Thermo Mechanical Pulping (TMP) of Common Reed

• Process Overview:

  • TMP involves two main steps: steam pre-treatment and mechanical refining.

  • Steam pre-treatment softens lignin in the biomass, facilitating fibre separation without significant chemical degradation.

  • Mechanical refining uses high-pressure forces between rotating discs to separate fibres while preserving much of the wood's structure.​

• Equipment Used:

  • Andritz lab-scale 12-inch disc refiner at FCBA.

  • Operational parameters: 45 kW motor power, 3000 rpm rotation speed, 80 kg/h capacity, steam pressure of 3–4 bar, and refining temperature of 100–150°C.​

• Material Processed:

  • Two batches of common reed supplied by LUKE: one with flowers and stems, and one with stems only.

  • Pre-heating conditions: 135°C temperature, 5-minute residence time, and 3.5 bar pressure.​

• Refining Conditions:

  • Disc reference: Defibring disc D2B507.

  • Motor speed: 2900 rpm; feeding screw speed: 6 rpm.

  • No water added during refining.

  • Plate gaps varied: 50–250 µm for reed without flowers; 100–300 µm for reed with flowers, in 50 µm increments.​

• Fibre Quality:

  • Finer fibres produced at smaller plate gaps; coarser fibres at larger gaps.

  • Fibre morphology similar to reference wood fibres achieved with plate gaps between 50–200 µm.​

• Comparison with SOPREMA:

  • SOPREMA's system maintains constant defibration energy (105 ± 10 kWh/t) by adjusting plate gaps.

  • FCBA's system operates with constant plate gaps, measuring defibration energy throughout the process.

Extrusion of Reed Fibres

• Equipment Used:

  • Planetary Roller Extruder (PRE) L-WE 30 by Entex at LUKE's facilities.

  • Features a central spindle with six planetary spindles rotating counterclockwise.

  • Barrel divided into six zones with adjustable screw configurations and temperatures.​

• Material Preparation:

  • Reed material ground to 1 mm particle size using a Cutting Mill Pulverisette.​

• Extrusion Parameters:

  • Untreated Reed (CR):

    • Side feeder screw speed: 150 rpm; main screw speed: 150 rpm.

    • Solid feeding speed: 140 rpm; solid feeding rate: 25.6 g/min.

    • Water feeding: 35 g/min; solid content of feed: 31.1%; total feed rate: 60.6 g/min.

  • Hot-Water Extracted Reed (HWE-CR):

    • Side feeder screw speed: 200 rpm; main screw speed: 150 rpm.

    • Solid feeding speed: 110 rpm; solid feeding rate: 17.7 g/min.

    • Water feeding: 35 g/min; solid content of feed: 24.1%; total feed rate: 52.7 g/min.

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