Fast pyrolytic processes

Fast pyrolytic processes incorporate heating rates of 200 to 10 °C/s, temperatures higher than 600°C, and short vapour residence times (< 0.5 s). 

During the last six years a fluidized bed fast pyrolysis process for biomass has been developed at the University of Waterloo (The Waterloo Fast Pyrolysis Process). This process gives yields of up to 70% of organic liquids from hardwoods or softwoods, which are the highest yet reported for a non-catalytic pyrolytic conversion process. A fluidized sand bed is used as a reactor and optimum liquid yields are normally obtained in the range of 450 to 550 C at about 0.5 seconds gas residence time with particles of about 1.5 mm diameter or smaller. Two units are in use, one with a throughput of 20 to 100 gms/hr, and another with a throughput of 1 to 4 kg/hr. 

Alternatively, flash pyrolysis processes were developed for biomass liquefaction as well [5]. On a water- and ash-free basis, from wood typically 75% liquids (including 25% of water), 10% of solid char, and 15% of gases, mainly CO2 and CO, are formed at 5 00 ° C with gas retention times of only a few seconds. Several reactor concepts such as stationary and fluidized fluidized beds, the mechanically agitated rotating cone and Auger reactors, a well as ablative and vacuum pyrolysis have been carried out and operated on a semi-technical and pilot scale. For fast pyrolytic treatment of... 

Figure 3 Electrochemical response of the ferrocene-functionalized [Zn40(bdc-NH2)(btb)4/3] MOF. (a) Cyclic voltammograms for the ferrocene-functionalized MOF immobilized on pyrolytic graphite (electrolyte dichloroethane with 0.1 MNBu4PFg scan rates (i) 10, (ii) 35, and (hi) 100 mV s" ). (b) Cyclic voltammograms of the ferrocene-functionalized MOF immobilized on pyrolytic graphite (electrolyte aqueous 0.1 M phosphate buffer pFl 1 scan rate 20 mV s the first four scans are shown), (c) Plot of the peak potential for process 1 versus pH (scans i-iii). The dashed line corresponds to 30 mV pH . (d) (1) Schematic description of the ferrocene-functionalized MOF reactivity in aqueous electrolyte (2) drawing of the pore redox process involving removal of one electron, fast expulsion of one proton, and hydroxide attack (3) schematic description of the ferrocene-functionalized MOF reactivity in organic electrolyte. (Reproduced by permission of The Royal Society of Chemistry, Ref 29.)...

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