Comprehensive Evaluation of an Ionic Liquid Based Nh3 Deep Purification Process Through Simulation and Optimization

Abstract

Ammonia (NH 3 ) emission has caused serious environment issues and aroused worldwide concern. The emerging ionic liquids (ILs) provides a greener way to efficiently capture NH 3 . This paper provides rigorous process simulation, optimization and assessment for a novel gas stripping enhanced NH 3 capture purification process using IL. Besides conventional process, an enhanced process was designed and investigated by process simulation and optimization, using ionic liquid [C 4 im][NTF 2 ] as absorbent. Three objective functions, total purification cost (TPC), total process CO 2 emission (TPCOE) and thermal efficiency ( η eff ) were employed to optimize the absorption process. Process simulation and optimization results indicate that at same purification standard and recovery rate, the enhanced process can achieve lower cost and CO 2 emission compared to conventional process. After process optimization, the optimal functions can achieve 0.02726 $/Nm 3 (TPC), 311.27 kg CO 2 /h (TPCOE), and 52.21% ( η eff ) for enhanced process. Moreover, enhanced process could decrease purification cost (22.54% and 5.90% of water scrubbing and conventional process) and CO 2 emission (63.42% and 20.10% of water scrubbing and conventional process). The results provide a novel strategy and guidance for deep purification of NH 3 capture.

Keywords: NH3 Capture, Gas Stripping, Enhancement Process, ionic liquid, process simulation, Process Optimization