Liquid fuel
As a liquid fuel , liquid fuels , mostly hydrocarbons , referred to in internal combustion engines and turbines as well as in rocket engines are used.
If the oxidizer is a gas such as oxygen that becomes liquid under pressure and cold and is carried in tanks, this is also referred to as liquid fuel. In today's launch vehicles , for example, liquid oxygen and hydrogen are often used. The first ballistic missile , the German A4 from 1940, was also powered by ethanol and liquid oxygen.
Nowadays, research is being carried out into new, regenerative liquid fuels for vehicles , as petroleum reserves are increasingly being depleted.
Common alternative fuels: