Fuel

Fuel gives us power.

It can make heat. It can make light. We use wood for fires. We use oil for cars.

It helps us do work. Fuel can be a solid. Wood and coal are solids. Fuel can also be a liquid. Oil is a liquid fuel. Some fuel is a gas.

This gas can move through pipes. We use many kinds of fuel every day.

Fuel is any material that can release power.

It can make heat or light. It can also help us do work. People have used fuel for a long time. Early humans used firewood for fire.

Most fuels come in three forms. Some are solids, like wood or coal.

Some are liquids, like gasoline or kerosene.

Some are gases, like propane.

Many fuels are fossil fuels. These are made from dead plants and animals. They formed under heat and pressure over millions of years. Common fossil fuels include coal, petroleum, and natural gas.

Because they take so long to make, they are non-renewable. This means we cannot replace them quickly. Burning them also makes carbon dioxide. This can cause global warming. Today, many people look for renewable fuels. These are fuels that can be replaced quickly, like biofuels from plants.

Fuel is any material that can release energy. This energy can be heat or light. It can also be used to do work. Some fuels release energy through a reaction called combustion. This is a way of burning. This heat can turn into mechanical energy using a heat engine. Living things also use fuel. Cells use organic molecules to release usable energy through cellular respiration.

Fuels come in different forms. Some are solid, like wood, coal, or peat. These are often burned to provide heat. Other fuels are liquids, such as gasoline, diesel, or kerosene. Most liquid fuels come from the remains of ancient plants and animals. Some fuels are gases, like natural gas or propane. These gases can travel easily through pipes to where they are needed.

Humans have used fuel for a very long time. Nearly two million years ago, Homo erectus used firewood for fire. For most of history, people used plants or animal fat. Around 6,000 BCE, people used charcoal to melt metals. In the 18th century, European forests became thin. People began using coke, which comes from coal, instead of charcoal.

History shows many clever ways to use fuel. Persian chemists once distilled crude oil into kerosene. A man named Muhammad ibn Zakarīya Rāzi wrote about this in his book, Kitab al-Asrar. In the 1700s, the steam engine changed how we use coal. Coal helped run ships and locomotives. By 2005, coal provided 40% of the world's electricity.

Many fuels we use today are fossil fuels. These formed from dead plants and animals under heat and pressure. This process took millions of years. Because they take so long to form, they are non-renewable. This means we can run out of them. Burning them releases carbon dioxide into the air. Today, many people are looking for renewable fuels like biofuels.

Fuel is any material that can react with other substances to release energy. This energy is often released as thermal energy, which is heat. It can also be used for work or to provide light through combustion. While we often think of fuel as something we burn, the concept includes other energy sources. For example, nuclear energy is used through processes called nuclear fission and nuclear fusion. The heat from these reactions can be converted into mechanical energy using a heat engine. This allows us to turn heat into movement for machines.

Chemical fuels release energy through a specific process called combustion. This is a reaction where the fuel interacts with substances around it. We can classify these chemical fuels in two different ways. First, we look at their physical state: solid, liquid, or gas. Second, we look at how they occur in nature. Primary fuels are natural, while secondary fuels are artificial. For instance, wood is a primary solid fuel, but charcoal is a secondary solid fuel made from wood.

Solid fuels are materials used to produce heat and energy, usually by burning. Common examples include wood, coal, peat, and dung. Some people also use pellets made from grains like corn or wheat. Coal was particularly important because it powered the Industrial Revolution. It allowed people to fire large furnaces and run steam engines. Today, coal and peat are still used to generate electricity. However, some cities limit the use of solid fuels like coal because they release toxic emissions.

Liquid fuels are molecules that can be used to create mechanical energy. Most of these fuels are derived from fossilized remains of ancient plants and animals. These remains were transformed by heat and pressure inside the Earth's crust. Liquid fuels like gasoline, diesel, and kerosene are very important for transportation. They are easy to transport and handle in many engineering applications. Some liquid fuels, like hydrogen or ethanol, are different from traditional petroleum products.

Fuel gases are fuels that exist as gases under normal conditions. Many of these are hydrocarbons, such as methane or propane. One major advantage of gas is that it can be moved through pipes directly to where it is needed. This makes it easier to distribute than solid or liquid fuels. However, gas can be dangerous because it can collect in areas undetected. To prevent accidents, workers add odorizers so people can smell a leak. Natural gas is the most common type of fuel gas used today.

Fossil fuels are a specific group of hydrocarbons like coal, petroleum, and natural gas. They formed over hundreds of millions of years from dead plants and animals. This process happened deep underground without oxygen. In 2007, fossil fuels made up 86.4% of the world's primary energy consumption. Petroleum accounted for 36.0%, coal for 27.4%, and natural gas for 23.0%. Because they take millions of years to form, they are non-renewable resources. This means we are using them much faster than nature can replace them.

Using fossil fuels has significant effects on our planet. When we burn them, they release about 21.3 billion tonnes of carbon dioxide each year. Natural processes can only absorb about half of that amount. This creates a net increase of 10.65 billion tonnes of carbon dioxide in the atmosphere. This process is linked to global warming. Because of these environmental concerns, there is a global move toward renewable energy. This includes biofuels, which come from biomass like plants that can be replenished quickly.