Practical Tips for Guzzolene

I like tidy systems.

Ultraviolet Grasslands has a very tidy inventory-supply-time system. People consume 1 sack of supplies per week. An unencumbered person can carry 1 sack of supplies or a personal inventory full of adventuring gear. A horse can carry 2 sacks, so 2 weeks of supplies or 1 person and their stuff.

The system has full support for grazing animals or air-breathing autogolem wagons. But if you want to transport larger volumes of goods, you need fuel or power.

There's not much support for fuel. No prices, no size guidelines. VOMEs might make fuel, but do other factions distill it? Are there gas stations? Tankers? Herds of petroleum-dripping cattle?

It's not stated. So, because my players have found an RV with tank treads, I'm going to write some material for guzzolene-powered vehicles.

This introduction isn't meant as a proper tutorial or course. I've simplified everything and ignored some complicated or inconvenient bits. You've been warned.
 

Part 1: Drilling for the Blood of the Earth

Crude oil sometimes bubbles naturally to the surface. For post-apocalyptic purposes, or modern purposes, this isn't relevant. There's no such thing as a free lunch.

Mining for oil with traditional shafts and pits, works if the oil is close enough to the surface and you don't mind oil going everywhere. It's not efficient, but you don't need any fancy technology or tools.

But for practical purposes, drilling is the most sensible method. In a typical post-apocalyptic landscape, reclaiming existing oil wells is probably the best plan, but it might be useful to briefly go over the options for starting a new well.
 

Auger Drilling

An auger is your common woodworking or metalworking drill, but bigger, and on the back of a truck. It spirals into the earth, draws up soil or stone, and ejects it. It's not practical for oil drilling. Oil is typically deep underground. The length of auger required, and the torque needed to turn it, would be ridiculously impractical.
 

Cable Drilling

Making a drill several hundred feet long is difficult. A cable drill is a sort of jackhammer. A sharp bit is raised and lowered in the bore, chipping away at the rock. Every so often, a bailer (a bucket with a bottom that opens and closes) is sent down to remove the chips.

In a typical '50s steel-and-v8 post-apocalyptic landscape, cable drilling trucks are probably abundant. These days, not so much.
 

Rotary Drilling

The most common method these days, though variants and refinements exist. Take a length of pipe. Stick some sharp wheels on the end. Spin it and send it down a hole. Since you don't want to add a new pipe segment every 10 minutes (or take ages and ages removing segments), adding a long pipe section each time makes the most sense. That's why oil derricks exist. They're towers to line up and assemble pipes over a well.

The rotating drill bit churns solid rock into grit. You can send down a bailer every so often to remove the cuttings or, more sensibly, force a liquid down the hollow pipe. The liquid picks up the cuttings and pushes them out of the way, either into the surrounding rock or back up the sides of the borehole.

This method has another massive practical advantage. Oil is typically under pressure. Drill a hole normally and all that oil will come flooding out. Oil-bearing rock also contains lighter hydrocarbon gas (i.e. natural gas). If you don't keep a lid on it and keep the borehole pressurized, gas is likely to flood upwards and detonate.

Drilling mud is a moderately toxic mixture of clay, water, and hydrocarbons. Endless variants exist for every situation. Making drilling mud isn't too complicated, but you will need water and pumps.

Part 2: Extracting Oil

Oil pressure might be sufficient to propel a useful volume to the surface. Controlling or storing the flow is relatively trivial. Just build some tanks or dump it in a pit.

But if the oil doesn't flow upwards, you'll need to install some sort of pump. Pumpjacks, those grasshopper- or donkey-type nodding things, are relatively trivial to build. They convert rotational energy (from an electric motor, a few donkeys, or a bunch of barbarians) into translational energy to, in a sense, scoop the oil out of the well. If that doesn't work, sending liquid down the well to fracture the oil-bearing rock (fracking) can increase well yield. 

So, you've got your oil. Now to turn it into fuel.

To do that, I need to teach you how an oil refinery works.

Part 3: Build an Oil Refinery in 5,960 Easy Steps

You can't run a car on crude oil. At sensible temperatures, crude oil doesn't flow easily or burn cleanly. To do anything complicated with crude oil, we need to separate useful from useless compounds.

