The Babcock & Wilcox Company

Mcdermott Technology, Inc.

Gerald T Amrhein

Dennis W Johnson

Robert B Myers

William Downs

Stanley J Vecci

John M Rackley

Paul S Nolan

Peter VanSmith

A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S,ions to convert Hg,ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe,ions, which could otherwise induce the unwanted reduction of Hg,to the form, Hg,.

Mercury removal in utility wet scrubber using a chelating agent

A method for cleaning a flue gas containing flyash, sulfur dioxide and other contaminants includes providing a slurry source having a slurry of primarily water, magnesium sulfite and magnesium hydroxide along with small quantities of magnesium sulfate and magnesium chloride. The flyash is first removed from the flue gas and the flue gas is sprayed with the slurry for forming reaction products in the flue gas. The reaction products are then collected from the flue gas and a first portion of the reaction products is provided to the slurry source. A remaining portion of the reaction products is heated for decomposing into sulfur dioxide and magnesium oxide. The magnesium oxide is then provided to the slurry source. Magnesium sulfate and magnesium chloride are purged from the slurry source.

Regenerable magnesium dry scrubbing

A vertical, co-current dry scrubber comprises a housing having a waste gas inlet and a treated gas outlet. A plurality of airfoil mounted atomizers extend across the interior of the housing for discharging slurry into the gas stream for treatment of the gas. The use of airfoil mounted atomizers reduces pressure drop across the chamber.

Low pressure drop dry scrubber

A process and apparatus for simultaneously removing NO.sub.X and SO.sub.X from the exhaust of a furnace includes an injection of limestone into a region of the furnace having a temperature of about 2,000.degree.-2,400.degree. F., and an injection of ammonia into a region in the furnace having a temperature of about 1,600.degree.-2,000.degree. F. The limestone absorbs at least some of the SO.sub.X and the ammonia absorbs at least some of the NO.sub.X. The exhaust from the furnace which contains particulate and gases, is supplied to a dry scrubber where further reactions take place between unused ammonia and SO.sub.X, and calcium sorbent and SO.sub.X. Sorbent and ammonia regeneration can also be utilized to further improve the efficiency of the system.

Furnace ammonia and limestone injection with dry scrubbing for improved

An apparatus and method for measuring the wet and dry bulb temperatures of a hot flue gas stream containing fly ash and particulates by providing a sample sheath (12) in a gas duct (10) with a dry bulb sensor (16) and a wet bulb sensor (18) located within the sample sheath (12). The sample sheath (12) includes a self-cleaning dust filter (14) which removes the ash and particulates from the flue gas stream and a self-regulating water reservoir (26, 28) to continuously supply water for the wet bulb sensor (18).

Growing community of inventors

Louisville, OH, United States of America

Gerald T Amrhein