Abstract: Method of delignification of plant material, said method comprising: providing said plant material comprising cellulose fibres and lignin; exposing said plant material requiring to a composition comprising: an acid; a modifiying agent selected from the group consisting of: sulfamic acid; imidazole; N-alkylimidazole; taurine; a taurine derivative; a taurine-related compound; alkylsulfonic acid; arylsulfonic acid; triethanolamine; and combinations thereof; a metal oxide; and a peroxide; for a period of time sufficient to remove substantially all (at least 80%) of the lignin present on said plant material.

Abstract: A packed bed catalyst in a pressurized vessel/reactor during contact with a dioxide species precursor enhances catalytic conversion of the precursor to the dioxide species, compared with the same catalytic conversion performed in a non-pressurized vessel/reactor.

Abstract: A vacuum draw apparatus for preparing a fiber and/or particle web comprising a means for drawing a vacuum on a mass of fibers and/or particles, said vacuum draw means having an opening for applying a vacuum to said mass of fibers and/or particles, an access gate having a patterned opening located between the mass of fibers and/or particles and opening of said vacuum means, and means for moving said access gate, whereby the vacuum draw system will provide an oscillating pull on a mass of fibers and/or particles to work said mass to redistribute and/or further consolidate the fibers and/or particles.

Abstract: The pulper device for waste paper material comprises: a container (9) for collecting said waste, having an inlet opening (11) for said waste, at least one pressurized water nozzle (13; 15) which produces a jet of water which intercepts the waste which falls into said container, and a first pump (27) which removes the water and waste from said container.

Abstract: An Improved method of recovering and beneficially treating cellulosic fibers from compacted waste material containing waste paper before fibrillation by confining the waste material within a closed chamber containing a beneficially treating fluid and subjecting the contents of the closed chamber to one or more cycles of consecutive additions of beneficially treating fluid and removals of beneficially treating fluid.

Abstract: The invention relates to a method and arrangement for removing gas from a fibre/liquid suspension in a fibre treatment line in a pulp mill, which line includes at least one stage in which the fibre/liquid suspension is treated and/or stored in a large container (2) before being conveyed for further treatment. The fibre/liquid suspension is conveyed to the large container via a vessel (15) which with its lower part communicates with the large container and has a significantly smaller horizontal sectional area than the large container, but extends upwards above the level (4) of the fibre/liquid suspension in the large container, with gas being removed from the fibre/liquid suspension (19) in the area (18) of the upper part of the smaller vessel by means of the area being subjected to a subatmospheric pressure.

Abstract: Liquor removal from particulate solids such as wet wood pulp is achieved by applying a pneumatic or vapor pressure force through a pad of the wood pulp to compress the solids and to expel liquor from the solids. If air is used as a displacing medium, no wash liquor is added and the solids are simply compressed and some of the liquor is replaced by the gas passing through the suspension. If steam is used, not as a heating medium but as a pressure medium, an increase in liquor removal occurs over and above that removed by gas only due to the condensation of the steam to form a liquid front travelling before the steam through the solid suspension. Hence, in principle, a combination of pressure washing and displacement occurs resulting in a high efficiency in washing. Gas or steam could therefore simply be applied to any conventional operation to increase the washing efficiency both by compression and by displacement.

Abstract: A process for the production of a cellulose moulded body, particularly cellulose fibres, characterized by the combination of the measures offeeding a cellulose-containing material into an aqueous solution of a tertiary amine-oxide in order to suspend said cellulose-containing material,removing water from the suspension while intensively mixing it and providing elevated temperature and reduced pressure, until a solution of cellulose is produced andmoulding said solution by means of a moulding device, particularly a spinneret, and introducing it into a precipitation bath in order to precipitate the dissolved cellulose,provided that as said cellulose-containing material, basically shredded waste paper, shredded cellulose-containing fibre assemblies and/or shredded, mechanically and/or chemically broken up annual plants are used.

Abstract: An improved method of processing baled waste material containing waste paper having fibers contaminated to various degrees for recovering usable cellulosic fiber pulp from the bale in which the bale contents are impregnated with a fiber swelling and debonding fluid by enclosing the bale within a closed chamber and subjecting the chamber and contained bale to multiple pressure environmental conditions, that preferably includes a vacuum, while submerging the bale in the debonding fluid. The impregnated bale contents are allowed to soak for a sufficient period that the lesser degree contaminated fibers become swollen after which the bale is subjected to a sufficiently low degree of pulping agitation as initiates separation of the swollen fibers without significant damage to the fibers and which does not significantly decrease the sheet size of higher degree contaminated bonded fibers and other contaminants.

