Ultrasonic vibration-assisted (UV-A) pelleting can increase cellulosic biomass density and reduce biomass
handling and transportation costs in cellulosic biofuel manufacturing. Effects of input variables
on pellet density in UV-A pelleting have been studied experimentally. However, there are no reports
on modeling of pellet density in UV-A pelleting. Furthermore, in the literature, most reported density
models in other pelleting methods of biomass are empirical. This paper presents a constitutive model
to predict pellet density in UV-A pelleting. With the predictive model, relations between input variables
(ultrasonic power and pelleting pressure) and pellet density are predicted. The predicted relations are
compared with those determined experimentally in the literature. Model predictions agree well with
reported experimental results.