Economical Glycol Contactor Design determined by Novel Column Internals

Daniel Egger and Kurt Breu, Sulzer Chemtech Ltd, Winterthur, Switzerland

For gas dehydration with glycol the contactor consists of inlet scrubber, contacting section and outlet scrubber either in separate vessels or integrated. The contacting section is equipped with trays, random or structured packings and the outlet scrubber with a knitted wire mesh pad, a vane pack, a swirldeck or multi cassettes and sometimes with a combination.

The design of the scrubbing section strongly depends on the equipment in the contacting section. The requirement for a separate feed inlet scrubber depends on the gas / liquid composition and operating conditions. In general, a standalone feed inlet scrubber gives the highest operating flexibility. An integrated outlet scrubbing section in the glycol contactor vessel gives sufficient operating flexibility while being most cost efficient.

The challenge is to choose the right and most economical combination of internals in the contacting and scrubbing section for the specified gas, liquid flowrates, compositions and operating pressures.

This paper shows design characteristics for the different mass transfer and demisting internals and compares capacity, efficiency, pressure drop, glycol loss, sensitivity to fouling and moving conditions, operating pressure and costs.