(61a) Membranes for Advanced Gas Separations-Key Compoents in Large Scale Energy Efficiency Strategies

Improved separation processes can provide competitive advantages to early adopters through economical reductions in energy intensity by debottlenecking large scale processes for transforming raw materials into higher value-added components.   This fact alone makes it worthwhile to pursue the topic of energy-efficient separations, and membranes are the vanguard in this movement.  This presentation identifies goals and strategies being pursued to implement this approach.  The collaboration with industrial partners focuses on different gas technology areas, including natural gas purification, olefin-paraffin separation and nitrogen enrichment of air. 

As molecular size differences between desired permeating components vs. rejected components become more similar, molecular scale “sorption-diffusion” discrimination is required to allow selective permeation that enables separation using membranes.  Conventional solution-processable polymers and inorganic materials both have important areas of applications, but  each have limitations that prevent their use across the spectrum of membrane-based separation applications needed in the broad spectrum of gas separation opportunities.   For polymers, penetrant size and shape-discriminating ability is often lower than desired, while cost of production of large scale modules is a serious hurdle preventing the use of zeolite and silica membranes. 

Hybrid materials comprising both polymers and inorganic components offer a good compromise to address limitations of either of the individual components.   Moreover, carbon molecular sieve membranes combine desirable characteristics of both polymers and molecular sieving inorganic membranes within the existing economical processes for membrane and module formation. A framework will be provided to understand a strategy for major innovations across a broad range of gas separation applications will be discussed.  Key challenges and opportunities will also be presented to encourage discussion related to this strategy.