Low temperature pyrolysis was employed to produce solid fuel biochars from woody (pine wood) and
non-woody biomass (coconut fiber) in the present study. Chemical evolution of biomass under pyrolysis
conditions was determined and fuel qualities of the biochars were evaluated including energy densities,
ash-related problems and combustion behaviors. The results showed that dehydration reaction of the
biomass had same preference with decarboxylation reaction under pyrolysis conditions. The hemicellulose
and cellulose in non-woody biomass showed faster decomposition than those in woody biomass. The
biochars derived from coconut fiber showed lower energy densities and energy yields than those from
pine wood under identical conditions. All major ash forming metals originally contained in raw biomass
were accumulated in the resultant biochars and more serious slagging and fouling problems were present
during combustion of pyrolytic biochars compared to raw biomass. The reactivity of biomass decreased
and the main mass loss shifted to elevated temperature zone with the increasing pyrolysis temperature,
indicating increased thermal efficiency and environmental benefits were achievable during biochar combustion
compared to raw biomass combustion. Taking into account combustion characteristics and
energy yield, optimal pyrolysis temperatures for solid fuel production were around 300 C for coconut
fiber and 330 C for pine wood.