Research on the Mechanical Behavior of the Biomass Densification Process Based on a Thick-walled Cylinder

Yu Wang, Yu Sun, Kai Wu


The mechanical behavior of the biomass densification process has noticeable influences on energy consumption and pellet quality. In the authors’ previous work, a method was proposed to determine the inner pressure by testing the circumferential strain of the outer die wall. Based on this method, a device was developed with strain gauges in the form of a single pellet unit. With this device, experiments were conducted with wood shavings, rice straw, and wheat straw under different levels of particle size, compression rate, and moisture content. The effects of these factors on the inner pressure were analyzed. The relationships among the inner pressure, pellet density, and specific energy consumption were obtained. Results showed that the pressure ratio increased linearly and then decreased and became constant during the relaxation period. The pressure change during the relaxation period was isotropic. The results could provide mechanical explanations for the phenomena in biomass densification processes.


Biomass; Densification; Pellets; Single pellet unit

Full Text:


Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022,; Lucian A. Lucia, (919) 515-7707, URLs:; ISSN: 1930-2126