1. Liquid Crystalline Membranes for Olefin/Paraffin Separations
Stephen M. Martin, Eva Marand, Department of Chemical Engineering, Virginia Tech
The separation of olefin and paraffin gases is one of the most important processes in the petrochemical industry. Clearly, the ability to efficiently separate and reform the chemical constituents of crude oil into pure components in an efficient manner relates directly to the financial bottom line as well as to environmental well-being. Currently olefin/paraffin separations are carried out using low temperature distillation, which is very expensive and energy intensive due to the close relative volatilities of the constituents. An alternative method which as been widely explored uses membranes - which require less energy and can be easily scaled-up using modular components.
Our approach uses thermotropic liquid crystalline materials to produce membranes which :
are selectivity targeted for specific olefin/paraffin separations
have structural regularity and specific molecular interactions
have liquid crystalline materials with specific chemical groups or moieties
enable us to match the molecular structure of one of the gas components
The idea is to enhance solubility and diffusion of the targeted component by enhancing molecular interactions and the ability of the gas component to fit into the liquid crystalline structure.
MBBA in polysulfone