THERMOPULP - A NEW ENERGY-EFFICIENT MECHANICAL PULPING PROCESS

A new two-stage refiner mechanical pulping system, referred to as Ther mopulp, is presented, where the well-known reduction of energy to rupt ure in the wood structure at a temperature well above the softening po int of lignin has been utilized to reduce the energy in the production of mechanical pulp for printing grades. The energy consumption in mil l-scale refining to produce news quality pulp has been reduced by abou t 20% compared to the reference system, which consists of a two-stage double-disc TMP system, is already considered to be an energy efficien t System, producing TMP at 150 mL CSF at a specific energy consumption of 1650 kWh/t The quality of the pulp from the Thermopulp process is equivalent to that of the reference pulp with the exception of a small reduction in brightness and also tear index.