Non-Aqueous Solvent (NAS) CO_2 Capture Process

摘要

The NAS CO_2 Capture Process is being developed based on a conventional acid-gas scrubbing process arrangement with few, yet significant, modifications to accommodate the non-aqueous nature of the solvent. Several key aspects of the NAS CO_2 Capture Process have been evaluated at the laboratory scale using a small, continuous-flow, absorber-regenerator system with emphasis on understanding the operation of a NAS process and the effect that water from the flue gas has on the NAS CO_2 capture process, specifically in terms of system operability, CO_2 capture efficiency, and energy consumption. To date, over 1,000 hr of on-stream testing has been performed with the NASs in a lab-scale system with results indicating that: 1. the process is capable of stable operation for extended periods, 2. the NASs are capable of achieving predicted CO_2 working capacity, 3. the water balance in the process can be controlled and manipulated, and 4. the regeneration heat duty for NASs is substantially lower than a 30 wt% MEA-water solvent. Current development efforts funded by the US DOE are focused on addressing and overcoming specific challenges related to solvent make-up costs, improving the fidelity of the NAS CO_2 capture process design, and ultimately demonstrating the feasibility and substantially lower regeneration energy (＜2,000 kJ_t/kg of CO_2 captured) of the NAS CO_2 capture process at the (large) bench-scale. The overarching objective of this next development phase is to demonstrate the superior technical performance of the NAS CO_2 capture process and reduce uncertainty to accurately determine the ability for this process to reduce the cost associated with CO_2 capture.