>>> it takes about 0.05 kg of fuel to boil a kg of water in an
>>> unspecified amount of time.

>> 0.05 kg of which fuel?
>> Each delivers is different amount of energy per unit.

> Not really.  All the hydrocarbons are approximately CH2(n) and
> deliver significantly similar amounts of energy per gram.  Coal
> (pure C, sorta), hydrogen (pure H) and more complex fuels (wood)
> may be signficantly different, but they're not that common as 
> "fuels"


Extracted from various place in my "energy" file with no attempt to 
give them context.

There are a few contradictory figures here but overall it gives a 
reasonable indication.

Hydrogen is king :-)
Ethanol has over 25% more energy per than Methanol but is well down on 
liquid hydrocarbon fuels.
Anthracite is better than alcohols (but really hard on the injectors).
Interestingly, diesel is notably higher in energy content than petrol 
(depending which of my 'data' you believe :-( ) -  and is far cheaper 
per volume in this country than petrol - and "super" petrol is 
slightly lower in energy content than standard grade ie octane rating, 
which relates to resistance to compression ignition, and energy 
content are not well correlated,



    RM

________________________________

Propane         12.9 kWh/kg  7.5 kWh/l
LPG gives 14 KWH/Kg
LPG             27 MJ/l
Petrol          35
Diesel          46
Mobil petrol    Gross calorific value
        91      47.5 MJ/Kg
        96      47   MJ/Kg      = 13 KWH

Fuel           Btu/lb  cal/g =?Joule

Petrol          20500   11400
Kero            20000   11200
Diesel          19000   10500
Alcohol         11500    6400
Hydrogen        61000  ~34000


                kJ/kg
Carbon          32780
Hydrogen       142017   39.45 kWh/kg        <-- !!!!!!
CO              10111
Methane         55533
Ethane          51923
Propane         50402
n-Butane        49593
isoButane       49476
n-Pentane       49067
isoPentane      48955
neoPentane      48795
n-Hexane        48767
Ethylene        50325
Propylene       48958
n-Butene        48506
isoButene       48324
n-Pentene       48195
Benzene         42296
Toluene         43033
Xylene          43382
Acetylene       50014
Napthalene      40247
Methyl Alcohol  23860
Ethyl Alcohol   30612
Ammonia         22485


      Energy Content   Heat of Vaporization   Oxygen Content
              Net MJ/kg          MJ/kg                   wt%
Methanol        19.95             1.154                  49.9
Ethanol         26.68             0.913                  34.7
MTBE            35.18             0.322                  18.2
ETBE            36.29             0.310                  15.7
TAME            36.28             0.323                  15.7
Gasoline       42 - 44            0.297                   0.0

Typical values for commercial fuels in megajoules/kilogram are [37]:-

                              Gross        Net

Hydrogen                      141.9       120.0
Carbon to Carbon monoxide     10.2          -
Carbon to Carbon dioxide      32.8          -
Sulfur to sulfur dioxide      9.16          -
Natural Gas                   53.1         48.0
Liquified petroleum gas       49.8         46.1
Aviation gasoline             46.0         44.0
Automotive gasoline           45.8         43.8
Kerosine                      46.3         43.3
Diesel                        45.3         42.5

Lignite         8  - 10 Mj/kg  70% moisture     > 40,000 yrs
Black Coal      24 - 28 MJ/kg   3% moisture     65-1-5 M yrs
Anthracite      32      MJ/kg

                yrs are "received" age.

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