Carbonization And Activation Of Waste Foam Polystyrene

Waste plastics endangering the environment have aroused attention from worldwide. We take it as "new" resources and make comprehensive utilization rather than a garbage disposal. Actually, domestic and overseas experts have done application and background researches widely and deeply, and they have gained plentiful achievements at this aspect.Waste foam polystyrene (FS) has an enormous quantity, so that it should be disposed with more than one appropriate method. Activated carbons have being used widely, and with the economic growth, its supply should rise to meet the demand of society. What we have done is to prepare activated carbon using waste FS.The residue char can't be obtained if waste FS is under common carbonized conditions. By carbonization after waste FS has been treated with concentrated sulfuric acid we got it. The yield of char is about 80% when waste FS is under a 600℃ carbonization temperature. Thermal analysis, FT1R and element analysis have be used to clarify this process, and based on it carbonization mechanisms have been discussed. Element analysis showed that the higher of the carbonization temperature, the higher sulfur content in the residue char. When we use a 700℃ carbonization temperature, the sulfur content in the residue is 15.01%.We prepared activated carbons from waste FS by physical and chemical method respectively. Phosphoric acid, potassium hydroxide and zinc chloride were used as activating agents in chemical method. The surface area of powdered activated carbon prepared by Phosphoric acid method is 1217.25m2/g; and the ash content is less than 3.0%. Under optimized condition the 0.15% methylene blue adsorption value is 11.7ml/0.1g, and the iodine number is 1180mg/g. When used potassium hydroxide and zinc chloride as activating agents, the surface areas of the result activated carbons were not more than 500 m2/g. We also have done some corresponding experiments about recovery of chemicals; it is proved that H2SO4 and H3PO4 can be reclaimed respectively.Steam is used as an activating gas in physical method. Powdered activated carbon, shaped and unshaped activated carbon is made respectively. We used wood tar as a blending agent to produce shaped activated carbon and the abrasion resistance of it is larger than 85%; the BET surface area is 1577.55m2/g. The abrasion resistance of unshaped activated carbon is 80% and BET surface area is 1789.87m2/g. The ash contents of powdered activated carbon, and unshaped activated carbon prepared by physical method are less than 0.2%; the iodine number is 1200 mg/g; the maximum 0.15% methylene blue adsorption value is 18ml/0.1g.