Oxygen: Properties and Production Methods

Oxygen

• First appeared in Earth's atmosphere ~2 billion years ago.
• Discovered in 1772 by Carl Wilhelm Scheele.
• Priestley independently discovered it in 1774.
• Derived from Greek words "oxy" and "genes," meaning "acid-forming."
• Makes up 20.948% of the atmosphere.
• Colorless, odorless, tasteless gas.
• Non-flammable but involved in expansion.

Oxygen Manufacturing

• Various methods used, including air separation, chemical, and electrolysis.

Liquid Oxygen Storage

• Stored in cylinders or manifold cylinder banks.
• Vacuum Insulated Evaporator (VIE) is the most economical method for storage and supply.
• Safety valve opens at 1700kPa to regulate evaporation when demand increases.
• Evaporation requires heat (latent heat of vaporization), helping maintain low temp.
• Warmed outside the vessel in a copper coil (pipe line)
• At 15°C, liquid oxygen expands 842 times its volume as gas.

Oxygen Concentrators

• Zeolites are hydrated aluminum silicates of alkaline earth metals in powder/granular form.
• Air is filtered, pressurized to ~137kPa and passed through a zeolite molecular sieve column.
• Sieve retains unwanted gases.
• Maximum oxygen concentration is 95%.
• Argon is the remaining constituent.

Nitrous Oxide

• Colorless, odorless, non-explosive, and non-flammable gas.
• An Inorganic anesthetic gas.
• Kept as a liquid under pressure at room temperature.
• Manufactured by heating ammonium nitrate to 250°C. N2O + 2H2O

Entonox

• Compressed gas mixture (50% oxygen, 50% nitrous oxide).
• Medical uses: labor, dental extraction, causality.
• Compressed to 13700kPa
• Poynting effect: temperatures below -5.5°C cause separation, mixture mostly nitrous oxide with 20% oxygen, flow constant rate causes high O2 concentration initially, followed by evaporating N2O (hypoxic mixture).
• Disadvantages: prolonged use, risk to patient (bone marrow suppuration, eye surgery, air embolism, pregnant women).

Compressed Air

• Medical-grade air supplied at 400kPa from compressors.
• Filtered & separated into oil-free air.
• Dry air is prepared before use.

Generalized Vacuum System

• Consists of a pump creating -53kPa (-400mmHg) negative pressure.

This quiz explores the history, properties, and production methods of oxygen, from its discovery to modern manufacturing techniques. Learn about the gas's behavior, storage challenges, and the technology behind oxygen concentrators. Test your knowledge on this essential element vital for life.