Removal of marine NOx, SOx, and CO2 from flue gas: Simulation and experiment on a pilot plant
Nguyen Van Duc Long, Dong‐Hyung Lee, Choongyong Kwag, Young Mok Lee, Sung Won Lee, D. G. Lewis, Evgeny V. Rebrov, Volker Hessel, Moonyong Lee
Abstract
Flue gas treatment typically involves multiple scrubbing and absorbing stages, which increases capital and operating costs and requires large spaces; this process is particularly challenging for space-constrained ships. To address this issue, a highly practical, compact, efficient, intensified marine process for a diesel engine that simultaneously removes NO x and SO x to meet the current IMO MARPOL VI 14 regulations for SECAs and IMO MARPOL Annex VI Tier III for NECAs and captures CO 2 before compressing and liquefying it to comply with new IMO regulations. The proposed method uses NO ozonation and wet scrubbing with NaOH in a square marine scrubber, which reduces volume, weight, pressure drop, and associated costs. Mixed solvents, multiple feeds, rich solvent recycling, and heat integration were used to intensify CO 2 removal. Experimental results with a pilot scrubber on marine diesel engine flue gas agreed well with the results of Aspen Plus V12 simulations. Moreover, SO 2 absorption efficiency was > 97.0 %, NO 2 removal efficiency was > 92.2 %, and CO 2 removal efficiency increased from 87.4 % to 94.5 %. The stripper reboiler duty reduced to 38 kW (82.2 % savings) and the total operating costs (TOC) and total annual costs (TAC) reduced by 56.3 % and 13.9 %, respectively, compared with those of the base case.