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US 5,674,459 AGranted
Hydrogen peroxide for flue gas desulfurization
AssigneeThe Babcock & Wilcox Company
InventorsWadie F. Gohara, Dennis W. Johnson
Life of this patent
Estimating the term…
Abstract
A system for removing SO.sub.2, NO.sub.2, and other contaminants from flue gases uses hydrogen peroxide (H.sub.2 O.sub.2) as the reagent to convert the oxides of sulfur and some of the oxides of nitrogen (NO, NO.sub.2, etc.) to more stable oxidation states. Acids formed as a result of this conversion, namely sulfuric acid (H.sub.2 SO.sub.4) and nitric acid (HNO.sub.3) can then be neutralized with limestone or, alternatively, the sulfuric and nitric acids can be collected and processed for sale as an industrial product.
Claims18
A system for removing sulfur dioxide, nitrogen dioxide and other contaminants from a flue gas using hydrogen peroxide, comprising:
- a horizontal reaction chamber having a diverging inlet section for receiving the flue gas, a relatively constant cross-sectional area middle section, and a converging outlet section for discharging the flue gas;
- a staggered array of hydrogen peroxide spray headers located within said horizontal reaction chamber and arranged to spray hydrogen peroxide and/or liquid reaction products and unused reagent into the flue gas to desulfurize and denitrify same;
- a sump provided at the bottom of the reaction chamber for collecting liquid reaction products and unused reagent formed by the reaction of the flue gas with the hydrogen peroxide;
- means for controlling a level of said liquid reaction products and unused reagent in said reaction chamber bottom by discharging excess amounts of said liquid reaction products and unused reagent into a holding tank;
- means for controlling introduction of fresh hydrogen peroxide into the horizontal reaction chamber as a function of measured sulfur dioxide or nitrogen dioxide concentration in the flue gas downstream of said chamber;
- means for collecting said liquid reaction products and unused reagent from said holding tank for use, further processing, or sale as a commercial product;
- and
- means, connected to said holding tank, for recycling said liquid reaction products and unused reagent from said holding tank to said staggered array of hydrogen peroxide spray headers.
5 more elements
A system for removing sulfur dioxide, nitrogen dioxide and other contaminants from a flue gas using hydrogen peroxide, comprising:
- a pretreating chamber for removing ash particles and other contaminants, having a diverging inlet section for receiving the flue gas, a relatively constant cross-sectional area middle section, and a converging outlet section for discharging the flue gas;
- means, located within said pretreating chamber, for cooling the flue gas as it passes therethrough to a desired temperature range;
- a horizontal reaction chamber connected to the outlet section of said pretreating chamber for receiving said discharged flue gas, said horizontal reaction chamber having a diverging inlet section for receiving the discharged flue gas, a relatively constant cross-sectional area middle section, and a converging outlet section for discharging the flue gas;
- a staggered array of hydrogen peroxide spray headers located within said horizontal reaction chamber and arranged to spray hydrogen peroxide and/or liquid reaction products and unused reagent into the flue gas to desulfurize and denitrify same;
- a sump provided at the bottom of the reaction chamber for collecting liquid reaction products and unused reagent formed by the reaction of the flue gas with the hydrogen peroxide;
- means for controlling a level of said liquid reaction products and unused reagent in said reaction chamber bottom by discharging excess amounts of said liquid reaction products and unused reagent into a holding tank;
- means for controlling introduction of fresh hydrogen peroxide into the horizontal reaction chamber as a function of measured sulfur dioxide or nitrogen dioxide concentration in the flue gas downstream of said chamber;
- means for collecting said liquid reaction products and unused reagent from said holding tank for use, further processing, or sale as a commercial product;
- and
- means, connected to said holding tank, for recycling said liquid reaction products and unused reagent from said holding tank to said staggered array of hydrogen peroxide spray headers.
7 more elements
A combined wet scrubber and hydrogen peroxide flue gas desulfurization system for removing sulfur dioxide, nitrogen dioxide and other contaminants from a flue gas, comprising:
- a wet scrubber module having a flue gas side inlet, an array of spray headers, and an outlet for discharging the flue gas from the module into outlet flue work connected to and downstream of said module outlet;
- means for providing a desulfurizing reagent to said spray headers to cause the reagent to spray into the flue gas to desulfurize same;
- an array of mist eliminators located in the outlet flue work;
- means for washing said mist eliminators with hydrogen peroxide to further desulfurize the flue gas and to denitrify same as the flue gas passes across said mist eliminators;
- means for controlling a level of said liquid reaction products and unused reagents in said wet scrubber module by discharging excess amounts of said liquid reaction products and unused reagents into a holding tank;
- means for controlling the introduction of fresh hydrogen peroxide into the wet scrubber module as a function of measured sulfur dioxide or nitrogen dioxide concentration in the flue gas downstream of said wet scrubber module;
- means for collecting liquid reaction products and unused hydrogen peroxide reagent produced during the washing of said mist eliminators;
- means for transporting said liquid reaction products and unused reagent from said collecting means for use, further processing, or sale as a commercial product;
- and
- means for recycling the collected liquid reaction products and unused hydrogen peroxide reagent back over the mist eliminators for further reaction with the flue gas.
7 more elements
Dependencies are inferred from the claim text.