The screw extruder briquetting die is critical to determining the
quality of biomass briquettes. In this study, mathematical models were
developed to study pressure distribution along the briquetting die using the hot
extrusion scheme and assuming a plug flow. Parametric analysis to determine
the effects of design variables on die pressure distribution was carried out by
simulation using developed mathematical models. Results showed that pressure
along the die entry decreases rapidly with high yield strength of compacted
biomass and with increased friction coefficient at the briquetting die interface.
As friction coefficient at the die interface increases, there is rapid decrease in
pressure along the length of the die. Parameters resulting in rapid pressure
decrease along the briquetting die length would result in increased die pressure
at the end of the screw extruder. The developed mathematical models and the
results obtained could significantly contribute to design of briquetting dies.