Effects of pressure on the degradation of poly(vinyl chloride)

Production of hydrogen by steam gasification of dehydrochlorinated poly(vinyl chloride) or activated carbon in the presence of various alkali compounds

“…8 The yield of residue increased under high nitrogen pressure during the thermal decomposition of PVC. 9 The low hydrogen yield and the deposition of solid carbon imply that volatile matter derived from thermal decomposition of PVC may have adhered to, and carbonized on, the inner surface of the reactor, and that the physical contact between the sample and the molten sodium hydroxide was insufficient for gasification.…”

Recovery of Resources from End-of-life Industrial Products by Using Liquefaction or Gasification

“…Residue observed in our experiments is considered to be a mixture of the polyene intermediate and solid carbon. Without any solvent under high pressure, we detected characteristic paraffin formed from hydrogenation of the polyene intermediate by hydrogen that was derived from condensation reactions and yields increased with reaction pressure 10) . In the thermal decomposition of PVC in inert solvents such as decahydronaphthalene, condensation reactions resulting in solid carbon are retarded by the insertion of solvent molecules into polyene chains, and the physical properties of dissolution and dispersion are the solvent's most important roles.…”

Liquefaction of PVC Mixed Plastics

“…The pressure dependences of the product distribution and atomic ratio of hydrogen to carbon (H/C) imply that some of the liquid products were polycondensed with the dehydrochlorinated PVC and were retained in the residue under high pressure. Some of the polyene chains underwent hydrogenation to form linear paraffins under high pressure [37]. The decomposition of polyvinyl chloride using supercritical water was also performed by Sato et al [38].…”

“…It was concluded that PET will reduce the efficiency of dehydrochlorination during the pyrolytic recycling process in an autoclave. The yield of liquid products decreased with increasing reaction pressure during the PVC degradation, whereas the yield of residue increased, reaching maxima at 9.8 MPa (400 • C) and 22.4 MPa (440 • C) [37]. The pressure dependences of the product distribution and atomic ratio of hydrogen to carbon (H/C) imply that some of the liquid products were polycondensed with the dehydrochlorinated PVC and were retained in the residue under high pressure.…”