The natural gas that is put to commercial use is very different from the natural gas that is extracted from the earth. It needs to undergo several cleansing processes to be made fit for mass consumption. When natural gas is extracted, it contains several contaminants including liquids and solid particles. These particles are removed in order to be suitable for end use. Purification of natural gas is also important for compatibility with applications. The particulates in natural gas could harm the intricate components of equipment operating on natural gas. Hence, proper separation processes and equipment should be utilized for the same.
Raw natural gas is available from three main sources oil, gas, and condensate wells. The challenges of processing of gas extracted from each type of well are different and they need to be tackled accordingly. The natural gas needs to be isolated from water, liquid, and solid contaminants to deliver almost pure methane gas. This gas is termed as ‘pipeline quality’ dry natural gas. Only then can it be put to commercial use. The processes employed for purification and processing allow the gas company to extract ‘contaminants’ like butane, ethane, propane, and pentane, which can be put to further use or sold to interested parties. Hence, the purification process pays for itself multiple times over.
Different Stages of Natural Gas Separation
Different stages and mechanisms are utilized for separation of natural gas from solid and liquid contaminants. Some of these are mentioned below:
- Oil and Condensate Removal
Natural gas may be dissolved in oil. These two are separated using simple or complex technology depending on the type and level of contamination.
- Water Removal
Removal of water from the natural gas takes place at or near the wellhead. In this process, the natural gas is dehydrated using absorption or adsorption.
- Separation of Natural Gas Liquids
It is important to rid the natural gas from the other liquids present in the stream. This is a two-step process. First, the liquids are extracted out of the natural gas using absorption or adsorption. Second, the separate liquids are separated from one another. This process continues until only their base components are available.
- Sulfur and Carbon Dioxide Removal
Removal of sulfur and carbon dioxide from the natural gas is crucial. Presence of sulfur in the gas can be extremely harmful, even lethal. The sulfur can be extracted from the natural gas and sold separately. Selling of this by-product can help increase revenue for the organization.