alkanes as fuels
- Created by: Margaret Hobart
- Created on: 12-05-21 09:50
View mindmap
- alkanes as fuels
- fractional distillation
- crude oil
- 1.vaporised at 350
- 2.fractionating column hotter at the bottom and cooler at the top
- 3.vapour goes up the column
- gases condense at different fractions due to difference in boiling point
- 3.vapour goes up the column
- 2.fractionating column hotter at the bottom and cooler at the top
- 1.vaporised at 350
- petroleum
- mixture of hydrocarbons, mainly alkanes
- crude oil
- boiling points inccrease as chain gets longer due to increases VDWs
- more energy needed to overcome
- cracking
- cracking turns longer alkane chains into shorter alkene chains
- shorter alkenes are more useful
- catalytic
- 450 degrees
- 2atm
- zeolite catalyst
- cheaper
- slower
- thermal
- 1000 degrees
- 70 atm
- no catalyst
- more expensive
- quick
- cracking turns longer alkane chains into shorter alkene chains
- combsution
- incomplete
- not enough O2
- produces carbon monoxide and soot (carbon particles)
- E.g. 4CH4 + 5O2 ? 2CO + 2C + 8H2O
- complete
- excess O2
- exothermic
- produces water and carbon dioxide
- E.g. C3H8 + 5O2? 3CO2 + 4H2O
- internal combustion in car engines
- produces oxides of nitrogen
- high pressure an temperature
- react in sunlight to form O3
- smog
- N2 + O2 -> 2NO
- N2 + 2O2 -> 2NO2
- catalytic converters
- remove unburnt hydrocarbons, oxides of nitrogen and carbon monoxide from exhausts
- produces oxides of nitrogen
- sulfer dioxide
- acid rain
- Flue gas desulpherisaion
- powdered CaCO3 mixed with water to make alkaline slurry
- when flue gases mix with this SO2 reacts with calcium compounds to form salt (calcium sulfate)
- CaO3 + SO2 -> CaSO3
- CaSO3 + SO2 -> CaSO3 + CO2
- CaSO3 + [O] -> CaSO4
- CaSO3 + SO2 -> CaSO3 + CO2
- CaO3 + SO2 -> CaSO3
- when flue gases mix with this SO2 reacts with calcium compounds to form salt (calcium sulfate)
- powdered CaCO3 mixed with water to make alkaline slurry
- used as fuel because they release a lot of energy when burnt
- incomplete
- fractional distillation
Comments
No comments have yet been made