In one example, a fluid dynamic bearing motor having a shield member is provided. The substrate and the pressure transmitting member are accommodated in a housing. A lower end of the reinforcing member is bent toward the vehicle body center to form a flange. for a first stage time of 30 minutes to 2 hours at a first stage pressure of 105 to 150 psig; and the second steam pretreatment stage is carried out by heating the biomass with high pressure steam to raise the biomass temperature to a second stage temperature of 190\xb0 C. This provides portability across different RDF stores.