Polymeric Gas-Separation Membranes for Petroleum Refining

Table 3

Current technologies for carbon dioxide separation.

Technology	Advantages	Disadvantages
Chemical and physical absorption	(i) No need for pretreatment.; (ii) Can treat wider range of CO2.; (iii) High removal efficiency.	(i) High capital and operating costs.; (ii) Regeneration of solvent.
PSA	(i) Does not involve a solvent.; (ii) Better stability toward impurities in the feed.	(i) Low solid-to-gas capacity.; (ii) Low regeneration rate.; (iii) Pressure cycle is energy-intensive.
Cryogenic distillation	(i) Achieves >99% of CO2 capture.; (ii) Produces liquefied CO2 for easier storage.	(i) Economical only if the feed contains 50–70% CO2.; (ii) Higher pressure is required to avoid CO2 sublimation.
Membranes	(i) Requires minimum supervision.; (ii) Can remove H2S and H2O as well.; (iii) Long-operating life (>5 years).	(i) High capital cost.; (ii) Pretreatment is required to remove particulates and some inhibitors.