Polymeric Gas-Separation Membranes for Petroleum Refining

Table 10

Current technologies for dehydration of natural gas [141, 150].

Technology	Advantages	Disadvantages
Glycol absorption	(i) Continuous process.; (ii) Lower pressure drop compared to solid desiccants.; (iii) Better chemical stability.	(i) Difficult to achieve water dew point below −32°C.; (ii) Harmful VOCs are formed during the regeneration of solvent.
Alumina desiccant	(i) Ability to adsorb heavy hydrocarbons.; (ii) Performance is nearly independent of the feed operating condition.	(i) High pressure drop.; (ii) Regeneration is needed.
Zeolite molecular sieving	(i) Ability to achieve dew point of −101 to 149°C.; (ii) Stable under sour gas.	(i) More energy is needed for regeneration.
Polymeric membranes	(i) Ability to separate hydrogen sulfide, carbon dioxide, and heavy hydrocarbons (C3+) in one step.; (ii) Long life (7 years).; (iii) No need for regeneration.	(i) Pretreatment may be required.; (ii) Energy requirement for compressors.; (iii) Not suitable for large volume.