Method and device for coupling-suppressing white fog by purifying CO in flue gas

Abstract

The present invention discloses a method and device for purifying CO from a flue gas and coupling-suppressing white fog, where the flue gas is introduced into a ceramic honeycomb carrier coated with a CO catalyst, sufficient O.sub.2 in the flue gas is utilized to generate CO.sub.2 from a low concentration of CO through catalytic oxidation, so as to achieve the purpose of purifying CO, and the flue gas is heated up by the heat released from the catalytic oxidation reaction to more than 110° C. and then discharged into the air, which meets the temperature requirement of coupling-suppressing white fog; the device includes a CO concentration sensor, a temperature sensor, a CO catalytic oxidation layer, an oxidation reaction tower, a desulfurized sintering flue gas, a packing layer I, a packing layer II, a chimney, and a solenoid valve II.

Claims

1. A method for purifying CO from a flue gas and coupling-suppressing white fog, wherein the flue gas is introduced into a ceramic honeycomb carrier coated with a CO catalyst, CO.sub.2 is generated from CO through catalytic oxidation, and the flue gas is heated by the heat released from the catalytic oxidation reaction to more than 110° C. and then discharged into the air, when a volume percent concentration of CO in the flue gas is less than 1%, the flue gas is a mixed flue gas of a desulfurized sintering flue gas of steel or iron and a blast furnace flue gas, and when the volume percent concentration of CO in the flue gas is greater than or equal to 1%, the flue gas is the desulfurized sintering flue gas of steel or iron, wherein active composition and mass percentage content of the CO catalyst are 20-25% of CuO, 25-35% of MnO.sub.2, 20-25% of CeO.sub.2 and 20-25% of Co.sub.3O.sub.4.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a device for purifying CO in the flue gas and coupling-suppressing white fog according to Example 1 of the present invention; in which, 1 represents an aspirator pump; 2 represents a controller; 3 represents a CO concentration sensor; 4 represents a temperature sensor; 5 represents a CO catalytic oxidation layer; 6 represents a blast furnace flue gas; 7 represents an oxidation reaction tower; 8 represents a solenoid valve I; 9 represents a desulfurized sintering flue gas; 10 represents a packing layer I; 11 represents a packing layer II; 12 represents a chimney; 13 represents a gas transmission pipeline; 14 represents a blast furnace flue gas pipeline; and 15 represents a solenoid valve II.

DESCRIPTION OF THE EMBODIMENTS

(2) The present invention will be described in detail below with reference to specific embodiments.

Example 1

(3) A device for purifying CO from a flue gas and coupling-suppressing white fog, as shown in FIG. 1, included an aspirator pump 1, a controller 2, a CO concentration sensor 3, a temperature sensor 4, a CO catalytic oxidation layer 5, a blast furnace flue gas 6, an oxidation reaction tower 7, a solenoid valve I 8, a desulfurized sintering flue gas 9, a packing layer I 10, a packing layer II 11, a chimney 12, and a solenoid valve II 15. The desulfurized sintering flue gas 9 was connected to a flue gas inlet at the bottom of the oxidation reaction tower 7 through a gas transmission pipeline 13. The CO concentration sensor 3 was arranged on the gas transmission pipeline 13. The flue gas inlet at the bottom of the oxidation reaction tower 7 was provided with the solenoid valve II 15. The oxidation reaction tower 7 was provided with the packing layer I 10, the CO catalytic oxidation layer 5, and the packing layer II 11 from top to bottom sequentially therein. A flue gas outlet at the top of the oxidation reaction tower 7 was provided with the temperature sensor 4. The flue gas outlet at the top of the oxidation reaction tower 7 was connected to the chimney 12. Also a blast furnace flue gas pipeline 14 was connected on the gas pipeline 13. The blast furnace flue gas pipeline 14 was connected to the blast furnace flue gas 6, and the blast furnace flue gas pipeline 14 was provided with the aspirator pump 1 and the solenoid valve I 8 thereon. The aspirator pump 1, the CO concentration sensor 3, the temperature sensor 4, and the solenoid valve I 8 were respectively connected to the controller 2. The controller 2 was a conventional PLC controller as long as it is capable of realizing the receipt of data and feedback. The CO concentration sensor 3 is used for detecting the concentration of CO in the flue gas pipeline 13, and the CO concentration sensor with the model of MOT500-CO as manufactured by Shenzhen Korno Electronic Technology Co., Ltd. is adopted.

