A Primer – What’s in a “Tar Sands” Pipeline?

In the wake of renewed interest in the Keystone Pipeline project and the likelihood that Obama will eagerly approve it unless we stop him, there’s a lot of interest in what actually flows through those pipes.

Van Jones has called it “planet-cooking goo.” I’ve called it “sludge.” But what is it really?

To answer that question, we need to look at:

▪ What is “tar sand“?
▪ What is extracted from it (answer, bitumen or “tar”)?
▪ What is done to the bitumen to make it “flow”?

All of which produces a great bottom line. Click any of those links to jump to that section.

The primary source, though not the only source, of this information is a great article and slideshow at the Scientific American website. Feel free to click and read as we walk through this material.

What is “tar sand”?

“Tar sand” is sand with a mix of tar, clay and water stuck to the surface of its grains. Yes, literally tar (more on that below).

To see tar sand in action, watch just a few seconds of this video, part of a piece made by Raul Grijalva and Adam Sarvana [corrected] to illustrate some of what’s wrong with Keystone and why it should be opposed. What Adam dumps into the water is clumped tar sand.

Watch the whole video if you like, but for this, the first few seconds after you hit Play is enough. (Note: The video and text that overlays it implies that “liquified” sand flows through the pipes; it doesn’t. The part about sinking in water is correct, but it’s not “liquified tar sand” that sinks, it’s the tar itself after the sand is removed.)

This is a picture of tar sand from the SA slideshow (click to open in a new tab). The caption reads (my emphasis):

Water and a film of bitumen [tar] surrounds each grain of sand, making Alberta’s oil sands the easiest to work with to free oil. A typical “ore” will be 73 percent sand, 12 percent bitumen, 10 percent clay and 5 percent water. There are an estimated 170 billion barrels worth of bitumen in Alberta that could be recovered with today’s technology, which means Canada has the third-largest proved oil reserves in the world behind Venezuela and Saudi Arabia.

More on that term “bitumen” in a moment. Are you noting the industry-friendly phrasing in this, by the way? “Alberta’s oil sands” indeed; as you’ll read shortly, it’s not oil until it’s processed. It’s not even crude oil yet. And the oh-boy cheerleading for oil reserves in the last sentence doesn’t sound like the writer thinks of oil as Demon Carbon, Killer of Grandkids, does it?

Oil sands, tar sands, in Alberta, Canada - Keystone Pipeline

Oil sands in Alberta, via Shutterstock

Tar sand clumps together. That clumping is so pronounced that the gluing makes them acts like rocks, as Raul’s video shows above. Here’s a before-and-after picture of a “crusher bit” used to de-clump the tar sand (again, opens in a new tab).

The first step in manufacturing (there are many) is to remove the sand, clay and water and accumulate just the tar. This is done at or near the site where the tar sand is mined (yes, by scoop-loaders and dump truck like these).

The tar is removed in vats by adding boiling water, creating a froth that causes the sand to sink and the tar to rise and then overflow to be captured for further processing and shipment. As the slide-writer says:

Add hot water to tar sands and, with a little mixing, the oil, water and sand begin to separate. “You take the ore, mix it up with warm water, and the bitumen floats to the top and you skim it off,” explains Murray Gray, scientific director of the Center for Oil Sands Innovation at the University of Alberta. “The sand sinks to the bottom and the clays cause problems everywhere in the middle.”

This is what the industry-friendly text above, from the University of Alberta, means by “warm water”:

At a typical mining operation large separation cells—giant funnels that mix 80-degree Celsius [176°F] hot water and chemicals to reduce acidity with the oil sands—produce a bitumen froth that overflows into catchment basins. From ore to froth takes roughly 30 minutes, and the process is measured in cubic meters per hour. The remaining sand and water are pumped to vast ponds for settling and storage.

This is one of the vats; notice the “froth” oozing out in the left foreground. That’s where the tar is, or as the experts call it, “bitumen.”

What is “tar”?

Here’s where it gets interesting — if you don’t already think the strip-mining and the toxic “tailings” like filthy water and other residue from what you’ve just read about is interesting.

The terms “tar,” “pitch,” “asphalt,” and “bitumen” are nearly synonymous, so long as you’re referring to something naturally occurring. In fact, bitumen was once called “asphaltum.” The exceptions are “road asphalt” and “road tar,” which are manufactured substances that don’t have a lot of the gunk that the natural stuff has. (All of this is explained here, if you’re interested.)

What we care about is the natural product, tar or bitumen — what it is, what it contains, and how it acts.

What is tar? It’s not just a mixture of chemicals in the ordinary sense. It’s something called a colloidal suspension — in this case, small particles of a bunch of solids suspended in a liquid. (Milk is also a suspension, by the way, but a liquid-in-liquid one.) That matters because suspensions can be made to separate, and when that occurs to bitumen, even the diluted bitumen (called “dilbit”) found in the pipelines, the solids sink in water.

After all of the refining and manipulation that makes it possible to move diluted bitumen goo through a pipe (more below), at the end of the day, it’s still a suspension, a solid in a liquid. When the pipe breaks or leaks, the solids separate from the lighter liquid and end up underwater or carried underground by rain.

The biggest onshore pipeline oil spill in the U.S. was a diluted bitumen–containing pipe that leaked into the Kalamazoo River in 2010. They’re still trying to get the tar from the bottom of the river. Many think it will be there almost forever. From the NRDC blog:

Nearly three years after Enbridge [a Canadian oil company, like TransCanada] spilled a million gallons of tar sands crude into the Kalamazoo River watershed and almost a billion dollars has been spent on cleanup, and 38 miles of that river are still contaminated.

