Everyone knows that hydrocarbons like oil and gas contain large amounts of energy. Thanks to the process of combustion, that energy is available to us.
What exactly is combustion? And what role has it played in human history?
The history of combustion extends much further back in history than the invention of the automobile or the power plant. Combustion, it seems, has always been a part of human survival.
Indeed, people have been burning things since ancient times, using fire to stay warm, cook food, and fend off the darkness.
Fire is the result of a simple reaction. Heat from an ignition source, like a match, causes the molecules of a fuel to break apart and combine with oxygen. The reaction, called combustion, creates heat and light, as well as products of the reaction, like water, carbon dioxide, carbon monoxide, and soot. These products can run the gamut from benign, like water, to toxic, like carbon monoxide.
The concept of combustion may sound simple, but its impact on human history has been enormous.
Archeologists have discovered the remains of campfires a million years old. For at least that long, humans and fire have been inseparable.
Many scientists think that the use of fire for cooking allowed people to spend less energy digesting raw food, which left them with more energy for brain development.
What have we been using these large brains for? Among other things, we’ve been coming up with new ways to harness the power of combustion. The history of combustible materials is a repetition of a common theme: resource discovery, followed by depletion, followed by the development of a new resource that has a greater energy density.
As human population expanded in Europe during the middle ages, native forests were cleared for fuel and agriculture. Europe’s colder winters strained fuel supplies of all types. By the end of the 1500s, Europe had little wood left to burn. At the same time, people increasingly used the heat provided by fires for a new purpose – the production of metal. Fuel was still necessary for warmth and cooking, but the intensive nature of smelting and smithing soon stretched all combustible resources to their limits.
If no new sources of fuel had been discovered, the future would have looked grim.
Coal
People turned to coal. This fuel, made up of the ancient remains of wetland plants, could be found throughout Europe, just waiting to be dug up. It wasn’t always easy to get it – but it was worth the effort. Coal has a higher energy density than wood, meaning that it can produce more heat by weight when burned.
People had been aware of the combustible nature of coal for centuries, but the difficulty of acquiring it, compared to say dung, that’s just lying on the ground; or peat, that IS the ground; or trees, that stick out of the ground; made it a less desirable commodity. But when other sources became scarce and new technologies were developed that could better utilize coal, and in some cases were only possible with coal, it became valuable. Like anything valuable, people found ways to get it.
After the surface outcrops of coal were used, coal mines were dug deep into the ground. As they got deeper, water started seeping into those mines. Someone had to drain that water if the coal was to be safely retrieved.
Now an interesting twist occurred. Someone thought it might be worth exploring the idea of using a steam engine to pump water out of mines, and what better way to power a steam engine at a coal mine than with coal! So they built an engine powered by coal and used it to get more coal. It proved to be a powerful and efficient system, and it gave people a lot of new ideas.
Soon, coal-powered steam engines began to replace horses and mules all over the place. The amount of work that could be done grew at previously unheard of rates.
Thus began the industrial revolution, and demand for coal skyrocketed.
And why not? Coal was cheap, and by this time relatively easy to dig up, and full of energy. But, like any source of energy, it was not without its downsides.
Heavily industrial cities such as London and Pittsburgh, Pennsylvania, began to experience pea-soupers, days when residual soot from burning coal blacked out the sun. Streetlights were lit at midday, and health problems were common. Additionally, it was not convenient or safe to use coal for light inside people’s homes, at least not in its natural state.
So what did people use to fuel their domestic lamps?
Whale Oil
Whale oil was a popular choice among the wealthy. Although expensive, it was clean burning and did not have a strong odor. Between 1700 and 1850, fleets of ships based in New England scoured the world’s oceans for whales, driving many species to the brink of extinction.
Poorer people were stuck with candles or lamps that burned smelly, sooty oil made from rendered animal fat.
Fortunately for the whales, and coughing city dwellers, the development of two new fuel sources with even higher energy density than coal once again revolutionized combustion.
“Conventional” Oil & Gas
In the 1830s, a process for extracting flammable gas from coal began to spread across Europe and North America.
This coal gas as it was called, was used to light city streets and private homes. But by the mid 1800s, coal gas was being abandoned in favor of natural gas, which is gas produced from wells in a readily usable form. The first of these wells was drilled in the state of New York in the United States.
By the 1850s, yet another energy source arrived on the scene. Petroleum, which can reach the earth’s surface through natural seeps, had long been known as a cure-all medicinal balm. But it wasn’t until 1853 that Polish pharmacist Ignacy Łukasiewicz realized that petroleum could be refined to produce kerosene, a cheap, clean-burning lantern oil.
After that, changes started coming more quickly. We greatly improved the refining process of oil and invented many machines to use the resulting products. We learned how to convert crude oil into diesel, gasoline, jet fuel, and many other combustible liquids. Indeed, we were burning things like never before.
Petroleum became the fuel of the 20th century.
We burned it in our power plants.
We burned it in our vehicles and factories.
We fought wars over who would control its production.
We used it to produce plastic and other products.
In short, oil made the modern world possible.
But history is repeating itself. Just like wood and whale oil before them, “conventional” oil and gas resources, those that are relatively easy to extract, have mostly been depleted.
“Unconventional” Resources
In response, we have developed unconventional resources. These were once considered too difficult and expensive to extract. But as the supply of conventional resources has diminished, it has become more and more profitable to extract oil and gas using unconventional methods such as horizontal drilling and hydraulic fracturing. Once again, when fuel sources become scarce, they become more valuable. And when things are valuable, people will find a way to get them.
One day, we will deplete even our unconventional oil and gas resources. When or before that time comes, we better have come up with a plan for new sources of energy. We’re always going to need heat and light. Will we continue to burn things to make them as we have for the last million years? It’s up to us to decide.
As you can see, combustion has remained a part of our society for thousands of years. But we’ve come far since the days of burning manure and peat for warmth. Our civilization is now powered by hydrocarbons, liquids and gases extracted from deep underground.
Unlike peat, wood, or even whale oil, the extraction of oil and gas requires complex technology and highly developed scientific expertise. Despite this complexity, the fact remains – the modern energy industry is really just the most recent manifestation of humanity’s ancient need to burn things.
Images: “Fire” by photo-nomad via iStock; “Archaeological Tools” by Openfinal via Shutterstock; “Coal Mine” by Detroit Publishing Company via Library of Congress; “Downtown Smoke” by University of Pittsburgh Libraries; “Grand Ball Given by the Whales” by Vanity Fair, 1861; “Signal Hill Oil Field, Long Beach, California” by Spence Air Photography via Library of Congress