You are here:

Thermodynamics/Self heating cans

Advertisement


Question
What chemicals are used to heat up food and drink in self heating cans?
What reaction is it?

Answer
Hi Bethany,

There are 3 types of systems in use to heat canned food by exothermic chemical reactions.

1. Reaction of a metal with air (Example fine powdered Iron or Zinc with air 2Zn +O2 -> 2ZnO)

2. Reaction of a reagent with water (Example CaO + H20 -> Ca(OH)2)

3. Reaction of two solids (Example CuSO4 + Zn -> ZnSO4 + Cu)

The type chosen depends on the intended use and the heat needed. In Principle any exothermic reaction that did no corrode the can! would do.

I hope this helps
Best wishes

Kevin

Thermodynamics

All Answers


Answers by Expert:


Ask Experts

Volunteer


Kevin

Expertise

Thermodynamics, chemistry, chemical reactions, kinetics, chemical reaction safety, dust explosion technology, static electricity. General science.

Experience

Over 40 years experience as a practicing thermochemist in industry. Head of the fire and explosion laboratory of a major European chemical company (Ciba-Geigy). Now retired.

Organizations
Institute of Chemical Engineers. Royal Society of Chemistry.

Education/Credentials
Chartered Chemist, Member of the Royal Society of Chemistry (C.Chem MRSC). Msc Sheffield.

©2016 About.com. All rights reserved.