Sorbent injection scrubber

Particulate removal equipment includes electrostatic precipitators, fabric filters, or mechanical particulate collectors, such as cyclones. SOx removal equipment includes sorbent injection technologies and wet and dry scrubbers. Both types of scrubbers result in the formation of calcium sulfate and sulfite as waste products. 

The furnace sorbent injection process removes acid gas from coal anissions at less cost than expensive scrubbers (Chapter 23). In this process a highly absorbent material (called a sorbent), such as powdered limestone, is injected into the boilers, where the powdered limestone reacts with the acid gases emitted by the burning coal. The used powder is siphoned away through the boiler out-take and is captured (with fly ash) in a baghouse or electrostatic precipitator. 

Flue gas desulfurization (FGD) Removal of the sulfur gases from the flue gases (stack gases) of a coal-fired boiler—typically using a high-calcium sorbent such as lime or limestone three primary types of flue gas desulfurization processes commonly used by utilities are wet scrubbers, dry scrubbers, and sorbent injection. 

Coal gasification does not consume limestone for sulfur recovery. Limestone- or hme-based desulfurization systems produce at least 1.4 pounds of CO2 per pound of sulfur removed. The dry desulfurization systems such as fluidized bed combustion, spray dry scrubbers, and sorbent injection, require large amounts of excess limestone or lime and therefore produce 3-5 pounds of COj per pound of sulfur removed. 

Of the three categories, the packed column is by far the most commonly used for the absorption of gaseous pollutants. Miscellaneous gas-absorption equipment could include acid gas scrubbers that are commonly classified as either wet or diy. In wet scrubber systems, the absorption tower uses a hme-based sorbent liquor that reacts with the acid gases to form a wet/solid by-product. Diy scrubbers can be grouped into three catagories (1) spray diyers (2) circulating spray diyers and (3) dry injection. Each of these systems yields a diy product that can be captured with a fabric filter baghouse downstream and... 

The Alka/Sorb air pollution control system is designed to remove dioxin, furans, toxic metals, acid gases, and particulates from industrial and medical incinerator off-gas. The Alka/Sorb system consists of a dry treatment/wet scrubbing process during which incinerator off-gas is cooled, contacted with an alkaline powder, injected with a sorbent, filtered by a baghouse and then wet-scrubbed for final removal of trace acid gases. Two central parts of the Alka/Sorb system include a wet-acid scrubber and a patented sorbent called Diox-Blok, which prevents the formation of dioxins and furans in air emissions. 

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