SO2-Removal Technology

Dow Chemical's Gas/Spec Technology Group (Houston, TX) has teamed with a TurboSonic Technologies, Inc. (Waterloo, ON) to market the TurboTak SO2 system for eliminating stack sulfur dioxide emissions. The system uses regeneratable amine absorbent for removing SO2 without generating the lime sludge produced by conventional gas scrubbers.

The heart of the system is a gas- and liquid-phase nozzle that efficiently atomizes the absorbent. The atomized spray contacts the gas stream to be scrubbed. The contacting column requires no packing or trays.

Dow reportedly developed its amine technology about a decade ago for possible application in coal-fired power plants. However, it did not consider marketing the technology until early in the 1990s when it became aware of the TurboTak technology.

Like most absorption strippers, TurboTak's contacts flue gas with the absorbent liquid, generally in the 120-140 °F range. The SO2 preferentially binds with the amine. A regeneration step reclaims the absorbent at 150 °F, releasing the SO2 with minimal loss of amine.

A TurboSonic spokesperson said that the process has been used on gas streams ranging up to 7 percent SO2 (70,000 ppm). Above this, it becomes more economical to feed the gas stream directly to, for example, an acid plant. The spokesperson added that TurboTak SO2's capital cost can be half that of conventional multistage absorbers, and requires less plant space. A demonstration project is underway at a paper mill.

TurboSonic will be marketing the system. TurboSonic Inc., 550 Parkside Drive, Suite A-14, Waterloo, ON, Canada N2L 5V4. Tel: 519.885.5513; Fax: 519.885.6992