Kinetics of thermal de-chlorination of PVC under pyrolytic conditions

Journal Article · Tue May 15 04:00:00 EDT 2012 · Waste Management

DOI:https://doi.org/10.1016/j.wasman.2012.01.004· OSTI ID:21612965

Castro, Alexandra ^[1]; Soares, Delfim; Vilarinho, Candida; Castro, Fernando ^[2]

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1. CVR - Centro para a Valorizacao de Residuos (Center for Waste Valorization), Guimaraes (Portugal)
2. CT2M - Centre for Mechanical and Materials Technologies, Mechanical Engineering Department of Minho University, Guimaraes (Portugal)

Highlights: Black-Right-Pointing-Pointer Several tests were performed in DTA/TGA for understanding the thermal behavior of pure PVC. Black-Right-Pointing-Pointer We did a kinetic model for the de-chlorination of PVC molecule. Black-Right-Pointing-Pointer A temperature of 340 Degree-Sign C was defined as the optimum temperature for breaking the bond of chlorine in the PVC molecule. Black-Right-Pointing-Pointer The experimental validation of this temperature, led to a removal rate of 99.9% chlorine. - Abstract: Although PVC-containing wastes are an important potential source of energy they are frequently disposed in landfill. In thermal treatment processes such as pyrolysis and gasification, the presence of poly(vinyl chloride) (PVC), a compound with 56.7% of chlorine, may cause problems concerned with environmental protection, as consequence of the formation of hydrochloric acid, chlorine gas and dioxins, as well as corrosion phenomena of the reactor/equipment materials. Thus, a possible solution may involve a previous removal of the chlorine from PVC containing waste through a pyrolysis process at low temperatures before the material being submitted to a subsequent thermal treatment, for energetic valorization. In this work, a kinetic model for the thermal decomposition of PVC has been developed, in view of its de-chlorination. DTA/TGA testing at different temperatures indicated a first order reaction and an activation energy of 133,800 J/mol. An almost completed de-chlorination reaction was obtained at 340 Degree-Sign C under an inert atmosphere. The resulted material is a C{sub n}H{sub n} type polymer with potential to be used in an energy recovery process. Validation test performed at laboratory scale indicate that the temperature of 340 Degree-Sign C enables the removal of {approx}99.9% of the chlorine present in PVC. The chloride can be fixed in the form of an aqueous solution of HCl or calcium chloride, driving to an alternative full process with environmental benefits and reduction of the costs associated to the PCV - containing materials/wastes management.

• OSTI ID: 21612965
• Journal Information: Waste Management, Journal Name: Waste Management Journal Issue: 5 Vol. 32; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACTIVATION ENERGY
ALKALINE EARTH METAL COMPOUNDS
AQUEOUS SOLUTIONS
ATMOSPHERES
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHEMICAL REACTIONS
CHLORIDES
CHLORINATED ALIPHATIC HYDROCARBONS
CHLORINATION
CHLORINE
CHLORINE COMPOUNDS
CONTROLLED ATMOSPHERES
CORROSION
COST
DECOMPOSITION
DIOXIN
DISPERSIONS
ELEMENTS
ENERGY
ENERGY RECOVERY
ENVIRONMENTAL PROTECTION
GASIFICATION
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HALOGENATION
HALOGENS
HEAT TREATMENTS
HETEROCYCLIC COMPOUNDS
HOMOGENEOUS MIXTURES
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
INERT ATMOSPHERE
INORGANIC ACIDS
INORGANIC COMPOUNDS
KINETICS
MANAGEMENT
MIXTURES
NONMETALS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC POLYMERS
POLYMERS
POLYVINYLS
PROCESSING
PVC
PYROLYSIS
REACTION KINETICS
SANITARY LANDFILLS
SOLUTIONS
TESTING
THERMOCHEMICAL PROCESSES
VALIDATION
WASTE DISPOSAL
WASTE MANAGEMENT
WASTE PROCESSING