Category Archives: Pyrolysis

Vacuum Pyrolysis

Vacuum or vacuum moving bed pyrolysis includes a combination of slow and fast pyrol­ysis conditions. Course solids are heated relatively slowly to temperatures higher than those of slow pyrolysis, while the gas is removed from the hot temperature zone relatively quickly by applying a reduced pressure of less than 0.20 atm in the process. Vacuum pyrolysis is not a rapid heating technique and is in the same thermal regime of time and temperature as slow pyrolysis (charcoal production); however, yields of liquid that are over 50% of the original biomass are achieved by removing the vapors as soon as they are formed by operating under a partial vacuum—essentially the converse of work at high pressures, in which the liquids are held in the charring mass to increase the yield of char.