Semi-active carbon and aromatics produced by pyrolysis of scrap tires

Very promising results have been obtained in pyrolysis experiments carried out in a sieve-tray reactor, of our design, in the temperature range 400-700° C, employing a suitable gas stream in order to rapidly remove the pyrolysis products from the reactor and at the same time to activate the char. By pyrolysis of shredded rubber from scrap tires 36-38% of activated carbon, 49-38% of oil products and 15-30% of gas were obtained. The pyrolysis carbon shows specific adsorption, towards dyes for industrial uses, which seems higher than those of commercial active carbon and yields adsorption isotherms with a usual slope. The oils are characterized by high aromatic hydrocarbons and low sulphur contents (0.6% with nitrogen as a carrier gas, 0.2% with carbon dioxide); they could be used as plasticizers for rubber. The pyrolysis gases (mainly methane, hydrogen, ethylene, hydrogen sulphide) have a heat value of 6.000-7.000 kcal m-3. The paper describes results that were obtained in pyrolysis experiments carried out in a sieve-tray reactor in the temperature range 400-700 degree C, employing a suitable gas stream in order to rapidly remove the pyrolysis products from reactor and at the same time to activate the char. By pyrolysis of shredded rubber from scrap tires 36-38% of activated carbon, 49-38% of oil products and 15-30% of gas were obtained.