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).