Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 3, 1999
Previous Article Next Article

Catalytic transformation of the gases evolved during the thermal decomposition of HDPE using acid-activated and pillared clays

Abstract

HDPE was thermally decomposed in a thermobalance and the evolved gases were passed through a bed of catalyst. Two acid activated clays of different structure were used, i.e. sepiolite (SEP), which is a fibrous clay mineral, and smectite (K10) which is a layered mineral. In addition two pillared smectites were studied one which was pillared with an Al species (AZA) and the other with an Al/Fe-species (FAZA). The thermal and catalytic decomposition of HDPE was studied under dynamic (35 to 650 °C at 10 °C min –1 ) and isothermal (60 min at 420 °C) conditions. The evolved gases were analysed using TG-OTM-GC-MS. The thermal decomposition of HDPE yielded characteristic quartets of peaks assigned to n-alkanes, alk-1-enes, alk-x-enes and α,ω-dienes in the range C 4 -C 20 . Species of higher molecular weight than C 20 were not detected. All four catalysts converted the alkenes present in the thermally generated off gases into light gases and aromatic species including respectable quantities of toluene, xylenes, tri- and tetra-methylbenzenes. Ethylbenzenes and naphthalenes were produced to a lesser extent. AZA and FAZA produced the largest yield of aromatics and sepiolite is considered to produce significant quantities of low molecular weight gases in the isothermal process. The product distribution over sepiolite suggested that there were fewer dehydrocyclisation sites on this catalyst. None of the catalysts used was capable of cracking the saturated alkanes.

Back to tab navigation
Please wait while Download options loads

Article type: Paper
DOI: 10.1039/A808882I
Citation: J. Mater. Chem., 1999,9, 813-818
  •   Request permissions

    Catalytic transformation of the gases evolved during the thermal decomposition of HDPE using acid-activated and pillared clays

    C. Breen and P. M. Last, J. Mater. Chem., 1999, 9, 813
    DOI: 10.1039/A808882I

Search articles by author