Natural gas dehydration systems remove saturated water from gas streams to meet sales gas specification and avoid other problems associated with the transportation of wet gas such as corrosion, water condensation and hydrate formation.
The methods used for gas dehydration are absorption, adsorption, membrane processes and refrigeration. These methods may be used individually or combined to achieve the desired water content for specific application.
There are three main types of gas dehydration:
- Glycol Dehydration Systems are the most common in industry. Triethylene Glycol (TEG) is the most universally used glycol. Glycol dehydration is used to absorb the water from the process gas stream followed by mechanical refrigeration to knock out hydrocarbons.
- Silica Gel Conditioning involves removing water and heavier hydrocarbons by passing the gas through adsorber beds. Silica gel is the most widely used solid desiccant for normal dehydration of natural gas to pipeline specifications. Regeneration is carried out at high pressures and temperatures.
- Molecular Sieve Beds are a class of aluminosilicates and work in a similar fashion to silica beds. In comparison with silica gel, molecular sieves have a lower water capacity, which means that a larger bed is required to achieve the same duty. Molecular sieves are known to produce the lowest water dew points.
Each of the dehydration technologies are suitable for specific applications and OSL have highly skilled gas process engineers to prepare Best Available Technology (BAT) Assessment for your application. Typical sales gas water content ranges from 2 – 7 lb/MMSCF, whilst water content for processes such as LPG recovery and LNG production are much lower at 1ppmv. We will use our in-house capabilities to assess the dew point depression requirement and select the most appropriate dehydration process technology.
Our multi-discipline engineering team has successfully delivered gas dehydration projects and has a good understanding of operational bottlenecks. OSL provides clients with the following services and solutions:
- BAT Assessment
- Process Simulation
- Front End Engineering Design
- Plant troubleshooting and tuning
- Process and Heat Integration Analysis