Designing Organic Solvent Reverse Osmosis Membranes for The Separation of Liquid Hydrocarbons
Author(s)
Ren, Yi
Advisor(s)
Editor(s)
Collections
Supplementary to:
Permanent Link
Abstract
Liquid phase hydrocarbon separation accounts for 40-70% of both capital and operational costs in the chemical, pharmaceutical, food, and petroleum industries since most of these processes are heavily involved with organic solvents. As energy demand and associated carbon emission rises due to increasing global population, the development of large-scale sustainable separation methods with lower energy penalty and carbon footprint is essential to help mitigate the worse effects of energy and climate crisis. Membrane-based separations are considered a promising augment to conventional thermally driven based separations such as distillation due to inherently higher energy efficiency, lower carbon footprint and less space requirements. Polymeric membranes such as cellulose acetate have been extensively used in seawater reverse osmosis desalination process due to their excellent processability and high scalability, but would suffer from swelling, plasticization and dissolution when exposed to organic solvents. The low solvent stability of polymeric membranes serves as a major gap in applying highly scalable and processable polymer membranes to organic solvent environment separations.
This dissertation aims to fill this major gap and focuses on two main methods to engineer solution-processable materials with enhanced chemical stability, either through engineering existing materials or designing completely new materials. For engineering existing materials, vapor phase infiltration (VPI) is used as a post-treatment process for polymer materials after being cast into their membrane form. This one additional step transforms the pure polymer material into an organic-inorganic hybrid composite with enhanced properties, including solvent stability essential for organic solvent separations. For designing new materials, a new series of polymers is developed via the incorporation of fluorine-rich moieties in the aromatic polymer backbone to control the swelling of polymers, balancing practical separation productivity and separation efficiency of the membrane. Both strategies are discussed in detail, providing insights into developing next generation membrane fabrication methods for challenging organic solvent separation processes.
Sponsor
Date
2024-12-02
Extent
Resource Type
Text
Resource Subtype
Dissertation (PhD)