How Natural Gas is Dehydrated

Posted on Thursday, September 23, 2021

Natural gas needs to be dehydrated to be stored and transported efficiently. Storage is important because it can help to reduce the dependency on having natural gas supply. It also helps to maximize the capacity of distribution lines.

The most common period when gas is stored is during the summertime since there is a significantly lower demand for gas. The winter is when the demand for natural gas is at peak levels due to it being used to heat homes and businesses or as an essential energy resource.

Why Dehydrate Gas?

You may be wondering why gas needs to be dehydrated and how the dehydration process effectively removes water vapor from the process. As helpful as water is for people, it is not optimal in natural gas processing systems because it can carry chlorides or contaminants that may corrode natural gas processing piping systems and equipment.

When natural gas is initially removed from a well, it is filled with water vapor. If the gas was transmitted with all of the water vapor, it would cause a degradation of the infrastructure it comes into contact with (this can be in the form of corrosion or a blockage). When this occurs, natural gas dehydration comes into play.

Natural gas will go through various separation steps and one of those steps is dehydration.

Water in Gas

An issue that often arises is when gas is stored and becomes saturated with water vapors. This can sometimes be caused by the temperature in pipeline walls falling below the ideal temperature, or by a number of other reasons associated with the chemical composition of the gas as it comes out of the well.

When temperatures fall below a certain temperature, water vapors start to condense on cold surfaces, which can lead to internal and external corrosion or other issues.

For one, natural gas can form as a solid compound called methane hydrate, which in large amounts, can become trapped within the crystalline structure of water and can form a solid similar to ice. This can lead to plugged valves, fittings, or pipelines.

Condensed water can also cause erosion and slug flow in pipelines. This is another reason why natural gas dehydration is important.

Natural Gas Dehydration Methods

There are three primary commercial methods used to dehydrate natural gas that are widely used in industry: absorption, adsorption, and condensation.  The absorption method is the most widely used industrial natural gas dehydration that occurs when low temperatures absorb the water that is then boiled out to end with a higher temperature.

The adsorption method is where water is adsorbed on a mole sieve, alumina, or silica gel. The condensation method uses gas cooling to turn water molecules into liquid and then remove them from the stream.

Natural Gas Dehydration Process

Glycol dehydration is a technique used to remove water from natural gas. It is also one of the most common systems used and is commonly referred to as a TEG unit (Triethylene Glycol). TEG Dehy units are commonly fabricated and assembled on modular skid structures for ease of transportation and assembly during plant startup.

Kinder Morgan Treating LP (KMT) offers competitive pricing on movable modular Dehy units in standard packages or custom-designed packages. These packages include full engineering and design, drafting, fabrication, and can also include operation support. KMT’s customer-dedicated support service is unparalleled in the industry.

Contact Kinder Morgan For a Complete List of Services

Contact us for information and products that can help with natural gas dehydration. Call KMT at 713-369-8544 or 713-369-8535 today. We have dedicated project managers ready to work with you to meet all of your needs.

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