Evaluation of compaction equations applied to four biomass species

摘要

The compression behavior and compaction mechanism of wheat and barley straws, corn stover, and switchgrass grinds were investigated using three compaction equations viz. Heckel, Cooper-Eaton, and Kawakita-Lildde models. Compression tests of biomass samples were conducted at different applied forces, moisture contents, and particle sizes using the single pelleter-Instron tester. For each test, the pressure-density data were collected to characterize the compression behavior of biomass grinds. Among the four biomass grinds studied, corn stover grind reached its maximum density at low pressure, whereas the other biomass grinds required high pressure to reach maximum density. The compression data were fitted to three compaction models for explaining thecompaction mechanisms Among the three models, the Kawakita-Ludde and Cooper-Eaton models fitted well with the pressure-density data for all biomass grind samples. The Cooper-Eaton model parameters showed that the dominant compaction mechanisms for biomass grinds were rearrangement of particles followed by elastic and plastic deformation and that mechanical interlocking was negligible. From the Kawakita-Ludde model, it was found that compacts prepared from switchgrass grind had higher yield strength than compacts made from other biomass grinds Lower yield strength was predicted by the Kawakita-Ludde model for compacts from corn stover grind.