Amazon Filters Blog

How do natural gas filter separators work?

Written by Amazon Filters | January 18, 2022

Natural gas filter separators use filtration materials to remove impurities from natural gas. This is an essential process that prevents damage from occurring to downstream systems. 

In this article, we will explore:

  • The importance of natural gas filter separators
  • How they work
  • Why choosing the right filtration solution saves both time and money

The importance of natural gas filter separators

Natural gas filter separators are needed to remove contaminants from the flow stream. You’ll find filter separators across all areas of the flow stream where contaminants are or may be present. This may be after compression, before dehydration units, or at the delivery point. 

Typical contaminants extracted by separators include:

  • High and medium surface tension liquids such as water and hydrocarbons
  • Compressor lube oil
  • Non-shear-sensitive solids such as sand, corrosion compounds, and abrasives
  • Pipeline and plant chemicals
  • Iron sulphide

Without filter separators, gas will fail to meet quality and safety requirements for its purity. In addition, filters prevent the build-up of liquids in downstream systems, which makes them safer and better optimised.

How does a natural gas filter separator work?

A filter separator is a hardy, general solution for filtering solids out of natural gas. Filter separator vessels are either high-pressure (500 PSI or higher) or low-pressure (anything lower than 500 PSI). The vessel type depends on the process conditions and application.

Generally, they have one or two stages, depending on the filtration requirements. The first stage captures solid particulate and coalesces any liquids into larger droplets from gas. In the second stage, those coalesced liquids are removed.

The captured solid particulate matter is removed from the separator when the disposable filter cartridges are changed. 

Natural gas filter separators

Moisture-laden gas enters the filter separator and makes initial contact with the filter media on the outside. The media holds all the solids, aided by a loss in velocity and gravitational effects. The liquid coalesces, and gas comes out one end, free of heavier liquids. 

In the second stage, the demister captures any remaining liquid droplets. The resulting gas stream is then virtually free of all particles smaller than the microfilter used.

Normal filter separators release gas that’s 99.9% free of all solids and liquids 1 micron and larger. They’re sufficient for most use cases.

However, if you need to filter out very fine liquids – as fine as 0.3 microns – you need a vertical absolute coalescer.

Coalescing filters 

Coalescing filters are designed to capture liquids. They take very small droplets and amalgamate (coalesce) them into larger droplets that the filter media can capture. Coalescing filters contain low-energy polymers such as fluoropolymer or silicone to keep the droplets from sticking to the filter and help it shed the liquids.  

These filters use gravity to separate heavier droplets from gas by gravity, applying a force proportional to the diameter squared. The bigger the droplets, the easier they separate. This level of fine liquid filtration can be found in certain pharmaceutical and oil and gas processes.

How to optimise your natural gas separators

As you can see, filter separators come in a variety of specifications, depending on your requirements. Getting the right solution is key:

  • Inefficient filters lead to poor filtration, a risk to equipment and staff, and reduced product quality
  • Filter separators that are too efficient can be wasteful if they work too well, shortening the life of the filter

The challenge we face is striking the balance between minimising how many disposable cartridges you use and maximising the quality of the filtration process. To achieve this, you need to understand the materials you’re working with and the latest filtration technology that’s available.

Amazon Filters can help you optimise your system, so it only removes what needs to be removed. This means your filter lasts longer, helps protect equipment, and maximises efficiency.

We take a hands-on approach so we can understand your filtration requirements, what you’re processing, and what your optimal specification needs to be. This allows us to provide you with the filter separator that works best for you.

From managing OPEX and capital costs to logistics, size, or governance, we can help you align your filtration solution to your key business drivers.