minnesota's gasoline come from?

If you answered Saudi Arabia or Iraq, you'll be surprised at the correct answer -- just as I was when I heard it recently, in conversations with Roger Garton and Sean Muller of the Rural Renewable Energy Alliance (RREAL) in Pine River.

Answer: It comes from Canada. Specifically, from large mines in the boreal forests of Alberta.
That is only one of many surprising realities Sean, Roger, and several other members of the RREAL team heard about in April, during a forum at Bemidji State University. The university's sustainability office hosted the forum, "Our Energy Future," which included a presentation about Canadian oil production and a panel discussion about America's energy options for the next 50 years. (Organizers invited RREAL founder Jason Edens to share his passion for renewable energy on the panel.)

Recently Sean, an AmeriCorps VISTA volunteer serving at RREAL, and Roger, a former VISTA newly hired at RREAL, filled me in on one of the hot topics at the forum: a type of oil-producing substrate known as bitumen sands.

A Hidden Resource

Sean and Roger learned about bitumen sands from Marc Huot of the Pembina Institute, who presented at the forum. Bitumen sands -- also dubbed "tar sands" or "oil sands" -- are a thick mixture of sand, clay, and bitumen (a tarry substance) deposited underground in certain regions of Canada, Venezuela, and other countries.

One of the largest and shallowest deposits lies in northeastern Alberta, buried beneath a vast patchwork of boreal forest and muskeg as big as the entire state of Florida, or 2/3 of Minnesota (see map at left). Mining companies extract the sands and then crush, wash, heat, centrifuge, and otherwise process them until they yield crude oil. Refineries further process the crude into gasoline, which ends up in many Minnesotans' gas tanks.

About 10% of that Florida-sized Alberta wilderness harbors bitumen sands that are actually worth extracting at current oil prices. On these relatively few prime acres, mining companies extract bitumen sands using several techniques, some of which are still experimental. In one technique, workers use giant shovels to strip away what the industry refers to as "overburden" -- forest, bog, and soil, along with an underlying layer of sand and clay up to 75 meters thick (that's three-fourths the length of a football field!) -- in order to access the bitumen sands beneath. Another technique involves injecting steam into the ground to heat the bitumen until it flows like warm molasses into underground pipes, through which it is then pumped to the surface.

Pros and Cons of Bitumen Sands Mining

The burgeoning bitumen sands industry is already an economic powerhouse in Alberta, by one estimate employing around 50% of Albertans directly or indirectly. That Canada would invest so heavily in the industry is understandable, considering that its forests and bogs may overlie enough bitumen to propel Canadian oil reserves to the world's no. 2 spot, behind only Saudi Arabia. Thorough bitumen sands extraction could clearly do wonders for North American energy independence, at least in the short term. In fact, the Pine Bend refinery in Rosemount, MN -- one of the USA's top processors of oil from Canadian bitumen sands -- supplies most of the jet fuel for the Minneapolis / St. Paul International Airport.

What about the costs of extracting bitumen sands? Coaxing a barrel of crude oil from this thick, tarry subterranean source requires much more energy than producing a barrel from conventional oil wells. Sean and Roger also explained that washing the sands generates a toxic mixture of solvents, water, and particulate matter that's stored in settling ponds, often near rivers. Another byproduct of the mining and purifying process is a large amount of waste sulfur, which accumulates on-site in spectacular bright yellow piles easily visible from a passing aircraft.

Critics of bitumen sands extraction also warn of lax remediation standards -- mining companies need only restore land to an "equivalent economic value," not to the original forest or muskeg -- and serious negative impacts on downriver Inuit communities and caribou herds. Additionally, they point out that many jobs in the bitumen sands industry exist to expand the industry (e.g. road construction, pipeline installation) and so will only last as long as the industry is growing.

An Appeal for Conservation

To be clear, my goal in writing this article is not to convince you that bitumen sands extraction is good or bad. As an Energy Conservation Minnesota GreenCorps member, one of my primary functions is to encourage people to conserve energy -- at home, at work, in the car -- regardless of where that energy comes from. Of course, using energy wisely is especially important if your energy source -- coal, natural gas, crude oil from bitumen sands -- is nonrenewable.

As I listened to Sean and Roger relating Marc Huot's presentation, I was reminded of this fact: that so much of the energy we use to heat our homes and power our electrical devices derives from dwindling resources we cannot replenish. The bitumen sands are a sizable but nonetheless limited resource, and extracting the oil requires a large investment of labor, time, resources, and capital. If we Minnesotans wish to maintain a supply of that resource for decades to come, and to ensure Canada's investment in bitumen sands mining doesn't bottom out in the face of overexploitation, then it makes sense to limit our use of gasoline to what's needed. It also makes sense to remember what Jason Edens says about our energy future -- that there are many renewable energy technologies out there, such as RREAL's solar-powered furnace, that can contribute to a diverse "golden buckshot" (rather than a single "silver bullet") of 21st century energy solutions.

Sean Muller and Roger Garton, pers. comm.
Rural Renewable Energy Alliance (

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