Particle size affected the degree to which air was drawn around
the particles in the gasification process. The pressure in the gasifier
was kept slightly negative compared to atmosphere and a smaller
amount of air was exhausted without reacting with char from the
gasifier. Generally, more air as sucked out from the larger particles
due to large spacing between them. Fig. 6 gives the steady state
gasification temperature profile for three different size juniper
samples. The gasification temperature increased with the increase
of particle size in the combustion zone. This conclusion was
confirmed with the theoretical and experimental studies of wood
chips in a fixed-bed reactor [21].