| 摘要 |
PROBLEM TO BE SOLVED: To make a woody waste or its carbonized material utilizable as a high- performance adsorbent, a high-performance catalyst and a high-performance ion exchanger by heat-treating the woody waste or its carbonized material as main starting raw materials at a specific temperature in a vapor-phase atmosphere containing oxygen. SOLUTION: Sawdust, tree barks, residual wood in forest lands, wood fibers, wood chips, vegetable fibers, pulp refuses, waste paper, etc., are cited as starting raw materials. Otherwise, a carbonized material prepared by heat-treating the woody materials at about <=350 deg.C in a nonoxidizing atmosphere can be used as the starting raw materials. The starting raw materials are heat-treated at 250-400 deg.C, preferably 300-350 deg.C in a vapor-phase atmosphere containing about 1-25% of oxygen and then allowed to naturally cool. Since acidic groups in the resultant carbonized product function as adsorption active sites, the carbonized product can be utilized as an adsorbent for basic gases such as ammonia. The carbonized product can be subjected to an alkali treatment, preferably dipped in a 0.01-1.0 N aqueous solution of sodium hydroxide, separated by filtration, washed with water and dried to be usable as an ion exchanger for supporting or adsorbing metal ions. |
