For many folks this is an afterthought. It may be that they have stored a few cans of sterno, or plan to use the burner on their patio grill. While great back up plans, Sternos in particular, may get you by for a couple of days. Sternos are very expensive per British Thermal Unit (BTU), quite toxic, and it doesn't produce that much heat. Sternos were designed to heat chafing dishes on buffet lines; not to replace a proper cook stove. The preparedness marketing for sterno type products is just that... clever marketing.
If you're ready to graduate from sterno, to something along the lines that is much better, alcohol is an option. Just Google 'alcohol stove' and you will see dozens of designs for DIY burners made from pop cans, aluminum beer bottles, even cat food cans. This is a great option that will do well in a pinch. Another great thing about alcohol stoves is that the alcohol flames can be put out with water; a no-no for petroleum burners.
Commercial alcohol stoves are available from companies like Trangia and Vargo. While alcohol is a great option it has some flaws. First of all, it's expensive. A gallon of SLX Denatured alcohol runs about $15 a gallon at my local home depot. More than Coleman fuel. A lot more expense than kerosene. But, alcohol has roughly half the heat potential of the petroleum options. This means that $10 worth of Coleman fuel or $4 worth of Kerosene, is equal in heat potential to $30 worth of Alcohol. Yes, this is also why you get terrible fuel economy in flex fuel cars running E-85.
The propane option isn't all bad, especially if you run your whole home heating system on propane with one of those giant tanks positioned somewhere on your property. You're probably good, unless the disaster caught you just before a needed fill up. The barbecue grill option is a little more problematic. First of all most, people only have one tank. That tank has probably been used somewhat, and it’s very difficult to gauge how much fuel is left. Additionally, grills are designed for outdoor use only and may emit carbon monoxide. Outdoors, carbon monoxide is not a problem, but cold and wind may tempt you to bring the appliance inside. Don't.
Another issue with propane is storage. Propane storage in the ubiquitous 20lb tanks, which most people use, is bulky and expensive. While you should never store bulk fuels in your home, your next best option would be to store fuel in a detached outbuilding, a shed, or garage. But, take care the tanks should not be stored in a hot building. Those exchange-a-can storage cages they have at the gas stations would be fine, but they might advertise your property in a time of shortage. This may not be a good thing. Lastly, unless you have a small tank adapter, propane can only be used in appliances physically attached to the storage tank.
Coleman Fuel (White Gas)
While most garages in rural America have one of those old red and silver Coleman gallon-sized fuel cans, with a couple of quarts of fuel sloshing around in it, it's not a great option for stockpiling. For one, it is expensive at about $10 gallon. Also it is dangerous to store in hot buildings; warming a can will cause pressure to build within the can. The “pressure” property of Coleman fuel is actually required for some appliances that run it.
In times of disaster, people will raid their camping gear, and may elect to grab that old Coleman suitcase stove and the eight year old can of lantern fuel from the garage. While this may be a good option especially in warmer months, these stoves should never be used indoors. While generally safe, they can have catastrophic failures. And, when they do, they can be pretty spectacular and you better be outside.
Kerosene is cheaper to buy in bulk than Coleman fuel or Alcohol. Depending on where you live, Kerosene can be cheaper than Propane.
Kerosene can run in multiple autonomous appliances like stoves, lanterns, and portable heaters.
Kerosene has a higher BTU potential per volume, especially when compared to alcohol, and is also slightly better than Propane. Even if Kerosene is more expensive than propane, it produced more BTUs, and the cost per BTU is lower.
Kerosene is more stable than lighter fuels, and is better for long term storage. Here, propane has an advantage, since it has an indefinite shelf-life. Kerosene is more tolerant of a hot environment than Coleman Fuel and gasoline. Lastly, it does not produce flammable vapors as easily, as gasoline type fuels.
As to the sustainability of Kerosene, or any of these petro-based fuels, obviously they have a limited scope; unless you have a large supply. However, once the fuel runs out, you may not be able to resupply. But, having some fuels on hand can make our 'on the grid' homes livable following a disaster; and might as well do the trick during a short to medium term event.