NSF Award
9561441
DMI-9561441 Bromberg This Small Business Innovation Research Phase I project has the potential to substantially reduce the energy consumed in distillation processes, particularly for separating azeotropes and other close-boiling mixtures. It also has the potential to improve product purity, reduce environmental pollution and reduce equipment costs. The project proposes a novel process in which azeotropic distillation is augmented with reversible gel absorption requiring approximately half the energy of conventional azeotropic distillation, as components in a mixture can be selectively absorbed and recovered without undergoing a phase change. Whereas conventional hybrid processes are generally limited to aqueous azeotropes, the gel system is expected to be useful for a broad range of commercially important aqueous and non-aqueous mixtures. The objective of the Phase I investigation is to synthesize and characterize a gel suitable for at least one commercially important azeotropic system. The project will build on recent work in which polyethylene-based gels were found to absorb components selectively from mixtures of close-boiling liquids. Information on gel selectivity and the phase transition process will be obtained and used to estimate energy costs for the new process. Further enhancement of gel performance is planned for Phase II, including a study of absorption kinetics and a pilot-scale demonstration. If successful, the gel-absorption hybrid distillation process will be of use in the organic chemical and petroleum industries. It is of particular interest for distillation and purification of ethanol-water and will enable economical reuse and recycling of solvents in the specialty chemical, pharmaceutical and medical industries, where the addition of an entrainer compromises product purity. The process promises to save $100-300 million per year in energy costs, substantially increase azeotropic distillation capacity at small capital cost, and create a new $5-50 million market for se paration gels.
