Coprocessing of waste plastics with coal and with petroleum resid was
investigated to determine the effect of resid on reactivity and conver
sion. The coal used in this,study was Blind Canyon bituminous coal, th
e resids were Maya and Manji, and the model plastics tested were polys
tyrene, poly(ethylene terephthalate) (PET), and low-density polyethyle
ne (LDPE). Tl;ree systems, the individual species, binary combinations
, and ternary combinations, were reacted at conditions of 430 degrees
C and 8.7 MPa of H-2 introduced at ambient temperature for 60 min of r
eaction time. Presulfided NiMo/Al2O3 was used as the catalyst, typical
ly at 1 wt % loading, although other catalyst loading levels of 3 and
10 wt % were tested. Under these conditions polystyrene and PET reacte
d readily, while LDPE was difficult to convert. Binary reactions with
resids resulted in high conversions of similar to 94% from polystyrene
and PET, while the reactions with LDPE yielded somewhat less conversi
on of similar to 72%. By contrast, reactions of plastics with coal con
verted substantially less, ranging from 70.2% for polystyrene and coal
to 39.9% for LDPE and coal. Ternary reactions with coal, plastic, and
resid resulted in high conversions for all systems (similar to 89-95%
) except those with LDPE (similar to 77-81%). The effect of coprocessi
ng binary and ternary systems compared to individual systems on the ba
sis of conversion, hexane solubles, and gas productions was determined
. The effect of adding a third species into the binary systems was als
o evaluated. The hexane-soluble products from the three reaction sets
were analyzed by simulated distillation to determine the amount of the
reaction product boiling at less than 500 degrees C. Reactions contai
ning LDPE produced substantially less material that boiled below 500 d
egrees C than did the other reactions.