The present invention relates to a process for obtaining cellulose or a mixture containing at least cellulose and at least lignocellulose from at least one substrate that is at least to some extent amenable to fermentation comprising at least the steps of (1) to (3) and optionally (4), namely conversion of the substrate via addition of at least one inorganic base into an aqueous mixture with pH≥8.5 (step 1), ultrasound treatment of the aqueous mixture obtained after step (1) (step 2), separation of the aqueous mixture obtained after step (2) into a liquid aqueous phase and a disperse mixture containing, cellulose or a mixture containing at least cellulose and at least lignocellulose (step 3) and optionally purification of the disperse mixture obtained after step (3) containing cellulose or of the mixture containing at least cellulose and at least lignocellulose (step 4), where step (1) and step (2) of the process respectively are carried out at a temperature <100° C. and Where the ultrasound treatment in step (2) takes place in one or more treatment phases, where the duration of a treatment phase is in the range from 0.2 to 60 seconds and each treatment phase is carried out with a sonotrode frequency in the range from 14 to 22 kHz.

The present invention relates to a process for obtaining cellulose or a mixture containing at least cellulose and at least lignocellulose from at least one substrate that is at least to some extent amenable to fermentation comprising at least the steps of (1) to (3) and optionally (4), namely conversion of the substrate via addition of at least one inorganic base into an aqueous mixture with pH≥8.5 (step 1), ultrasound treatment of the aqueous mixture obtained after step (1) (step 2), separation of the aqueous mixture obtained after step (2) into a liquid aqueous phase and a disperse mixture containing, cellulose or a mixture containing at least cellulose and at least lignocellulose (step 3) and optionally purification of the disperse mixture obtained after step (3) containing cellulose or of the mixture containing at least cellulose and at least lignocellulose (step 4), where step (1) and step (2) of the process respectively are carried out at a temperature <100° C. and Where the ultrasound treatment in step (2) takes place in one or more treatment phases, where the duration of a treatment phase is in the range from 0.2 to 60 seconds and each treatment phase is carried out with a sonotrode frequency in the range from 14 to 22 kHz.

A method of producing chemical pulp including at least the following steps: a) wood chips or other comminuted ligno-cellulosic fibrous material is treated with a polysulfide-containing cooking liquor in an impregnation stage at a temperature of 90-145° C., and b) slurry of fibrous material from step a) is heated into cooking temperature and cooked for producing pulp having a desired kappa number. After step a) mercaptide ions are added into the slurry of fibrous material and the fibrous material is treated at cooking temperature in step b).

A system for treatment of a biomass material, said system comprising: a first vessel (3) in which said biomass material is treated under a first pressure; a second vessel (5) in which said biomass material is received and held at a second pressure which is lower than the first pressure; a transporting pipe (7) connecting an outlet (9) of the first vessel (3) with an inlet (11) of the second vessel (5) for transporting the biomass material from the first vessel to the second vessel; and a valve (15; 15′; 15) arranged in said transporting pipe (7), said valve being configured for controlling the flow of biomass material and fluid in the transporting pipe (7), wherein said transporting pipe (7) is asymmetrically connected to an outlet (33′; 33) of said valve (15; 15′; 15) such that a generated jet stream of biomass material delivered out from the outlet (33′; 33) of the valve (15; 15′; 15) is received closer to a transporting pipe longitudinal central axis (A1) than if the outlet (33′; 33) of the valve (15; 15′; 15) and the transporting pipe (7) would have been connected symmetrically.

The invention relates to an improved profile bar screen for draining treatment liquor from a suspension of comminuted cellulose material and treatment liquor in an essentially cylindrical digester vessel. According to the invention is a profile bar screen designed with horizontal support arches 11 with integrated support shoulders 12 only at the outer ends of the support arch which support shoulders rest against the inside of the vessel wall 1. The invention combines the techniques from self-supporting screens with support members of weaker screen designs, avoiding need to make any additional welds in the classified pressure vessel wall of the digester. Installation of new screens in compartments previously equipped with blind plates in checkered screen rows may be done quickly and at less costs during shorter down time of digester.

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.

The multi-stage modular horizontal digester is primarily comprised of a single auger in a horizontal orientation. The single auger includes sections of lesser and greater inner diameter, thus creating sections of that allow for mixing and time to operate on the contents, and sections where the liquids are squeezed out. As compared to the known processing methodology, the multi-stage modular horizontal digester creates numerous benefits. For example, by maintaining elevation of the pulp, it can be directly expelled into the hydrapulper without the need for an additional pump. Processes can be changed quickly by altering the rotation speed, auger sections, or chemical inputs and outputs without the need to move heavy tanks or adjust pumps. In other words, there is no need for the standard cascade-style system where the pulp descends through a step, is raised to the next step, and so forth.

A system for treatment of a biomass material, said system comprising: a first vessel (3) in which said biomass material is treated under a first pressure; a second vessel (5) in which said biomass material is received and held at a second pressure which is lower than the first pressure; a transporting pipe (7) connecting an outlet (9) of the first vessel (3) with an inlet (11) of the second vessel (5) for transporting the biomass material from the first vessel to the second vessel; and a valve (15; 15′; 15) arranged in said transporting pipe (7), said valve being configured for controlling the flow of biomass material and fluid in the transporting pipe (7), wherein said transporting pipe (7) is asymmetrically connected to an outlet (33′; 33) of said valve (15; 15′; 15) such that a generated jet stream of biomass material delivered out from the outlet (33′; 33) of the valve (15; 15′; 15) is received closer to a transporting pipe longitudinal central axis (A1) than if the outlet (33′; 33) of the valve (15; 15′; 15) and the transporting pipe (7) would have been connected symmetrically.

A pulp-digester screen cleaner having a pneumatic actuator with a cylinder and a rod coaxially disposed within the cylinder. An actuator mounting plate is used to mount the actuator outside of a pulp-digester screen housing pipe. A rod seal has a body disposed on the pipe that prevents any loss of fluid or pressure, yet allows the rod to pass into the pipe. The cylinder contains all of the mechanics of the pneumatic actuator and can be easily serviced without draining the digester. The rod is disposed through a first aperture of each of a pair of scrapers. A treated edge of each of the pair of scrapers varies to match different digester screen types and patterns. The present pulp-digester screen cleaner eliminates the need for chemical cleaning or other mechanical cleaning solutions. It will also improve pulp quality, increase pulp production, and promote overall digester efficiency.