Grado 7

Grado 7Combustible y energía


Types of fuel


In the study of fuel and energy, it is important to understand the different types of fuel. Fuels are substances that release energy when they undergo a chemical or nuclear reaction. This energy can be used for a variety of purposes, such as driving vehicles, heating homes, and generating electricity. We can classify fuels into several types based on their source and form. In this discussion, we will go into detail about the different types of fuels available today, which will provide a comprehensive understanding for learners at the basic chemistry level.

Fossil fuels

Fossil fuels are energy sources that come from the decomposed remains of prehistoric plants and animals. They have been buried for millions of years and subjected to heat and pressure. The main types of fossil fuels are coal, oil, and natural gas.

Coal

Coal is a solid black or brownish-black sedimentary rock composed primarily of carbon. It is formed from the remains of lush plants that grew in swampy forests millions of years ago. There are different types of coal, such as lignite, bituminous and anthracite, which are classified based on carbon content and energy density.

Example: The chemical reaction of burning coal is represented as:

C + O 2 → CO 2 + Energy
Coal

Oil

Oil, also known as petroleum, is a liquid fossil fuel formed from tiny marine organisms. Over millions of years, these remains are buried under sediments and undergo chemical changes to form oil. Crude oil can be refined into various forms such as gasoline, diesel, and kerosene.

The general formula for the constituent alkanes of crude oil is:

C n H 2n+2
Oil

Natural gas

Natural gas is a gaseous fossil fuel composed primarily of methane. It is formed by the same processes that make oil and coal. It is the cleanest-burning fossil fuel, producing less carbon dioxide than coal and oil.

Combustion of methane, the primary component of natural gas:

CH 4 + 2 O 2 → CO 2 + 2 H 2 O + Energy
Gas

Biomass fuel

Biomass fuels are derived from organic matter, such as plant and animal waste. They are renewable and can be replenished naturally. Biomass can be burned directly or converted into other forms of fuel such as bioethanol and biodiesel.

Wood

Wood was one of the first sources of energy used by humans. It is still used for heating and cooking in many parts of the world. When wood is burned, energy stored through photosynthesis during the life of the plant is released.

The basic chemical reaction for burning wood is:

C 6 H 10 O 5 + 6 O 2 → 6 CO 2 + 5 H 2 O + Energy
Wood

Bioethanol

Bioethanol is an alcohol derived from fermented sugars in plants such as corn and sugar cane. It is commonly used as a fuel additive for gasoline to reduce emissions.

The fermentation reaction of glucose to form ethanol is:

C 6 H 12 O 6 → 2 C 2 H 5 OH + 2 CO 2
Bioethanol

Biodiesel

Biodiesel is a diesel alternative made from vegetable oils and animal fats. It is biodegradable and can be used in diesel engines with little or no modifications.

The general transesterification reaction to produce biodiesel from triglycerides is:

Triglyceride + 3 Methanol → Glycerol + 3 Biodiesel molecules
Biodiesel

Alternative fuel

Alternative fuels are those that serve as an alternative to traditional fossil fuels. They are often more environmentally friendly and can help reduce pollution and dependence on non-renewable resources.

Hydrogen

Hydrogen is a clean fuel that can be used in fuel cells or internal combustion engines. When hydrogen burns, it combines with oxygen to form water which is the only byproduct.

The basic reaction for hydrogen fuel cells is:

2 H 2 + O 2 → 2 H 2 O + Energy
Hydrogen

Electricity

Electricity is an energy carrier that can be generated from a variety of sources, such as fossil fuels, nuclear, wind and solar energy. Electric vehicles (EVs) use electricity stored in a battery pack to drive an electric motor.

Example: A simple representation of power generation using a hydroelectric dam:

hydroelectric dam

Nuclear fuel

Nuclear fuels such as uranium and plutonium are used in nuclear reactors to produce electricity. They undergo nuclear fission, in which the nucleus of an atom splits into smaller parts, releasing a large amount of energy.

Uranium

Uranium is a heavy metal and an important source of concentrated energy. It is fissioned in nuclear reactors to release energy.

The nuclear fission reaction of uranium-235 is:

U 92 235 + n → Ba 56 141 + Kr 36 92 + 3 n + Energy
Uranium

Plutonium

Plutonium is another nuclear fuel used in modern reactors and nuclear weapons. It is made from uranium-238 in a nuclear reactor.

Example of a plutonium-239 fission reaction:

Pu 94 239 + n → Xe 54 140 + Zr 40 99 + 2 n + Energy
Plutonium

Conclusion

Fuel is vital to keeping our world moving, from the cars we drive to how we make electricity. Understanding the different types of fuel enables us to make informed decisions about energy use and environmental impacts. As we move towards a sustainable future, it is important to use renewable and less polluting fuel options. Through advances in technology and changes in consumption habits, we can find more efficient and environmentally friendly ways to meet our energy needs.


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