Novel and Fundamental Studies of Separation Methods Leading to Very High Degree of Separation of Molecular Mixtures and Related Studies

Abstract

Separation of molecular mixtures will often require in chemistry, biology, physics and material science. Existing methods of separation can at best yield a separation factor of 10^4 . They also incur huge expenditure of energy. A new and novel method of separation is proposed in the thesis based on Levitation and Blowtorch effects. This method has been applied for the separation of the four different mixtures, (i) n-pentane-neopentane, (ii) 2,2-dimethyl butane-n-pentane, (iii) n-hexane-neopentane, and (iv) 2,2-dimethyl butane-n-pentane. The results based on Non-Equilibrium Monte Carlo simulations suggest that this method can yield very high separation factors (10^16) with very little consumption of energy. The experimental approach to be employed for the realization of separation is discussed. The changes to the potential energy landscape in the presence of a hot zone are discussed for (i) one-dimensional and three-dimensional systems, (ii) interacting and non-interacting systems, and (iii) hydrocarbons in zeolite system, and compared with Landauer’s suggestion. Extremely small diffusivity of monoatomic species in zeolite NaCaA as a function of diameter of diffusant has been computed with the help of Replica Exchange Transition Interface Sampling (RETIS) technique. Diffusion of a small solute in the body centered cubic lattice is seen to exhibit maxima as a function of the solute diameter. This observation explains the existence of solutes with high diffusivity (for example Co in γ-U and β-Zr, Cu in Pr, or Au in Th). A new potential as a function of Si/Al ratio for modelling zeolite Y and A has been proposed and shown to predict lattice parameter, bulk modulus, infrared spectra, etc in agreement with the experiment.