(71c) New Water-Lean Amine-Based Solvents for Carbon Dioxide Capture with Low Regeneration Energy

Carbon dioxide capture and storage (CCS) of anthropogenic CO₂ released from large point sources such as coal fired power plants is required in order to mitigate adverse environmental effects like climate change. Toward this goal numerous CO₂ capture processes have been developed, the most advanced technology utilizes aqueous solutions of primary and secondary alkanolamines such as MEA or diethanolamine (DEA) for chemical absorption of CO₂. The regeneration energy of these aqueous amine solvents is very high due to the high heat capacity of water. To address this problem water-lean transformational solvent systems have been developed. As part of an ongoing program studying multiple solvent chemistries and combining the key findings from different solvent classes, we have developed a new class of water-lean non-aqueous amine-based solvents with potential to be energy efficient CO₂ capture materials. These amines bind CO₂ at standard temperature and pressure (STP) to form liquid carbamate salts with high gravimetric capacity ~ 20 wt%. These solvents have low thermal regeneration temperature (70-100 °C) and low CO₂â??rich solvent viscosity compared to other water-lean materials. The regeneration temperature can be lowered to 60 °C by applying polarity swing assisted regeneration (PSAR) making it feasible to utilize lower grade heat from the power plant for CO₂ stripping resulting in energy savings.