This parameter is essential for the optimization of the energy conversion process, because inad­equate particle size can cause the following problems: clogging or system damage in conveying and transportation, bridging in storage and conveying systems, increasing resistance to air flow in aeration and drying, inhibition of particle spreading on fire beds, dust formation during trans­portation, combustion efficiency and emissions control. There are three methods available to determine biofuel size: oscillating screen, vibrating screen and rotating screen method; how­ever, they all measure the quantity of biomass, which is sieved through screens of varying dimensions.