Carbon capture simulation studies

T vo carbon-capture processes have been studied in this chapter. Both use a two-column absorber/stripper flowsheet. The low-pressure amine system presents more problems in dynamic simulation than does the high-pressure physical absorption system. The plantwide control structures that are effective for the two systems are quite sunilar. 

Babarao R, Dai S, Jiang D (2012) Nitrogen-doped mesoporous carbon for carbon capture— a molecular simulation study. J Phys Chem C 116 7106-7110... 

Comparison of the common electrolyte solvents (EC, propylene carbcaiate [PC], dimethyl carbonate [DMC], EMC, vinylene carbonate [VC], dimethoxyethane [DME]) oxidative stability with experiments was reported by Zhang et al. [3]. While trends of the oxidative stability were reasonably captured in this study, typical deviations between experiments and simulations were reported to be around 0.5-1.0 V. Note that Zhang et al. [3] did not use the value of 1.4 V to convert from the absolute to Li /Li potential scale, instead they used the Li/LF and M/M" cycles with a number of calculated/estimated quantities, resulting in the absolute potential versus LF/Li being around 2.2 V. Application of the value of 1.4 or 1.54 V derived from SHE potential in water and acetonitrile and using the standard LF/Li vs. SHE potential will result in an improved agreement between QC-based values reported by Zhang et al. [3] and experiments. 

Wang et al. [162] did perform a numerical study of hydrogen production by the SE-SMR process with in-situ CO2 capture. The SMR- and adsorption of CO2 processes were carried out simultaneously in a bubbling fluidized bed reactor. Enhanced production of hydrogen was achieved in the SE-SMR process compared with the conventional SMR process. The hydrogen molar fraction in the gas phase was near the equilibrium composition. The effects of inlet gas superficial velocity and steam-to-carbon ratio (or mass ratio of steam to methane in the inlet gas) on the process performance were examined. The reactor system design parameters used in the numerical simulation are listed in Table 4.14. 

Hybrid composite sj tems that comprise mixtures of different filler types guarantee great versatility in capturing preferred electrical prop)erties combined with additional desired properties. For example, the electrical properties of carbon black/poljTner composites were enhanced significandy by the addition of just a small fraction of the more expensive CNTs. Similarly, numerical simulations by Rahatekar et rtf show that addition of spheres to a fiber system does not modify the percolation threshold of the fiber system significantly when the fraction of spheres is small, as the contribution of the fibers in the overall network fonnation is dominant. These studies suggest that hybrid composites can combine rodlike fillers to control the electrical properties and spherical fillers to modulate the mechanical, thermal, or optical properties. The possibilities are even further extended by the opportunities presented by combining disaete nanopartides with continuous fiber composites. 

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