Sour Gas Amine Filtration Enhancement

Saudi Aramco Gas Operations can process over 8 BSCFD of gas. Diglycolamine (DGA) is the most widely used Amine in gas treatment facilities. Similar to other types of amines such as monoethanolamine (MEA), diethanolamine (DEA) and methyl diethanolamine (MDEA), the performance of DGA is mainly reduced by accumulation of contaminants, e.g. suspended solids, hydrocarbon liquids and degradation products. Foaming, solvent loss, fouling and other operational problems are associated with DGA contaminants in high-pressure (HP) DGA systems. Low pressure systems generally have more stable performance with less operational issues. These issues are generally managed by anti-foam injection, fresh solvent addition and installation of mechanical filters. The gas treatment system is equipped with inlet gas filtration and amine filtration to reduce the contamination level in DGA, e.g., suspended solids, pipe corrosion due to aging and hydrocarbons. Slug catchers remove the bulk of liquid in the gas. Three phase separators with coalescing element remove liquid aerosols and solid particulates. DGA filtration consists of a pre-coat filter (1 micron rating) and a mechanical filter (5 micron rating) installed on a slip stream. The pre-coat filter consists of diatomaceous earth (diatomite or kieselguhr) coating material bonded to a mechanical screen or leaf. The filtration media is chemically inert and contain a silica skeleton. A precoat filter removes suspended solids, contaminants and other particulate matter; to build a pre-coat primary filter medium layer to be deposited on the basic screen. The correct cake buildup is essential for optimum filtration results. Sometimes pre-coat filter performance is not up to a satisfactory level due to the quality of cake build up. Gas plants are putting extra efforts to maintain gas treatment units to control amine quality.