A look at clean coal technology in the 21st century
Clean coal technologies impact our daily lives, Gates writes. One of those clean coal technologies is dry sorbent injection, which removes hydrogen chloride and other acid gases through two basic steps.
Clean coal technologies impact our daily lives, Gates writes. One of those clean coal technologies is dry sorbent injection, which removes hydrogen chloride and other acid gases through two basic steps.
By Steve Gates, American Coalition for Clean Coal Electricity (ACCCE)
Dry Sorbent聽Injection聽(DRI)聽achieves between 40 to 75% removal of Sulfur Dioxide and acid gases and is one of the numerous clean coal technologies that impact our daily lives. 聽According to the聽U.S. Energy Information Administration,聽DSI systems remove hydrogen chloride (HCl) and other acid gases through two basic steps:
- Step one.聽A powdered sorbent is injected into the flue gas鈥攃ombustion exhaust gas exiting a power plant鈥攚here it reacts with the HCl. The sorbents most commonly associated with DSI are聽trona聽(sodium sesquicarbonate, a naturally occurring mineral mined in Wyoming), sodium bicarbonate, and hydrated lime.
- Step two.聽The compound is removed by a downstream particulate matter control device such as an electrostatic precipitator (ESP) or a fabric filter (FF), also referred to as a baghouse. Fabric filters are generally more effective (when combined with DSI) than ESPs, with respect to overall HCl reduction. For modeling purposes,聽EPA estimate聽a DSI system with a fabric filter is expected to achieve 90% removal of HCl, while an ESP only achieves 60% removal, although actual performance will vary by individual plant.