Ozone Production:

Because Ozone has such a short half-life, it cannot be compressed and stored. Instead, it must be generated on-site and used immediately. Electrical generation is the only practical and safe method for large-scale applications of ozone. The most widely used electrical generation technology is the corona discharge method. A corona discharge generator accelerates electrons so as to give them sufficient energy to split the oxygen-oxygen double bond upon impact with another oxygen molecule. The two oxygen atoms which are produced by the collision react with other diatomic oxygen molecules to form ozone according to the following equation: 3O₂+ Energy = 2O₃.

When enough high-energy electrons bombard gas molecules so that they are ionized, a light emitting gaseous plasma is formed. This is commonly referred to as a corona. In practice, ozone concentrations of 1-2% using air, and 3-8% using oxygen can be obtained by corona discharge generators. Because the speed of ozone destruction by decomposition is proportional to the ozone concentration, producing higher ozone concentrations with corona discharge is not feasible.

Properly designed corona discharge generators that utilize higher frequencies (typically 300 - 1000Hz) are favored because greater ozone production can be achieved with less electrode surface area and less electrical consumption.

A typical corona based ozone system consists of three fundamental units:

• An air preparation or oxygen generation unit
• A corona discharge generator
• An Ozone contactor

Air passing through an ozonator must be free from particulate matter and dried to a dew point of a least -40^o C to properly protect the corona discharge device. For specific applications requiring a 3-4 % Ozone concentration, oxygen is used as the feed gas instead of prepared air.

The corona discharge device can be fabricated and configured in many different ways. The primary feature is to generate a corona between two electrode surfaces so that as air or oxygen is passed between these electrodes, ozone production and concentration is maximized.

Corona discharge units that are properly designed and contain modern safety features can produce ozone reliably, efficiently, and safely for many years.

Ozone contactor system can be as simple as bubbling the ozonated gas stream into water, or as involved as specifically engineered diffusers and/or gas-to-liquid eductor systems.

Ozone: home
Background
Chemical Properties
Ozone Production
Ozone Chemistry
Ozone Environmental and Health Aspects