Example 2

(4) A method for purifying CO from a flue gas and coupling-suppressing white fog included the following specific steps:

(5) (1) the flow rate of the wet desulfurization flue gas was 1000 Nm.sup.3/h, and the composition of the flue gas was 1.2% of CO, 21% of O.sub.2, 13% of H.sub.2O, 63.4% of N.sub.2, and 1% of SO.sub.2+NO, the initial temperature of the flue gas was 65° C., a CO catalyst was coated on a ceramic honeycomb carrier, and the carrier was charged into the CO catalytic oxidation layer 5 of the device of Example 1, where the active composition and the mass percentage content of the CO catalyst were 25% of CuO, 25% of MnO.sub.2, 25% of CeO.sub.2, and 25% of Co.sub.3O.sub.4, and the packing layer I 10 and the packing layer II 11 were filled with a spherical filler with a diameter of 3 cm, and the filler was a turbulence sphere;

(6) (2) the desulfurized sintering flue gas of steel or iron in the desulfurized sintering flue gas 9 was introduced into the bottom of the oxidation reaction tower 7, and the CO concentration sensor 3 fed the detection data back to the controller 1 when the CO concentration sensor 3 detected that the volume percentage concentration of the CO in the desulfurized sintering flue gas of steel or iron was 1.2%, then the solenoid valve II 15 was opened such that the desulfurized sintering flue gas of steel or iron normally entered the oxidation reaction tower 7, passed through the packing layer II 11, and passed through the packing layer I 10 to reach the outlet on the top of the oxidation reaction tower 7 after the CO was catalytically oxidized at the CO catalytic oxidation layer 5 in the oxidation reaction tower 7, and when the temperature sensor 4 detected that the temperature of the flue gas was 127° C., the flue gas was introduced into the chimney 12 for discharging, and no white fog phenomenon was observed at the outlet of the chimney 12. Upon detection, the residual amount of CO in the flue gas at the outlet of the chimney 12 was less than 200 ppm, reaching the emission standard.

(7) When an emergency circumstance occurred, for example when the volume percentage concentration of CO as detected was ≥1%, and when the temperature detected by the temperature sensor 4 did not reach 110° C., indicating that there was a malfunction inside the device, then at this point the solenoid valve II 15 was subjected to emergency shut-down to check the inside of the device and the activity of the CO catalyst.

Example 3

(8) A method for purifying CO from a flue gas and coupling-suppressing white fog included the following specific steps:

(9) (1) the flow rate of the wet desulfurization flue gas was 1000 Nm.sup.3/h, and the composition of the flue gas was 0.6% of CO, 21% of O.sub.2, 13% of H.sub.2O, 63.4% of N.sub.2, and 1% of SO.sub.2+NO, the initial temperature of the flue gas was 60° C., the flow rate of the blast furnace flue gas was 35 Nm.sup.3/h, the composition of the blast furnace flue gas was 20% of CO and 80% of N.sub.2+CO.sub.2, and the initial temperature of the blast furnace flue gas was 60° C., a CO catalyst was coated on a ceramic honeycomb carrier, and the carrier was charged into the CO catalytic oxidation layer 5 of the device of Example 1, where the active composition and the mass percentage content of the CO catalyst were 20% of CuO, 35% of MnO.sub.2, 25% of CeO.sub.2, and 20% of Co.sub.3O.sub.4, and the packing layer I 10 and the packing layer II 11 were filled with a spherical filler with a diameter of 4 cm, and the filler was quartz sand particles;

(10) (2) the desulfurized sintering flue gas of steel or iron in the desulfurized sintering flue gas 9 was introduced into the bottom of the oxidation reaction tower 7, and the CO concentration sensor 3 fed the data back to the controller 2 when the CO concentration sensor 3 detected that the volume percentage concentration of the CO in the desulfurized sintering flue gas of steel or iron was less than 1%, then the controller 2 activated the aspirator pump 1 and opened the solenoid valve I 8 to pump the blast furnace flue gas in the blast furnace flue gas 6 into the blast furnace flue gas pipeline 14 and then into the gas transmission pipeline 13, and the CO concentration sensor 3 fed the detection data back to the controller 1 when the CO concentration sensor 3 detected that the volume percentage concentration of the CO in the mixed flue gas was 1.25%, then the solenoid valve II 15 was opened such that the mixed flue gas entered the oxidation reaction tower 7, passed through the packing layer II 11, and passed through the packing layer I 10 to reach the outlet on the top of the oxidation reaction tower 7 after the CO was catalytically oxidized at the CO catalytic oxidation layer 5 in the oxidation reaction tower 7, and when the temperature sensor 4 detected that the temperature of the flue gas was 127° C., the flue gas was introduced into the chimney 12 for discharging, and no white fog phenomenon was observed at the outlet of the chimney 12. Upon detection, the residual amount of CO in the flue gas at the outlet of the chimney 12 was less than 200 ppm, reaching the emission standard.

(11) When an emergency circumstance occurred, for example when the volume percentage concentration of CO as detected was ≥1%, and when the temperature detected by the temperature sensor 4 did not reach 110° C., indicating that there was a malfunction inside the device, then at this point the solenoid valve II 15 was subjected to emergency shut-down to check the inside of the device and the activity of the CO catalyst.

