DF11: Other Fuels

What are aromatic hydrocarbons and their effects in petrol?

Aromatic hydrocarbons make up as much as 40% of petrol

they may cause higher emissions of carbon monoxide, hydrocarbons, nitrogen oxides

and some may be carcinogenic like benzene which is strictly controlled

Why might butane content in petrol be reduced in the future?

Butane is volatile and contributes to evaporative emissions leading to ozone formation and photochemical smogs

What is the role of oxygenates in petrol?

Oxygenates such as ethanol are added as a possible solution to reduce harmful emissions

What is LPG and its composition?

Liquefied petroleum gas (LPG) is a mixture of propane and butane typically around 60% propane

What are the advantages of LPG?

LPG produces about 20% less carbon dioxide per mile than petrol and has lower emissions of unburnt hydrocarbons and nitrogen oxides

What is LNG and its primary component?

Liquefied natural gas (LNG) is mainly methane cooled to below −160°C

What are the advantages of LNG?

suitable for large vehicles

has a high carbon to hydrogen ratio

produces less NOₓ and CO compared to diesel

What are biofuels?

alternative fuels derived from renewable plant and animal materials such as ethanol and biodiesel

How is ethanol produced?

fermenting carbohydrate crops like sugarcane

What are the advantages of ethanol?

carbon-neutral

renewable

reduces CO emissions

What is biodiesel?

Biodiesel is made by chemically reacting fats and oils with alcohol through transesterification

What are the advantages of biodiesel?

Biodiesel is carbon-neutral biodegradable and produces fewer particulates CO and hydrocarbons compared to petrol and diesel

What are the disadvantages of biodiesel?

It produces more nitrogen oxides than conventional fossil fuels

What are examples of green diesel?

Green diesel is derived from algae or biogas from animal manure and organic matter

What are the advantages of hydrogen as a fuel?

Hydrogen is renewable produces only water when burned and can be used in fuel cells to generate electricity

What are the disadvantages of hydrogen as a fuel?

Hydrogen requires large storage volumes is less energy-dense than petrol and its production often relies on electricity from fossil fuels

How do fuel cells work?

Fuel cells convert chemical energy from a fuel into electricity via an electrochemical reaction with oxygen producing water as the main product