Fuels & Crude Oil

Chapter 18 FUELS & CRUDE OIL 1. Natural Gas colourless & odourless 1. Consists mainly of methane 2. Burnt in excess O ₂ to produce energy: CH ₄ (g) + 2O ₂ (g) → CO ₂ (g) + 2H ₂ O(g) 3. "Cleanest" fossil fuel ( ✗ air pollutants produced) 4. Liquefied for consumers → ease of transport & safety 2. Crude Oil (Petroleum) ● A raw natural resource that is extracted from the Earth & used to propel vehicles, heat buildings, produce electricity, & make everyday products ● Contains mixture of hydrocarbons ● Needs to be separated before use ● Found beneath land & ocean floors (obtained by drilling) ⚠ Natural gas & crude oil are non-renewable (will be used up) 3. Biofuels What is it? Biofuels are alternative renewable energy sources to crude oil & natural gas. Biofuels come from: 1. Sugar cane → fermentation of sugar to produce ethanol 2. Corn → ethanol produced from plants = bioethanol 3. Animal waste → decomposed organic waste produce biogas Advantages 1. Renewable

2. Cleaner energy 3. Reduces oil dependence 4. Uses waste Disadvantages 1. Competes with food 2. Land & water use 3. Energy intensive 4. Environmental impact 4. Ways to Conserve Crude Oil 1. Reduce number of vehicles ○ drive smaller cars / take public transport 2. Use alternative energy (biofuels) 3. Improve design of power stations & vehicles to be more efficient 5. Competing Uses of Crude Oil 90% used as fuel 10% petrochemical feedstock → Supply is limited! 6. Fractional Distillation of Crude Oil Crude oil is heated & boiled to abt 400°C. The vapour is passed into the fractionating column. Furnace Heats and vaporises the crude oil before it enters the column.

Fractionating Column ● Hottest @ the bottom, cooler towards the top ● Fractions with higher boiling points condense @ higher temperatures (at the lower level) ● Fractions with lower boiling points rise up the column before they condense & collect Level (bottom → top) Fraction Use Highest temp Bitumen Road surfacing ↑ Fuel oil — ↑ Diesel oil Fuel for vehicles ↑ Kerosene — ↑ Naphtha Chemicals ↑ Petrol Fuel for vehicles Lowest temp Petroleum gas Fuel for cooking 7. Naming Prefixes (No. of Carbon Atoms) Prefix No. of C atoms

Meth- 1 Eth- 2 Prop- 3 But- 4 Pent- 5 Hex- 6