What is the Difference Between Solid Liquid and Gaseous Fuels

The key difference between solid liquid and gaseous fuels is that solid fuels have a definite shape, and liquid fuels have no definite shape and take the shape of the container, whereas gaseous fuels have no definite shape and spread through the space.

The three major fossil fuels are coal, petroleum, and natural gas. These three fuels come under the groups of solid fuels, liquid fuels, and gaseous fuels, respectively.

CONTENTS

1. Overview and Key Difference
2. What are Solid Fuels 
3. What are Liquid Fuels 
4. What are Gaseous Fuels 
5. Solid vs Liquid vs Gaseous Fuels in Tabular Form
6. Summary – Solid vs Liquid vs Gaseous Fuels

What are Solid Fuels?

Solid fuels are solid forms of materials that can release energy upon burning, which provides heat and light through the process of combustion. These fuels are discussed in contrast to liquid fuels and gaseous fuels. Some common examples are wood, charcoal, peat, coal, hexamine fuel tablets, dry dung, wood pellets, corn, wheat, rye, etc.

Generally, solid fuels are used extensively in rocketry and solid propellants. These fuels have been useful throughout human history in creating fire. Somehow, solid fuels are still in use as a widespread fuel throughout the world at present.

The most common types of solid fuels include wood, biomass, peat, coal, coke, smokeless fuel, municipal waste, and rocket propellant. The calorific value for these fuels varies depending on the carbon content, hydrogen content, non-combustible or ash content, and water content. We can measure the heat produced by burning as the heat of combustion, which is an exact measure typically determined with bomb calorimetry.

Solid fuels are often cheaper than liquid and gaseous fuels. Moreover, these are easier to extract and more stable to transport. In addition, solid fuels are readily available in many places. Coal is a particularly important solid fuel that is used by about 38.1% of the world’s electricity generation. This is because it is less expensive.

What are Liquid Fuels?

Liquid fuels are liquid forms of material that can release energy that can be used for work. The most common forms of liquid fuels include petroleum, including crude oil and products of petroleum refining, natural gas liquids, biofuels, liquid-derived hydrocarbons, etc.

Liquid fuels can undergo combustion to generate energy and can be harnessed to generate mechanical energy such as kinetic energy. Liquid fuels take the shape of a container, similar to other liquids. Typically, the fume of the liquid is flammable instead of the liquid itself.

Moreover, liquid fuels are usually formed from fossil fuels. Several other forms, such as hydrogen fuels that have automotive use, ethanol, and biodiesel, can also be categorized as liquid fuel. These liquid fuels play a primary role in the economy and transportation needs.

What are Gaseous Fuels?

Gaseous fuels are gas forms of material that can release energy to perform work. These are also known as fuel gas. These are in the gas phase under ordinary conditions. Typically, fuel gas contains hydrocarbons, hydrogen, carbon monoxide, etc. Gaseous fuels are great sources of potential heat energy or light energy. We can readily transmit this energy and distribute it through pipes.

Gaseous fuels can be liquefied to store and transport easily. The gaseous nature of these fuels has advantages, though it is difficult to transport as it is, and there are dangers of leakage. This can, in turn, cause gas explosions. Therefore, we can add deodorizers to most gaseous fuels to detect their smell easily.

We can find two major types of gaseous fuels as manufactured fuel gas and well or mined extracted fuel gas. Some examples of manufactured fuel gases include coal gas, water gas, producer gas, syngas, wood gas, biogas, etc. Some examples of mine extracted fuel gases include propane, butane, and liquefied petroleum gas.

What is the Difference Between Solid Liquid and Gaseous Fuels?

Fossil fuels are very important in the world’s energy consumption. The three major types of fossil fuels, i.e., coal, petroleum, and natural gas, occur in solid, liquid, and gaseous states. The key difference between solid liquid and gaseous fuels is that solid fuels have a definite shape, and liquid fuels have no definite shape and take the shape of the container, whereas gaseous fuels have no definite shape and spread through the space.

The following table summarizes the difference between solid liquid and gaseous fuels.

Summary – Solid vs Liquid vs Gaseous Fuels

The key difference between solid liquid and gaseous fuels is that solid fuels have a definite shape, and liquid fuels have no definite shape and take the shape of the container, whereas gaseous fuels have no definite shape and spread through the space.

Reference:

1. “Classification of Fuels.” Gaseous Fuels.

 Image Courtesy:

1. “Coal and Fire” By snty-tact (Talk) – Self-photographed (CC BY-SA 3.0) via Commons Wikimedia
2. “Flaming cocktails” By Nik Frey (niksan) – (CC BY 2.5) via Commons Wikimedia
3. “Light my fire (2152952690)” By Michal Osmenda from Brussels, Belgium – Light my fire (CC BY-SA 2.0) via Commons Wikimedia