A method of producing chemical cellulose pulp from sawdust utilizing a static down-flow retention vessel comprising the steps of continuously pressurizing a flow of sawdust using a progressive cavity pump to produce a pressurized sawdust feed for a treatment vessel, passing the pressurized sawdust feed at super-atmospheric pressure downwardly in the treatment vessel, adding treatment white black liquor to the treatment vessel, and treating the pressurized sawdust feed in the treatment vessel with treatment white black liquor to form a treated sawdust, and discharging treated sawdust from the treatment vessel.

A method of producing chemical cellulose pulp from sawdust utilizing a static down-flow retention vessel comprising the steps of continuously pressurizing a flow of sawdust using a progressive cavity pump to produce a pressurized sawdust feed for a treatment vessel, passing the pressurized sawdust feed at super-atmospheric pressure downwardly in the treatment vessel, adding treatment white black liquor to the treatment vessel, and treating the pressurized sawdust feed in the treatment vessel with treatment white black liquor to form a treated sawdust, and discharging treated sawdust from the treatment vessel.

One embodiment provides an apparatus for cooking lignocellulosic material, comprising a pressurizable, inclined top separator including a sluicing liquor inlet for receiving a sluicing mixture comprising impregnated lignocellulosic material and sluicing liquor, a hot black liquor inlet, an excess liquor outlet, and an impregnated lignocellulosic material outlet; a continuous digester vessel including an impregnated lignocellulosic material inlet in communication with the impregnated lignocellulosic material outlet, and a warm black liquor outlet; and a black liquor circulation and heating loop including a warm black liquor inlet in communication with said warm black liquor outlet, a heater for heating warm black liquor to produce hot black liquor, and a hot black liquor outlet in communication with said hot black liquor inlet. Methods of making and using the apparatus are also provided.

One embodiment provides an apparatus for cooking lignocellulosic material, comprising a pressurizable, inclined top separator including a sluicing liquor inlet for receiving a sluicing mixture comprising impregnated lignocellulosic material and sluicing liquor, a hot black liquor inlet, an excess liquor outlet, and an impregnated lignocellulosic material outlet; a continuous digester vessel including an impregnated lignocellulosic material inlet in communication with the impregnated lignocellulosic material outlet, and a warm black liquor outlet; and a black liquor circulation and heating loop including a warm black liquor inlet in communication with said warm black liquor outlet, a heater for heating warm black liquor to produce hot black liquor, and a hot black liquor outlet in communication with said hot black liquor inlet. Methods of making and using the apparatus are also provided.

The method is for producing pulp in batch digesters. More particularly, the method is for ending a treatment phase of the digester content. In order to obtain a more uniform pulp quality from the process is the treatment phase ended by displacing a liquor volume (WLP) through the digester vessel with an imposed increasing temperature in the displacement liquor added to digester.

The method is for producing pulp in batch digesters. More particularly, the method is for ending a treatment phase of the digester content. In order to obtain a more uniform pulp quality from the process is the treatment phase ended by displacing a liquor volume (WLP) through the digester vessel with an imposed increasing temperature in the displacement liquor added to digester.

A method and system for pulp manufacturing used in connection with a kraft process includes a vertical pressure vessel operated in batch mode, a single-vessel or multi-vessel continuous digester, and other equipment for further processing brown stock, such as for washing, oxygen delignification, bleaching, and drying. A feeder and conveyance system may include a high pressure feeder or direct pump system, and selectively provides fiber-containing material to the continuous digester when making lower grade pulp product and to the vertical pressure vessel when making higher grade pulp such as dissolving pulp. The vertical pressure vessel is used for pre-hydrolysis and neutralization, after which the resulting pulp is fed to the continuous digester for cooking. White liquor and black liquor from the same mill may be used for the neutralization fluids. The same continuous digester is selectively used for cooking in connection with making pulp products of different grades or quality.

A method and system for pulp manufacturing used in connection with a kraft process includes a vertical pressure vessel operated in batch mode, a single-vessel or multi-vessel continuous digester, and other equipment for further processing brown stock, such as for washing, oxygen delignification, bleaching, and drying. A feeder and conveyance system may include a high pressure feeder or direct pump system, and selectively provides fiber-containing material to the continuous digester when making lower grade pulp product and to the vertical pressure vessel when making higher grade pulp such as dissolving pulp. The vertical pressure vessel is used for pre-hydrolysis and neutralization, after which the resulting pulp is fed to the continuous digester for cooking. White liquor and black liquor from the same mill may be used for the neutralization fluids. The same continuous digester is selectively used for cooking in connection with making pulp products of different grades or quality.

The present invention relates to a paper pulp preparation device comprising a wood component cooking unit and a hydrothermal liquefaction unit.

The invention also relates to the use of such a device in a method of treating the black liquor resulting from pulping and a method of preparing paper pulp from wood.

The present invention relates to a paper pulp preparation device comprising a wood component cooking unit and a hydrothermal liquefaction unit.

The invention also relates to the use of such a device in a method of treating the black liquor resulting from pulping and a method of preparing paper pulp from wood.