Desulfurization scrubbing in a squared spray column for a 720 kW marine diesel engine: Design, construction, simulation, and experiment

Abstract

Square-shaped absorption towers are compact and provide high volumetric efficiency, enabling the installation of closed-loop flue gas desulfurization (FGD) in limited spaces of a ship. For FGD processes, diluted sodium hydroxide (NaOH) has been considered as a viable absorbent. Thus, a square-shaped scrubber with square spray nozzle distributor using a diluted NaOH solution was proposed for marine sulfur oxides removal, aiming to reduce volume/space, weight, pressure drop, investment, and operating and maintenance costs while increasing efficiency. A systematic methodology for the square-shaped FGD design was proposed, experiments to treat the flue gas released from a marine diesel engine (720 kW) were performed, and simulation and sensitivity analyses were conducted using Aspen Plus V10. Good agreement was observed between experimental and simulated results. A liquid-to-gas mass ratio of approximately 4.32 kg.kg−1 provided SO2 removal efficiency higher than 95 %. Most part of mass and heat transfers occurred in the bottom section of the scrubber and a low pressure drop was achieved.