Oxygen Candle: Chemical Oxygen Generator

What an Oxygen Candle Is

An oxygen candle is a device that generates oxygen through a chemical reaction. It consists of a sodium chlorate (NaClO3) solid, which decomposes into sodium chloride (NaCl) and oxygen gas (O2) when ignited or heated.

This process is exothermic, meaning it releases heat as it progresses, making the candle self-sustaining until all reactants are consumed.

How It Works

When activated, the sodium chlorate decomposes according to the following reaction: 2 NaClO3 → 2 NaCl + 3 O2. This reaction is catalyzed by a small amount of iron powder or another suitable catalyst, which lowers the activation energy and speeds up the process.

The heat generated from this reaction further accelerates the decomposition, creating a self-sustaining burn front that continues until all sodium chlorate has been consumed.

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Why It Matters

Oxygen candles are essential for emergency oxygen supplies in confined spaces such as submarines and aircraft. They provide a reliable source of oxygen when conventional systems fail, ensuring the safety of passengers and crew.

In space applications like the International Space Station (ISS), these devices are critical backup systems that can be used to supplement or replace primary life support systems.

Real-World Applications

Oxygen candles have been a part of submarine and aircraft emergency equipment for decades, providing a quick source of oxygen in case of decompression or other emergencies.

In space exploration, they are used as backup systems to ensure the safety of astronauts during critical phases such as launch and re-entry.

Frequently asked questions

How long can an oxygen candle provide breathable air?

The duration depends on the size of the candle, but it typically provides enough oxygen to last several minutes, which is sufficient for emergency situations.

Can oxygen candles be used in all types of environments?

Oxygen candles are designed for use in confined spaces where conventional oxygen sources may fail. They are not suitable for open-air environments due to the risk of fire and the need for controlled conditions.

Are there any safety concerns with using oxygen candles?

Yes, oxygen candles can pose a fire hazard if not used properly. The exothermic reaction generates heat, which must be managed to prevent overheating or ignition of flammable materials nearby.

What are the alternatives to oxygen candles for emergency oxygen supply?

Alternatives include chemical oxygen generators with different reactants, such as barium peroxide, and mechanical systems like compressed gas cylinders or solid oxygen canisters.

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