There is a huge amount of speculation, and one or two myths surrounding the use of Butane versus Propane, so we thought it was time to take a look at the facts surrounding these two fuel types, and their applications.
Propane Versus Butane
Firstly, the basics; Butane is universally sold in blue gas cylinders, whilst propane is sold in red / orange cylinders. These cylinders are available in various sizes, but the most commonly used item sizes, for camping, are 4.5kg and 7kg for Butane and 3.9kg / 6kg for Propane. Remember, however, this is the weight of the liquified gas inside. The total weight of the gas plus cylinder is likely to be some three times the weight of the gas alone, meaning that a 13kg cylinder will, actually, weigh as much as 40kg.
The bottles are maintained at different pressures, and it is imperative, therefore, that any gas cylinder is used with the appropriate regulator, in order to avoid damaging your onboard gas system. This is not difficult to achieve, as, not only are the regulators colour coded, but they also have different connection types, and internal valve sizes (21mm for butane, and 27mm for Propane) so no problems with getting them mixed up.
There are a couple of myths surrounding the use of these gasses, which are probably worth dispelling. The first is that Butane freezes at around zero degrees, rendering it unsuitable for Winter use. Whilst it is, indeed, true that Propane is far superior for usage in Winter temperatures, it is not true to say that either gas freezes. In order to burn, each product needs to be in a gas form. It will not burn as a liquid. At around zero degrees, Butane turns from a gas, back into a liquid, rendering it ineffectual for use in our camping equipment. Propane, on the other hand, has a boiling point of around minus 44 degrees Centigrade, making it far more suitable for Winter usage. Although Butane will cease to be a gas at zero degrees, it begins to lose effectiveness at around 10 degrees Centigrade, making it most effective only for Summer applications. For the record, and the anoraks among us, the actual freezing points are -140 degrees C for Butane and -188 degrees C for Propane.
The second myth is that one gas burns hotter than the other. I say; ‘one gas’ here, because some people argue that Butane burns hotter, and others that Propane does. So, who is right?
To put things into perspective, the natural gas we use in our homes gives off 38 Megajoules of energy per cubic metre burned.
Compare this with 96 Megajoules for Propane and 126 Megajoules for Butane, and you can see that Butane does actually generate a lot more heat energy than the other two, and hence many will argue that it burns hotter. However, Propane regulators release the gas at a faster rate, to compensate (and hence the importance of using the correct regulator for the gas being used) which is why some people argue that Propane is, in fact a hotter flame. OK. So what is the reality? Well, in these conditions, due to the function of the different regulators, Butane burns at 1,970 degrees Centigrade, whilst Propane burns at 1,967 degrees. So, in general use, contrary to popular opinion, there is no noticeable difference between the two gasses.
Common Terms & Gas Types
Butane is an LPG (Liquid Petroleum Gas) suitable for temperatures above freezing (and, ideally, above 10 degrees C.) It is found in blue bottles, and modern regulators are also blue, to ensure ease of matching. This gas is most commonly used for barbeques and Summer camping applications. Common cylinder sizes are 4.5kg, 7kg and 15kg.
Likewise, Propane is an LPG, although, unlike Butane, it can operate, effectively, as low as minus 44 degrees C. It is found in red / orange cylinders, again, with matching regulator, and typical sizes are 3.9kg, 6kg and 13kg. It is better suited to gas fired heaters and Winter camping applications than Butane.
Pronounced camping gas, this is a brand of Butane / Propane gas, manufactured by the French company, of the same name. It is available in two formats; the small, portable, disposable cylinders that many will recognise from the portable camping gas stoves and lamps of their youth, and this gas is still in common use today. These days, however, it is also available in refillable gas bottles, again, with their own specific type of regulator.
The Campinggaz regulator is easy to identify, as the cylinder attaches to the bottom of the regulator, as opposed to the side of it. These cylinders are smaller than their competitors, and are available in 0.45kg, 1.81kg and 2.72kg configurations. The main advantage of these cylinders is that, being French made, they are far more readily available on the continent, should you find yourself running short on a European trip. The small, disposable, cylinders contain a mixture of Butane and Propane, whereas the larger cylinders are Butane only.
Although a widely used term, particularly in DIY and gardening shops, it is, basically, just a marketing term for Propane, as it is suitable for all patio applications, from barbeques, to patio heaters. In spite of the distinctive green and red bottles, it is no different to the propane found in the red / orange cylinders, above.
Think that pretty much covers it. Remember though, whilst we can use all gas types equally safely in our camping situations; Butane = Summer usage, Propane = all year round, Campinggaz = best for continental travel. Slight over simplification, but those are the key factors.