Butane or Propane Calor Gas?

[Sgeir]

Our old boat came with Camping Gaz which we very quickly changed over to the blue Calor Gas Butane bottles. Having since changed boats we now have two more Camping Gaz cylinders to add to our already extensive collection (we have two CG bottles from our camping days plus two from the old boat....).

Anyway, so I'm going to change the new boat to Calor Gas, what should I get - the blue butane or the red propane?

AFAIR from when I did a proper job, propane is probably hotter (I used it for lead plumbing and brewing my tea....) and I believe operates better than butane at lower temperatures (although never had a problem with butane even at sub-zero temperatures).

On the other hand, butane bottles of similar dimensions seem to have more gas by weight, and I wonder if butane is slightly "cleaner".

We have a Plastimo two burner cooker with grill and oven, but cannot determine whether they have a preference for either gas.

Any views?

 

[PotatoNavigator]

You want butane, unless it gets quite cold, in which case propane.

 

[sarabande]

I understand that the new regulators are suitable for both gases, so worth getting a new one.

I'd go for propane. I buy the big tall cylinders and decant into the smaller ones at HUGE savings. It's not illegal, and you don't need a degree in Risk Management to buy the connector and do the transfer.

Using propane at home for Rayburn lighting it is sometimes useful that propane continues to flow in very cold conditions whereas the butane used to be very sluggish.

 

[Sandyman]

Living in the Frozen North it has to be Propane

 

[GHA]

Homebase gaslite grp bottles are worth a look.

 

[Gordonmc]

If its a case of one or the other, go for Propane.
Even in the sultry climes of Argyll I incurred the wrath of crew when I couldn't brew-up because the butane wouldn't work. That was in early March.
My little gas locker now has one butane and one propane bottle.
They both go through the same regulator.

 

[maby]

We converted from butane to propane soon after the boat was delivered. Even in the south of England, you can find yourself trying to cook a meal over a flame the size of a cigarette lighter in the middle of January if you install butane.

 

[Sybarite]

Iirc a standard cylinder contains 32 lbs of butane or 25 lbs of propane.

In our former family business we used to be distributors.

 

[maby]

Iirc a standard cylinder contains 32 lbs of butane or 25 lbs of propane.

In our former family business we used to be distributors.

and butane is more energy-dense than propane

 

[cindersailor]

I changed over from Calor butane to Calor propane last year as I had problems with low pressure early and late in the season. I noted that you get only 3.9 Kg in a propane cylinder, but 4.5 Kg of butane in one the same size so I did the calculation to see whether this meant less energy per cylinder. Ignoring the energy needed for vapourisation (which is pretty similar for the two) you get about 223 MJ from burning 4.5 Kg of butane, but only 195 MJ from 3.9 Kg of propane. The two are generally the same price, so Joule for Joule propane is about 14% more expensive.

Edit: before anyone says anything, I just realised that you can ignore vapourisation in any case as the energy for this comes from the surroundings and not the propane/butane.

 

[Murv]

Also converted from butane to propane.
It's only used for cooking on my boat so the extra cost is completely outweighed by the benefit of being able to use it in cold weather.

 

[mikemanor]

I have propane on both my boat and caravan. Wouldn't go back to butane.

All year round boating and caravanning is no issue with propane. I have sufficient spare bottles that I can buy direct from my nearby Calor depot which gives a discount to "Caravan Club" and "Camping and Caravanning Club" members. GoOutdoors also gives a 10% discount to "Camping and Caravanning Club" members on top of their GoOutdoors discount card.

I never buy gas at a marina.

 

[pyrojames]

I have both connected to the same T reg. I use butane normally, and then simply swap to propane if the temperature drops too low.

 

[JumbleDuck]

and butane is more energy-dense than propane

Propane's enthalpies of combustion are 50.35MJ/kg and 46.35MJ/kg. Butane's are 49.5MJ/kg and 45.75MJ/kg, 1.7% and 1.3% lower.

Of course butane is denser, so at the same temperature and pressure it has more enthalpy of combustion per unit volume.

 

[FullCircle]

I changed over from Calor butane to Calor propane last year as I had problems with low pressure early and late in the season. I noted that you get only 3.9 Kg in a propane cylinder, but 4.5 Kg of butane in one the same size so I did the calculation to see whether this meant less energy per cylinder. Ignoring the energy needed for vapourisation (which is pretty similar for the two) you get about 223 MJ from burning 4.5 Kg of butane, but only 195 MJ from 3.9 Kg of propane. The two are generally the same price, so Joule for Joule propane is about 14% more expensive.

Edit: before anyone says anything, I just realised that you can ignore vapourisation in any case as the energy for this comes from the surroundings and not the propane/butane.

Where I get my gas, Propane is significantly cheaper?

 

[AngusMcDoon]

Propane's enthalpies of combustion are 50.35MJ/kg and 46.35MJ/kg. Butane's are 49.5MJ/kg and 45.75MJ/kg, 1.7% and 1.3% lower.

Of course butane is denser, so at the same temperature and pressure it has more enthalpy of combustion per unit volume.

Why the 2 values for each, or should some of the units be MJ/l?

 

[Steve_N]

..and I wonder if butane is slightly "cleaner".

Any views?

My experience is that propane is the cleaner fuel; butane leaves sooty residues on the bottom of pans and kettle while propane leaves them squeaky clean.

 

[JumbleDuck]

Why the 2 values for each, or should some of the units be MJ/l?

Burning hydrocarbons produces water, and you get slightly more heat out (the Higher Heating Value) if the water ends up as liquid and slightly less (the Lower Heating Value) if it ends up as steam. For example, modern condensing boilers improve their efficiency by turning the water in the combustion products to liquid and therefore get the HHV out of the fuel.

Propane contains proportionally more water in the combustion products (C₃H₈ + 5O₂ -> 3CO₂ + 4H₂O) than butane (C₄H₁₀ + 6.5O₂ -> 4CO₂ + 5H₂O) so the effect is proportionally greater. It matters more for ethane, more still for methane and most of all for hydrogen.

 

[AngusMcDoon]

Burning hydrocarbons produces water, and you get slightly more heat out (the Higher Heating Value) if the water ends up as liquid and slightly less (the Lower Heating Value) if it ends up as steam. For example, modern condensing boilers improve their efficiency by turning the water in the combustion products to liquid and therefore get the HHV out of the fuel.

Propane contains proportionally more water in the combustion products (C₃H₈ + 5O₂ -> 3CO₂ + 4H₂O) than butane (C₄H₁₀ + 6.5O₂ -> 4CO₂ + 5H₂O) so the effect is proportionally greater. It matters more for ethane, more still for methane and most of all for hydrogen.

I presume it's the LHV then that's relevant to boats as the combustion products aren't condensed when cooking (apart from a bit at the start with cold water in a pan), or in Propex type heaters.

 

[Sgeir]

Thanks for all the comments, folks, very interesting and informative. I think I'm persuaded to go for propane.

Cheers!