Pyrolysis of polyolefins for increasing the yield of monomers' recovery

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

DOI:https://doi.org/10.1016/j.wasman.2011.10.009· OSTI ID:21612964

Kaminsky, W ^[1]; Buzeto, F ^[2]; Yang, W ^[3]

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1. University of Hamburg, Institute of Technical and Macromolecular Chemistry, Martin-Luther-King Platz 6, 20146 Hamburg (Germany)
2. State University of Campinas - UNICAMP, College of Chemical Engineering, Department of Polymer Science - Av. Albert Einstein 13083-852 Campinas (Brazil)
3. Royal Institute of Technology, School of Industrial Engineering and Management, Division of Energy and Furnace Technology, Brinellvagen 23, 100-44 Stockholm (Sweden)

Highlights: Black-Right-Pointing-Pointer Thermal and catalytic pyrolysis of mixed polyolefins in fluidized bed has been studied. Black-Right-Pointing-Pointer We tested applicability of a commercial Ziegler-Natta catalyst (Z-N: TiCl{sub 4}/MgCl{sub 2}). Black-Right-Pointing-Pointer The catalyst has a strong influence on product distribution, increasing gas fraction. Black-Right-Pointing-Pointer At 650 Degree-Sign C the monomer generation increased by 55% when the catalyst was used. Black-Right-Pointing-Pointer We showed the concept of treatment of mixed polyolefins without a need of separation. - Abstract: Pyrolysis of plastic waste is an alternative way of plastic recovery and could be a potential solution for the increasing stream of solid waste. The objective of this work was to increase the yield the gaseous olefins (monomers) as feedstock for polymerization process and to test the applicability of a commercial Ziegler-Natta (Z-N): TiCl{sub 4}/MgCl{sub 2} for cracking a mixture of polyolefins consisted of 46% wt. of low density polyethylene (LDPE), 30% wt. of high density polyethylene (HDPE) and 24% wt. of polypropylene (PP). Two sets of experiments have been carried out at 500 and 650 Degree-Sign C via catalytic pyrolysis (1% of Z-N catalyst) and at 650 and 730 Degree-Sign C via only-thermal pyrolysis. These experiments have been conducted in a lab-scale, fluidized quartz-bed reactor of a capacity of 1-3 kg/h at Hamburg University. The results revealed a strong influence of temperature and presence of catalyst on the product distribution. The ratios of gas/liquid/solid mass fractions via thermal pyrolysis were: 36.9/48.4/15.7% wt. and 42.4/44.7/13.9% wt. at 650 and 730 Degree-Sign C while via catalytic pyrolysis were: 6.5/89.0/4.5% wt. and 54.3/41.9/3.8% wt. at 500 and 650 Degree-Sign C, respectively. At 650 Degree-Sign C the monomer generation increased by 55% up to 23.6% wt. of total pyrolysis products distribution while the catalyst was added. Obtained yields of olefins were compared with the naphtha steam cracking process and other potentially attractive processes for feedstock generation. The concept of closed cycle material flow for polyolefins has been discussed, showing the potential benefits of feedstock recycling in a plastic waste management.

• OSTI ID: 21612964
• 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

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
ALKALINE EARTH METAL COMPOUNDS
ALKENES
CATALYSTS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CRACKING
DECOMPOSITION
DENSITY
FLUIDIZED BEDS
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
MAGNESIUM CHLORIDES
MAGNESIUM COMPOUNDS
MAGNESIUM HALIDES
MANAGEMENT
MATERIALS
MINERALS
MONOMERS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OXIDE MINERALS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHYSICAL PROPERTIES
PLASTICS
POLYETHYLENES
POLYMERIZATION
POLYMERS
POLYOLEFINS
POLYPROPYLENE
PYROLYSIS
PYROLYSIS PRODUCTS
QUARTZ
RECYCLING
SOLID WASTES
SOLIDS
STEAM
SYNTHETIC MATERIALS
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TITANIUM CHLORIDES
TITANIUM COMPOUNDS
TITANIUM HALIDES
TRANSITION ELEMENT COMPOUNDS
WASTE MANAGEMENT
WASTES