Desulfurization method for gas containing sulfur oxide and desulfurization apparatus

A desulfurization apparatus, comprising:

• a reaction tank;
• gas introduction device for introducing a first gas containing sulfur oxide, which is a gas to be treated, to the reaction tank;
• humidifying liquid contact device for bringing the first gas into contact with a humidifying liquid;
• humidifying liquid separation device for separating at least part of the humidifying liquid from a second gas obtained by the bringing the first gas into contact with a humidifying liquid;
• sulfur oxide removal device for bringing a third gas obtained by the separating at least part of the humidifying liquid from a second gas into contact with an alkaline agent-containing liquid and oxygen to remove the sulfur oxide from the third gas;
• gas discharge device for discharging, from the reaction tank, the third gas from which the sulfur oxide has been removed by the sulfur oxide removal device;
• circulation device for circulating the alkaline agent-containing liquid brought into contact with the third gas and oxygen by the sulfur oxide removal device to use the alkaline agent-containing liquid as the humidifying liquid to be brought into contact with the first gas by the humidifying liquid contact device;
• humidifying liquid acquisition device for acquiring at least part of the humidifying liquid separated by the humidifying liquid separation device;
• gas removal device for removing a gas from the humidifying liquid acquired by the humidifying liquid acquisition device;
• and
• by-product recovery device for recovering a by-product generated through a reaction among the sulfur oxide, the alkaline agent-containing liquid, and oxygen from the humidifying liquid from which the gas has been removed by the gas removal device,
• wherein the by-product recovery device is arranged only downstream of the humidifying liquid acquisition device.

A desulfurization apparatus, comprising:

• a reaction tank comprising:
• a humidifying liquid contact chamber communicating with an introduction port for a gas to be treated for introducing a gas to be treated;
• and
• an alkaline agent-containing liquid chamber for accommodating an alkaline agent-containing liquid in a lower portion thereof, the alkaline agent-containing liquid chamber communicating with a discharge port for a gas to be treated for discharging the gas to be treated, and with the humidifying liquid contact chamber, and being arranged below the humidifying liquid contact chamber;
• a humidifying liquid supply pipe for spraying a humidifying liquid to the gas to be treated;
• a first oxygen supply pipe for supplying oxygen into the alkaline agent-containing liquid accommodated in the alkaline agent-containing liquid chamber;
• circulation device for extracting the alkaline agent-containing liquid accommodated in the alkaline agent-containing liquid chamber and supplying the alkaline agent-containing liquid to the humidifying liquid supply pipe;
• a liquid descending pipe for allowing the humidifying liquid spontaneously separated from the gas to be treated to which the humidifying liquid has been sprayed to descend therethrough, the liquid descending pipe being arranged so as to extend downward from a bottom surface of the humidifying liquid contact chamber and reach below a liquid level of the alkaline agent-containing liquid accommodated in the alkaline agent-containing liquid chamber;
• a gas descending pipe for allowing the gas to be treated, the gas being obtained by spontaneously separating the humidifying liquid from the gas to be treated to which the humidifying liquid has been sprayed, to descend therethrough to be dispersed in the alkaline agent-containing liquid accommodated in the alkaline agent-containing liquid chamber, the gas descending pipe being arranged so as to extend downward from the bottom surface of the humidifying liquid contact chamber and reach below the liquid level of the alkaline agent-containing liquid accommodated in the alkaline agent-containing liquid chamber;
• a pot including a side wall surrounding a lower end portion of the liquid descending pipe from a side;
• a second oxygen supply pipe for supplying oxygen into the pot;
• a pipe for extracting the humidifying liquid from an inside of the pot;
• an air separator arranged in the pipe for extracting the humidifying liquid from an inside of the pot;
• and
• solid-liquid separation device arranged downstream of the air separator.

A desulfurization apparatus, comprising:

• a reaction tank configured such that:
• a gas to be treated is introduced from an introduction port for a gas to be treated arranged at an upper surface thereof;
• the gas to be treated is discharged from a discharge port for a gas to be treated arranged at a side wall thereof;
• and an alkaline agent-containing liquid is accommodated in a lower portion thereof;
• a humidifying liquid supply pipe for spraying a humidifying liquid to the gas to be treated, the humidifying liquid supply pipe being arranged in an upper portion of the reaction tank;
• a first oxygen supply pipe for supplying oxygen into the alkaline agent-containing liquid accommodated in the reaction tank;
• circulation device for extracting the alkaline agent-containing liquid accommodated in the reaction tank and supplying the alkaline agent-containing liquid to the humidifying liquid supply pipe;
• a separation plate including:
• an inclined plate of a doughnut shape, the inclined plate being arranged below the humidifying liquid supply pipe in the reaction tank and inclined downward toward a central portion thereof;
• a funnel-shaped liquid collector of a doughnut shape having an outer diameter larger than an inner diameter of the inclined plate, the funnel-shaped liquid collector being inclined downward toward a central portion thereof;
• and
• a liquid descending pipe for allowing the humidifying liquid spontaneously separated from the gas to be treated to which the humidifying liquid has been sprayed to descend therethrough, the liquid descending pipe being arranged so as to be connected to a hole of the funnel-shaped liquid collector in the central portion and reach below a liquid level of the alkaline agent-containing liquid accommodated in the reaction tank;
• a pot including a side wall surrounding a lower end portion of the liquid descending pipe from a side;
• a second oxygen supply pipe for supplying oxygen into the pot;
• a pipe for extracting the humidifying liquid from an inside of the pot;
• an air separator arranged in the pipe for extracting the humidifying liquid from an inside of the pot;
• and
• solid-liquid separation device arranged downstream of the air separator.