DESULFURIZATION METHOD AND DESULFURIZATION DEVICE FOR GAS CONTAINING SULFUR OXIDES

摘要

Provided is a desulfurization method for gas containing sulfur oxides that has a simple constitution, can suppress loads on wastewater treatment means and can recover byproducts with a high recovery rate and high purity. The desulfurization method has: a humidification liquid contact step in which a first gas that includes sulfur oxides is brought into contact with a humidification liquid and a second gas is obtained; a humidification liquid separation step in which at least part of the humidification liquid is separated from the second gas and a third gas obtained; a sulfur oxide elimination step in which the third gas is brought into contact with a liquid containing an alkali agent and oxygen and sulfur oxides are eliminated from the third gas; a circulation step in which the liquid containing the alkali agent that was brought into contact with the third gas and oxygen is circulated and used as the humidification liquid that is brought into contact with the first gas in the humidification liquid contact step; a humidification liquid acquisition step in which at least part of the humidification liquid separated from the second gas in the humidification liquid separation step is acquired; a gas elimination step in which gas from the humidification liquid acquired in the humidification liquid acquisition step is eliminated; and a byproduct recovery step in which byproducts a rising because of the reaction of the sulfur oxides, liquid containing the alkali agent, and oxygen are recovered from the humidification liquid from which the gas has been eliminated in the gas elimination step. The byproduct recovery step is carried out only on the downstream side of the humidification liquid acquisition step.