2.3. Biochar pelletization
A press machine (Measurement Technology Inc., USA; Model: MTI50 K)wasusedforcompressing biocharintopellets.Acylinder of 6.35 mm inside diameter and 70 mm in length with a piston of 6.30mm in diameter and 90mm in length was installed to the machine for making a single pellet. The cylinder was wrapped by a heating tape with a thermocouple and a temperature controller to preheat the cylinder to a certain temperature (also called die