Determination of Kinetic Parameters for CO 2 Methanation (Sabatier Reaction) over Ni/ZrO 2 at a Stoichiometric Feed-Gas Composition under Elevated Pressure
Methanation of CO 2 using H 2 obtained by renewable energy sources has been gaining attention as one of the promising options for utilizing captured CO 2 and surplus power obtained when intermittent power sources such as solar and wind energy are used. Herein, kinetics of CO 2 methanation over Ni/ZrO 2 was studied using a tubular quartz reactor at 0.9 MPa. The Sabatier reaction (CO 2 + 4H 2 = CH 4 + 2H 2 O, Δ H r 298K = – 165 kJ mol –1 ) was carried out under stoichiometric gas feeding (CO 2 /H 2 = 1/4 v/v to CH 4 /H 2 O = 1/2 v/v), and its reaction rate was determined. The exothermic nature o... Mehr ...
Methanation of CO 2 using H 2 obtained by renewable energy sources has been gaining attention as one of the promising options for utilizing captured CO 2 and surplus power obtained when intermittent power sources such as solar and wind energy are used. Herein, kinetics of CO 2 methanation over Ni/ZrO 2 was studied using a tubular quartz reactor at 0.9 MPa. The Sabatier reaction (CO 2 + 4H 2 = CH 4 + 2H 2 O, Δ H r 298K = – 165 kJ mol –1 ) was carried out under stoichiometric gas feeding (CO 2 /H 2 = 1/4 v/v to CH 4 /H 2 O = 1/2 v/v), and its reaction rate was determined. The exothermic nature of CO 2 methanation and extremely high catalytic activities increased the reaction temperature to 400–600 °C even when the feed-gas temperature was as low as 250–400 °C, and the gas hourly space velocity was as high as 3 × 10 6 h –1 . Nonlinear regression analyses based on one- and multistep kinetic models were used to investigate the reaction rates to estimate the kinetic parameters. Both models with optimized parameters can reproduce the experimentally obtained CH 4 formation rates for the entire range of the feed-gas conversion with a coefficient of determination ( R 2 ) of over 0.98.