The Element Oxygen
Oxygen, represented by the symbol ‘O’ and atomic number 8, is a highly reactive non-metallic element. It is a vital component for life on Earth and plays a crucial role in numerous natural and industrial processes. At standard temperature and pressure, oxygen exists as a diatomic gas (O₂), which is colourless, odourless, and tasteless.
Everyday Applications of Oxygen
Oxygen’s pervasive nature leads to its involvement in many daily activities and essential services.
Respiration
All aerobic life forms, including humans and animals, depend on oxygen for cellular respiration. This biochemical process allows organisms to convert nutrients into energy, sustaining vital bodily functions. The atmospheric oxygen inhaled by individuals in India and worldwide is integral to this fundamental process.
Combustion
Oxygen is essential for most forms of combustion, which releases energy in the form of heat and light. This principle is utilized daily in various ways:
- Burning of cooking gas (LPG) in Indian households.
- Combustion of firewood or coal for heating and cooking in rural areas.
- Internal combustion engines in vehicles across cities like Mumbai, Delhi, and Chennai.
Medical Support
In healthcare, oxygen therapy is a critical intervention. Oxygen cylinders and concentrators are routinely used in hospitals and emergency settings to support patients with respiratory difficulties, such as those suffering from asthma, pneumonia, or chronic obstructive pulmonary disease (COPD). During health crises, the demand for medical oxygen often highlights its indispensable role in public health infrastructure across India.
Water Treatment
Aeration processes in water purification plants rely on oxygen to oxidize impurities and support the growth of beneficial microorganisms that break down organic matter. This ensures the availability of cleaner drinking water for communities, a practice employed by municipal corporations managing water supply in Indian cities. Furthermore, oxygen is used to maintain healthy aquatic environments in fish farms and aquariums.
Support in Extreme Environments
Specialized breathing apparatus for activities like mountaineering and scuba diving contain concentrated oxygen. This provides vital breathing support in environments where atmospheric oxygen is scarce, such as high altitudes in the Himalayas or underwater during deep-sea exploration off India’s coasts. Similarly, pilots in non-pressurized aircraft utilize oxygen masks at high altitudes.
Natural Presence of Oxygen
Oxygen is one of the most abundant elements on Earth, found in various forms across different spheres.
Atmospheric Oxygen
Approximately 21% of Earth’s atmosphere by volume consists of diatomic oxygen (O₂). This atmospheric oxygen is continuously replenished through photosynthesis carried out by plants and algae.
Oxygen in Water and Earth’s Crust
In the Earth’s hydrosphere, oxygen is a fundamental component of water (H₂O), making up about 89% of its mass. Within the Earth’s lithosphere, oxygen is the most abundant element by mass, primarily found in the form of oxides within minerals and rocks, such as silicates and carbonates, which constitute a significant portion of the Indian subcontinent’s geological formations.
Industrial Production and Utility in India
Industrial Production Method
Industrial-scale oxygen is predominantly produced through the fractional distillation of liquid air. Air is first purified, compressed, and cooled to extremely low temperatures, causing it to liquefy. Due to differences in their boiling points, liquid nitrogen (boiling point -196 °C) and liquid oxygen (boiling point -183 °C) can then be separated through distillation. Cryogenic air separation units (ASUs) operated by companies like Linde India and INOX Air Products are common across industrial hubs in India.
Applications in Indian Industries
Oxygen finds extensive use across a multitude of industries within India:
- Steel Manufacturing: A significant quantity of oxygen is consumed in basic oxygen steelmaking (BOS) processes, which decarburize molten pig iron to produce steel. Major steel plants in India, such as those operated by Steel Authority of India Limited (SAIL) in Bhilai, Durgapur, Rourkela, and Bokaro, extensively utilize oxygen to enhance efficiency and quality.
- Chemical Industry: Oxygen is a key reactant in the production of various chemicals, including nitric acid, ethylene oxide, and vinyl chloride monomer. These chemicals are integral to India’s growing petrochemical and fertilizer sectors.
- Welding and Metal Cutting: Oxy-fuel welding and cutting techniques, particularly oxy-acetylene, are widely employed in fabrication workshops, construction sites, and manufacturing units throughout India for cutting and joining metals.
- Pulp and Paper Industry: Oxygen is used as a bleaching agent in the paper industry, offering an environmentally friendlier alternative to chlorine-based bleaching methods.
- Glass Manufacturing: Oxygen is injected into furnaces during glass production to achieve higher temperatures and improve energy efficiency.