The amine-treating unit is of great importance in gas processing and refinery operations for treating acid gases. It is also attracting increasing attention from the pressing needs of environmental compliance and for meeting stringent levels of H2S and CO2 removal.
Amine scrubbing solutions used for gas treatment at refineries, chemical, sulphur and gas processing plants remove hydrogen sulphide (H2S) and carbon dioxide (CO2) from gas streams. Yet, one of the problems with amine solutions is the gradual accumulation of byproduct contaminants called heat stable salts (HSS). An increased HSS concentration in the amine loop leads to corrosion-related maintenance problems, frequent filter replacements, amine losses, excessive foaming, capacity reduction and more.
Ion exchange resins have been employed in the removal of HSS, but because of the different affinities the various anionic HSS contaminants have towards the resin, successful removal is restricted. However, the continuous online removal of HSS rather than periodic or batch treatment helps to ensure a more stable and uniform conditioning operation (see Figure 1).
A proprietary system from EcoTec has proven successful over the years in achieving efficient online HSS removal. To date, 57 of these systems, known as AmiPur, have been supplied in the US, Mexico, Europe, China, India and Saudi Arabia. This article details the technology and its various applications, including CO2 sequestration.
Various examples are presented, with two case studies in China and Aruba.