Systematic development of predictive molecular models of high surface area activated carbons for the simulation of multi-component adsorption processes related to carbon capture
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Date
26/11/2015Author
Di Biase, Emanuela
Metadata
Abstract
Adsorption in porous materials is a promising technology for CO2 capture and storage.
Particularly important applications are adsorption separation of streams associated with the
fossil fuel power plants operation, as well as natural gas sweetening. High surface area
activated carbons are a promising family of materials for these applications, especially in the
high pressure regimes. As the streams under consideration are generally multi-component
mixtures, development and optimization of adsorption processes for their separation would
substantially benefit from predictive simulation models.
In this project we combine experimental data and molecular simulations to systematically
develop a model for a high surface area carbon material, taking activated carbon Maxsorb
MSC-30 as a reference.
Our study starts from the application of the well-established slit pore model, and then evolves
through the development of a more realistic model, based on a random packing of small
graphitic fragments.
In the construction of the model, we introduce a number of constraints, such as the value of
the accessible surface area, concentration of the surface groups and pore volume, to bring the
properties of the model structure close to the reference porous material.
Once a plausible model is developed, its properties are further tuned through comparison
between simulated and experimental results for carbon dioxide and methane. The model is
then validated by predictions for the same species at different conditions and by prediction of
other species involved in the carbon capture processes.
The model is applied to simulate the separations involved in pre and post combustion capture
processes and sweetening of sour natural gas, using realistic conditions and compositions for
the multicomponent mixtures. Finally, it is used to explore the effect of water in pre and post
combustion separations.