Estimation of pyrolysis product of LDPE degradation using different process parameters in a stirred reactor

Document Type: Original research

Authors

1 Chemical Engineering, Energy Department, Kermanshah University of Technology, P.O. Box 67178-3766, Kermanshah, Iran

2 Polymerization Engineering, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran

3 Department of Forest, Rangeland and Fire Sciences, University of Idaho, PO Box 441132, Moscow, ID 83844-1132, USA

Abstract

Pyrolysis of low density polyethylene (LDPE) by equilibrium fluid catalytic cracking (FCC) was studied in a stirred reactor under different process parameters. In this work, the effect of process parameters such as degradation temperature (420-510°C), catalyst/polymer ratio (0-60%), carrier gas type (H2, N2, ethylene, propylene, Ar and He), residence time and agitator speed (0-300 rpm) on the condensate yield (liquid, gas and coke) and product composition were considered. Reaction products were determined by GC analysis and shown to contain naphthenes (cycloalkanes), paraffins (alkanes), olefins (alkenes) and aromatics. Higher temperature and more catalyst amount enhanced LDPE cracking. The maximum “fuel like” condensed product yield was attained at 450°C and 10% catalyst, respectively and gaseous products increased with increases in temperature. Hydrogen as a reactive carrier gas increased the condensed and paraffinic product yield. Appropriate heat transfer (by stirring) increased the catalyst efficiency in a stirred reactor.

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Main Subjects


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