Oxidation control for improved flue gas desulfurization performance

Patent metadata

Field	Value
Publication number	US-9321006-B2
Application number	US-201213469620-A
Country	US
Kind code	B2
Filing date	May 11, 2012
Priority date	May 11, 2012
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A system and method for controlling oxidation of sulfites in a slurry. The system includes a tank having an inlet for receiving a slurry used in wet flue gas desulfurization. The tank also includes an inlet for receiving a gas. The inlet for receiving the gas is configured so that at least a portion of the gas received in the tank is dispersed through at least a portion of the slurry received in the tank. A sensor is configured to measure a sulfite concentration S 1 of the slurry received in the tank. In some embodiments, the sensor is a sulfite analyzer. In other embodiments, the sensor is a virtual analyzer. The system includes a controller. Software executing on the controller generates a signal indicative of an adjustment of a flow rate of gas into the tank based at least in part on the sulfite concentration S 1 .

First claim

What is claimed is:

1. A system for controlling oxidation of sulfites in a slurry, comprising:
a tank having an inlet for receiving a slurry and an inlet for receiving a gas, the inlet for receiving the gas configured so that at least a portion of the gas received in the tank is dispersed through at least a portion of the slurry received in the tank;
a sulfite concentration measuring sensor arranged in contact with the slurry received in the tank to real time measure a sulfite concentration S 1 of the slurry received in the tank to obtain a real time sulfite concentration S 1 measurement transmitted by the sulfite concentration measuring sensor as a signal to a controller;
software executing on the controller for generating a signal indicative of an adjustment of a flow rate of gas into the tank based at least in part on the sulfite concentration measuring sensor transmitted real time sulfite concentration S 1 measurement to maintain a predetermined less than 100% oxidation rate for increased sulfur dioxide removal; and
an inlet operative for supplying ammonia, sodium or magnesium cations to the slurry to achieve a slurry alkalinity for bisulfite formation therein.

2. The system of claim 1 , wherein the signal is further based on a predetermined sulfite concentration of the slurry.

3. The system of claim 2 , wherein the gas comprises oxygen.

4. The system of claim 3 , wherein the slurry is received from a spray tower configured to perform wet flue gas desulfurization.

5. The system of claim 4 , wherein the sulfite concentration measuring sensor comprises a sulfite analyzer.

6. The system of claim 4 , wherein the sulfite concentration measuring sensor comprises a virtual analyzer.

7. The system of claim 1 , wherein the inlet for supply of cations to the slurry is arranged in the tank.

8. A method of controlling the rate of oxidation of sulfites in a slurry comprising the steps of:
receiving a slurry in a tank, the slurry comprising one or more sulfites;
providing a flow of a gas into the tank;
measuring real time a sulfite concentration S 1 of the slurry received in the tank with a sulfite concentration measuring sensor arranged in contact with the slurry received in the tank to obtain a real time sulfite concentration S 1 measurement;
adjusting a flow rate of the gas into the tank based on the real time sulfite concentration S 1 measurement transmitted as a signal from the sulfite concentration measuring sensor to a controller to maintain a predetermined less than 100% oxidation rate; and
supplying ammonia, sodium or magnesium cations to the slurry through an inlet to achieve a slurry alkalinity for bisulfite formation therein.

9. The method of claim 8 , wherein the adjustment of the flow rate of the gas is further based on a predetermined sulfite concentration of the slurry.

10. The method of claim 9 , wherein the sulfite concentration measuring sensor includes a sulfite analyzer used to real time measure the sulfite concentration S 1 .

11. The method of claim 10 , wherein the oxidation of sulfites in the slurry received in the tank is less than 100% for increased sulfur dioxide removal.

12. The method of claim 11 , wherein the cations supplied to the slurry increases the concentration of dissolved sulfites in the slurry for improved flue gas SO 2 removal therewith.

13. The method of claim 12 , wherein the cation comprises magnesium.

14. The method of claim 13 , wherein the gas comprises oxygen.

15. The method of claim 8 , wherein the sulfite concentration measuring sensor comprises a virtual analyzer.

Assignees

• Laslo Dennis James
• Alstom Technology Ltd

Inventors

• Laslo Dennis James

Classifications

• B01D53/346 Primary

  Controlling the process · CPC title

• B01D2251/11

  Air · CPC title

• B01D53/501

  by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound · CPC title

• B01J19/00

  Chemical, physical or physico-chemical processes in general; Their relevant apparatus · CPC title

• B01J19/0006

  Controlling or regulating processes (controlling or regulating in general G05) · CPC title