Enhancement of Reactivity in Surfactant-Modified Sorbents for Sulfur Dioxide Control

摘要

Injection of calcium-based sorbents into the postflame zone of utility boilers is capable of achieving sulfur dioxide (SO2) captures of 50-60% at a stoichiometry of 2. Calcium hydroxide (Ca(OH)2) appears to be the most effective commercially available sorbent. Recent attempts to modify Ca(OH)2 by adding calcium lignosulfonate with the water of hydration have succeeded in enhancing its effectiveness. The particle size reduction, which in some applications accompanies lignosulfonate addition, does not appear to be a prerequisite for increased SO2 capture. Similarly, the accelerated rate of dehydration observed in modified hydroxides does not appear to be an important mechanism in the enhancement. The primary cause of increased reactivity in modified sorbents is the ability of calcium lignosulfonate to retard the rate of sintering and thus to retain pore volume and reactive surface area. (Copyright (c) The American Chemical Society, 1989.)