Energy from fuels

What does combustion involve?

Fuel

Oxygen

Ignition source

What are the types of combustion?

• Complete combustion - with sufficient oxygen

• Incomplete combustion - limited oxygen

Metals: oxidation vs combustion

Most metals oxidised but not all combust. Non-reactive metals or less reactive metals dont combust while more reactive metals do combust.

Complete combustion of organic compounds

Organic compounds are normally used as fuels because they don’t spontaneously combust since their activation energy is so high.

Which organic compounds are typically used as fuels?

Alkanes and alcohols

What is complete combustion?

Burning a substance with excess oxygen to produce CO2 and H20.

What is incomplete combustion?

This is when oxygen is limited during combustion as a result produces water but either CO or C rather than CO2.

What is a fossil fuel?

any of a class of hydrocarbon-containing materials of biological origin occurring within Earth’s crust that can be used as a source of energy.
(Britannica)

Advantages of coal

Long lasting

Cheap and widely available

Advantages of oil.

Easy to store

Impurities can easily be removed.

Advantages of natural gas

Produces minimal harmful emissions

Easy to transport in pipelines

Disadvantages of Coal

Pollution from combustion

Habitat destruction due to mining

Disadvantages of oil

Contributes to global dimming

Oil spills are harmful for both the wildlife and the people

Disadvantages of natural gas

Risks from storing under pressure.

Expensive and time consuming to extract.

Examples of biofuels

Bioethanol

Biodiesel

Biogas

What is transesterification?

When triglyceride oils are converted into esters of methanol. This is essentially what biodiesel is.

How is biogas made?

when organic molecules are broken down by microogranisms in the absence of oxygen

What is Bio ethanol?

Ethanol made by a biological source.