Simulation design and optimization of reactors for carbon dioxide mineralization

To achieve a synergistic solution for both sustainable waste management and permanent CO_(2) sequestration,CO_(2) mineralization via fly ash particles is an option.Based on computational fluid dynamics,two specialized reactors for fly ash mineralization were designed.The reactor designs were strategically tailored to optimize the interactions between fly ash particles and flue gas within the reactor chamber while concurrently facilitating efficient post-reaction-phase separation.The impinging-type inlet configuration dramatically enhanced the interfacial interaction between the fly ash particles and the gaseous mixture,predominantly composed of CO_(2) and steam.This design modality lengthens the particle residency and reaction times,substantially augmenting the mineralization efficiency.A rigorous investigation of three operational parameters,that is,flue gas velocity,carrier gas velocity,and particle velocity,revealed their influential roles in gas-particle contact kinetics.Through a computational investigation,it can be ascertained that the optimal velocity regime for the flue gas was between 20 and 25 m⋅s1.Concurrently,the carrier gas velocity should be confined to the range of 9-15 m⋅s1.Operating within these finely tuned parameters engenders a marked enhancement in reactor performance,thereby providing a robust theoretical basis for operational efficacy.Overall,a judicious reactor design was integrated with data-driven parameter optimization.

Molecular simulation on carbon dioxide capture performance for carbons doped with various elements

Among the different types of CO_(2)capture technologies for post-combustion,sorption CO_(2)capture technology with carbon-based sorbents have been extensively explored with the purpose of enhancing their sorption perfor-mance by doping hetero elements due to the rapid reaction kinetics and low costs.Herein,sorption capacity and selectivity for CO_(2)and N 2 on carbon-based sorbents doped with elements such as nitrogen,sulfur,phosphorus,and boron,are evaluated and compared using the grand canonical Monte Carlo(GCMC)method,the universal force field(UFF),and transferable potentials for phase equilibria(TraPPE).The sorption capacities of N-doped porous carbons(PCs)at 50℃were 76.1%,70.7%,50.6%,and 35.7%higher than those of pure PCs,S-doped PCs,P-doped PCs,and B-doped PCs,respectively.Its sorption selectivity at 50℃was approximately 14.0,nearly twice that of pure PCs or other hetero-element-doped PCs.The N-doped PCs showed the largest sorption heat at 50℃among all the PCs,approximately 20.6 kJ·mol^(−1),which was 9.7%−25.5%higher than that of the pure PCs under post-combustion conditions.Additionally,with the product purity of 41.7 vol.%−75.9 vol.%for vacuum pressure swing sorption,and 53.4 vol.%−83.6 vol.%for temperature swing sorption,the latter is more suitable for post-combustion conditions than pressure-swing sorption.