Laying it on thick

So, you’ve heard about oil sands in a documentary or on the news. You’ve heard, perhaps, in conversation or classroom debates, about its impact on the environment. Perhaps you even know some people who have packed their bags and headed to Alberta to get their own nugget of black gold and share in the wealth. But this Texas, er…Alberta tea doesn’t come up from the ground like a bubbling crude as Jed observed in the famous classic, Beverly Hillbillies.

Instead, it comes in the form of bitumen… gummy, gooey and thicker than molasses in January. To make matters worse, it’s mixed right in with the sand, presenting a grueling challenge for industry. How to separate such an unruly brew from the ground is for another story, but this is a tale about the origins of bitumen’s thick skin and how we toil to tame this intractable taffy of the turf.

Thicker than peanut butter, but not quite as tasty, Athabasca bitumen has a viscosity, or resistance to flow, of more than 500,000 centipoise (cP) at room temperature.

Now, with every story you have some sort of conflict, a rising action, a climax and a conclusion. The conflict here is bitumen’s high viscosity, and the implications it has on this resource’s means of production and impact on the environment.

That’s a heavy story man

A penetrating glimpse inside the molecular structure of bitumen reveals the cause behind its thickness. Are you ready for it? Bitumen is thick because… (insert drum roll)… it is heavy.

You may have heard the term “heavy oil” before, but few people know what this actually means. What makes heavy oil heavy? What makes oil sands heavier than conventional oil or methane?

Essentially, when we say a certain oil is heavy, what we’re really saying is that it is carbon heavy, meaning that type of oil has longer and more complex carbon chains than other types of oil. Light crude oil, such as conventional Alberta crude, contains many small, hydrogen-rich hydrocarbon molecules whereas heavy crude oil contains many large carbon-rich hydrocarbon molecules.

As you can see, the antagonist in this particular story is the carbon molecules.

So, in order to bring bitumen to a viscosity that refiners can actually work with, you have to upgrade the bitumen, which essentially means, getting rid of some of the carbon, resulting in a product that is less thick. In fact, when you consider the extra process bitumen has to go through in order to get rid of all that heavy carbon, you can see where the environmental conflict lies. Additional energy is required to separate bitumen from the sands and upgrade it. As well, heavy crude oil requires more refining to transform it into transportation fuels. And of course, more energy equals more greenhouse gas emissions if the energy being used to power the extraction, upgrading and refining processes is natural gas.

So the rising action in this story has everything to do with the rising demand for cheap energy around the world, the important role of oil sands in meeting that demand and the unrelenting challenge of reducing greenhouse gases. The plot starts to thicken as the bitumen thins because at each stage of carbon removal, the viscosity of the bitumen becomes less and less, making it easier to work with. But the overall energy used becomes more and more. It’s really annoying.

Technology is starting to change all that. Scientists are exploring ways to reduce the energy used in oil sands extraction and upgrading. One approach in the pipes is adding bacteria to bitumen deep underground, converting it into methane, which is easier and less energy intensive to extract. Another in-situ approach of extraction is Toe to Heel Air Injection (THAI) which involves injecting air into the ground, causing combustion. As the bitumen heats it becomes less viscous allowing it to flow towards the well. As it flows it leaves some of the heavy carbon behind in a process called “coking”. Coking usually happens above ground as part of the upgrading process but doing it underground results in a lighter product that can be transported through pipelines, is partially upgraded and results in fewer lifecycle greenhouse gas emissions.

Of course, another approach is to use renewable energy to power any or all of these processes. The challenge here is that renewable energy is not as cheap and bountiful. But as society and governments evolve towards increased sustainability, that could soon change.

Although renewables are rapidly being embraced across the globe, it is important to recognize the degree to which we depend on oil, even as we make the transition to greener alternatives. Sure we can heat our homes with solar and earth energy, and derive electricity from nuclear, wind and hydro, but there remains a conundrum surrounding our cars. Solar, nuclear, wind and hydro-powered cars are still a long way off. Sure we have hybrids, but for the most part they still run on gasoline and electric cars have very limited ranges and low speeds. As well, a lot of electricity used to power them is coal or natural gas fired thermal electricity.

Now, every good story must have at least a few literary devices, and the most delicious of them is irony. We labour to make bitumen and the resulting crude products less viscous right from the extraction phase (especially with in-situ extracting techniques) through to the upgrading and then refining phase. The most premium petroleum products are the highly refined and less viscous transportation fuels such as jet fuel and gasoline. Ironically, lubricating oil, which is a highly refined product, needs to be more viscous so as not to ruin the engine. So after all this work to make it less viscous, additives are put in to make sure it retains its viscosity.

