Enhanced Distillation via Membranes for Elimination of Trapped Water

Distillation is a major chemical unit operation and consumer of significant energy. Often, water or some other intermediate boiling component can become trapped within the distillation column and accumulate. This causes various operating difficulties such as flooding, slugging, cycling, instability, and off-spec product. This project will develop a chemically-resistant, non-porous, water-venting membrane technology to improve distillation operating efficiency in systems that are prone to water trapping. In Phase I, chemically and thermally resistant membrane modules were fabricated and used to separate water from target distillation products. The membrane process was modeled and simulated, and an economic analysis was performed to quantify the economic and energy value of eliminating the trapped water. Phase II will demonstrate that the technology: (1) can be used to significantly reduce the concentration of water in a specific process when water trapping is occurring; (2) has the necessary mechanical strength and chemical resistance to provide stable performance over extended periods of exposure to process materials at the process temperature and pressure; and (3) will provide economic benefits in comparison to other available techniques. Commercial Applications and Other Benefits as described by the awardee: Water is a ubiquitous substance and is a common cause of component trapping problems in distillation columns. The membrane technology should enhance the distillation process in many situations when distillation trapping is a major problem. The membrane technology should have additional value in other distillation applications where removal of water is difficult (e.g., azeotropes).