Ultrasonic-Vibration Assisted Pelleting for Cellulosic Ethanol Manufacturing: Effects of Particle Size and Moisture Content on Power Consumption

Ethanol produced from cellulosic materials is an alternative to petroleum-based transportation fuels. However, its manufacturing costs are too high to be competitive at present. Raw cellulosic biomass materials have low density, causing their transportation and handling expensive, contributing to high manufacturing costs of cellulosic ethanol. Pelleting can increase the density of cellulosic biomass and reduce their transportation and handling costs. Ultrasonic vibration-assisted (UV-A) pelleting is a new pelleting method. Earlier studies show that moisture content and particle size have significant effects on pellet quality and sugar yield. However, their effects on power consumption in UV-A pelleting have not been studied. Since power consumption directly affects ethanol manufacturing costs, it is desirable to understand how input variables affect power consumption. The objective of this paper is to study effects of moisture content and particle size on power consumption in UV-A pelleting of wheat straw. Results show that higher moisture content and larger particle size result in higher power consumption.