Because the oil sands and its continually evolving technologies are a work in progress, this story is too. There are yet so many variables that could affect the outcome, such as the direction of the economy, incentive to invest in research and development and carbon pricing laws. While the U.S. is introducing a tough stance on carbon emissions through its Green Energy and Security Act, Canada is waiting to see what happens before coming up with anything definitive.

But the rest of the world isn’t holding its breath. Already the wheels are in motion to come up with a global carbon pricing scheme in an effort to reduce world greenhouse gas emissions and to ensure an even playing field for renewable energy to compete in the global energy market. It may be safe to predict that the outcome of the upcoming conference of world leaders in Copenhagen this December could serve as a climax for this story.

Most importantly, however, is the conclusion and that rests in the hands of energy consumers as well. Mitigating climate change is a heavy topic and while many remain thick headed towards a potentially warming planet, many more are working towards a positive conclusion for the planet – one where energy, the economy, the environment and its inhabitants live happily ever after.

The Great Oil Sands Journey Part 3

Bitumen finally grows up

Once you manage to get the bitumen separated from the sand, the next step is to get it upgraded, a process needed to convert bitumen into a product with a density and viscosity similar to conventional light crude oil. Upgrading, like life, comes in a series of stages.

Wells to Wheels
Part three of a five-part series

The first stage deals with breaking up the enormous carbon molecules. We’ll look at this as similar to being a child because they still have many school years to complete before they are ready for a career, though, to be fair, they have already come quite a long way. For bitumen, the ultimate goal is to get a career in fueling cars, jets or furnaces, or becoming a plastic or asphalt. Just as there are many jobs in the world, so too are there many petroleum products.

Bitumen contains more carbon-rich hydrocarbon molecules than conventional oil, so it’s important to upgrade the bitumen into a product that refiners can work with. This is usually done through a process called “coking” which breaks down heavy oil molecules into lighter ones by removing the carbon. Another approach is hydro-processing, which adds hydrogen under high-pressure to help balance out the carbon to hydrogen ratio. If you’re torn between which of the processes to use next time you want to break down some carbon-heavy molecules, a common approach is to do both.

The second stage is a process called hydrotreating. We’ll look at this stage as similar to being a highschool student. These students have accomplished many years of school and soon they will be graduating. If there is anything still childish in them, they are encouraged to get it out of their systems now. The same is so with bitumen. Hydrotreating, for example, removes childish things like sulphur and nitrogen.

Once upgrading has happened, the oil must be refined. This is the process of transforming the crude oil into a classy, well-dressed product. Well, actually, we’re going to look at this phase as the college student phase. First, what refining does is distill the oil at various temperatures to make various products. Of course, all refineries are different, but ultimately they separate and process the mix of hydrocarbons in the oil, transforming it into a whole array of different products like gasoline, lubricants, diesel or jet fuel, depending on which tray it evaporates up to and settles on after it has been heated. Think of this as like specialization. Before people can enter the work world, they should specialize their learning in certain subjects that match their interests and aspirations. The crude oil’s final product – its destiny – is determined by its makeup, its boiling point and the tray upon which it settles.

Here’s refining in a nutshell

This separation is done through an atmospheric distillation tower which is a tall steel tower layered with perforated trays at different levels. Each petroleum product has a different boiling point so the distillation tower is able to separate the different products through heating and cooling. The distillation process is continuous and begins by heating crude oil in a furnace until it turns into a vapour which rises through perforations in the trays. As the vapours rise, they shed their heaviest components, which condense onto the tray, liquefy and are then drawn off the tray by pipes. Heavier hydrocarbons boil at a much higher temperature than lighter ones, so they settle in trays near the bottom or middle-bottom, resulting in products like jet, diesel and furnace fuels. Lighter oils collect at the top, resulting in products like light gasoline and petrochemicals.

Interestingly, despite the fact that much of Canada’s fuel demand is met through oil sands, much of the bitumen is sold to U.S. refiners rather than being refined here in Canada. This is mainly because Canada’s older refineries are designed to process predominately low-sulphur light crude oil. However, some Canadian refineries are being retrofitted to handle synthetic crude.

The fact that oil sands refining jobs and opportunities go south has caused quite a stir in recent times. With the struggling economy, many organizations, such as the Alberta Federation of Labour, are speaking out and urging the Alberta Government to intervene and stimulate the creation of refineries, and jobs, in Alberta.

So there you have it… the full process of oil’s journey from the oil sands mine or in-situ well, right up to the point where it becomes a refined product that is ready and willing to do its job. And just as it is so in life, entering into the work world is just another beginning.

Next week:  Wheels to Winds – Everyone wants a piece of the plump pump pie