Chapter 1 - Fuels Flashcards
fuel
substance with stored chemical energy that can be released relatively easily for us as heat or power
fossil fuels
produced over thousands of years by the breakdown of organic material at high temperatures and pressures underground
non-renewable
used faster than it can be replaced
formation of fossil fuels
from buried ancient plants and animals
coal
mixture of large molecules made from carbon, hydrogen, nitrogen, sulfur and other elements.
non-renewable
crude oil
mixture of hydrogen molecules that are mostly members of the homologous series of alkanes.
non-renewable.
separated by fractional distillation
fractional distillation
uses heat to seperate a mixture into a number of different fractions or parts
natural gas
composed of methane together with small amounts of other hydrocarbons
fracking
extraction of natural gas from coal or shale deposits.
used to fracture rock or coal to release gas
liquified petroleum gas
mixture of propane and butane operated from natural gases or crude oil.
non-renewable
biofuels
renewable fuels derived from plant materials, vegetable wastes and oils
renewable
can be replaced as fast as they’re used
bioethanol
made from fermenting the sugar and starch components of plants using yeast
fermentation
enzyme catalysed breakdown of starch to glucose
biogas
gas formed by the anaerobic breakdown of organic waste
biodiesel
mixture of long-chain alkyl esters derived from vegetable oil or animal fat
energy content
chemical energy in a substance
energy transformation
energy converted from one form to another
energy efficiency
percentage of energy converted to useful energy
combustion
substance burns in oxygen to produce carbon dioxide and water.
thermal energy released
energy transformations in burning coal
chemical energy in coal. thermal energy of burning coal. thermal energy of stream. mechanical energy of turbine. electrical energy from generator
efficiency of electricity from coal
30-40%
efficiency of electricity from natural gas
40%
petrol
mixture of hydrocarbons including octane
greenhouse gas
gas that is able to absorb and radiate heat radiation and contribute to greenhouse effect
examples of greenhouse gases
water vapour.
methane.
carbon dioxide.
greenhouse effect
sun heats the earths surface and some heat radiated back into atmosphere
enhanced greenhouse effect
increasing levels of greenhouse gases causing global warming and climate shift
fuels that produce carbon dioxide when burnt
coal, natural gas, LPG, petrol, ethanol
carbon neutral
process that absorbs the same amount of carbon dioxide as it generates
advantages of coal
easily transported.
relatively high energy content
advantages of natural gas
more efficient than coal for electricity production.
easily transported.
relatively high energy content
advantages of biogas
renewable.
reduces waste disposal.
CO2 absorbed during photosynthesis
advantages of petrol
high energy content.
ease of transport
advantages of LPG
low cost.
relatively high energy content.
fewer particles than petrol
advantages of bioethanol
renewable.
CO2 absorbed during photosynthesis.
fewer particles than petrol
disadvantages of coal
non-renewable.
high level of emissions
disadvantages of natural gas
non-renewable.
polluting but less than coal and petrol
disadvantages of biogas
low energy content.
supply of waste raw materials limited
disadvantages of petrol
non-renewable.
polluting but less than petrol.
limited reserves
disadvantages of LPG
non-renewable.
polluting but less than petrol
disadvantages of bioethanol
lower energy content than petrol.
may require farmland otherwise used for food production
petrodiesel
produced from crude oil by fractional distillation
transesterification
process in which triglyceride reacts with an alcohol to form esters
viscosity
measure of liquids resistance to flow
cloud point
measure of performance at low temperature.
temperature at which small crystals start to form
hygroscopic
substance that absorbs water easily
