Part 6: Solvent recycling and reclaiming issues

Abstract

Purification of solvents is required to maintain quality and absorption capacity for better performance and economics for CO 2 capture plants. An effective technique is needed to separate degradation products from their parent amines to prevent operational problems such as corrosion, foaming, fouling and change of solvent physicochemical properties. To overcome these problems, an amine reclamation process is used to clean up the solvent. Over 30 years ago, only five amine clean-up methods - solvent changeover, solvent purging/feeding, mechanical filtration, activated carbon filtration and neutralization of organic/inorganic acids - existed, which are reviewed in this article. More specific and advanced approaches developed later to achieve more effective removal of impurities and degradation products from the solvents are also summarized. This article also gives future trends for reclamation techniques in amine-based CO 2 capture processes including hybrid processes or improvement of the current technologies such as extraction, ion exchange, thermal distillation and electrodialysis. © 2012 Future Science Ltd.