Diesel

Diesel is a type of liquid fuel derived from crude oil through fractional distillation. It is used in diesel engines, which ignite the fuel through high compression of air in the cylinder, rather than using spark plugs to create ignition.

Diesel is heavier and less volatile than petrol. It has greater energy density than petrol, making it the preferred fuel for heavy vehicles, trucks, ships, trains, and power generators.

How it is produced

Crude oil is heated in an oil refinery in a distillation tower. Different components of oil evaporate at different temperatures: gas and petrol vaporize at low temperatures, diesel at medium temperatures, and heavy fuel oil and bitumen at high temperatures. Diesel can also be produced from plant and animal oils, known as biodiesel.

How diesel engines work

A diesel engine first compresses air in a small cylinder (piston chamber). The compression raises the temperature of the air. Diesel fuel is then injected directly into this hot air and ignites spontaneously. This process allows the engine to produce high power from a small amount of fuel, but requires sturdy, heavy construction.

Use in Somalia and the Horn of Africa

In areas without reliable electricity grids, diesel is the primary source of power. Businesses, hospitals, water treatment facilities, and telecommunications companies depend on diesel-powered generators. Fishing vessels and commercial trucks also use diesel. The price of diesel directly affects the cost of electricity and market goods.

Pollution and environmental impact

Burning diesel releases particulate matter and nitrogen oxide gas, which affect respiratory health and urban air quality. Many countries have introduced regulations limiting the sulfur content in diesel and developed advanced filters for exhaust gases. Since the early twenty-first century, many countries have begun reducing the number of privately owned diesel vehicles, shifting toward electricity and alternative technologies.