bed reactor) and the Land Development Department
(cylinder reactor) at 400-550oC which is close to the
temperature of the traditional kiln (~350oC). The aim of
this work was to characterize rice husk biochar,
including morphology, mineralogy and chemical
composition to identify if the method of manufacture
affects these properties.
Materials and Methods
Manufacture of Rice Husk Biochars
A bulk rice husk sample was obtained from a
commercial rice mill that processes jasmine rice.
Pyrolysis was carried out using KU (Kasetsart
University) and LDD (Land Development Department)
equipment and in a traditional farmers kiln under
limited oxygen atmosphere as shown in Fig. 1. The KU
reactor produced biochar from a load of 700 cm3 of
biomass at 400-550oC, 10-20oC/min heating rate and N2
was added into the reactor at 200 cm3/min flow rate
with a 1 hr residence time (Fig. 1a). The LDD reactor
produced biochar at 400oC with a 300 cm3/min N2 flow
rate (Fig. 1b) from a load of 5,000 cm3 biomass. Biochar
was produced in a traditional farmer kiln shown in Fig.
1c where organic waste fuel is burnt in an outer metal
cylinder to heat the rice husks in the inner cylinder
from which air is excluded. The operating temperature
is approximately 350oC with a load of 2,500 cm3
biomass (Figu. 1c).