Dear Jogendra,

as mentioned by Abdulfatah Abdu Yusuf a smaller particle size makes the particles (cellulose) more accessible to hydrolysis etc. From an economic point of view, however, one needs to bear in mind that comminution is a very energy intensive (read costly) process step, hence an overall optimum particle size needs to be determined. There are 3 models commonly referred to in literature: Bond, von Rittinger and Kick.

All models are based on the same differential equation and just differ by the exponent:

dE=C dX / X(n)

n = 1 (Kick) / 1.5 (Bond) / 2 (von Rittinger)

The optimum particle size depends on the initial particle size, moisture content and biomass. From my reading von Rittinger appears to model the comminution of biomass best.

Here are some papers you can study:

Article Von Rittinger theory adapted to wood chip and pellet milling...

Article Specific energy consumption for reducing the size of alfalfa...

Article Energy requirment for comminution of biomass in relation to ...

All the best, Rob.

Dear J. Singh,

Perhaps you could carry out optimization using response surface methodology to determine the optimal particle size. But as a rule of thumb, smaller particle sizes will suffice. Best of luck.

Regards,

BBN