Abstract: A process for gas phase delignifying wood pulp comprising: contacting wood pulp in the first stage of pulp bleaching with chlorine dioxide-containing gas to delignify said wood pulp; wherein(a) said wood pulp has a consistency of at least about 15 percent;(b) said chlorine dioxide-containing gas contains less than about 3% by weight chlorine gas, based on the weight of chlorine dioxide in said gas; and(c) said contacting is conducted at a subatmospheric pressure from about 15 to about 750 mm Hg. This process reduces the formation of chloroform and significantly reduces the amounts of toxic by-products such as dioxin and other organic chlorides. These undesirable by-products, collectively identified as absorbable organic halides (AOX), require effluents from pulp bleaching processes to undergo expensive treatment methods to eliminate AOX's prior to discharges to sewers. The effluent discharge from this process generally has less than 2.0 kg adsorbed organic halides (AOX) per ton of wood pulp.

Abstract: The invention concerns a process for pretreatment of cellulosic chip-formed raw material by impregnation. In the process, first a vacuum treatment is carried out without preceding moistening treatment, and as soon as possible after the vacuum treatment penetration is carried out with a solution of chemicals or with water at the atmospheric or a higher solution pressure. In this way the fiber cavities can be filled optimally, which promotes a uniform and adequate diffusion of the solution into the fiber walls significantly. The process can be carried out, e.g., in a device which comprises a tank (11) for the treatment of the raw material and therein a feed opening (18) for the solution as well as an opening (14) for removal of the raw material, which said opening (14) communicates preferably with a reception tank, wherein the atmospheric or a higher pressure prevails.

Abstract: A method and apparatus for deaerating a suspension of solids in a liquid such as, for instance, papermaking stock. The suspension is flashed in a vacuum tank connected to a condenser. The vapor released when the suspension is flash cooled in the tank is condensed into an absorption liquid having a higher temperature but a lower vapor pressure than that of the released vapor on a heat exchange surface of the condenser. The flash cooled suspension is used as the cooling medium in the condenser. The diluted absorption liquid is regenerated in an evaporator and recirculated to the condenser. The vapor released in the evaporator can be condensed to heat the suspension further or for other suitable heating purposes.

Abstract: Oxygen delignification of paper pulp (comminuted cellulosic material in a slurry) at medium consistency (i.e., about 6-18%) is practiced without the necessity of a separate mixer. The pulp is drawn into the inlet of a fluidizing centrifugal pump capable of pumping medium consistency pulp. The pump typically has a vacuum system associated with it for effecting degassing of the pulp. As the pulp is pumped out of the pump outlet, oxygen gas is added to the pulp. This is accomplished utilizing a shear plate having a central opening and one or more radial bores, oxygen being introduced under pressure into the bores to pass into the pulp flowing through the plate central opening. A tube may be disposed in the bore(s) and have an oxygen permeable portion (such as a porous stone or sintered metal) extending into the central opening in the plate, the oxygen being introduced in the form of very small bubbles by the oxygen permeable portion.

Abstract: A method is described for increasing the brightness of reductively bleached high yield pulps, comprising bleaching the pulps with a reductive bleaching solution under anaerobic conditions and maintaining the bleached pulps under anaerobic conditions during all handling steps subsequent to bleaching, including paper formation, wet pressing, and drying of the paper formed therefrom. The bleached paper has higher brightness than the same paper produced under aerobic conditions, and the bleaching and handling-derived portion of this higher brightness is retained after storage of the finished paper.

Abstract: The invention relates to a process comprising the saturation of a lignocellulosic or cellulosic pulp in gaseous ammonia. In one embodiment this is followed by subjection of the saturated pulp to vacuum. The treatment promotes the kinking of pulp fibres and/or improves the tearing strength of paper prepared therefrom.

Abstract: Particulate lignocellulosic material, having a moisture content of about 10-80 weight percent, is treated at temperatures below about 50.degree. C. with 2 to 8 weight percent nitric oxide based on the weight of dry lignocellulosic material. Thereafter, said nitric oxide treated material is reacted with molecular oxygen to form nitric acid in situ. This reaction is followed by washing of said material with alkali and extraction of said material with alkali at a temperature above about 140.degree. C. to delignify the lignocellulose and form pulp.

Abstract: A slurry of cellulosic material is diluted to a flowable consistency and subjected to a pressure differential on a permeable surface to increase the slurry consistency to a value between the consistency of the diluted slurry and the consistency of the slurry prior to dilution thereby forming a mat of cellulosic material on the permeable surface. The liquid and solids which pass through the permeable surface as a result of the pressure differential are recycled for use as slurry diluent, and to the mat of cellulosic material, while the mat remains on the permeable surface and subject to the pressure differential, is countercurrently applied, in a plurality of treatment stages, a treating liquid, such as a wash liquid, including application of a fresh treating liquid to said mat in the last stage of said treatment stages, whereby the treating liquid displaces at least a portion of liquid present in said mat from said mat and through the permeable surface in each treatment stage.

Abstract: A slurry of cellulosic material is diluted to a flowable consistency and subjected to a pressure differential on a permeable surface to increase the slurry consistency to a value between the consistency of the diluted slurry and the consistency of th slurry prior to dilution thereby forming a mat of cellulosic material on the permeable surface. The liquid and solids which pass through the permeable surface as a result of the pressure differential are recycled for use as slurry diluent, and to the mat of cellulosic material is applied a treating liquid, such as a washing liquid.