Novel Separation Methods using Electrodialysis/Electrodeionization for Product Recovery and Power Generation

The use of electrodialytic separations for the purification of products has been a vital technique for the past 50 years in the chemical industry. Originally used for demineralization and desalination, electrodialysis and its counterparts have expanded to assist in product purification, waste and hazard removal, and power generation. This research focused on the development of high purity organic acids purification with low power requirements. Work resulted in the development of a new type of electrodialysis process, specifically the use of ionic liquids as a secondary solvent for the development of dual solvent electrodialysis. Through dual solvent electrodialysis, ions were recovered and concentrated from products streams while enacting a solvent change. This allowed the requirements and scope of secondary purification steps to be greatly reduced and, in some cases, no longer necessary. Application of ion exchange wafers further improved separation performance of dual solvent electrodialysis. This electrodeionization technique resulted in separation efficiencies and power consumption levels similar to those of commercially implemented organic acid recovery methods with reduced complexity. Additional efforts in power generation through a technique known as reverse electrodialysis were also pursued and a discussion on the implication technology on meeting future energy demands will presented. Through this research, new avenues and applications for electrodialytic separation are now possible.