Transient simulation of SO2 absorption into water in a bubbling reactor.

A bubbling reactor is an important type of gas scrubber to reduce SO₂ emissions in maritime shipping. Both experiments and simulations were conducted to study the relationship between the periodic gas bubbling process and SO₂ concentration at the outlet of the reactor, and the entrainment of liquid droplets on SO₂ absorption. The accuracy of the model was verified by comparing the bubble size, the depth of bubbles injected into the water, and the SO₂ concentration obtained in both experiments and simulations. The gas bubbling process is accompanied by bubble formation, rise, and collapse. The gas bubbling period is affected by the disturbance of the liquid level. The period of the SO₂ concentration at the outlet of the gas bubbling reactor is smaller than that at the gas jar outlet which acts as the gas buffering region. The amounts of water carried out of the bubbling reactor by the gas bubbling process increase with the gas flow rates. The droplets and liquid film in the gas jar and the connecting tube play an important role in the absorption of SO₂. This study encourages more research to reduce the fluctuation of SO₂ concentration and consider droplet entrainment in the design of bubbling reactors.