Abstract: An improved process is provided for reducing cellulosic biomass into air suspendable micropowder. Although the process is particularly suitable for processing empty fruit bunches of oil palms, it is adaptable to most cellulosic biomass. The incoming biomass has a water content of around 50% and is reduced to centimeter scale pieces by a chipper or similar device. These pieces are then processed by a tandem line of four pairs of grooved rollers each successive roller having a larger number of grooves. This process squeezes moisture from the biomass and reduces the material into millimeter scale pieces. After an optional drying stage, the material is fed into a terrace line of three or four essentially smooth rollers which squash the material and reduce the particle size into a micrometer scale. Finally, the material is suspended in an air stream and fractionated by a cyclone and bag filter system.