What Even Is Crude Oil?

Crude oil poison.

Crude oil is natural.

Crude oil makes modern life possible.

Crude oil is fuel.

Crude oil is plastic.

Crude oil is medicine.

Crude oil is food. 

Crude oil is everywhere.  

 

What is crude oil? 

When we were young, many of us were taught that crude oil and other fossil fuels are made of dinosaurs. Some gasoline brands even use dinosaurs as their mascots. While this isn't entirely wrong, it's not exactly the truth either. 

Fossil fuels like oil, coal, and natural gas (methane) are all the remains of creatures that lived millions of years ago and gradually decomposed over those millions of years. Coal, the solid fossil fuel, is made up mostly of hard-bodied organisms, i.e. plants. Coal is made mostly of ancient trees and other plants, and it shares a lot in common with charcoal, which is also made of wood. Oil, the liquid fossil fuel, is made up of mostly soft-bodied organisms. This includes ancient animals like dinosaurs, but in reality most crude oil is made of ancient algae, because much like today, there was a lot more total algae on Earth than there were animals when dinosaurs walked the earth. Natural gas, also known as methane, is a byproduct of the decomposition of all of those creatures, essentially it's bacteria farts. 

What makes crude oil (and other fossil fuels) so useful? 

Living things are incredible chemical factories. Every organism on Earth is constantly taking in various chemicals from their environments and rearranging them in thousands of unique ways to grow their bodies, adapt to their environments, and harness energy for movement. This is accomplished through a symphony of delicately choreographed processes within and between cells that often involve carefully shepherding individual molecules to a desired location to be linked together with specific other molecules. This results in complex lattices made of woven together blends of thousands of different chemicals. The specific processes that make life possible involve a level of complexity that strains human understanding, and a level of delicate craftsmanship that has so far never been possible for humans to achieve artificially. 

Although humans have accomplished amazing things using synthetic chemistry, comparing the greatest human chemical accomplishments to the greatest natural chemical accomplishments is like comparing a masterful Lego creation to a cathedral. While the level of work, detail, and artistry on display in professionally made Lego creations are incredibly impressive, there is so much more on display in a cathedral. Cathedrals carry the benefit of using much more customizable materials like stone and stained glass, which can be manipulated into a huge array of shapes and patterns, and they also benefit from the collective labor and resources of thousands of individuals across multiple generations. All of those analogies hold for human chemistry vs. natural chemistry. Nature performs chemistry using much more sophisticated tools than humans have developed, and the processes nature uses for chemistry have been refined over millions of years. By comparison human chemistry in its modern form has only existed since the 1700s. We've made some amazing things with our chemistry Lego sets, but at the end of the day we're still just building with Legos.

Since humans haven't figured out how to build molecules atom by atom the way nature does, instead we need to use shortcuts. We take chemicals made by nature and use them as the metaphorical Lego bricks for our creations. This is the reason why crude oil is so incredibly useful. Think of a living thing, like a lizard for example (a dinosaur perhaps?), as a complex pre-built Lego set, and you want to build something else out of those same Legos. You could break down the Lego set into pieces and rearrange the pieces into something else, but as anyone who has torn down a Lego set knows, the disassembly process is time consuming and often frustrating. It would be so much easier if all the pieces were already disassembled so you could just focus on building your own creation. The slow decomposition process that turns living things into crude oil is amazing, because it breaks down the living things into nice useful chemical chunks, as though someone disassembled a Lego set and handed you a bucket filled with all the pieces. Sifting through the bucket of mixed Lego pieces (i.e. oil refining) can be a slog, but it's much easier than carefully disassembling the previous Lego set on your own. 

Crude oil deposits are also not only made up of one living thing, they are a blended up mix of the remains from many different living things. So imagine if your bucket of mixed Legos doesn't just contain the pieces from one set, it contains the pieces from every Lego set ever made. Think of the endless possibilities you could have in combining so many pieces any way you want! Of course there are some things you could never hope to make using all those Legos--you couldn't build a cathedral out of them--but with so many building blocks and enough creativity you could spend lifetimes coming up with unique and amazing things to build. 

That is exactly what chemists (particularly organic chemists) have been doing for the past few hundred years. Crude oil is used to make plastic, medicine, fuel, food, tools, and much much more. Crude oil is often seen today as being dangerous and toxic, which it is, but that isn't the whole story. The natural world also creates many dangerous and toxic things--remember that snake venom and cyanide are both all-natural, and remember that crude oil is a jumbled up mix of EVERYTHING that was part of those once living creatures, including the safe useful stuff and the dangerous scary stuff. The craft and responsibility of chemistry is to carefully separate the safe useful stuff from the toxic dangerous stuff, and the wisdom to know which one is which. Many many mistakes have been made in distinguishing those parts from each other, and many irresponsible chemists have used otherwise safe chemicals to build new dangerous creations. The study of chemistry and its ethics are still evolving, and for now crude oil is still the greatest source of raw material for that study. That can be a very good or very bad thing depending on how that resource is used. 

