| 摘要 |
<p>PURPOSE:To improve the recovering rate and purity of S when SO2 released from a desulfurizing agent is reduced to recover S, by using coal contg. a decreased amount of a volatile component and having a low carbonization degree as a reducing agent. CONSTITUTION:SO2 in waste gas contg. SO2 is allowed to be adsorbed on activated carbon as a desulfurizing agent in a stack gas desulfurizing plant. The activated carbon having the adsorbed SO2 is charged into a regenerator 1 and heated to release the adsorbed SO2. The carbon is regenerated as a desulfurizing agent. The released gaseous SO2 is introduced into a reduction tower 2. Coal having a relatively low carbonization degree such as lignite, brown coal or sub- bituminous coal is heated to 700-900 deg.C in the presence of steam to remove most of the contained volatile component, and the resulting coal as a reducing agent is charged into the tower 2 from a hopper 3 at the same time. By heating the coal at a relatively low temp. such as 500-800 deg.C, the SO2 is reduced to gaseous S, which is then fed to a condenser 4, condensed by cooling and recovered as high purity solid S in a high yield.</p> |
