An intelligent solution
for amine wash

Refineries, oil and gas industry

FAUDI Activated Charcoal Filters type p62

The demand of natural gas increases constantly in the recent decades. Natural gas became one of the most important energy carrier nowadays and for the future as well. However, the underground natural gas reservoirs often contain e.g. carbon dioxide (CO₂) and hydrogen sulphide (H₂S) as well as various other impurities. These impurities are undesirable compounds that cause various technical and functional problems such as corrosion and foaming during the processing and use of the natural gas.

FAUDI has supplied a consortium of customers with activated carbon adsorbers, which are part of a complete amine filtration package including cartridge filters, instrumentation, valves and piping, for a project to develop a significant natural gas field in south-western Algeria. The amine filtration package is part of the Acid Gas Removal Unit (AGRU). Planning, procurement, construction and pre-commissioning of the necessary pipelines and a central gas processing facility were carried out by a Korean engineering company.

For gas processing facilities, refineries and petrochemical plants the removal of the impurities from natural gas is essential for an efficient operation as well as to meet transportation, sales and liquefaction specifications and to comply with environmental regulations. Gas sweetening by amine process systems has been considered as the most common process in gas processing industries.

In gas sweetening processes aqueous solutions of different types of amines are utilized, including for example, monoethanolamine (MEA), diethanolamine (DEA) and methyldiethanolamine (MDEA), to remove via chemical adsorption H₂S / CO₂ components from the gas while being brought in contact with the gas stream in the contactor column. The spent or loaded amine solution is then subjected to a regeneration process to release the contained sour gas loading, enabling a continuous sweetening process. Unfortunately, under process conditions, the amine solution is also loaded with solid particles, liquid heavy hydrocarbons, surface active impurities, etc., which increases the tendency to foam. Treating the amine solution with a FAUDI amine filtration system is a proven practice to reduce such loadings and achieve stable operation.

Typical amine filtration systems consist of the following components:

• The Pre-Filter (also called Primary Filter) removes solid particles, scale, iron sulfites at a filtration fineness of 5 to 10 micron and thus is protecting the carbon bed from particles originating from corrosion and amine degradation mainly.
• In the Activated Charcoal Filter the trace liquid hydrocarbons and dissolved organic acids are removed by adsorption using an activated carbon bed.
• The Fine Filter (also called Secondary or After Filter) is located downstream the Carbon Filter and is removing fines originating from the activated carbon bed.

As a usual practice, cartridge filters with replaceable filter elements are considered as pre-filter. Traditionally, because of the solids load, the pre-filter is often designed as a duplex filter unit, i.e. one filter in operation and one filter in standby. However, for larger filtration systems or Rich Amin Filtration with cartridge filters as pre-filters, the operating costs can become very high. In such cases, an automatically cleanable pre-filter system becomes a viable option. FAUDI is ready to offer its customers also automatic pre-filter units such as precoat filter systems or backflush filters with forward purging instead of the manual cartridge filters.