Example 4

(12) A method for purifying CO from a flue gas and coupling-suppressing white fog included the following specific steps:

(13) (1) the flow rate of the wet desulfurization flue gas was 1000 Nm.sup.3/h, and the composition of the flue gas was 1% of CO, 21% of O.sub.2, 13% of H.sub.2O, 63.4% of N.sub.2, and 1% of SO.sub.2+NO, the initial temperature of the flue gas was 60° C., the CO catalyst was coated on a ceramic honeycomb carrier, and the carrier was charged into the CO catalytic oxidation layer 5 of the device of Example 1, where the active composition and the mass percentage content of the CO catalyst were 23% of CuO, 32% of MnO.sub.2, 22% of CeO.sub.2, and 23% of Co.sub.3O.sub.4, and the packing layer I 10 and the packing layer II 11 were filled with a spherical filler with a diameter of 5 cm, and the filler was quartz sand particles;

(14) (2) the desulfurized sintering flue gas of steel or iron in the desulfurized sintering flue gas 9 was introduced into the bottom of the oxidation reaction tower 7, and the CO concentration sensor 3 fed the detection data back to the controller 1 when the CO concentration sensor 3 detected that the volume percentage concentration of the CO in the desulfurized sintering flue gas of steel or iron was 1%, then the solenoid valve II 15 was opened such that the desulfurized sintering flue gas of steel or iron normally entered the oxidation reaction tower 7, passed through the packing layer II 11, and passed through the packing layer I 10 to reach the outlet on the top of the oxidation reaction tower 7 after the CO was catalytically oxidized at the CO catalytic oxidation layer 5 in the oxidation reaction tower 7, and when the temperature sensor 4 detected that the temperature of the flue gas was 110° C., the flue gas was introduced into the chimney 12 for discharging, and no white fog phenomenon was observed at the outlet of the chimney 12. Upon detection, the residual amount of CO in the flue gas at the outlet of the chimney 12 was less than 200 ppm, reaching the emission standard.

(15) When an emergency circumstance occurred, for example when the volume percentage concentration of CO as detected was ≥1%, and when the temperature detected by the temperature sensor 4 did not reach 110° C., indicating that there was a malfunction inside the device, then at this point the solenoid valve II 15 was subjected to emergency shut-down to check the inside of the device and the activity of the CO catalyst.

Example 5

(16) A method for purifying CO from a flue gas and coupling-suppressing white fog included the following specific steps:

(17) (1) the flow rate of the wet desulfurization flue gas was 14,000 Nm.sup.3/h, and the composition of the flue gas was 0.8% of CO, 21% of O.sub.2, 13% of H.sub.2O, 63.4% of N.sub.2, and 1% of SO.sub.2+NO, the initial temperature of the flue gas was 65° C., the flow rate of the blast furnace flue gas was 340 Nm.sup.3/h, the composition of the blast furnace flue gas was 20% of CO and 80% of N.sub.2+CO.sub.2, and the initial temperature of the flue gas was 65° C., a CO catalyst was coated on a ceramic honeycomb carrier, and the carrier was charged into the CO catalytic oxidation layer 5 of the device of Example 1, where the active composition and the mass percentage content of the CO catalyst were 20% of CuO, 30% of MnO.sub.2, 25% of CeO.sub.2, and 25% of Co.sub.3O.sub.4, and the packing layer I 10 and the packing layer II 11 were filled with a spherical filler with a diameter of 3 cm, and the filler was a turbulence sphere;

(18) (2) the desulfurized sintering flue gas of steel or iron in the desulfurized sintering flue gas 9 was introduced into the bottom of the oxidation reaction tower 7, and the CO concentration sensor 3 fed the data back to the controller 2 when the CO concentration sensor 3 detected that the volume percentage concentration of the CO in the desulfurized sintering flue gas of steel or iron was less than 1%, then the controller 2 activated the aspirator pump 1 and opened the solenoid valve I 8 to pump the blast furnace flue gas in the blast furnace flue gas 6 into the blast furnace flue gas pipeline 14 and then into the gas transmission pipeline 13, and the CO concentration sensor 3 fed the detection data back to the controller 1 when the CO concentration sensor 3 detected that the volume percentage concentration of the CO in the mixed flue gas was 1.256%, then the solenoid valve II 15 was opened such that the mixed flue gas entered the oxidation reaction tower 7, passed through the packing layer II 11, and passed through the packing layer I 10 to reach the outlet on the top of the oxidation reaction tower 7 after the CO was catalytically oxidized at the CO catalytic oxidation layer 5 in the oxidation reaction tower 7, and when the temperature sensor 4 detected that the temperature of the flue gas was 122° C., the flue gas was introduced into the chimney 12 for discharging, and no white fog phenomenon was observed at the outlet of the chimney 12. Upon detection, the residual amount of CO in the flue gas at the outlet of the chimney 12 was less than 200 ppm, reaching the emission standard. When an emergency circumstance occurred, for example when the volume percentage concentration of CO as detected was ≥1%, and when the temperature detected by the temperature sensor 4 did not reach 110° C., indicating that there was a malfunction inside the device, then at this point the solenoid valve II 15 was subjected to emergency shut-down to check the inside of the device and the activity of the CO catalyst.