University of Cincinnati

University of Tennessee Research Foundation

The United States of America As Represented by the Administrator of the U.S. Environmental Protection Agency

Timothy C Keener

Soon-Jai Khang

Subhas K Sikdar

Rajender S Varma

Wayne T Davis

Yuhong Ju

Joo Youp Lee

Antoinette Weil Stein

Gregory D Reed

Oxidative sorbents are provided for adsorbing elemental or oxidized mercury from mercury-containing fluids such as flue gas from a coal-burning power utility or the like at a temperature range of about 50 to 350&#xb0; C. The method of preparing and using the oxidative sorbents is also provided. The oxidative sorbent compositions include one or more silicates capable of cation exchange with a plurality of active metal cations and their counter anions. The silicates may include those selected from clays such as montmorillonite, laumonite, bentonite, Mica, vermiculite and kaolinite, and from silica gels, natural and synthetic molecular sieves, zeolites, and ashes from stoker- and pulverized coal-fired boilers. The one or more oxidative metal halides and/or sulfates may be selected from the group consisting of CuCl, CuBr, CuCl, CuBr, CuSO, FeCl, FeCl, FeSO, Fe(SO), ZnCl, ZnBr, NiCl, and NiSO. The oxidative sorbents may also include activated carbon.

Compositions and methods for removing mercury from mercury-containing fluids

A multiple-field precipitator, flue-gas treating device, in accordance with the principles of the invention, includes a first section having a dual-function, sensible-cooling heat exchanger/electrostatic precipitator, a second section having a wet electrostatic precipitator, and a middle section fluidly connecting the first and second sections. In the first section, the exchanger/precipitator sensibly cools the flue gas and collects most of the dust from the flue gas. In the middle section, the dust-reduced flue gas is combined with an alkaline material, thereby forming reaction products. These reaction products and several other pollutants are captured by the wet electrostatic precipitator, in the form of a pollutant-laden liquid. The pollutant-laden liquid is directed to a series of heat exchangers and settling tanks, where various pollutants such as SO, metals, NO, and chlorides are removed in different stages. In addition, ammonia is liberated from the pollutant-laden liquid, and circulated back to the middle section, where it is combined with additional dust-reduced flue gas to form additional reaction products for subsequent capture in the wet electrostatic precipitator.

Method for treating flue gas

A two stage method is described for the removal of NO,and SO,from flue gas. The first stage removes all NO,by sodium sulfite sorbent injection. The second stage removes SO,by sodium bicarbonate injection. The sodium sulfite product formed in the second stage is transferred to the first stage for injection.

Process for removal of nitric oxides and sulfur oxides from flue gases

An apparatus and process for desulfurizing and denitrifying coal by pyrolysis and subsequently treating the gaseous pyrolysis by-products with a solid sorbent to substantially reduce the release of SO.sub.x gases to acceptable levels. In one aspect of the invention, coal is pyrolyzed in the inner chamber of the desulfurization and denitrification apparatus to drive off the sulfur and nitrogen compounds contained therein. In another aspect of the invention, the gaseous by-products of pyrolysis are treated with a solid sorbent in the outer chamber of the desulfurization and denitrification apparatus to substantially desulfurize those gases. In a further aspect of the invention, the desulfurized gases, which contain nitrogen compounds, are combusted under controlled conditions to minimize the production of NO.sub.x gases.

Method and apparatus for desulfurizing and denitrifying coal

A system for the removal of sulfur compounds from the flue gas from a high-sulfur coal combustion unit. The flue gas is contacted with a combination of a calcium hydroxide slurry and gaseous ammonia in a combined stoichiometric ratio which provides for near 100% utilization of the calcium hydroxide and ammonia with a sulfur dioxide removal efficiency approaching 100%. The system is useful in treating flue gas from high-sulfur coal combustion to remove the sulfur dioxide therefrom so that the flue gas can be exhausted to the atmosphere.

Growing community of inventors

Cincinnati, OH, United States of America

Timothy C Keener