%0 Journal Article
%T CO2 Adsorption: Experimental Investigation and CFD Reactor Model Validation
%A Ronald W. Breault
%A Lawrence J. Shadle
%A James L. Spenik
%A E. David Huckaby
%J Journal of Computational Environmental Sciences
%D 2014
%R 10.1155/2014/503194
%X The National Energy Technology Laboratory is investigating a new process for CO2 capture from large sources such as utility power generation facilities as an alternative to liquid amine based adsorption processes. Many of these advanced dry processes are based upon sorbents composed of supported polyamines. In this analysis, experiments have been conducted in a laboratory-scale fluidized bed reactor and compared to CFD reactor predictions using kinetics obtained from TGA tests. Batch experiments were conducted by flowing a mixture of CO2, H2O, and N2 (simulated flue gas) through a fluidized bed of sorbent material. The exit gas composition time series data is compared to CFD simulations using a 3-dimensional nonisothermal reacting multiphase flow model. The effects of the gas flow rate, distributor design, and particle size are explored through the CFD simulations. It is shown that the time duration for CO2 adsorption decreased for an increase in the gas flow. Fluid bed hydrodynamics indicated that there were regions in the reactor where the inert FCC particles segregated and defluidized; without adversely affecting the capacity of the sorbent to adsorb CO2. The details of the experimental facility and the model as well as the comparative analysis between the data and the simulation results are discussed. 1. Introduction Over the past two to three decades, there has been increasing concern over the importance of carbon dioxide emissions to the environment and the possible effect these emissions have on global climate shifting. Historical atmospheric CO2 levels have been greater and less than the preindustrialized values shown in Figure 1 [1]. Also shown in Figure 1 are the CO2 concentration levels over the past 30 years [2]. These values start in 1980 with a concentration of 338£¿ppm, already outside the normal range over the past 400,000 years, and increase to a value of 392£¿ppm in 2012, the last year that data exist. Based on these CO2 numbers there is little doubt that CO2 is higher now than in the recent past. Extrapolating the trend in the data taken over the past 30 years backwards (Figure 1) this trend intersects with that of the historical data in the time frame of the beginning of the industrial age. This implies with strong confidence that the increased values of CO2 are likely caused from human activity. The recent divergence between the temperature data and the CO2 concentration data refutes assertions that global warming can be attributed to increased CO2 concentration as does the trend in the temperature variation between 1940 and the late
%U http://www.hindawi.com/journals/jces/2014/503194/