But first, a few definitions.
  

Temperature

Temperature is a measurement of the average kinetic energy of particles. "Average" is a key word. Some particles will be traveling faster than others, some slower. It's a bell curve. This is why you can see steam rising from boiling water before it reaches 100 degrees. Some water molecules have enough energy to transition into the gas phase despite the average molecule not having enough energy.
 

Volatility

A measure of how easily a substance transitions from the liquid to the gas phase. Lighter fluid (butane) is volatile. Bricks are not volatile. Decreasing pressure also decreases the energy required to boil a substance; in effect, lower pressures increase volatility.
 

Density

How heavy a substance is per unit volume. Bricks sink in water. Oil floats on water. Air floats above oil. Etc. In a dense mixture of substances (crude oil, mayonnaise), the easiest way to achieve density separation is to heat the substance to, essentially, let its components move past each other.
 

Refinement

Density refinement like separating a mix of sand and gravel by shaking the container. Larger rocks sink, smaller rocks float. Alternatively, it's like separating oil and water by letting your salad dressing sit in the fridge for a few days or heating up your mayonnaise.

Phase change separation (or distillation) is like separating a mix of ice, lead, and gravel by heating the mixture until the ice melts and can be poured out, then by heating the lead until it melts and can be poured out, and then by throwing the gravel away or going a bit mad and melting it too.Phase change distillations are convenient because turning a liquid into a gas separates it from the remaining liquid mixture. It can be cooled, condensed, and collected.

Because crude oil is an awful mess of compounds, it's measured in fractions with similar boiling points rather than by specific compound names. Light fractions are more volatile, heavy fractions are less volatile.
 

Primitive Refinement

Say it's 825 and it's time to repave the roads of Baghdad with tar or make some greek fire for the Byzantine navy. You take some crude oil and heat it. If you're making asphalt, you don't care what happens to the lighter products, so you can heat it in an open barrel. If you're making greek fire, or any lighter combustable mixture, you can collect and condense the vapours or just heat the mixture until it's more fluid, pour off the upper layers, and leave the dense residue behind.

This is primitive batch distillation. Given time and some very expensive equipment (for the era), you could probably produce a few litres of very dirty gasoline or diesel per day. Considering you can run a modern-ish combustion engine on almost anything (ethylene gas, ethanol, deep fat fryer oil, hydrogen gas, etc) with a few modifications, I'd say it's good enough for post-apocalyptic purposes... in a pinch.
 

Batch Refinement

Depending on who you believe, advanced batch distillation of crude oil didn't start until the 1850s. A fancy version of batch distillation is used today at most liquor distilleries, so the basic process may sound familiar.

Crude is added in batches to a tank (or "kettle") heated by burning the light hydrocarbons naturally produced by oil wells (or other fuels, if those weren't available). Free fuel is free fuel.

Hydrocarbons evaporate and pass through the wonderfully evocatively named Dephlegmator. Just as a decanter removes the cants from your brandy, a dephlegmator removes the phlegm from the crude oil. OK, that's not entirely true, but the basic ideas is there. The dephlegmator aids in heat exchange and helps control which fractions reach the condenser. The condenser uses cold water to turn a hydrocarbon from a gas to a liquid.

There are a few problems. A simple condenser or still (i.e. a cold tube that condenses vapour flowing through it) is not very efficient at separating compounds. Remember, temperature is a range. If you're trying to collect substance A, which has a lower boiling point (is more volatile) than substance Z, some of Z will almost inevitably creep into the vapour, be condensed, and mix with your output. A distillation column (there are many designs) tries to ensure all fluids and vapours inside are at a nice even temperature and pressure.

The system needs to be run in batches because tar and other unsuitable products build up in the kettle and towers. It's also not particularly effective at large volumes. On a benchtop scale you can get pretty decent fractionation, but with either kerosene or vodka, multiple distillations are required.

If you can pump oil out of the ground continuously, why not distill continuously? Why bother shutting down every few hours? The simplest way to perform continual distillation is to chain a bunch of batch distillation setups together. You can either shut down one for cleaning and run another, or run the first one so hot that the tar flows out immediately.

