Fuel oil is a type of petroleum product derived from crude oil through a refining process. It is widely used as a fuel source for heating systems, power generation, and marine propulsion. With its dense, viscous consistency and high energy content, fuel oil is an efficient choice for various industrial applications that require large-scale energy production, such as furnaces and boilers.

Fuel oil is categorized into different grades based on its viscosity and sulfur content. Lower viscosity and low-sulfur fuel oils are generally preferred for their cleaner combustion properties, reducing the environmental impact. These lighter grades are commonly used in residential and commercial heating systems, as well as in engines designed for lower emissions. Conversely, heavier fuel oils are often used in large-scale industrial applications, such as ships and power plants, due to their higher energy density.

However, fuel oil combustion can result in the emission of pollutants, including sulfur dioxide (SO₂), nitrogen oxides (NOₓ), and particulate matter. These emissions can have adverse environmental and health effects, contributing to air pollution and respiratory issues. In response, global efforts are being made to develop cleaner alternatives to traditional fuel oils, such as biodiesel and renewable fuels. These innovations aim to reduce both emissions and reliance on fossil fuels, offering more sustainable energy solutions for the future.

As a vital component of energy production, fuel oil continues to play a crucial role in industries worldwide, while the transition to cleaner, more efficient alternatives progresses.