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US 9,080,286 B2Granted
Method in the treatment of odorous gases of a chemical pulp mill
AssigneeAndritz Inc.
InventorsEsko Mattelmäki, Kari Saviharju
Life of this patent
Estimating the term…
Abstract
A method for treating odorous gases of a chemical pulp mill, according to which method odorous gases are combusted in a separate combustion device and flue gas generated therein is scrubbed. The scrubbed flue gas is led into a recovery boiler. The flue gas is scrubbed in a series of scrubbers wherein scrubbing solution discharged from one scrubber may be fed to a preceding scrubber.
Claims21
A system to treat odorous gases in a pulp mill comprising:
- a combustion device having inputs receiving the odorous gases and combustion air, in which the odorous gases are combusted with excess air to oxidize compounds in the odorous gases, and having a discharge for flue gas generated by the combustion of the odorous gases;
- a first stage of a scrubbing unit having a gas inlet receiving the flue gas from the combustion device, a solution inlet coupled to a source of a liquid scrubbing solution to mix with the received flue gas, an outlet for a liquid containing oxidized compounds extracted from the flue gas in the first stage and entrained in the liquid, and a gas outlet discharging scrubbed flue gas from the first stage, and
- a second stage of the scrubbing unit having a gas inlet receiving the scrubbed flue gas from the first stage, a solution inlet coupled to a source of a liquid scrubbing solution to mix with the received scrubbed flue gas, an outlet for a liquid containing oxidized compounds extracted from the received scrubbed flue gas in the second stage and entrained in the liquid, and a gas outlet for scrubbed flue gas from the second stage wherein the gas outlet directs the scrubbed flue gas to a recovery boiler.
A method for treating odorous gases in a pulp mill comprising:
- combusting the odorous gases in a combustion device, wherein the combustion is performed with excess air to oxidize sulfur compounds in the odorous gases and generate flue gas including sulfur dioxide;
- scrubbing the flue gas generated from the combustion of the odorous gases to remove the oxidized sulfur compounds, wherein the scrubbing includes mixing the flue gas with a liquid scrubbing solution;
- separating the scrubbed flue gas from a liquid scrubbed solution resulting from the mixing of the flue gas and the liquid scrubbing solution, and
- feeding the scrubbed flue gas to a recovery boiler separate from the combustion device.
1 more element
A method for treating odorous gases in a pulp mill comprising:
- feeding the odorous gases to a combustion device and combusting the odorous gases in the combustion device separately from combusting other fluids produced by the pulp mill, wherein the combustion is performed with excess air to oxidize compounds in the odorous gases;
- scrubbing in a first scrubbing stage flue gas generated in the combustion device from the combustion of the odorous gases to remove the oxidized compounds and discharging scrubbed flue gas from the first scrubbing stage, wherein the scrubbing in the first scrubbing stage includes mixing the flue gas with a liquid scrubbing solution and separating in the first scrubbing stage a liquid scrubbed solution from the scrubbed flue gas;
- feeding the scrubbed flue gas from the first scrubbing stage to a second scrubbing stage;
- scrubbing in the second scrubbing stage the scrubbed flue gas from the first scrubbing stage and discharging scrubbed flue gas from the second scrubbing stage, wherein the scrubbing in the second scrubbing stage includes mixing the scrubbed flue gas with a liquid scrubbing solution and separating in the second scrubbing stage a liquid scrubbed solution from the scrubbed flue gas, and
- feeding the scrubbed flue gas discharged from the second scrubbing stage to a recovery boiler.
2 more elements
A method for treating odorous gases in a pulp mill comprising:
- combusting the odorous gases in a combustion device, wherein the combustion is performed with excess air to oxidize sulfur compounds in the odorous gases and generate flue gas including sulfur dioxide;
- injecting the flue gas and a liquid solution including sodium hydroxide into a first scrubber, wherein the sodium hydroxide reacts with the sulfur dioxide in the flue gas to form a solution containing sodium bisulfite (NaHSO3) and scrubbed flue gas having reduced sulfur dioxide as compared to the flue gases injected into the first scrubber;
- separately discharging from the first scrubber a solution containing sodium bisulfite and the scrubbed flue gas;
- injecting the scrubbed flue gas and an oxidized white liquor into at least one other scrubber, wherein the oxidized white liquor reacts with the scrubbed flue gas to form a solution containing sulfites;
- separately discharging the solution containing the sulfites and a rescrubbed flue gas having reduced sulfur dioxide as compared to the scrubbed flue gas injected into the at least one other scrubber, and
- feeding the rescrubbed flue gas to a recovery boiler that is separate from the combustion device.
3 more elements
Dependencies are inferred from the claim text.