Separation of CO2 from flue gases using hydroquinone clathrate compounds

Hydroquinone (HQ) samples reacting with (CO2+N-2) gas mixtures with various compositions at pressures ranging from 10 to 50 bar are analyzed using spectroscopic methods and an elemental analyzer. The results indicate that while both CO2 and N-2 can react with HQ to form clathrate compounds, CO2 has higher selectivity than N-2. In particular, at an operating pressure of 20 bar or greater, the CO2 content in the clathrate compound is 85mol% or higher regardless of the feed gas composition. Moreover, if a two-step clathrate-based process is adapted, CO2 at a rate of 93 mol% or higher can be recovered from flue gases. Thus, the clathrate compound described here can be used as a CO2 separation/recovery medium for CO2 in flue gases.