Trials of Additives for Sulfur-Dioxide Removal in Industrial Plants

Abstract

Trials of additives for the removal of sulfur dioxide from combustion gases have been made by several investigative groups. Three of these—an industry and local government cooperative group in Chicago, and two industry groups—are discussed in this paper. Materials tested include limestones, dolomites, red mud, and nahcolite.

The Use of Nahcolite Ore and Bag Filters For Sulfur Dioxide Emission Control

“…In these studies, hot flue gases were allowed to contact finely divided solid nahcolite in a suitable contacting device. The monitoring of the SO2 inlet and outlet concentrations across the contacting device gave an indication of the extent of SO2 removal achieved as a result of the postulated overall gas-solid reaction SO 2 (g) + 2NaHCO 3 (s) + ^O 2 (g) -Na 2 SO 4 (s) + 2CO 2 (g)t + H 2 O(g)t (1) This postulated reaction is apparently based on the fact that heat from the flue gas causes decomposition of sodium bicarbonate into sodium carbonate. Thus, Reaction 1 may conveniently be represented by the sum of the following two reactions: 2NaHCO 3 (s) -* Na 2 CO 3 (s) + CO 2 (g)t + H 2 O(g)t (2) Na 2 CO 3 (s) + SO 2 (g) + \ O 2 (g) -Na 2 SO 4 (s) + CO 2 (g)t…”