Gas In Your Business for Chemicals, Pharmaceuticals and Petroleum Industry

Oxygen (O2)
Oxygen is used as a raw material in many oxidation processes. Very large quantities of oxygen are used in coal gasification to generate a synthesis gas that can be used as a chemical feedstock or precursor for more easily- transported and easily-used fuels. 
Oxygen is used to enrich the air feed to catalytic cracking regenerators, which increases capacity of the units. Oxygen is also used to regenerate catalysts in refineries.
Oxygen is used to achieve more complete combustion and destruction of hazardous and waste materials in incinerators.

Nitrogen (N2)
Refineries, petrochemical plants and marine tankers use nitrogen to purge equipment, tanks and pipelines of dangerous vapors and gases (for example, after ending a production run) and to maintain an inert and protective atmosphere in tanks storing flammable liquids.
Cold nitrogen gas is used to cool reactors filled with catalyst during maintenance work. The cooling time can be reduced substantially.
Cooling to low temperature allows better control of side-reactions in complex reactions in the pharmaceutical industry.
Liquid nitrogen is used during well completion and to maintain pressure in oil and natural gas producing formations.  Unlike carbon dioxide, which is also used for pressurization, nitrogen has little affinity for liquid hydrocarbons, thus it builds up in and remains in the gas cap.
Nitrogen is used an inert gas to push liquids though lines, to clear lines and to propel through pipelines to sweep out one material before using the line to transport another material.

Carbon dioxide (CO2)
Large quantities are used as a raw material in the chemical process industry, especially for methanol and urea production.
Carbon dioxide is used in oil wells for oil extraction and maintain pressure within a formation.. When CO2 is pumped into an oil well, it is partially dissolved into the oil, rendering it less viscous, allowing the oil to be extracted more easily from the bedrock and increase the production.

Hydrogen (H2)
Hydrogen is used in large quantities as a raw material in the chemical synthesis of ammonia, methanol, hydrogen peroxide, polymers, and solvents. 
In refineries, it is used to remove the sulfur that contained in crude oil.  The pharmaceutical industry uses hydrogen to manufacture vitamins and other pharmaceutical products.