Table 1. Visual observations of the bio pellets with the ratio between SCGs and pine wood charcoal
Testing
HM
BM
4:6
6:4
4:6
6:4
Flame duration (minute)
24.30
23.01
29.10
26.06
Combustion rate (g/minute)
0.0407
0.0375
0.0379
0.0427
Compressive strength (kgf/cm
2
)
1.3309
0.9760
2.9005
2.3960
SCGs: spent coffee grounds, HM: hammer mill, BM: ball mill.