Recovery Act - Distillation Revisited: New Approaches to Energy Savings Using Integrated Distillation-Membrane Processes

Separations using distillation consume 5 to 6 quads of energy annually in the United States. We propose to develop a combination distillation-membrane vapor separation process that cuts the use of energy for distillation in half. Separation of aromatic/aliphatic mixtures, an important process in refinery and chemical operations, has been chosen as the first target application for this project. In Phase I, bench scale membrane modules will be made and tested with a model mixture: toluene/methylcyclohexane. Phase I work will confirm that modules capable of efficiently performing the target separations are stable at the operating conditions of use, and that process designs based on these results can deliver the expected energy and cost savings. In Phase II, a pilot scale system including a small distillation column will be built. The system will be used to optimize the membranes and membrane modules, and to demonstrate the process with complex refinery feed mixtures. Commercial Applications and Other Benefits: Aromatic/aliphatic separations are used as the first step in the preparation of nine of the top 50 chemicals produced in the United States. Our technology could reduce the energy use of these separations by half.