The acid and water/steam pre-treated wheat straw material
mix was fed into a horizontal preheater and refined in a pilot plant pressurized single-disc refiner, type OHP 20” Defibrator
(Metso Panelboard, Sundsvall,Sweden) fitted with a horizontal
pre-heater. Refining was performed at a rotational speed of
1500rpm and a pressure of 0.7MPa. The retention time in the
defibrator system was set to 3min. The refined fibres were
vented from the refining house into the blowline. Chemicals
were injected into the defibrator system at separate injection
points.