Using Sodium Bicarbonate for SO^sub 2^ Mitigation

摘要

The Mirant Potomac River Power Plant is in Alexandria, VA, close to Washington, DC. The plant has five coal-fired boilers built between the late 1940s and the mid-1950s. The nominal design capacity of each unit is around 100 MW. Due to the plant's unique location, it is critical to control air pollutants such as sulfur dioxide (SO2) and particulate matter. A five-hour sodium bicarbonate injection test was conducted on Unit 2 in late November 2007. In addition, a test was conducted on Unit 4 to determine the effects on SO2 mitigation with unmilled sodium bicarbonate as a sorbent. Tests show that milled sodium bicarbonate is more effective in removing SO2 than unmilled trona. The savings in the amount of sorbent needed also means less fly ash generated and like trona, sodium bicarbonate was shown to be very effective in removing both HCl and HF. Lower sodium levels in sodium bicarbonate fly ash also result in improved ash storage characteristics.