Monte Carlo simulation and statistical mechanics modelling of mixture adsorption in silicalite.
Doctoral thesis, UCL (University College London).
Adsorption in zeolites is widely and increasingly used in many industrial processes. For the design of new processes and improvement of the performance of existing ones, basic adsorption data is needed but due to the difficulties of experimentation it is lacking. In this thesis, different methods have been used to calculate the adsorption isotherms of benzene, methane, ethane and CO, mixtures as well as Propane, i-butane and n-butane and their binary and ternary mixtures in zeolites. Firstly, Lattice Model has been used to calculate benzene adsorption isotherms in silicalite zeolite whose experimental adsorption isotherms exhibit unusual features. The zeolite is modelled as two types of quasi one- dimensional pores. The lattice model has dimer states to represent molecules lying in extended states with the aromatic ring on average parallel to the pore wall, the monomer state to represent molecules standing perpendicular to the principle axis of the pores. Vacant sites or holes allow for incomplete filling of the lattice sites. For a wide range of interaction parameters the model gives steps in the adsorption isotherms similar to those observed experimentally for benzene adsorption in silicalite. The model attributes the experimentally observed steps in the level of adsorption with rising pressure, to re-orientational transitions amongst molecules in the adsorbed phase. Secondly Conventional Grand Canonical Monte Carlo techniques have been used to calculate methane, ethane and co, binary mixture adsorption isotherms in silicalite as well as propane, i-butane and n-butane equimolar binary and ternary mixture adsorption in silicalite. In the last part of the thesis, studies have made of lattice models of CH, I C,H, and CO, adsorption in silicalite and the results compared with the Monte Carlo data. One dimensional lattice models have also been used to calculate the binary and ternary mixture adsorption of propane, i-butane and n-butane. The isotherms were compared with the Monte Carlo results.
|Title:||Monte Carlo simulation and statistical mechanics modelling of mixture adsorption in silicalite|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science > Chemical Engineering|
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