glycol purity enhancement methods

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Fig. 5.13EBook of Gas

Glycol P

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ffect of stripProcessors S

urity En

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e hot glycol.

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There are a couple of ways of flowing this gas into the hot glycol. One way is simply to flow the

gas into the glycol below the overflow line from the reboiler to the surge drum or directly into

the glycol in the reboiler vessel through a perforated pipe below the fire tube. The other way is to

install a small packed column between the reboiler and the surge drum and admit the gas at the

base of this column. By contacting the hot glycol with natural gas, an additional small amount of

water is "stripped" from the glycol into the gas, increasing the purity of the lean glycol. If a

packed column is used as a contacting means between the glycol and the stripping gas, the

stripping efficiency is considerably improved, as seen in Fig. 5.13.

The stripping gas that is added to the glycol in the regeneration section is emitted into the

atmosphere with the released water vapor, unless the vapors from the still columns are routed to

a heater or an incinerator, or are captured by a compressor and recompressed.