A method and apparatus for controlling a cellulosic pulp process for producing a pulp product having a desired pulp property is disclosed. The method involves illuminating an in-process portion of pulp using a first wavelength of light, and receiving a scattered light spectrum from the illuminated portion of pulp, the scattered light spectrum including spectral components that have been shifted in wavelength through interaction with a constituent of the illuminated portion of pulp. The method also involves filtering the scattered light spectrum to separate the spectral components, and identifying spectral features in the filtered scattered light spectrum that correspond to the pulp property. The method further involves generating a control signal for controlling the pulp process based on variations in the identified spectral features to cause the pulp property to fall within a desired range.

A cooking method and a digester system wherein partly digested cellulosic fiber source is compressed during cooking to provide high molecular weight lignin and pulp.

A cooking method and a digester system wherein partly digested cellulosic fiber source is compressed during cooking to provide high molecular weight lignin and pulp.

A method is disclosed for optimization of continuous digestion process. Exemplary embodiments can control a delignification process in a continuous pulp digester in an optimal way for different pulp grades taking into account process disturbances and model uncertainties. This can be achieved by customizing a generic mathematical model for a continuous digestion process which runs through a software application on a dedicated electronic device. The model can be updated periodically based on on-line information, and used with a plant optimization component involving multi-objective optimization to evaluate optimal set points for the controllers. A system is also disclosed for optimizing control of a continuous pulp digester.

A method is disclosed for optimization of continuous digestion process. Exemplary embodiments can control a delignification process in a continuous pulp digester in an optimal way for different pulp grades taking into account process disturbances and model uncertainties. This can be achieved by customizing a generic mathematical model for a continuous digestion process which runs through a software application on a dedicated electronic device. The model can be updated periodically based on on-line information, and used with a plant optimization component involving multi-objective optimization to evaluate optimal set points for the controllers. A system is also disclosed for optimizing control of a continuous pulp digester.

The invention relates to a method and an impregnation vessel where the bulk volume of impregnation liquor added is in form of hot black liquor having a residual alkali content. Hot black liquor is added in an upper central pipe supplying the hot black liquor as impregnation liquor and flashing off steam for driving off air from the comminute cellulose material. During this first steaming is the wood acidity released from the material and spent impregnation liquor with wood acidity content is withdrawn from an upper withdrawal screen to recovery, a lower withdrawal screen recirculates the remaining impregnation liquor to a second lower central pipe in order to equalize the alkali content well before the remaining retention time in the impregnation vessel. According to the invention is additional alkali added to the hot black liquor and the recirculated impregnation liquor respectively dependent on established alkali level in the liquor withdrawn from the upper withdrawal screen and the alkali level established below the lower withdrawal screen.

A method for continuously treating biomass material includes: feeding the biomass material into a substantially vertically arranged pressurized vessel; adding steam to said pressurized vessel for hydrothermal treatment of the biomass material, wherein said adding steam comprises adding steam at a lower portion of the pressurized vessel; discharging the biomass material from a bottom portion of the pressurized vessel using a discharge device; withdrawing vapor from a top portion of the pressurized vessel, and adding said vapor to the discharge device; controlling differential pressure between said top portion of the pressurized vessel and said discharge device by controlling a flow of said vapor; and determining a minimum flow of steam needed to heat the biomass material in the pressurized vessel to a predetermined temperature, wherein said adding steam comprises adding steam at a flow that is higher than said minimum flow.

A method for continuously treating biomass material includes: feeding the biomass material into a substantially vertically arranged pressurized vessel; adding steam to said pressurized vessel for hydrothermal treatment of the biomass material, wherein said adding steam comprises adding steam at a lower portion of the pressurized vessel; discharging the biomass material from a bottom portion of the pressurized vessel using a discharge device; withdrawing vapor from a top portion of the pressurized vessel, and adding said vapor to the discharge device; controlling differential pressure between said top portion of the pressurized vessel and said discharge device by controlling a flow of said vapor; and determining a minimum flow of steam needed to heat the biomass material in the pressurized vessel to a predetermined temperature, wherein said adding steam comprises adding steam at a flow that is higher than said minimum flow.

An arrangement for installations of monitoring sensors of a vessel for treatment of lignocellulosic material, which vessel (1) has a central pipe (2) including at least one concentric pipe (3), mounted coaxially within the vessel (1). At least one sensor channel (4) is arranged along the outermost wall of the concentric pipe (3) of the central pipe (2) and that the at least one sensor channel (4) is connected to a cable conduit (5), which cable conduit (5) connects the exterior of the vessel (1) to the at least one sensor channel (4)) and the sensor channel (4) is several meters long and has plurality of holders (13) for sensors (11) and/or is configured to contain plurality of thermal sensors (11) with their cables (8).

An arrangement for installations of monitoring sensors of a vessel for treatment of lignocellulosic material, which vessel (1) has a central pipe (2) including at least one concentric pipe (3), mounted coaxially within the vessel (1). At least one sensor channel (4) is arranged along the outermost wall of the concentric pipe (3) of the central pipe (2) and that the at least one sensor channel (4) is connected to a cable conduit (5), which cable conduit (5) connects the exterior of the vessel (1) to the at least one sensor channel (4)) and the sensor channel (4) is several meters long and has plurality of holders (13) for sensors (11) and/or is configured to contain plurality of thermal sensors (11) with their cables (8).