There’s crap on the surface of the river, but also junk on the river bed itself. Imagine cleaning a river bed.


Keep that in mind — bitumen (tar) is a suspension, so even when it’s diluted, it’s still a suspension. It isn’t “dissolved” in its dilutant the way salt is dissolved in water. It’s a suspension when they pull it out of the ground, and it’s a suspension until they take it apart at the refinery. The solids (or near-solids) will always separate out when a pipeline spills or leaks.

What does bitumen contain? The stuff is complex, chemically. Different deposits contain different ingredients, but some ingredients are frequently found (and very nasty):

One writer stated although a “considerable amount of work has been done on the composition of asphalt, it is exceedingly difficult to separate individual hydrocarbon in pure form”, and “it is almost impossible to separate and identify all the different molecules of asphalt, because the number of molecules with different chemical structure is extremely large“.

Most natural bitumens contain sulfur and several heavy metals, such as nickel, vanadium, lead, chromium, mercury, arsenic, selenium, and other toxic elements.

Are these elements present in the bitumen-containing pipelines? Yes. They’re removed at the refineries, where oil and gas are extracted and made. But at the source, where the mining occurs, the only task is to remove the sand, as much of the clay as possible, and get the stuff in condition to flow.

How does bitumen act? In addition to its properties as a suspension with heavier-than-water solids in it (see above), it’s extremely viscous, thick and resistant to flowing. It does flow, but at a snail’s pace at room temperature. (Actually, snails move faster, as the famous “pitch drop” experiment shows. It took 70 years for eight drops to fall.) We’re calling it a “solid” but it’s technically a “near-solid.”

Why does that matter? Because of what it takes to move it through a pipe.

How are tar sands processed for “shipping” to refineries?

For the obvious reason (expense), tar sand mining companies want to do the least they have to in order to ship their product to refineries, where actual oil and gas products are made. Those refineries can be near the mining sites, further inland (some Alberta pipelines terminate in the Midwest, for example) or on coasts near shipping ports.

Tar intended for shipment to Asia and other world markets are often refined near places that can also handle super-tankers, such as the Texas gulf coast. The proposed new Keystone Pipeline extension is intended to ship tar (diluted bitumen, “dilbit”) to Texas.

That in itself should tell you all you need to know about who the customer is going to be (hint: not you). And it should also tell you to start digging into how many of these “Canadian” companies are partly owned by Chinese companies.

But back to shipping via pipelines. The bitumen “froth” is converted both to usable oil products and to pipe-able bitumen via “upgrading” — partial refining near the mining sites. Some upgrading produces usable oil products:

To turn thick bitumen into saleable petroleum products, oil sands operators rely on upgraders—mini-refineries to transform bitumen into crude oil using heat, pressure and chemistry like the Syncrude Canada plant pictured here. The Suncor Energy plant produces enough diesel to fuel its own heavy hauler mining trucks as well as much of Alberta’s diesel demand—some 30,000 barrels of diesel alone per day.

Here’s a picture of that lovely Syncrude Canada plant in operation. There are also “coking” operations at these sites. The byproducts are coke (dirty coal) plus some of the stuff used to dilute the bitumen for shipping (piping). Read the following carefully; it covers both aspects:

At the core of the upgrading plant looms the 88-meter-tall coking tower, where bitumen is cracked into shorter-chain hydrocarbons, including diesel and naphtha, used to dilute some bitumen and ship it via pipeline instead of upgrading it on-site.

What remains are deposits of nearly pure carbon, known as coke, which is essentially low-grade and very dirty coal that the plant burns as fuel to generate heat and electricity. Suncor alone makes 500,000 tons of coke per year.

So naphtha, diesel and other hydrocarbon products are produced by “upgrading” some of the bitumen, which is then used to dilute the rest of the bitumen for shipping via pipelines.

So what flows through the pipes?

If you thought that diluted bitumen, as produced by the upgrading plants, is now capable of flowing through a pipeline to the cash registers in Texas (or wherever), you’d be wrong. Even in diluted form, bitumen doesn’t flow. To make it flow, it has to be heated — often to 150°–160°F — and then forced through the pipelines under high pressure.

So what flows through the pipeline? Keeping those cash registers in mind, you now have all the pieces. Tar sand pipelines contain:

A carbon-rich colloidal suspension …

Made up of lighter-than-water, easily-evaporated toxic liquids (like diesel) …

And heavier-than-water solids (the tar or bitumen itself) that sink to the bottom of rivers and below the mud in fields …

Which has been heated hot enough to burn your hand — or accelerate the external corrosion of the pipeline itself, including pinhole breaks …

Which has been forced to move under high pressure …

And which contains poisons and toxins like sulphur, arsenic, nickel, lead and mercury …

All so megalomaniacal carbon billionaires can make even more money.

That’s what flows through the pipelines. Or to put it more simply:

What flows through the pipes is the unmonetized assets of the try-and-stop-me CEO class, which if it spills, will poison everything it touches for decades or centuries, and if it gets into the air, will turn most of our grandchildren — the ones that survive — into hunter-gatherers.

Bill McKibben counts those unmonetized assets (proven reserves) at $27 trillion dollars. Add in reserves that are likely but not proven, plus the ones in the melting Arctic that are yet to be found, and you’re talking real money. The billionaire class won’t walk away from that in a hurry.

And that, kids, is Science Talk for today. We learned a little about a lot, didn’t we — everything from colloidal suspensions and bitumen “froth,” to billionaire psychopathology and cash registers in Texas. To those of you who got to this end of the post, my thanks!


To follow or send links: @Gaius_Publius

Gaius Publius is a professional writer living on the West Coast of the United States.

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