Patent ID: 9511323
Filing Date: 2016-12-06
CPC Classification: B01D

Claim Text:
1. A method of reducing a water content of a gas stream by using a contactor having at least a first contacting zone and a spatially distinct second contacting zone, the method comprising: feeding a first desiccant stream into the first contacting zone; feeding a second desiccant stream into the second contacting zone, wherein the first and the second desiccant streams are fed using separate lines into the contactor; forming a comingled desiccant stream using the first and the second desiccant streams, the comingled desiccant stream exiting from a bottom of the second contacting zone; directing the gas stream through the second contacting zone and then through the first contacting zone, the gas stream first contacting the comingled desiccant stream and then only the first desiccant stream; reducing a pressure of the comingled desiccant stream with a pressure reducer; separating a co-absorbed gas in the comingled desiccant stream from the pressure reducer in a flash separation vessel to form a co-absorbed gas stream and a liquid desiccant stream; flowing the liquid desiccant stream from the flash separation vessel through a stripping column; flowing a first stripping gas stream through the stripping column in a direction counter to the flow of the liquid desiccant stream; boiling the liquid desiccant stream exiting the stripping column in a reboiler; dividing the liquid desiccant stream in the reboiler into at least a first regenerated stream and a second regenerated stream; directing the first regenerated stream into a polishing column; feeding a second stripping gas stream into the polishing column in a direction counter to the flow of the first regenerated stream, wherein the second stripping gas stream reduces a water concentration of the first regenerated stream to a level lower than a water concentration of the second regenerated stream; cooling the first regenerated stream exiting the polishing column and directing the first regenerated stream into the first contacting zone, the first regenerated stream being the first desiccant stream; and cooling the second regenerated stream exiting the reboiler and directing the second regenerated stream into the second contacting zone, the second regenerated stream being the second desiccant stream.