Japanese cedar and Mulia coal from Indonesia were
employed as the woody biomass and the brown coal feedstock,
respectively. Each feedstock was pulverized to a
sieve size ranging from 0.5 to 1.0 mm because each feedstock
with a smaller particle size was difficult to be steadily
supplied. The proximate (accepted basis) and ultimate (dry
ash-free basis, d.a.f) analyses of each feedstock were performed
using a Rigaku Thermo Plus 2 thermogravimetric
differential thermal analyzer (TG-DTA) and a Thermo
Quest EA 1110 automatic elemental analyzer, respectively.
In addition, the higher heating values (HHV, dry basis
(d.b.)) of each feedstock were analyzed using an IKA C
2000 basic calorimeter system. The analysis results of each
feedstock are shown in Table 1. Less than 0.001 wt%
(d.a.f.) sulfur was detected in the Mulia coal pulverized
to a sieve size ranging from 0.5 to 1.0 mm, which is below
the detection limit. However, coal generally has relatively
highly-concentrative sulfur. Therefore, the Mulia coal
pulverized to a sieve size ranging from 0 to 106 lm was also
analyzed. As a result, less than 0.058 wt% (d.a.f) sulfur was
detected in the Mulia coal. Thus, sulfur was concentrated
in coal particles with a smaller size.