Particle size
Removing the particles smaller than 85 um from the milled bagasse and maintaining the same initial solids concentration (95 kg/m3) reduced the pressure drop during the reaction from 248-296 kPa/m to 33 kPa/m, only slightly higher than in the switchgrass reactor (21 kPa/m). Consistent with previous studies showing that smaller particle size result in lower drainage rates ( Lee and Bennington, 2015), the presence of more fine particles in the milled bagasse compared to switchgrass and poplar mostly explain the higher pressure drop across the packed bed shown in
Fig 2. No pressure drop was detected for reactors packed with the same initial concentration of bagasse with no particle size reduction. Hence, smaller average particle size causes larger pressure drop.