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TIP: The online Bushwalk Inventory System can help bushwalkers with a variety of bushwalk planning tasks, including: Manage which items they take bushwalking so that they do not forget anything they might need, plan meals for their walks, and automatically compile food/fuel shopping lists (lists of consumables) required to make and cook the meals for each walk. It is particularly useful for planning for groups who share food or other items, but is also useful for individual walkers.Re: Cooking with Gas (The Right Mixture)
Sat 25 Jul, 2009 8:20 am
LPG (butane/propane) and petrol are about the same bang for your buck in terms of weight, at least before you figure in the container. Ethanol (spirits) is about 2/3 heavier than either for the same amount of energy, all else being equal (which it usually isn't).
The Primus claim of "equivalence of approximately 1 l of methylated spirits" is stretching things even before you include the canister weight. 450 grams of LPG has the same energy content as only 0.92 liters of methylated spirits. Total weights make the Primus claim seem worse. A full large Primus canister weighs 686 grams (your number). That 0.92 liters of spirits weighs 725 grams. Instead of a sig bottle use a 1 liter soda bottle (about 50 grams?) and the total is 775 grams for the spirits.
Some handy numbers:
energy density (MJ/kg)
30 - ethanol
46 - petrol
49 - LPG
volumetric energy density (MJ/l)
24 - ethanol
34 - petrol
28 - LPG
density (g/ml)
0.79 - ethanol
0.7 - petrol
0.57 - LPG
The Primus claim of "equivalence of approximately 1 l of methylated spirits" is stretching things even before you include the canister weight. 450 grams of LPG has the same energy content as only 0.92 liters of methylated spirits. Total weights make the Primus claim seem worse. A full large Primus canister weighs 686 grams (your number). That 0.92 liters of spirits weighs 725 grams. Instead of a sig bottle use a 1 liter soda bottle (about 50 grams?) and the total is 775 grams for the spirits.
Some handy numbers:
energy density (MJ/kg)
30 - ethanol
46 - petrol
49 - LPG
volumetric energy density (MJ/l)
24 - ethanol
34 - petrol
28 - LPG
density (g/ml)
0.79 - ethanol
0.7 - petrol
0.57 - LPG
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