Effects of moisture change on the physical and thermal properties of sericea lespedeza pellets

Abstract

The bulk density, unit density, porosity, hardness, gross calorific value, thermal conductivity, thermal diffusivity, and specific heat at different moisture content were determined for sericea lespedeza (SL, Lespedeza cuneata) pellets. It was observed that most physical properties of the SL pellets were significantly affected by moisture contents varying from 7.26% to 15.55% wet mass basis (w.b.). The maximum values of bulk density and unit densities were 547.72 and 1101.74 kg/m 3 , respectively. At higher moisture content (m.c.), there was a decrease in pellet hardness from 196.64 N at 7.26% m.c. to 68.76 N at 15.55% m.c. Gross calorific value decreased with increase in moisture content from 18.02 MJ/kg at 7.26% m.c. to 16.54 MJ/kg at 15.55% m.c. Over a moisture range of 7.26% to 15.55%, thermal conductivities, thermal diffusivities, and specific heats of the SL pellets were in the range of 0.030 to 0.033 W m -1 ℃ -1 , 2.02×10 -7 m 2 /s to 2.18×10 -7 m 2 /s, and 260.14 kJ/kg ℃ to 314.85 kJ/kg ℃, respectively. The thermal conductivity and thermal diffusivity values of SL pellets were