Depolymerization of polystyrene at reduced pressure through a microwave assisted pyrolysis

被引:75
作者
Bartoli, Mattia [1 ]
Rosi, Luca [1 ]
Frediani, Marco [1 ]
Undri, Andrea [1 ]
Frediani, Piero [1 ]
机构
[1] Univ Florence, Dept Chem Ugo Schiff, I-50019 Sesto Fiorentino, Italy
关键词
Pyrolysis; Microwave assisted pyrolysis; Waste polystyrene; Recycling; BED REACTOR; WASTE TIRES; POLYOLEFINS; DEGRADATION; CARBON; FUEL;
D O I
10.1016/j.jaap.2015.01.026
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
Large amounts of styrene and other important aromatic hydrocarbons were obtained employing microwave assisted pyrolysis for the depolymerization of polystyrene in the presence of carbon as an absorber. Working at a reduced pressure the yield of liquid was increased (higher than 75%) with respect to those obtained at ambient pressure. This liquid was clear and showed a low viscosity and density. On the contrary a dark brown liquid was formed when pyrolysis was carried out in a stream of nitrogen, but the yield was 94.3 wt%. Using a fractionating system and a residual pressure of 21.3 kPa the maximum concentration of styrene in the liquid was reached (71.9 wt%) corresponding to the maximum amount of styrene recovered from the starting PS (60.6 wt%). The substitution of carbon with silicon carbide as MW absorber, gave almost the same amount of liquid but the rate of pyrolysis was strongly reduced. Composition of liquids was affected by residence time into the reactor and some different compounds might be obtained by reaction among intermediates formed in the course of the process. Reverse polymerization of PS through microwave assisted pyrolysis may be a way to solve some environmental problems caused by waste PS. Large amount of valuable chemicals such as styrene, alpha-methylstyrene and toluene was collected while gas and char, formed in low amount, may be used as fuel. (C) 2015 Elsevier B.V. All rights reserved.
引用
收藏
页码:281 / 287
页数:7
相关论文
共 25 条
[1]   Kinetics of polystyrene pyrolysis in a conical spouted bed reactor [J].
Aguado, R ;
Olazar, M ;
Gaisán, B ;
Prieto, R ;
Bilbao, J .
CHEMICAL ENGINEERING JOURNAL, 2003, 92 (1-3) :91-99
[2]  
[Anonymous], 2011, HDB CHEM PHYS
[3]   High-temperature microwave processing of materials [J].
Bykov, YV ;
Rybakov, KI ;
Semenov, VE .
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 2001, 34 (13) :R55-R75
[4]  
Cho KH, 2006, STUD SURF SCI CATAL, V159, P433
[5]   Viscoelastic properties and long-term stability of polystyrene-carbon nanotube nanocomposites. Effect of the nature of the carbon nanotubes and modification by ionic liquid [J].
Espejo, C. ;
Carrion-Vilches, F. J. ;
Bermudez, M. D. .
POLYMER DEGRADATION AND STABILITY, 2014, 103 :42-48
[6]   Functionalization of montmorillonite by end-chain mono-cationic polystyrene and end-chain mono-cationic poly(styrene-b-2-hydroxethyl acrylate) [J].
Greesh, Nagi ;
Sanderson, Ronald ;
Hartmann, Patrice C. .
APPLIED CLAY SCIENCE, 2014, 93-94 :38-47
[7]   The influence of reaction parameters on characteristics of pyrolysis oils from waste high impact polystyrene and acrylonitrile-butadiene-styrene using a fluidized bed reactor [J].
Jung, Su-Hwa ;
Kim, Seon-Jin ;
Kim, Joo-Sik .
FUEL PROCESSING TECHNOLOGY, 2013, 116 :123-129
[8]   A review of physical and kinetic models of thermal degradation of expanded polystyrene foam and their application to the lost foam casting process [J].
Kannan, Pravin ;
Biernacki, Joseph J. ;
Visco, Donald P., Jr. .
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS, 2007, 78 (01) :162-171
[9]   Microwave-induced pyrolysis of plastic wastes [J].
Ludlow-Palafox, C ;
Chase, HA .
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 2001, 40 (22) :4749-4756
[10]  
Maul J., 2000, Polystyrene and Styrene Copolymers in Ullmann's Encyclopedia of Industrial Chemistry