Building a batch refinery requires a lot of steel and some expertise, but it's very possible. The world is littered with large tanks and pipes. Tuning a refinery once it's operating is also possible, so you don't need to get it precisely right the first time.
 

Catalytic Refinement

So you've got crude oil flowing in one side of your refinery and tasty fuel oil flowing out the other... along with a lot of waste. It's all about fractions, and only a fraction of crude oil can be distilled into your product of choice. All the rest either floats off (if it's light) and can potentially be captured or burned, or sits around gumming up the works. There's a market for lubrication oil, asphalt, and tar, but not much of one.

But what if you could turn some of your otherwise useless fractions into delicious useful product? Thanks to the magic of catalysis, you can. Fluid Catalytic Cracking units (FCCs) are proper industrial magic.

Catalysts are special compounds (usually, quite expensive ones) that make a chemical reaction more probable. Heavier hydrocarbons can decompose into lighter ones, but a catalyst effectively turns it from a one-in-a-million chance into a one-in-a-hundred chance. The chance of you flipping a coin and it landing on its edge is very low, but it increases if you build a sloped ramp to slide the coin at just the right angle. The ramp is the catalyst.

For large-scale industrial processes, it's impractical to mix the catalyst into the liquid or gas and extract it later. Instead, catalysts are usually put on a solid substrate (a pellet) and mixed with very hot heavy hydrocarbons. The pellets can be recovered and reused. Ideally, catalysts aren't consumed in the reaction, but they can be neutralized (poisoned) by unwanted substances.

Instead of throwing away poisoned catalyst, refineries regenerate it by (in most cases) blasting it with heat and steam. The regenerated catalyst is sent back into the reactor. The regeneration process is violent, so to reclaim every atom of precious (and ridiculously expensive) catalyst, refineries often use electrostatic precipiators. Air from the regenerator passes over electrostatically charged plates. Metal catalyst particles are attracted, collected, and reused.

If the idea of a high-voltage system full of sparks, metal powder, hot air right next to towers full of highly flammable hydrocarbons seems ridiculously dangerous... you're entirely correct. Failures in the systems that separate the air-catalyst-lightning side of a catalytic cracking unit from the hydrocarbon-distillation side result in mass casualties and huge explosions.

Heating liquid hydrocarbons or flashing them into gasses right next to an open flame is generally considered a bad plan. Far safer to heat a non-flammable liquid (such as water) over here, then pump the hot liquid over there to heat up the flammable hydrocarbons, or use the hot output (which you want to cool down anyway) to heat up the input. Of course, then you need heat exchangers, and heat exchangers can get clogged...

For post-apocalytic purposes, catalytic cracking (or the thousands of other related processes that a modern refinery uses to turn unwanted hydrocarbons into useful ones) is not viable. Maybe in the middle of an oil-based city, but on the outskirts, it's far easier to dump or burn what you don't need and simplify the process. Rare metals are, well, rare and tend to corrode vital equipment.
 

Mad Max 2: The Compound

The tower at the centre of the compound is clearly a distillation column. It's not fancy. Given a welding shop, some existing steel tanks, and a few test runs, most post-apocalyptic communities could rig one up in a few weeks or months. The advantage of simple distillation and post-apocalyptic lack of regulation is that you can tune the process on the fly. There's no need to get it right the first time.

The system can be fuelled by hydrocarbon byproducts (natural gas or burning lighter distillates), so power isn't an issue. Water could be a problem. Pre-washing crude to remove soluble salts helps keep a distillation column from clogging with scale (the white stuff that builds up in your kettle).

Mad Max: Fury Road: Gastown

We only get a glimpse of Gastown in the film, but it looks like a full refinery complex. The thick grey smoke and multiple burnoff stacks suggests they aren't doing any fancy refinement. Anything not useful gets burned, either as fuel for the process or just to get it out of the way.

Next up: practical rules for RPGs, oil barons, factions, etc.

Further Reading:

PennState's online refinery course.
USCSB safety and incident videos.