Effects of Gas Stream Temperature on Homogeneous SO₂ to SO₃ Conversion Via Natural Gas Reburning


Because SO3 is more reactive than SO2, applications for localized increases of SO3 concentrations in coal-fired power generation include lowering fly ash resistivity and improved performance of dry scrubbing systems to removal sulfur gas. Homogeneous superequilibrium of SO3 forms when SO2 passes through a flame in the presence of excess O2. While this superequilibrium condition has been studied, little data exist about the effects of free stream gas temperature (as opposed to flame temperature) on this process. A pre-mixed methane flame was used to promote the conversion of SO2 to SO3 in a drop tube furnace with free stream gas temperatures from 450-1000K. Experimental results from solid sampling and SO2/SO3 measurements via wet chemistry coupled with numeric modeling of reactions and species concentrations indicate that a lower free stream temperature reduces the maximum conversion of SO2 to SO3 and considerably extends the duration of the super-equilibrium state. Results also indicate that the homogenous enhancement of sulfur reactivity and increased duration of superequilibrium may increase sulfur capture by dry sorbents.


Mechanical and Aerospace Engineering

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 1998 American Society of Mechanical Engineers (ASME), All rights reserved.

Publication Date

01 Jan 1998

This document is currently not available here.