@article{mao_edwards_kuznetsov_srivastava_2004, title={Three-dimensional numerical simulation of a circulating fluidized bed reactor for multi-pollutant control}, volume={59}, ISSN={["0009-2509"]}, DOI={10.1016/j.ces.2004.06.004}, abstractNote={Circulating fluidized bed adsorber (CFBA) technology is regarded as a potentially effective method for simultaneously controlling emissions of sulfur dioxide, fine particulate matter, and trace heavy metals, such as mercury vapor. In order to analyze CFBA systems in detail, a gas mixture/solids mixture model based on the three-dimensional Navier–Stokes equations is developed for particle flow, agglomeration, physical and chemical adsorption in a circulating fluidized bed. The solids mixture consists of two solids, one with components of CaO and CaSO4, and the other being an activated carbon. The gas mixture is composed of fine particulate matter (PM), sulfur dioxide, mercury vapor, oxygen and inert gas. Source terms representing fine particulate matter agglomeration onto sorbent particles, sulfur dioxide removal through chemical adsorption onto calcined lime, and mercury vapor removal through physical adsorption onto activated carbon are formulated and included into the model. The governing equations are solved using high-resolution upwind-differencing methods, combined with a time-derivative preconditioning method for efficient time-integration. Numerical simulations of bench-scale operation of a prototype CFBA reactor for multi-pollutant control are described.}, number={20}, journal={CHEMICAL ENGINEERING SCIENCE}, author={Mao, DM and Edwards, JR and Kuznetsov, AV and Srivastava, RK}, year={2004}, month={Oct}, pages={4279–4289} } @article{mao_edwards_kuznetsov_srivastava_2003, title={Development of low-diffusion flux-splitting methods for dense gas-solid flows}, volume={185}, ISSN={["1090-2716"]}, DOI={10.1016/S0021-9991(02)00049-9}, abstractNote={The development of a class of low-diffusion upwinding methods for computing dense gas-solid flows is presented in this work. An artificial compressibility/low-Mach preconditioning strategy is developed for a hyperbolic two-phase flow equation system consisting of separate solids and gas momentum and continuity equations. The eigenvalues of this system are used to devise extensions of the AUSM+ [1] and LDFSS [2] flux-splitting methods that provide high resolution capturing of bubble growth and collapse in gas-solid fluidized beds. Applications to several problems in fluidization are presented.}, number={1}, journal={JOURNAL OF COMPUTATIONAL PHYSICS}, author={Mao, DM and Edwards, JR and Kuznetsov, AV and Srivastava, RK}, year={2003}, month={Feb}, pages={100–119} } @article{mao_edwards_kuznetsov_srivastava_2002, title={A model for fine particle agglomeration in circulating fluidized bed absorbers}, volume={38}, ISSN={["0947-7411"]}, DOI={10.1007/S002310100260}, number={4-5}, journal={HEAT AND MASS TRANSFER}, author={Mao, D and Edwards, JR and Kuznetsov, AV and Srivastava, R}, year={2002}, month={Apr}, pages={379–388} } @article{mao_edwards_kuznetsov_srivastava_2002, title={Particle flow, mixing, and chemical reaction in circulating fluidized bed absorbers}, volume={57}, ISSN={["0009-2509"]}, DOI={10.1016/S0009-2509(02)00168-9}, abstractNote={Abstract A mixing model has been developed to simulate the particle residence time distribution (RTD) in a circulating fluidized bed absorber (CFBA). Also, a gas/solid reaction model for sulfur dioxide (SO 2 ) removal by lime has been developed. For the reaction model that considers RTD distribution inside the core and annulus regions of a CFBA, a macrochemical reaction can be simulated based on microchemical reaction dynamics. The presented model can predict SO 2 and lime concentration distributions inside the CFBA, and give the amount of lime needed to remove a given percentage of SO 2 . It is found that SO 2 concentration decreases with the increase of CFBA distance from the bottom in the core region. However, lime concentration exhibits a very slight variation in the core region. This means that lime is efficiently utilized to remove SO 2 . The model also predicts that SO 2 partial pressure at the exit of the CFBA decreases with the increase in the percentage of fresh lime injected in the CFBA.}, number={15}, journal={CHEMICAL ENGINEERING SCIENCE}, author={Mao, D and Edwards, JR and Kuznetsov, AV and Srivastava, R}, year={2002}, month={Aug}, pages={3107–3117} }