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Fossil fuels and fuels for the future? e.g. Possible Petrol Replacements
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Fuel Consideration Factor |
Hydrogen H2 |
Methane (Natural Gas) CH4 |
Liquefied Petroleum Gas L.P.G. mostly Propane C3H8, Butane C4H10 |
Methanol CH3OH An oxygenate fuel |
Ethanol CH3CH2OH An oxygenate fuel |
Coal Mainly Carbon but contains some Sulphur |
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Suitability for road transport |
Large volume. Not as convenient as petrol |
Large volume. Not as convenient as petrol |
Not as convenient as petrol but more dense than hydrogen or methane |
Hygroscopic, absorbs water, causes corrosion |
Hygroscopic, absorbs water, causes corrosion |
NO, too inconvenient, polluting and back to the steam engine! |
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Safety in use |
No more flammable or explosive than other gas fuels but more dangerous than liquids |
No more flammable or explosive than other gas fuels but more dangerous than liquids |
No more flammable than other gas fuels but more dangerous than liquids |
Volatile, flammable, toxic liquid |
Volatile, flammable, toxic liquid |
Very safe, not flammable but a bit ‘mucky’! |
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Availability and cost of supply |
Not readily available, made from water by electrolysis – needs energy source - Sun! |
Large naturally occurring reserves |
Large naturally occurring reserves |
More costly, has to be synthesised from CO + H2 |
More costly, has to be synthesised from ethene + water |
Big reserves, easily transported |
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Energy Density J/ kg |
Very high 143000kJ/kg |
High 55600 kJ/kg |
High 50000 kJ/kg |
Lower 22700 kJ/kg |
Lower 29717 kJ/kg |
Moderate 32800 kJ/kg max if pure C |
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Can existing car engines be adapted |
Yes |
Yes |
Yes |
Yes |
Yes |
Not applicable! |
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Ease of storage and distribution-can existing network be modified |
As for natural gas, so OK |
Piped delivery, OK |
Stored under pressure, much more dense than natural gas |
Readily stored and transported |
Readily stored and transported |
Readily stored and transported |
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Effect on Environment CO toxic SO2, NO2 irritant, toxic, acid rain Unburned CxHy carcinogens |
Product on combustion water, cleanest possible fuel, no pollutants emitted |
Produces carbon dioxide, a contributor to the ‘Greenhouse Effect’, less CO, NO2 |
Produces carbon dioxide, a contributor to the ‘Greenhouse Effect’ |
Cleaner than alkane fuels, produces less CO, unburned CxHy, NO2 |
Cleaner than alkane fuels, produces less CO, unburned CxHy, NO2 |
Very polluting, lung irritant, SO2 causes acid rain, carcinogens, Greenhouse Effect gases etc. etc. |
