The main aim of this study was to investigate the effect of red mud on the
decomposition and dechlorination of waste plastics. Thermal and catalytic d
egradation of a mixture of municipal waste plastics (MWP) and heavy vacuum
gas oil (HVGO) into fuel oil was carried out by a onestep and a two-step pr
ocess. One-step processing was performed at 430 degreesC by stepwise pyroly
sis. Red mud (RM) was used as a dechlorination catalyst. In two-step proces
sing, degradation in the presence and absence of solid acid catalyst (silic
a-alumina, SA1) was carried out at 430 degreesC followed by dechlorination
in a flow-type fixed-bed reactor at 350 degreesC over RM. Copyrolysis of MW
P with HVGO led to a synergic effect, increasing the liquid yield. TR99300
had a good dechlorination effect in two-step processing, however it was not
effective for MWP/HVGO mixture. In both processes, RM was very effective i
n the sorption of both inorganic and organic chlorine compounds. Hydrogen c
hloride (HCl) formation from the degradation of poly(vinyl chloride) (PVC)
in MWP was depressed by RM. In one-step processing, the yield of liquid pro
ducts from the degradation of MWP in HVGO was about 70 wt %. The chlorine c
ontent of the liquid product was 1127 ppm in the absence of RM, whereas it
decreased to the very low level of 90 ppm in the presence of RM. We obtaine
d oil having a negligible amount of chlorine using TR99300 and RM in the tw
o-step process. The carbon number distribution of liquid products was simil
ar in both processes. The liquid hydrocarbons derived from the degradation
of MWP/HVGO were distributed in a wide range of carbon number (C-5-C-25) Wi
th a big peak at C-9.