Coliquefaction

Resources, Conservation Recycling 23,Nos.l-2, 1998,p.47-56 ORGANIC SOLVENT EFFECTS ON WASTE PLASTICS-LIGNITE COLIQUEFACTION... 

M. M. Taghiei, Z. Feng, F. E. Hoggings, and G. P. Huffmann, Coliquefaction of waste plastics with coal, Energy Fuels, 8, 1228 (1994). 

The 1973 petroleum crisis intensified research on coal liquefaction and conversion processes. The technology developed in this field was later harnessed in chemical recycling of plastics. Mastral et al. [32], for example, employed two different batch reaction systems (tubing bomb reactors and magnetically stirred autoclave) and a continuous reactor (swept fixed bed reactor). Chemical recycling techniques such as pyrolysis [28, 33-38] or coliquefaction with coal [39, 40] convert plastic wastes into hydrocarbons that are valuable industrial raw materials. 

Coliquefaction with coal [69-71] in the process of coal and waste plastics coliquefaction, the hydrogen atoms contained in plastics transfer from plastics to coal, leading to partial or even total liquefaction of coal. On the one hand, as hydrogen donors, plastics can reduce the hydrogen consumption for coal coliquefaction dramatically. On the other... 

Figure 6.9 Thermal and catalytic coliquefaction of a coal + HDPE mixture (50/50% ).16...

Coliquefaction of Coal with Rubber and Used Tyres... 

In a further work, Tang and Curtis26 have studied the influence of the tyre components by replacing coal with model compounds 4-(l-naphthylmethyl)-bibenzyl (NMBB), dibenzothiophene and 5-methyl-8-(l-methylethyl)dibenzo-thiophen-4-ol (MMDH). Carbon black was active for the NMBB hydrocracking, whereas little activity was found with SBR, waste tyres and waste tyre liquefaction residues. However, when the latter residues were previously heat treated to remove organic coatings and recover the carbon black component, significant NMBB conversions were observed. Moreover, both carbon black and heat-treated residues were active for the hydrodesulfurization of dibenzothiophene and MMDH, particularly when combined with Mo naphthenate and S. These results confirm the catalytic properties of carbon black in coal-tyre coliquefaction, provided that its surface area is accessible. 

Chapter 6 deals with hydrogenation processes, usually based on the use of bifunctional catalysts. Plastic and rubber degradation in a hydrogen atmosphere is an effective treatment yielding highly saturated oils. Coliquefaction of plastics or rubber with coal is also considered. 

Huggins FE, Zhao J, Huffman GP, Kuo C-H, Tarter AR (1996) Investigation of zinc additives in coliquefaction of waste lubricating oil and a bituminous coal. J Environ Sci Health, Part A Environ Sci Eng Toxic Hazard Subst Control A31 1755-1766... 

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