Terminal Velocity Determination for Component Separation of Biomass

Biomass processors request a technology that will separate node and internode segments so to enhance the end product or overcome production cost. Separation techniques that take advantage of density and aerodynamic differences use pneumatic methods that segregate by terminal velocity as in the case of classifiers and cyclones. The objectives are to 1) determine terminal velocity differences between node and internode biomass segments of comparable diameter and volume, 2) evaluate the effects of switchgrass particle length and moisture content on terminal velocity of nodes and internodes, and 3) evaluate the effects of corn stalk pith, rind, and moisture content on terminal velocity of nodes and internodes. Theoretical terminal velocity values for segment properties were calculated using equations published by Mohsenin in 1970. An experimental wind tunnel constructed vertically provided a means to directly measure terminal velocity. Calculated values are compared to measured results from the testing station. This comparison is then subjected to statistical analysis to define the difference between node and internode segments. The proposed research will benefit the biomass processing industries by providing data that can be used to model for other botanical plant part separations in an area where resources are limited in the terminal velocity of segmented biomass. Only with a defined difference in segmented biomass can effective separation occur.