Fine-crushing of Wood-cellulosic Material Modified for its Hydrolysis for Bioethanol Production

A prototype of a fine-crusher (grinder) of wood-cellulosic materials has been constructed with flail-knives and a rotary sieve rotating independently of each other. Pieces of bamboo in batches were fed into the fine-crusher, the crushed material was then treated with pressurized hot water (sub-critical water) to modify its structure and then hydrolyzed into glucose. With an increase in the diameter of the pores of the rotary sieve, the specific energy requirement for fine-crushing decreased remarkably from 500 to 250 kJ/kg, while the estimated glucose yield at 200°C decreased negligibly from 38% to 35%. The best rotational speed of the rotor and the diameter of the sieve pores were 1500 rpm and 4 mm, respectively.