2.4. Fixed bed reactor
Fixed bed pyrolyzers are usually used for slow pyrolysis to
produce char [20]. The technology is simple, however, not flexible
with respect to process changes (for instance, it is rarely used for
fast pyrolysis). As shown in Fig. 5, a carrier gas enters the
distributer and passes through the bed to carry both the condensable
and non-condensable gases to the condenser. The fixed
bed reactor is usually used in the laboratory or bench scale due to
the simple structure [18]. A few 600 kg/h commercial units have
been constructed in China [18].