Ms. Luo et Cw. Curtis, THERMAL AND CATALYTIC COPROCESSING OF ILLINOIS NO 6 COAL WITH MODEL AND COMMINGLED WASTE PLASTICS, Fuel processing technology, 49(1-3), 1996, pp. 91-117
Coprocessing of waste plastics with coal was investigated at reaction
conditions typical of direct liquefaction using slurry phase Mo and Fe
hydrogenation catalysts. Reactions were performed with individual mod
el polymers including polyisoprene, polystyrene, and high and low dens
ity polyethylene (HDPE, LDPE), and with coal alone in the presence and
absence of a hydrogen donor solvent and catalysts at 400 degrees C an
d of an initial H-2 pressure of 5.6 MPa. Polyisoprene and polystyrene
liquefied readily at these conditions; however, neither HDPE nor LDPE
liquefied much with these catalysts or conditions. The conversion to T
HF solubles and product distributions from coprocessing reactions with
coal and each polymer performed at the same reaction conditions were
compared to those obtained with individual polymers. The coprocessing
reactions with polyisoprene and polystyrene yielded thermal and cataly
tic conversions in the range of 62.3 to 95.5% while the coprocessing r
eactions with HDPE or LDPE yielded low conversion in the range of 20.2
to 43.2%. Catalytic reactions using carbon black, minerals, and fluid
catalytic cracking catalysts were performed with HDPE and LDPE to eva
luate their effect on conversion. After pretreatment, the fluid cataly
tic cracking catalysts showed activity for converting LDPE at 440 degr
ees C with an initial H-2 pressure of 5.6 MPa. Subsequent coprocessing
reactions of LDPE and coal and commingled plastics and coal were perf
ormed with four fluid catalytic cracking catalysts and a zeolite HZSM-
5. HZSM-5 was the most effective catalyst for converting both coproces
sing systems although more gaseous products were produced than with th
e fluid catalytic cracking catalysts, The coprocessing reactions with
commingled plastics, which consisted primarily of HDPE with some polyp
ropylene, and coal yielded less conversion and less hexane-soluble mat
erials than the LDPE coprocessing system.