Rapidly drying sorghum biomass for potential biofuel production

The Southern U.S. has an ideal climate that may aid in growing large amounts of biomass suitable for biofuel; however, droughts during the growing season may reduce yields. Sorghum (Sorghum bicolor L.) may have great potential as an energy crop, because it is capable of high biomass yields and is drought tolerant. However, sorghum biomass has relatively high moisture content and should be conditioned and dried before transported to reduce costs. Sorghum-sudan hybrid was harvested with two different headers on a self-propelled windrower: a Massey Ferguson 9145 (sickle) and a Massey Ferguson 9185 (disc). The disc header was comprised of two pairs (rear front) of metal conditioner rollers which compressed the biomass, thus improving the drying process. The roller pairs were used with three different pressures (0, 3500 and 7,000 kPa), and with different gaps (0 and 0.02 m). Sorghum biomass samples were collected after harvest and the percentage of moisture content wet basis evaluated daily until they remained constant. Results revealed that the higher pressures and smaller gaps resulted in faster drying of biomass. Thus, the best settings for the disc header were “7,000 kPa -0 m” or “7,000 kPa - 0.02 m” which showed, respectively, moisture content levels of 13.6% and 16.8% after 14 days. However, when the disc header was set to “0 kPa - 0.02 m”, the moisture content was significantly higher (43.2%). These results indicate sorghum was adequately dried for bailing in Southeastern U.S. condition, when proper machinery and settings were applied. Keywords: moisture, sorghum, baling, windrower