RTS Pulping

RTS pulping is a thermo-mechanical pulping process performed at lower Retention time, higher Temperature, higher refiner Speed. Energy consumption is decreased by increasing the rotational speed of the primary refiner, leading to reduced residence time, smaller plate gaps, and higher refining intensity. Temperatures of about 165°C are used which results in a reduction in specific energy consumption without any loss in pulp quality and with brightness improvement. Reportedly, RTS pulp has slightly higher strength properties and comparable optical properties to TMP pulp (Kramer, et al., 2009. p. 99).

Development Status Products

RTS PulpingCosts & Benefits

Parent Process: Mechanical Pulping
Energy Savings Potential

A study estimates RTS pulp can be manufactured with about 15% lower specific energy requirements than pulp produced with conventional refining system. Another study reports specific energy of RTS pulping process 20% lower than Thermo-mechanical pulping. Increasing rotational speed on TMP refiners are estimated to reduce energy use between 15 to 30%, depending on plate type and refiner mode (Kramer et al., 2009. p.99).
Savings are estimated at 306 kWh/t-pulp (Martin et al., 2000. p. 24

CO2 Emission Reduction Potential

US flag Emission reduction potential is estimated at 128 kg CO2/t-pulp (Martin et al., 2000. p. 21)


US flag Implementation costs are estimated around $50/t-pulp (estimation from the year 2000) (Martin et al., 2000. p. 24)

For a typical mill with 1000 ton per day capacity, a reduction of 20% in motor power requirement translates into $5 million annual savings (Sabourin, 2006).

RTS Pulping Publications

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RTS Pulping Presentations