Production of light hydrocarbons from pyrolysis of heavy gas oil and high density polyethylene using pillared clays as catalysts

Abstract

Mesoporous catalysts are currently used in the petroleum and petrochemical industry to convert heavy hydrocarbons into light ones. There is a few papers on iron-pillared clays are available. In the catalytic pyrolysis, it was used a commercial clay fractionated to remove sand and silt and treated to remove soluble salts and the organic fraction. That clay was intercalated with iron or aluminum oligomers and calcined at specific temperatures to form pillars in the layers. The main advantage of the use of pillared clays in catalytic pyrolysis is that their cost is much more reduced than that of zeolite catalysts. All thermal pyrolysis at 500°C have high pyrolysis oil yield (>80%), except for the pyrolysis of high density polyethylene (HDPE) using zeolite as catalyst. It was observed significant difference in the catalytic pyrolysis of the HDPE at 450°C as the following: zeolite > Al-PILC–450≈Fe-PILC–450> Fe-PILC–300> Al-PILC-Fe-450. The presence of heavy gas oil (HGO) improves the oil yield from both thermal and catalytic pyrolysis of HDPE, which can be attributed to the solvency effect of HGO. Pyrolysis oils were analyzed by GCAR-MS and their profiles were compared to the standard diesel. The oil from the HGO/HDPE pyrolysis using the catalyst Fe-PILC-Fe-300 was the more similar to the GC–MS homologous series of standard diesel. That catalyst produced a light linear hydrocarbon content 63% higher than that produced with zeolite.