Abstract: A thermomechanical pulping method including: refining pulp with a high consistency refining stage, and a medium consistency refining stage processing the refined pulp discharge from the high consistency refining stage. Chemical pretreatments for improving pulp quality development during medium consistency refining can be optionally added at the pressurized chip press, fiberizer pre-refining step, primary high consistency refining step, and/or the standpipe feeding the medium consistency refiner.

Abstract: A mechanical pulping apparatus including: a pre-treatment defibration device receiving comminuted cellulosic material; a primary refiner receiving the comminuted cellulosic material discharged from the pre-treatment defibration device; a source of a biological agent; a first conduit from the source of the biological agent coupled to pre-treatment defibration device, wherein the first conduit delivers the biological agent to or immediately upstream of an inlet to the defibration device; a source of a chemical agent, and a second conduit from the source of the chemical agent coupled to primary refiner, wherein the second conduit delivers the chemical agent to the primary refiner.

Abstract: A mechanical pulping method including: defibrating a comminuted cellulosic material; mechanically refining the defibrated cellulosic material in a primary refining step; introducing to the cellulosic material at least one of a chemical agent and a biological during the defibration step or the mechanical refining step, and producing pulp from the refined and defibrated cellulosic material.

Abstract: A non-compression vessel, such as a digester, is employed for the chemical preconditioning of the chips followed by a fiberizing device to break the preconditioned chips down to fiber bundles, which are then washed before a high consistency chemical treatment. The digester may be one such as used in conventional chemical pulping of wood with or without screens for the extraction of chemical. If extracted this chemical could be recirculated to the digester with treatment in the circulation loop such as heating or the addition of dilution or other chemicals. This digester may be hydraulic or vapor phase (that is contain a vapor space within the digester), and operate in either a continuous or batch fashion. This digester allows for the discharge of material without the use of a screw mechanism. The digester treated material is then defiberized to convert the chips into course fiber bundles, which then is washed and dewatered.

Abstract: A thermomechanical pulping method including: refining pulp with a high consistency refining stage, and a medium consistency refining stage processing the refined pulp discharge from the high consistency refining stage. Chemical pretreatments for improving pulp quality development during medium consistency refining can be optionally added at the pressurized chip press, fiberizer pre-refining step, primary high consistency refining step, and/or the standpipe feeding the medium consistency refiner.

Abstract: A mechanical pulping method including: defibrating a comminuted cellulosic material; mechanically refining the defibrated cellulosic material in a primary refining step; introducing to the cellulosic material at least one of a chemical agent and a biological during the defibration step or the mechanical refining step, and producing pulp from the refined and defibrated cellulosic material.

Abstract: A non-compression vessel, such as a digester, is employed for the chemical preconditioning of the chips followed by a fiberizing device to break the preconditioned chips down to fiber bundles, which are then washed before a high consistency chemical treatment. The digester may be one such as used in conventional chemical pulping of wood with or without screens for the extraction of chemical. If extracted this chemical could be recirculated to the digester with treatment in the circulation loop such as heating or the addition of dilution or other chemicals. This digester may be hydraulic or vapor phase (that is contain a vapor space within the digester), and operate in either a continuous or batch fashion. This digester allows for the discharge of material without the use of a screw mechanism. The digester treated material is then defiberized to convert the chips into course fiber bundles, which then is washed and dewatered.