C1 – Air Quality Revision

What are the Gases?

17/04/2015 The Earth’s Atmosphere Carbon dioxide, water vapourOxygenNitrogenNoble gases Present day atmosphere contains 78% nitrogen, 21% oxygen, 1% noble gases and about 0.03% CO 2

Pollutants What are the Chemical Formulae?

Pollutants Carbon Monoxide –

Pollutants Carbon Monoxide – CO

Pollutants Carbon Monoxide – CO Nitrogen Oxides –

Pollutants Carbon Monoxide – CO Nitrogen Oxides – NO, NO 2

Pollutants Carbon Monoxide – CO Nitrogen Oxides – NO, NO 2 Sulphur Dioxide –

Pollutants Carbon Monoxide – CO Nitrogen Oxides – NO, NO 2 Sulphur Dioxide – SO 2

Pollutants Carbon Monoxide – CO Nitrogen Oxides – NO, NO 2 Sulphur Dioxide – SO 2 Particulates -

Pollutants Carbon Monoxide – CO Nitrogen Oxides – NO, NO 2 Sulphur Dioxide – SO 2 Particulates - unburnt carbon (C)

Problems Caused By Pollutants Carbon Monoxide : __________ Nitrogen Oxides : _________, Acid Rain Sulphur Dioxide: _______ ________ Particulates: ___________ __________, and Asthma

CO 2 dissolves in the oceans. What happens to air pollutants? CO 2 is absorbed by plants. Particulate carbon is deposited on surfaces, making them dirty. Ozone, O 3, is a secondary pollutant produced in the lower atmosphere. SO 2 and NO 2 react with water vapour in the atmosphere to make ‘acid rain’. CO is very poisonous and remains unchanged for some time. NO turns rapidly to the secondary pollutant NO 2.

What is needed for combustion to occur? Three key things are needed for combustion to occur: Fuel, Oxygen/Air, Heat

Hydrocarbons Chemicals made from ____________ and ______________ As Fuels, Usually come from _____ When burnt they release __________ __________ and ________

What are the Products of Combustion? The products are OXIDES of the fuel used As most fuels are made of Hydrocarbons, the products are mostly Carbon Dioxide and Water Fuel atomResult of Combustion Carbon C Carbon Dioxide CO 2 Hydrogen H Water H 2 O

Amount of Oxygen When fuels burn with insufficient oxygen, they do not completely burn RESULT Particulates are formed (CARBON – C) CARBON MONOXIDE is formed (CO)

What happens in a Car Engine? Air (Nitrogen and Oxygen) go in Mix and React with Fuel (Hydrocarbon) Hydrocarbons Burnt with Oxygen Exhaust Gases Contain: Carbon Dioxide, Water, Carbon Monoxide, Nitrogen Oxide and Nitrogen

17/04/2015 Burning Fuels – “Combustion” Lots of oxygen: Some oxygen: Little oxygen: C H H H H O O O O O H H O H H C O O MethaneOxygen+Water+Carbon dioxide Oxygen+ O O O O O O Methane C H H H H C H H H H Carbon monoxide C O C O Water+ O H H O H H O H H O H H C C H H H H Methane O O Oxygen+ O H H O H H Water+ Carbon

17/04/2015 Other products of burning fuels Sulphur dioxide: Nitrogen monoxide: Nitrogen dioxide: S O O Sulphur dioxide S O O SulphurOxygen+ Nitrogen monoxide N O N O Oxygen+ O O Nitrogen N N O O Oxygen+ Nitrogen monoxide N O N O Nitrogen dioxide N O O N O O

MOT exhaust emission test

MOT test results

Inputs and outputs of a car engine air (nitrogen + oxygen) carbon dioxide + water + nitrogen + carbon monoxide + nitrogen monoxide + particulates (carbon) fuel (mixture of hydrocarbons)

A catalytic converter catalytic converter conventional silencer honeycomb structure

Task Find out how a Catalytic Converter works

Flue gas desulfurization waste gases from furnace air lime and water cleaned gases to chimney calcium sulfate

A hydrogen-fuelled car

Task Find out what the advantages and disadvantages of Hydrogen Fuel are.