REPROCESSING OF USED TIRES INTO ACTIVATED CARBON AND CARBON MATERIALS

THE DISPOSAL OF 280 MILLION TIRES GENERATED EACH YEAR IN THEU.S. BY LANDFILL IS INCREASINGLY BECOMING AN UNACCEPTABLE SOLUTION. THE TIRES TAKE UP LARGE AMOUNTS OF VALUABLE LANDFILL SPACE AND ALSO REPRESENT A FIRE HAZARD. A BETTER SOLUTION FROM AN ENVIRONMENTAL AND ECONOMIC STANDPOINT IS TOTHERMALLY REPROCESS THE TIRES INTO VALUABLE PRODUCTS SUCH ASACTIVATED CARBON AND OTHER SOLID CARBON FORMS (CARBON BLACK,GRAPHITE, AND CARBON FIBERS). THE KEY TO PRODUCING SUCH A PRODUCT IS THE CHEMISTRY OF LOW TEMPERATURE CARBONIZATION. THE INNOVATION OFFERED IN THIS PROJECT IS TO PRECISELY CONTROL THE CARBONIZATION WITH: 1) A PREDICTIVE MODEL INCORPORATING A DETAILED UNDERSTANDING OF THE PHYSICAL AND CHEMICAL PROCESSES OCCURRING DURING CARBONIZATION; 2) THE USE OF THIS MODEL TO SUGGEST MODIFICATIONS IN THE STARTING MATERIALS; 3) ON-LINE MONITORING OF THE CARBONIZATION PROCESS; AND 4) IMPROVED CONTROL OF FABRICATION PROCESSES BASED ON ITEMS 1 AND 3. THE OBJECTIVE OF THE PHASE I PROGRAM IS TO DEMONSTRATE THAT CARBONIZATION CAN CONVERT USED TIRES INTO ACTIVATED CARBON OR SOME OTHER MARKETABLE CARBON FORM. THERE ARE PRELIMINARYRESULTS THAT SHOW THIS IS POSSIBLE. THIS PROGRAM WILL RELY ON THE PREDICTIVE CAPABILITY OF AFR'S UNIQUE CARBONIZATION MODEL AND THE APPLICATION OF A NOVEL TG-FTIR METHOD TO PROVIDE A BETTER UNDERSTANDING OF TIRE CARBONIZATION. THE PHASE I PROGRAM CONSISTS OF FOUR ELEMENTS: 1) SELECTION AND CHARACTERIZATION OF THE STARTING MATERIALS; 2) MEASUREMENT AND MODELING OF THE CARBONIZATION PROCESS; 3) CHARACTERIZATION OF THE CHAR PRODUCTS AND EVALUATION OF THE ACTIVATION STRATEGIES; 4) DESIGN OF THE PHASE II PROTOTYPE. THE PHASE II PROGRAM WOULD EXTEND THE STUDIES DEVELOPED IN PHASE I TO A WIDER RANGE OF CARBONIZATION CONDITIONS USING THE SAME EXPERIMENTAL METHODS AND MODELS. IN ADDITION, DIFFERENT WASTE STREAMS WOULD BE ADDRESSED: REJECTED POLYMERPARTS, CUTTINGS FROM TRIMMING OPERATIONS, RECYCLED PLASTIC, ETC. AN INTERMEDIATE SCALE PROCESS FOR LABORATORY EXPERIMENTS WOULD BE DEVELOPED IN PHASE II. SUCH A REACTOR SYSTEM WOULD PROCESS - 1 KG/HR AND THUS SIMPLIFY THE SCALE-UP NECESSARY IN PHASE III.