Optimization of CO2 Capture from Simulated Flue Gas Using K2CO3/Al2O3 in a Micro Fluidized Bed Reactor

The cost-effective dry regenerable K 2 CO 3 /Al 2 O 3 seems to be a promising sorbent for CO 2 removal from the flue gas of fossil fuel power plants. In this work, the characterization of the carbonation reaction and process optimization were performed in a so-called micro fluidized bed reactor (MFBR), which has recently been applied to study gas–solid reactions. The sorbent was also characterized by BET and SEM techniques. In addition, the most important gas–solid heterogeneous models were evaluated, and the kinetic parameters were determined by the model fitting approach. Based on the kinetic study results, the homogeneous model (HM) and the shrinking core model (SCM) were selected as the reaction models. Also, the effects of the independent variables including temperature, gas flow rate, and vapor pretreatment amount on the responses (adsorption capacity and reaction rate constant) were investigated by the response surface methodology (RSM) coupled with Box–Behnken design (BBD). Regarding to the analysis of variance (ANOVA) results, the temperature and gas flow rate are the most important factors affecting the adsorption capacity and the reaction rate constant, respectively. In addition, the semiempirical polynomials were developed to find the optimum condition corresponding to the highest adsorption capacity and reaction rate. Consequently, the optimum independent variables were 60 °C, 562 CCM, and 22.2 mg of H 2 O condition for the temperature, gas flow rate, and vapor pretreatment amount, respectively. The best response values of 65.29 mg of CO 2 /g of sorbent and 0.3402 (min –1 ) were predicted for the adsorption capacity and reaction rate constant, respectively, at the optimum conditions which were verified experimentally. The presented results are applicable and essential for future simulation and modeling CO 2 capture in the fluidized bed reactor.