High school chemistry was not my shining moment. But since then, I've discovered that science transforms a dirty liquid called crude oil into many useful products we use every day. Now most of this work is done by a refinery, and I'd like to give you a visual tour of what a refinery does, and how it makes dirty oil into jet fuel.
So let's go. Let's start with one principle that makes this all possible. Vaporization. As it turns out, crude oil is made up of a whole range of different liquids, all hydrocarbons, but very different characteristics, all mixed together.
One of the differences is the boiling point of each liquid type. Here's a picture of what that looks like. At the bottom is the heaviest liquids that need the most heat to boil.
That boiling point is over a thousand degrees Fahrenheit. These heavy liquids are used for asphalt and tar. Now on the other end of the spectrum are light liquids that turn into butane and gasoline.
They have a much lower boiling point, less than a hundred degrees. So that cool science-y information will make the whole refinery make a bit more sense. Let's start our refinery tour at the heart of the refinery.
which is the distillation tower. You can physically see these towers if you drive by a refinery. They're the tall tube that stands up taller than pretty much anything else in the refinery. Now before crude oil goes into this distillation tower, it's heated up to a scorching temperature that vaporizes all the liquids in the crude oil. Now based on our little graph earlier, that would be higher than a thousand degrees.
So the resulting vapor, super hot, goes into the bottom of the distillation tower and then as the vapor rises through the tower it starts to cool down. So think about it, what happens when a vapor cools down? It passes the boiling point of some of the vapor and as soon as it drops below the boiling point it turns into a liquid. For example, the first stage of the tower is around a thousand degrees and that's enough to start turning the heaviest components of the vapor back into a liquid.
Those that have a boiling point above a thousand degrees. This liquid gathers in a funnel and then gets piped out to the storage area and sold to asphalt companies. This idea keeps repeating itself as vapor cools along each stage and each lower temperature a new type of liquid gathers into the funnel and then gets shunted off to a process that applies to that specific liquid.
Finally we get to the top where we're left with gasoline vapors and what we call liquid petroleum gas or LPG. Now LPG turns into propane, butane and other things. That's the distillation tower and that's the heart of the refinery.
You can see these when you drive by at a refinery. Like I said, it's a big tank. that towers above the whole site and you can see the pipes coming off the side for the various liquids at the different boiling points. So we talked about heavy oil turning into asphalt and then as you go up the stack of end products you can see some of the other products that come out of a refinery like diesel fuel, jet fuel and motor gasoline. You may notice that some of these products show up in multiple spots on the product stack.
And that's what we want to talk about next. You see, the demand for products doesn't neatly line up with the supply. And so refineries have to come up with clever ways to transform between different liquid types, depending on what the demand is.
Now, the proportions or fractions that naturally come out of the distiller are heavily weighted toward the heavy oil at the bottom and the gases at the top. The demand, on the other hand, is heavily weighted toward the middle, where diesel, gasoline, and jet fuel come from. So as a result, there's two primary transformations that happen to make these middle products out of liquids that come from either end. On the heavier oils, they're sent through a coker or a cracker to break up the long, heavy molecules into smaller ones so that they can become fuel and gasoline. On the other end, some of the light liquids like naphtha can be reformed at a molecular level to gasoline.
And this part of the refinery is called a reformer. So to review, the crude oil comes into the refinery where it's heated to well above a thousand degrees. Then it moves through the distillation tower to separate out each fraction of the crude. And because of the demand is for products in the middle of this process, there's coking and cracking processes to transform the heavy oil into fuels. And then there's the reforming processes that transform NAFTA into gasoline.
Now in the end, the mix of output looks something like this, where gasoline is almost half of the volume exiting the refinery and the rest is made up of diesel, jet fuel and other products. This mix makes up 55% of the world's energy supply, and that needed volume isn't expected to change much in the near term, even if the percentage of total energy goes down. Refineries remain a critical part of our energy world. Until our consumption mix dramatically changes and we start transitioning to other forms of energy, this will be required. Cisco, the sponsor of this video, helps to make refineries more efficient, safer, and more sustainable.
For more information on how Cisco does that, visit cisco.com slash go slash oil and gas. Take care.