Shale oil extraction

Some rocks hold oil inside them.

People get this oil by using heat. They can dig the rocks up. Then they heat them in big machines. This makes the oil turn into a gas. The gas turns back into liquid oil.

Some people do this work underground. They heat the rocks deep in the earth. Then they pull the oil up through wells. This way, they do not have to mine.

The leftover rock can be used for things. It can help make bricks or cement. This is a clever way to use it.

People have used this for a long time.

Some rocks hold oil inside them. This oil is trapped in a material called kerogen. To get the oil out, people must use heat. This set of steps is called shale oil extraction.

There are two main ways to do this. One way is called ex situ. In this way, people mine the rocks from the ground. They take the rocks to a factory. They crush the rocks into small pieces. Then, they heat them in a machine called a retort.

One common way to heat the rocks is pyrolysis. This means heating them without oxygen. The heat makes the kerogen turn into oil vapors and gas. When these vapors cool down, they turn back into liquid oil. This leaves behind a solid waste called spent shale.

Another way is called in situ. This means the work happens in place. People heat the rocks while they are still deep underground. They then pull the oil up through wells. This way, they do not have to mine the rocks.

People have studied this for a long time. A doctor wrote about it in the 10th century. Today, countries like Estonia, Brazil, and China use these methods.

Shale oil extraction is a way to get fuel from special rocks. These rocks contain a substance called kerogen. Kerogen is not liquid oil yet, but it can become oil with heat. This process is important for making energy. It helps countries find fuel when they do not have much regular oil.

There are two main ways to do this work. The first way is called ex situ processing. This means the rocks are mined from the ground first. They are moved to a factory and crushed into small pieces. The second way is called in situ processing. This happens in place, deep underground. Heat is applied to the rocks while they stay in the earth. Then, the oil is pulled up through wells just like regular oil.

One common method is called pyrolysis. This is a way to heat the shale without using any oxygen. When the kerogen gets hot, it turns into oil vapors and gas. These vapors are collected and cooled until they turn into liquid shale oil. This process leaves behind a solid waste called spent shale. This waste can be used to make things like bricks or cement.

People have known about this for a very long time. A physician named Masawaih al-Mardini wrote about it in the 10th century. In 1684, the English Crown granted the first patent for this process. Later, in 1838, Alexander Selligue invented a process in France. James Young improved these ideas in Scotland a decade later. By the late 1800s, many plants were built in places like Australia and the United States.

Today, many countries use these technologies. Major industries are currently running in Estonia, Brazil, and China. In 2008, these three places produced about 930,000 tonnes of shale oil. Other places like Australia and Canada are testing new ways to do it. Some people worry about how this affects the air and water. They ask how to manage waste and pollution carefully.

Shale oil extraction is a specialized industrial process used to produce unconventional oil. This process targets a substance called kerogen, which is found within oil shale rocks. Kerogen is a solid organic material that can be converted into liquid shale oil. This conversion is vital for energy production when traditional crude oil is scarce. It also helps nations improve their energy security by using local resources.

To turn kerogen into oil, scientists use several chemical methods. The most common method is pyrolysis, also known as retorting. In pyrolysis, the shale is heated in an environment without any oxygen. This heat causes the kerogen to decompose into two different substances. The first is shale oil vapor, which can be condensed into liquid. The second is a non-condensable oil shale gas. Other methods include hydrogenation, which uses hydrogen, and thermal dissolution, which uses solvents.

Extraction technologies are categorized by where the work happens. Ex situ processing occurs above ground. In this method, the oil shale is mined from the earth and moved to a facility. The rocks are often crushed into small pieces to increase their surface area. This helps the heat work more efficiently. In contrast, in situ processing happens in place. Heat is applied to the shale while it remains deep underground. The resulting oil is then pulled up through wells, just like conventional crude oil.

Different machines and methods are used to transfer heat to the shale. Some methods use internal combustion, where the heat comes from burning materials inside the retort. Others use indirect heating, where a heat source is kept outside the retort. Heat can also be delivered through gas, solid materials, or even radio waves and microwaves. For example, vertical retorts often use gas to carry heat to the shale. Horizontal retorts might use rotating drums to move the material through the process.

History shows that humans have studied this process for centuries. The Assyrian physician Masawaih al-Mardini wrote about extracting oil from bituminous shale in the 10th century. Much later, in 1684, the English Crown granted the first formal patent for this extraction. Modern industrial methods began in the 19th century. Alexander Selligue invented a process in France in 1838. James Young later improved these techniques in Scotland. By the late 1800s, extraction plants were operating in Australia, Brazil, Canada, and the United States.

The industry has seen many ups and downs due to global oil prices. In the mid-20th century, the discovery of large conventional oil reserves caused the industry to shrink. However, high petroleum prices in the early 21st century sparked new interest. As of 2010, major industries were operating in Estonia, Brazil, and China. In 2008, these three locations produced approximately 930,000 tonnes of shale oil. This amount equaled about 17,700 barrels per day.

While shale oil provides energy, the process has notable side effects. Pyrolysis produces a solid residue known as spent shale. This residue contains minerals and a carbon residue called char. If the char is burned off, it leaves behind oil shale ash. Both spent shale and ash can be reused to make cement or bricks. However, critics raise concerns about environmental management. They focus on issues like air pollution, waste disposal, and the extensive use of water.