What are SO2 and SOx Emissions?

Sulfur dioxide (SO2) is a gaseous air pollutant comprised of sulfur and oxygen. It forms secondary particulate (PM2.5) as it oxidizes to sulfuric acid by combining with water vapor. It also reacts with ammonia to create ammonium sulphate. SOx is a generic term for sulfur oxides (e.g. SO2, SO3). Sulfur dioxide converts in the atmosphere to sulfates, a major contributor to fine particle pollution.

The dominant source of SO2 is the burning of fossil fuels by utilities and industry; lesser sources of SO2 emissions include metal extraction processing and off-road diesel equipment.

Tri-Mer’s SO2 scrubbers use dry sorbent injection of calcium or sodium-based sorbents (hydrated lime, sodium bicarbonate or trona) to control sulfur oxides (SO2, SO3), hydrochloric acid (HCl) and hydrogen fluoride (HF) with high efficiency and exceptional reliability.

Dry Sorbent Injection for SO2 Control

With dry sorbent injection in the duct, upstream of the filters, the additional particulate from the sorbent is captured easily along with the other pollutants. The SO2 removal reaction occurs within the duct prior to the filter and at the filter cake that accumulates on the filters’ surface.

 

The reaction of the sorbent with the acid gas creates a solid particle that is also captured on the filters, along with the unreacted sorbent and the process particulate.

With dry sorbent injection, SO2 capture is typically 90% or higher, with removal efficiencies as high as 97%. HCl removal is typically 95%, and often as high as 99%. Temperature range for effective removal is 300°F to 1500°F.

Dry sorbent injection and new developments in engineered sorbents have revolutionized dry removal of SO2, SO3, HCI and HF. Hydrated lime sorbents are readily disposed of in landfills because of minimal leaching. High SO2 removal is possible without the cost and complexities of spray-drying or wet waste.

SO2 scrubbers that remove acid gases such as SOx and HCl also capture PM in the process gas to very low levels. These systems can also be configured to simultaneously remove NOx, dioxins, O-HAPs, and mercury.

Want a simple, cost-effective, retrofit for dry sorbent injection? Check out our patented SorbSaver technology for a solution.