The Importance of Natural Gas Dehydration: Methods, Applications, and Best Practices

Natural gas dehydration is an essential process to ensure the safe and efficient transportation and use of natural gas. Removing moisture from the gas stream prevents a number of issues that greatly impact pipelines and equipment (details below).

Whether you are working with biogas, fuel gas, or sales gas, ensuring the gas is properly dried is critical to maintaining the integrity of your operations.

Why Natural Gas Dehydration is a Necessity

Moisture is a natural byproduct of raw natural gas as it comes out of the ground saturated with water vapor. This moisture, if not removed, can cause a host of problems, including corrosion, pipeline freeze-ups, reduced burner efficiency.

Corrosion

Water in natural gas can cause corrosion in pipelines, valves, and other equipment, because it combines with contaminants like hydrogen sulfide (H₂S) or carbon dioxide (CO₂) to form weak acids, such as carbonic acid. These acids are corrosive to metal surfaces in pipelines, valves, and other equipment. Over time, the acids can wear down these surfaces, leading to leaks, structural damage, and increased maintenance needs.

Pipeline Freeze-Ups

In colder environments, there is great danger in having moisture in your natural gas pipelines. That moisture can freeze, blocking pipelines and interrupting the flow of gas. It’s essential that water is removed from the natural gas line.

Reduced Burner Efficiency

Moisture reduces the efficiency of burners, leading to uneven combustion and lower energy output. Without getting into the details too much, water vapor lowers the calorific value of the gas, meaning there is less energy available for combustion. When gas containing moisture is burned, the water absorbs heat during combustion, which reduces the overall temperature of the flame. This leads to incomplete or uneven combustion, as the gas cannot burn as effectively at lower temperatures.

(Additionally, the presence of moisture can disrupt the air-to-fuel ratio, further affecting combustion efficiency.)

As a result, burners operate less efficiently, requiring more gas to achieve the same energy output, ultimately increasing fuel consumption and lowering system performance.

Common Methods of Natural Gas Dehydration

There are several key methods used to remove moisture from natural gas—each with its own advantages depending on the scale, location, and specific requirements of the gas stream.

That said, one of the most straightforward and low-maintenance methods, desiccant-based dehydration uses a solid material - like silica gel, activated alumina, or molecular sieve - to absorb water vapor from the gas.

The desiccant gradually breaks down as it absorbs moisture, making it a reliable option for environments where simplicity and durability are required. This method is often used in small flow rates and remote locations where power is unavailable.

Key Product Solutions for Natural Gas Dehydration

There are a range of dehydration products designed to tackle the challenges of natural gas moisture removal across various applications.

Inline Desiccant Dryers

Inline desiccant dryers are a low-maintenance option for small flow rates and pneumatic equipment requiring extremely dry gas. They deliver a -40°F pressure dew point and are ideal for instrument gas and small pneumatic equipment protection, handling flows of up to 15 SCFM at 100 psig.

These dryers are best suited for environments where dry gas is crucial for the operation of sensitive equipment, such as control valves and actuators.

PLD Pipeline Deliquescent Dryers

The PLD Pipeline Dryer is a robust and efficient solution for natural gas dehydration in environments where simplicity and reliability are key—think pipelines, biogas systems, wellheads, and fuel gas conditioning.

These dryers have no moving parts, require no electricity, and are commonly used for fuel gas, biogas, sales gas, and instrument gas dehydration. They can even replace traditional TEG dehydrators in some applications, offering an emission-free, low-maintenance alternative for remote or unmanned sites.

Portable Natural Gas Dehydration

For jobs that require mobility, the Gas Pak PRO provides a complete skid package designed for portable natural gas dehydration. It’s especially useful in offshore environments, remote pipelines, or emergency shutdown situations where gas must be dehydrated quickly and efficiently.

This skid package allows for flexible deployment and is perfect for on-the-go applications that demand a self-contained, portable system.

HLSXG Deliquescent Dryer

The HLSXG Dryer is built for harsh and hazardous environments. It uses regenerative desiccant technology to deliver extremely dry gas, even in challenging operating conditions. Rated for explosion-prone areas classified as Class I Division I, Groups C & D, this dryer is essential in hazardous zones where safety is paramount. Thus, uses include Fuel gas conditioning, instrument gas dehydration, and hazardous area operations.

GF200 Filters

The GF200 Series Filters provide a solution for removing contaminants such as particulates and coalescing liquids from natural gas systems. With flow capacities ranging from 15 to 1600 SCFM at 100 psig and connection sizes from ¼" to 3", these filters ensure clean, dry gas for downstream operations.

Applications of Natural Gas Dehydration

Natural gas dehydration is critical across various stages of production and transportation, as well as in different types of gas applications, as mentioned above. Here are a few key areas where dehydration is commonly applied:

Fuel Gas Dehydration

Fuel gas is often used in remote locations to power equipment when electricity is unavailable. Dehydrating the fuel gas before it is used ensures that the equipment operates efficiently and without the risk of moisture-related damage. Equipment such as compressors, turbines, and generating sets rely on moisture-free gas to run smoothly.

Biogas Drying

Biogas, which is produced from the breakdown of organic matter, also requires dehydration to prevent moisture from interfering with downstream processes. Deliquescent dryers, which do not require power or moving parts, are a popular choice for biogas operations because they can be used in unmanned, off-grid facilities.

Sales Gas Conditioning

Before natural gas can be sold or transported through pipelines, it must meet certain quality specifications, including moisture content. Dehydration systems ensure that the gas is dry enough to meet these specifications and can be safely transported through pipelines without risking freeze-ups or corrosion.

Instrument Gas Dehydration

In many production settings, natural gas is used to operate pneumatic instruments and control systems. Moisture in the gas can damage these delicate systems, so dehydration is essential to protect equipment and ensure reliable operations.

Pipeline Dehydration

Pipelines are particularly vulnerable to moisture issues. In addition to the risk of freeze-ups in cold climates, moisture in pipelines can lead to long-term corrosion and operational inefficiencies. Dehydrating gas before it enters the pipeline ensures smooth transport and avoids these risks.

Best Practices for Natural Gas Dehydration

When selecting a dehydration method, consider the specific requirements of your application.

Flow Rate and Gas Volume: Smaller operations may benefit from simpler, desiccant-based systems, while larger operations with higher flow rates might require glycol-based systems or other more robust options.

Location: Remote and off-grid facilities should prioritize low-maintenance systems that do not require power or frequent intervention. Desiccant dryers, with no moving parts or electrical requirements, are ideal for these scenarios.

Moisture Content Requirements: Ensure that your dehydration system can meet the moisture content specifications required for your gas, whether for sales, fuel, or instrument gas.

All said, natural gas dehydration is a critical part of ensuring the safety and efficiency of gas operations. From small pneumatic instruments to large-scale pipelines, moisture removal is essential to prevent freeze-ups, corrosion, and equipment damage.

For more information on Natural Gas Dehydration, check out our new Van Gas Linecard.