Lignosulfonate-Modified Calcium Hydroxide for Sulfur Dioxide Control

摘要

The article discusses the use of lignosulfonate-modified calcium hydroxide Ca(OH)2 for sulfur dioxide (SO2) control. The limestone injection multistage burner (LIMB) process is currently being developed at the U.S. EPA as a low cost retrofittable technology for controlling oxides of sulfur and nitrogen from coal-burning utility boilers. The most effective commercial calcium-based sorbent for this process is Ca(OH)2, with SO2 removals of about 50%. Additions of calcium lignosulfonate up to 1.5 mass % of the dry product, introduced with the water of hydration, increase the SO2 capture of the resulting Ca(OH)2 to 60%. This is achieved through particle size reduction in the modified hydroxides. The principal mechanism of size reduction appears to be deagglomeration of the Ca(OH)2 crystals; a secondary benefit is derived from crystal size reduction. (Copyright (c) 1987 by the American Chemical Society.)