Flameless fire

A fuel tablet burns without fire

Scientific name: Flameless burning of hexamine fuel tablet with Cr2O3 as a catalyst


Беспламенное горение уротропина

by Sergeu Atamanov


Wear eye protection throughout

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

(CH2)6N4 + 9O2 -[Cr2O3]→ 6CO2↑ + 2N2↑ + 6H2O↑

Step-by-step instruction

  1. Take a hexamine fuel tablet and put some chromium(III) oxide powder on top of that.
  2. Set the fuel tablet on fire to heat up the Cr2O3 powder.
  3. Then cover the fuel tablet with a glass to stop the fire but not long enough to allow the Cr2O3 poweder to cool down.
  4. Remove the glass.
  5. Now the Cr2O3 poweder will heat even stronger. It will stay red-hot until the hexamine fuel tablet is spent.

Scientific background

Cr2O3 acts as a catalyst for hexamine oxydation which generates a lot of heat.


Published on 21 August 2014

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst