Lab scale studies of miscanthus mechanical conditioning and bale compression

Miscanthus is a dedicated biomass energy crop that can be used as an alternative energy source for biofuel production to decrease dependency on petroleum-based fuel sources. The mechanical properties of miscanthus pose harvest and handling issues because of the crop's stiff stalk, tall height, high yield and dense growth. This research examined the effects of a mechanical conditioning system for miscanthus on bale density, the compressive force during small square bale compression as well as the energy consumed during the compression process through lab scale studies. Miscanthus crop samples were collected and brought into a lab. Part of the samples was manually conditioned using a conditioning device. Then, unconditioned and conditioned miscanthus crops were baled using a small square baler. These bales were used for bale compression tests. The most significant finding was that, when compared to unconditioned miscanthus, conditioned miscanthus required a statistically significant decreased energy consumption (37%) during bale compression while also requiring a statistically significant decreased peak compressive force (37%). In addition, an increase in compressed small square bale density (10%) was obtained along with and density increase of 13% for the compression process was found for conditioned miscanthus when compared to unconditioned miscanthus. Based on these results, a regression relationship between pressure and bulk density for conditioned and unconditioned Miscanthus was obtained.