There are many reasons why oxygen is undesirable in natural gas, on top of meeting the regulatory requirements for purity:
- Oxygen combines with other chemical gases, especially H2S, to form acids.
- Oxygen does not add to the heating value of the gas and is not of benefit.
- Oxygen degrades amine, which inhibits the process of removing carbon dioxide and H2S from the gas chemically.
- Oxygen can degrade some mercaptans reducing the effectiveness of these odorants in the gas.
- Oxygen accelerates corrosion in the mechanical components that come in contact with the gas.
- Oxygen in sufficient quantities and with a heat source can cause explosions.
The application note discusses the various oxygen measurement methods available, along with their benefits and disadvantages.