Hollow Fibers for Separations
Light olefin chemicals - ethylene and propylene - are some of the main petrochemical building blocks in many consumer and industrial products. Chemicals produced from ethylene are included in the supply chains for PVC, styrofoam, automotive tires, detergents, antifreeze, and numerous other products. Propylene is a key ingredient of polypropylene, used extensively in automobiles, packaging films, bottle caps, fiber ropes, helmets, and diapers. In order to make these products, the chemicals need to be in a pure form, and cannot be contaminated by similar petrochemicals, such as ethane and propane. This is typically achieved by separating the olefins using huge distillation columns. This process is the single largest energy consumer and CO2 emitter in the chemical industry, which is why there is a need for an alternative separation technology. However, for a new technology to displace distillation, it must function at enormous scale, provide substantially higher energy efficiency, and have much lower capital costs.
Project Innovation + Advantages:
Georgia Tech Research Corporation will develop hollow fiber membranes containing metal-organic framework (MOF) thin films to separate propylene from propane. The nanoporous MOF film is supported on the inside surfaces of the tubular polymeric hollow fibers. Chemicals introduced into the center of the tube are separated through the MOF membrane by a molecular sieving process. Traditional olefin production processes are performed at pressures up to 20 bar, requiring large energy and capital costs. A key feature of the team’s technology is the ability to synthesize membranes at near-ambient liquid-phase conditions and perform olefin separation at lower pressures as low as 6 bar. As the team evaluates using its MOF membranes to separate propylene from propane, the team will also develop detailed correlations between processing conditions, membrane morphology, and membrane performance. Another important task is to perform a detailed economic evaluation of the technology and establish its economic advantages compared to existing and other proposed technologies. The general separations concept also has potential to be used for a larger range of petrochemical and gas separations.