Electric Power Research Institute Incorporated

Miriam Stohs

David R Owens

Oliver W Hargrove, Jr

Robert E Moser

James H Wilhelm

James D Colley

Joseph R Peterson

Ron C Skarupa

David M Seeger

A process is provided for removing vapor phase selenium species produced by the combustion of selenium and sulfur-containing fuel of the kind used to generate electric power in conjunction with a flue gas desulfurization process. In one process embodiment the flue gas leaving the combustion system is humidified by the injection of atomized water or a dilute alkaline slurry at a selected location upstream of the flue gas desulfurization system to cool the flue gas from a temperature of about 300.degree. F. to a temperature of about 280.degree. F. so as to enhance the selenium removal efficiency. In another process embodiment the flue gas leaving the combustion system is first humidified to cool the flue gas from a temperature of about 300.degree. F. to a temperature of about 200.degree. F. so as to enhance the selenium removal efficiency, and then an alkaline sorbent material is injected into the humidified flue gas. Selenium species are removed from the flue gas with the particulates in a particulate control device between the combustion system and the flue gas desulfurization system.

Flue gas humidification and alkaline sorbent injection for improving

A flue gas desulfurization process and system employing a clear scrubbing liquor and an organic acid buffer conducted under forced oxidation conditions to produce a usable gypsum by-product without scrubber scaling and abrasion is provided. Calcium ion concentration and chloride concentration are suppressed to improve limestone utilization, reduce the consumption of organic acids and improve crystal growth. The FGD system includes a limestone reactor for precipitating gypsum separate from the scrubber system which allows the recovery of pure carbon dioxide and a clarifier/softener tank which allows the production of gypsum-free clear scrubbing liquor and a drier gypsum filter cake.

Clear liquor scrubbing of sulfur dioxide with forced oxidation in flue

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Austin, TX, United States of America

Miriam Stohs