In Vietnam, most of SBC factories burn charcoal by rectangular kilns in 13-20 days. Then, they cool down charcoal naturally within the kiln. It improves the quality of grade-A charcoal.
SBC has 2 shape:
Generally, square shape is in great demand in Japan. While hexagon shape is accepted in every other countries. People produce SBC from compressed sawdust with no chemical. SBC has a high burning temperature. It also has quite long burning time. It is about 3 hours over 650 Celcius degree. Consumers would like to use SBC.