Some physical properties of Napier grass before and after chopping for producing biomass pellets

Abstract

The objective of this research was to study some physical properties, before and after chopping of Pak Chong 1 Napier grass to produce biomass pellets. The experimental results of Napier grass before chopping were 39.67±26.68 leaves per stalk, 22.42±6.92 internodes per stem, weight per stalk of 0.64±0.24 kg, weight per stem of 0.53±0.19 kg, lengths of stalk, stem, apex and leaf were 429.5±52.58, 257.40±35.01, 172.04±36.96 and 70.42±15.33 cm respectively. Stem diameters at lower, middle and upper sections 19.42±2.43, 18.31±2.84 and 14.08±2.71 mm respectively. The lower and upper apical diameters were 10.83±1.55 and 6.25±1.21 mm respectively. Thicknesses of leaf at lower, middle and upper portions were 0.13±0.04, 0.14±0.05, and 0.19±0.67 mm respectively while widths of leaf at lower, middle and upper portions were 28.01±4.14, 34.88±4.71, and 29.01±4.94 mm respectively. The heating values of all parts of Napier grass were not significantly different. On the other hand, the experimental results of Napier grass after chopping indicated on optimum moisture content of 11.78 % w.b. by sun drying to produce biomass pellets. The coefficients of static friction on ply wood, rubber, mild steel and stainless steel plates were 0.78 0.69 0.79 and 0.62 respectively. Angle of repose was 57.54 degrees while bulk density was 39.46 kg/m³. Average particle size was 2.47±1.13 mm. The percent through sieve by using a size through a resolution sieve of 2.00 to 0.85 mm was 72.53 % and the maximum heating value at moisture content of 8.37 % w.b. was maximum at 3606.33 cal/g.