| Popis: |
Finely divided biomass was pyrolysed in heated tube reactors at 700–1000 °C and 250–300 K s − 1 of the materials. It is concluded that the main thermal parameter is the reactor temperature at various heights. The range 800–900 °C mainly gives a fuel gas, while 900–1000 °C yields a synthesis gas. A secondary thermal parameter is the heating rate, which depends on the reactor temperature and the particle size. The results obtained are as good as at higher rates and can be compared with those under calculated equilibrium conditions. A third thermal parameter is the quenching effect on the entities immediately after formation. This effect depends on the vector gas flow and on the reactor geometry in the hot zone. The complex ‘chemical plasma’ generated by flash decomposition combines almost as fast as it is produced, under conditions which are very far from equilibrium. Generally, the shorter the residence time, the greater the difference from the equilibrium values. At high temperatures, short residence times of gases in the hot zone appear to increase the intensity of thermal shock to the particles, so some characteristics such as gasified carbon can exceed equilibrium values. |
