|dc.contributor.author||Gibson, John Alastair Arran||
|dc.description.abstract||This work concerns the functionalisation of a variety of carbon materials for the
selective adsorption of carbon dioxide. A key challenge in post-combustion capture
from gas fired power plants is related to the low CO2 concentration in the flue gas (4-
8%). Therefore highly selective adsorbents have the potential to improve the efficiency
of the separation of carbon dioxide from gas mixtures.
The study was performed in conjunction with the EPSRC funded project ‘Adsorption
Materials and Processes for Carbon Capture from Gas-Fired Power Plants – AMPGas’.
The carbon materials investigated included multi-walled carbon nanotubes, a
microporous activated carbon, two types of mesoporous activated carbon and multi-walled
carbon nanotube/polyvinyl alcohol composite aerogels. The uptake of carbon
dioxide by these materials was enhanced through the addition of basic amine groups
to the materials.
The adsorption properties of the samples were tested by the zero-length column
technique, thermal gravimetric analysis and breakthrough experiments. The materials
were generally tested at conditions representative of those found in the flue gas of a
fossil fuel power plant: 0.1 bar partial pressure of CO2.
Two approaches were adopted for the chemical functionalization of the solid carbon
supports. First, amine groups were covalently grafted directly to the surface and
secondly amine molecules were physically adsorbed within the porous structure of the
material by wet impregnation. It was seen that wet impregnation enabled the
incorporation of a greater number of amine groups and the CO2 capacity of the
materials was investigated with respect to the carbon support structure, the type of
amine and the amount of amine loading. Larger pore volume mesoporous carbon
materials were seen to provide a more efficient support for the amine to interact with
the CO2. A greater than 12-fold increase in the CO2 capacity was observed when the
amine impregnated carbon material was compared to the raw starting material.
The extended zero-length column was introduced and fully characterized as a novel
breakthrough experiment. It requires a small sample mass (~50 mg) and it allows
binary selectivities to be calculated. It was shown, through multiple experiments and
simulations that the breakthrough experiments were conducted under close to
isothermal conditions which greatly simplifies the analysis of the breakthrough curves.
In addition, a new zero-length column model was proposed to account for the reaction
between the amine and the CO2 in the adsorbed phase and fitted to experimental data.
An interesting double curvature was observed in the concentration profile during the
desorption step which was attributed to the kinetics of the amine-CO2 reaction.
A brief investigation was carried out into the binary separation of biogas (45% CO2:
55% CH4) by zeolite 13X, activated carbon and an amine impregnated activated
Finally, initial investigations into the properties of low density carbon nanotube
aerogels which have a large accessible pore volume, were carried out. Their potential
as highly efficient supports for amine impregnation was investigated.
It was found that amine functionalized carbons strongly interact with carbon dioxide
and have the potential to be integrated as an adsorbent in a rapid temperature swing
process that separates carbon dioxide from dilute gas streams.||en
|dc.contributor.sponsor||Engineering and Physical Sciences Research Council (EPSRC)||en
|dc.publisher||The University of Edinburgh||en
|dc.relation.hasversion||J. A. Arran Gibson, Andrei V. Gromov, Stefano Brandani and Eleanor E.B. Campbell, The effect of pore structure on the CO2 adsorption efficiency of polyamine impregnated porous carbons, Microporous and Mesoporous Materials, 208, (2015) 129-139||en
|dc.relation.hasversion||J. A. Arran Gibson, Enzo Mangano, Elenica Shiko, Alex G. Greenaway, Andrei V. Gromov, Magdalena M. Lozinska, Daniel Friedrich, Eleanor E. B. Campbell, Paul A. Wright and Stefano Brandani, Adsorption Materials and Processes for Carbon Capture from Gas-Fired Power Plants – AMPGas, Ind. Eng. Chem. Res., 55, (2016) 3840-3851||en
|dc.title||Development of functionalised porous carbon materials for the separation of carbon dioxide from gas mixtures||en
|dc.type||Thesis or Dissertation||en
|dc.type.qualificationname||PhD Doctor of Philosophy||en