Separation of CO2 from simulated flue gas by hydrate method in an impinging stream reactor

Separating CO 2 from flue gas through hydrate method owns many advantages, including easy operation, environmental friendliness, low-energy consumption during the process, and the potential for water recycling in the reaction. This study investigated the effects of cyclopentane (CP, 5.0 vol%), methionine (L-Met, 0.2 wt%), and alkyl polyglucosides (APG) with various carbon chain lengths as additives on the kinetics of flue gas hydrate generation in a simulated power plant environment, with a focus on gas separation efficiency. Key parameters, including impinging strength ( β ), feed pressure, initial temperature, and APG carbon chain length, were systematically investigated to optimize the hydrate formation process. The results reveal that gas consumption ( Δ n H ), average reaction rate ( R H ), and CO 2 capture rate ( S.Fr. (CO 2 )) initially increases with β , reaching a peak before decreasing, while the CO 2 separation factor ( S.F. (CO 2 )) consistently increased. Higher feed pressures and lower initial temperatures enhanced gas consumption, thereby accelerating the hydrate formation and improving separation efficiency. Additionally, the optimal APG carbon chain length significantly enhanced both the kinetics of hydrate formation and gas separation efficiency. Specifically, under conditions of 6 MPa, 275.15 K, and β = 0.13, the CP+L-Met+APG0814 system achieved a maximum Δ n H of 0.509 mol, an R H of 0.102 mol/h, and a S.F. (CO 2 ) of 82.4 %, demonstrating the potential for improved CO 2 capture in hydrate-based separation processes.