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 process includes pretreating the biomass with a first basic solution such as sodium hydroxide and mechanically altering the fibers to provide a fluidized biomass. The fluidized biomass is then subjected to high frequency pulses and shear forces without denaturing the individual components of the biomass. The biomass is then subjected to compressive force to separate a first liquid fraction from a first fractionated biomass. The first fractionated biomass may again then be subjected to the same high frequency pulses and shear forces as previously, particularly if there are hemicellulose and/or sugars still present in the first fractionated biomass. Compressive forces are used to separate a second liquid fraction from a second fractionated biomass. The second fractionated biomass is subjected to oxidation such as with hydrogen peroxide at a pH of 8 to 12. The second fractioned biomass is then subjected to compressive forces to separate one or more water insoluble components of the biomass in water soluble form.

The process includes pretreating the biomass with a first basic solution such as sodium hydroxide and mechanically altering the fibers to provide a fluidized biomass. The fluidized biomass is then subjected to high frequency pulses and shear forces without denaturing the individual components of the biomass. The biomass is then subjected to compressive force to separate a first liquid fraction from a first fractionated biomass. The first fractionated biomass may again then be subjected to the same high frequency pulses and shear forces as previously, particularly if there are hemicellulose and/or sugars still present in the first fractionated biomass. Compressive forces are used to separate a second liquid fraction from a second fractionated biomass. The second fractioned biomass is then subjected to compressive forces to provide lignin in water soluble form.

Methods and systems of the present invention use mixed textile feedstock, which may include post-consumer waste garments, scrap fabric and/or other textile materials as a raw feed material to produce isolated cellulose and other isolated molecules having desirable properties that can be used and be used in the textile and apparel industries, and in other industries. A multi-stage process is provided, in which mixed textile feed material is subjected to one or more pretreatment stages, followed by at least two pulping treatments for isolating cellulose molecules and other molecular constituents, such as polyester. The isolated cellulose and polyester molecules may be used in a variety of downstream applications. In one application, isolated cellulose and polyester molecules are extruded to provide regenerated cellulose fibers and regenerated polyester fibers having desirable (and selectable) properties that are usable in various industrial applications, including textile production.

Methods and systems of the present invention use mixed textile feedstock, which may include post-consumer waste garments, scrap fabric and/or other textile materials as a raw feed material to produce isolated cellulose and other isolated molecules having desirable properties that can be used and be used in the textile and apparel industries, and in other industries. A multi-stage process is provided, in which mixed textile feed material is subjected to one or more pretreatment stages, followed by at least two pulping treatments for isolating cellulose molecules and other molecular constituents, such as polyester. The isolated cellulose and polyester molecules may be used in a variety of downstream applications. In one application, isolated cellulose and polyester molecules are extruded to provide regenerated cellulose fibers and regenerated polyester fibers having desirable (and selectable) properties that are usable in various industrial applications, including textile production.

In a process for oxidation of white liquor, in particular of white liquor used in a process of production of paper or cellulose, the oxygen required for the oxidation is supplied to the reactor or the reactors in which the oxidation is carried out at least partially in the form of oxygen-containing nanobubbles. Due to the relatively long lifetime of the nanobubbles this very efficiently provides oxygen also for oxidation reactions in the white liquor proceeding at different rates.

Described is a method of kraft pulping in which a phenolic compound is added to the cooking step. The phenolic compound is added at a time point between about 5 minutes and about 120 minutes prior to completion of the cooking step. The presence of the phenolic compound increases the extent of delignification in the cooking step.

An aqueous composition comprising: sulfuric acid; an alkanesulfonic acid; and a peroxide. Said composition being capable of delignifying biomass under milder conditions than conditions under which kraft pulping takes place.

An aqueous composition comprising: sulfuric acid; a substituted aromatic compound; and a peroxide. Said composition being capable of delignifying biomass under milder conditions than conditions under which kraft pulping takes place.

An aqueous composition comprising: sulfuric acid; a heterocyclic compound; an alkanesulfonic acid; and a peroxide. Said composition being capable of delignifying biomass under milder conditions than conditions under which kraft pulping takes place.