The source of the heat for the self-heated can is an exothermic reaction that the user initiates by pressing on the bottom of the can. The can is manufactured as three containers. A container for the beverage surrounds a container of the heating agent separated from a container of water by a thin breakable membrane. When the user pushes on the bottom of the can, a rod pierces the membrane, allowing the water and heating agent to mix. The resulting reaction releases heat thus warms the beverage surrounding it.
The heating agent and responsible reaction vary from product to product. Calcium oxide is used in the following reaction:
- CaO(s)+ H2O(l) → Ca(OH)2(s)
- CuSO4(s) + Zn(s) → ZnSO4(s) + Cu(s)
Books, general references
- Yam, K.L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6
- An article on the concept
- Single-serving coffee can heats itself
- Will Self-Heating Coffee Be Cool?
- BBC News Online - Hot drink can tested in Midlands
- An article with photos on disassembly