What is crude oil used for? 

Crude oil can be used in a huge variety of ways. For example, the "Lego bricks" of crude oil can be arranged into shapes that we see in nature. Many medicines and food flavorings are synthesized from crude oil, where the synthetic products are identical to natural medicinal chemicals or natural flavors that scientists had previously identified. Since all the building blocks are already readily available in the crude oil it is often faster and cheaper to recreate these natural chemicals artificially than it is to wait for plants to grow them from scratch. If humanity needs millions of pounds of aspirin to treat all the world's headaches, then it is much faster to make aspirin from crude oil than it is to wait decades for a forest's worth of willow trees to grow, only to extract the 1% aspirin that each tree contains. 

Crude oil can also be used to make things that have never existed in nature by putting together the once natural building blocks new ways. This process has given us things like plastic, synthetic fabrics, fertilizers, pesticides, and many medicines. The fact that these materials aren't natural doesn't necessarily mean they are harmful, however human-made synthetic chemicals are by definition new, so without thorough study it often isn't clear one way or another whether they pose any risk to human or environmental health. When paired with proper testing, this process has given humanity access to synthetic medications like antibiotics that have saved countless lives, and specialized materials that make joint implants and dissolving stitches possible. The place where this causes problems though, is that it is much faster and easier to create new combinations of oil-based chemicals than it is to test those new combinations for potential long term toxicity. When profit motives enter the picture, there can then be significant pressure to mass produce and sell a new chemical or material before it has been thoroughly tested. This can have dire consequences as demonstrated by the long term effects of leaded gasoline, which poisoned generations of children, mercury in hat manufacturing, which led to "mad hatter's disease," and modern toxins like microplastics and PFAS of which the impacts are not yet fully understood. The modern process for vetting new chemicals before they enter the marketplace is better than it has ever been, but it still has significant room for improvement.

Crude oil is a tool, and like any tool, it can be used for good or for ill, and it can be conserved or squandered. Burning crude oil for fuel has horrible environmental impacts, and beyond that it is also a huge waste to spend a limited resource that could be used to make medicine and tools by instead burning it for mere moments worth of power. At the same time though, modern life would not be possible without crude oil. We rely on it for our necessities and our luxuries, and if its potential had never been unlocked, the industrial revolution probably never would have happened. Thanks to centuries of innovation, humanity now has the first ever opportunity to maintain the quality of life we have come to enjoy while weaning ourselves off of the fuel that got us here. In many ways we have crude oil to thank for getting us this far, and as often happens when exchanging parting words, it is perfectly reasonable to say "thank you" to crude oil while we say "goodbye."

Can crude oil be replaced? 

Crude oil can be replaced, and for many applications it already has been replaced, but that it is often a difficult undertaking. Going back to our Lego analogy, the most effective way to use chemistry as we currently understand it is to take natural products, like plant oils and waste from food production, then break down those natural Lego sets into individual pieces so we can use them to build new things. This step of breaking down natural products isn't required when working with crude oil, since crude oil is already pre-deconstructed, and it takes additional time, tools, and energy. This is why naturally derived products often struggle to compete on price with crude oil derived products, because natural products require the additional deconstruction step and crude oil prices are subsidized by most governments worldwide. This is a major reason why products like biodiesel and bioplastics have struggled to gain mainstream success.

The areas where naturally derived crude oil alternatives have found the most success are in cases where clever chemists have found natural products that are already very nearly a fit for a product's needs. For example, lots of cosmetic products used to be made largely of crude oil in the form of petroleum jelly and crude oil-based detergents, but there are plenty of natural sources that produce similar molecules to those synthetic options. So rather than making cosmetics from crude oil, now there are many options that are made from natural products like palm oil, animal bones, and specific bacteria that have been given minor chemical modifications. In many cases this is even easier and cheaper than using crude oil, because it's easier to snap a chunk off of an existing Lego set, then tack a few Legos onto that chunk, than it is to build something from scratch. 

Through careful sourcing of natural alternatives and economic incentives to favor natural materials, crude oil could be completely replaced over time, although that isn't strictly necessary for the health of people and the planet. Crude oil is a tool, and like any tool it is possible to use it responsibly, even though historically that isn't how it has been used. Unfortunately though, chemicals derived from natural sources are tools too and can be used just as dangerously as crude oil often has. Pollution won't be solved by burning biodiesel instead of gasoline, it will be solved by moving beyond the need to burn anything at all, by using renewable energy sources like solar, wind, and hydro power. Toxic chemicals that end up in our products and waterways carry the same toxicity regardless of whether they were made from crude oil or corn husks. The solution to the environmental and health crises we face is responsible science and responsible public policy. A substantial reduction in the amount of crude oil that the world extracts and consumes will almost certainly be part of that, but after the transition to renewable energy is complete, if the world continues to use a trickle of crude oil for certain specialty cases, that is safe so long as the trickle is being used responsibly.