Science at Work Fuels from crude oil BP（在工作中科学从原油石油燃料）.pdfVIP

BP Educational Service Science at Work Fuels from crude oil What is crude oil? What is a fuel? BP uses crude oil to make petrol, diesel and other products. Crude oil is formed from the remains of tiny marine creatures. These creatures captured the Sun’s energy through photosynthesis. The energy was stored in their remains as chemical energy. Over millions of years, these remains were transformed into oil by heat and pressure. Nearly every molecule in crude oil is made up of just two elements: hydrogen and carbon. These elements combine in chains to create molecules called hydrocarbons. Because their chains are different lengths, each type of hydrocarbon has different properties. Crude oil is not very useful in its raw form. It does not release its energy very efficiently. Oil refineries convert crude oil into more useful forms. They separate the crude oil into its main parts and process these into different products. Each product needs the right mix of hydrocarbons. Some of the most important products are fuels, including petrol and diesel. Fuels are substances that contain stored chemical energy. Burning the fuel releases this energy. Filling up with petrol at the pump The energy can be used to do useful work. Drivers can use petrol as a fuel because it contains the chemical energy stored for millions of years in crude oil. 1. Cars use the energy from petrol or diesel. What form of energy does the fuel contain? What other forms of energy is it converted into? 1 Fractional distillationFractional distillation When a liquid is heated, it evaporates. Some liquids evaporate at different temperatures from others: they have different boiling points. Distillation is evaporation followed by condensation. This process can separate a mixture of liquids that have different boiling point