Molecular Sieves
Traditionally where the lowest water dew points are required (e.g. upstream LNG plants), solid desiccant adsorbers with molecular sieves have been used.
Despite performance improvements with enhanced proprietary glycol absorption, certain applications are best suited to solid desiccant adsorption.
In this cyclic process, a bed of solid desiccant adsorbs water molecules from wet feed gas. Once the bed is water-saturated it is regenerated by small back-flow of heated, dry process gas.
To provide continuous operation these units use multiple adsorption beds in a “swing” configuration. Automatically controlled valves orient process flows to regenerate one bed while the other (or others) is dehydrating gas and then when the operating bed needs regeneration, gas flow is swung to the regenerated bed.
