Differences between butane and propane domestic gas?

There are functional and legal barriers to this.

Let's get the legal ones out of the way first...The appliances are certified for use with propane. If you connect them to butane you will void any existing warranties. The manufacturer will also take no responsibility if the appliance causes property damage or injures anyone. This is because you have used the appliance "in a manner other than what it was intended". Insurance companies would deny any claims for the same reason. If there were any type of incident and an investigation, you would likely be fined by the "authority having jurisdiction" as well.

To run these appliances on butane you would need to contact the manufacturer of each appliance to see if they offer a conversion kit for it. If they do, fine! Have the kit installed by a qualified technician and away you go! If they do not, you cannot convert the appliance. Period. If you "McGyver" the appliance and convert it yourself, the same legal problems as above will apply. That being said, I've never seen propane to butane conversion kits for any appliances. There are lots of appliances convertible from propane to natural gas or vice versa, but not butane.

Now the functional issues...Butane has a lot higher boiling point than propane. If you try and use butane at anything approaching freezing temperatures you will have little or no gas pressure and the appliances will not operate properly, if at all. There is butane IN propane but it's a relatively low percentage. Also butane is a very oily fuel and would likely gum up the venting system and burner after a fairly short period of time.

Your only real option here is to get appliances that are set up for and burn butane or some other fuel from the factory. Using butane with a propane appliance isn't going to be an economical, or safe idea.

Hope this helps! I know it isn't making your life simpler, but the facts are the facts...

EDIT: The days of just changing orifices are long gone. An original manufacturer's conversion kit MUST be used. One of the most important things in that conversion kit is a new rating plate for the appliance. This is your proof that the manufacturer has tested and certified the appliance for use with that fuel.

Butane has 1 more carbon atom than propane and 2 more hydrogen atoms. Propane is C3H8 whereas Butane is C4H10 (the numbers are supposed to be in subscript).

u can not safely do this,,propane has 2550 btu per cubic foot,,butane has 3200,u must reduce the size of the bnr orfice using a chart,,this is not something the average person should do,can be very dangerous