Pyrolysis
“Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen. Pyrolysis typically occurs under pressure and at operating temperatures above 430 °C (800 °F). The word is coined from the Greek-derived elementspyr "fire" and lysis "separating".”
“Pyrolysis is a special case of thermolysis, and is most commonly used for organic materials, being, therefore, one of the processes involved in charring. The pyrolysis of wood, which starts at 200–300 °C (390–570 °F),[1]occurs for example in fires or when vegetation comes into contact with lava in volcanic eruptions. In general, pyrolysis of organic substances produces gas and liquid products and leaves a solid residue richer in carbon content. Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization.”
“The process is used heavily in the chemical industry, for example, to produce charcoal, activated carbon, methanol, and other chemicals from wood, to convert ethylene dichloride into vinyl chloride to make PVC, to produce coke from coal, to convert biomass into syngas, to turn waste into safely disposable substances, and for transforming medium-weight hydrocarbons from oil into lighter ones like gasoline. These specialized uses of pyrolysis may be called various names, such as dry distillation, destructive distillation, or cracking.”
(Wikipedia, Pyrolysis, 5/25/2011)
Analytical Pyrolysis
Degradation
Disposal
Carbonization
Polyethylene Pyrolysis
Pyrolysis of Tires
Reactions
Recycling
Recent US Patents
1/4/2011
7,862,691
Decomposition method of waste plastics and organics
Kitamura et al of Kusatsu Electric. Japan,developed a method for disposing of plastics and organic waste products by gasifying the wastes with titanium oxide catalysts at 420 to 560 C. The product is neutralized with lime and aluminum oxide.
Recent Journal Articles
Hydrorefining of the liquid products obtained in the pyrolysis of waste polyolefins. Part I. Refining of liquid products on the laboratory scale (Polish)
Polimery #6 (2011)
Tokarska, Poland, describedhydrorefining of the liquid products obtained in the pyrolysis of waste polyolefins. The waste polyolefin pyrolytic products were composed of 40—50 wt. % of unsaturated components (Table 1). Hydrorefining was performed over an industrial CoMo catalyst while hydrogenation was carried out in the presence of a NiCr catalyst (Table 2). The highest yields in the hydrorefining process were obtained at 300 °C under 6—8 MPa pressure (Figs. 2—4). About 80 % of the unsaturated components underwent saturation. Coke-oven gas and methanol have also been found to be possible hydrogen donors in the hydrorefining process (Fig. 6). The hydrorefined products can be applied as non-sulfuric components in engine fuels. (RDC 6/1/2011)