Bleaching methods and formulations for bleaching/delignification processes for chemical pulp are provided. The bleaching methods utilize peroxide and an organomanganese complex under aqueous caustic conditions, increasing bleaching efficiency of the overall bleaching/delignification process. Chemical pulp having increased brightness can be obtained at decreased temperatures and with reduced stage time, resulting in reduced chemical consumption and improved energy efficiency.

Disclosed are keratin fibre cellular components, specifically keratin fibre cuticle and cortical cells, and their use as absorption and filtration media, and in thermal insulation materials. The keratin fibre cellular components may be oxidised. The keratin fibre cellular components have improved absorbency and filtration capacity compared to the source keratin fibres. The keratin fibre cellular components may be used in, for example, various products for passive absorption and active filtration of gas or liquid media.

The present invention involves an environmentally friendly process and apparatus for the delignification of lignin-containing materials, such as cardboard newspaper or agricultural or tree pruning wastes. This process produces cellulose using low temperatures and low concentrations of hydrogen peroxide. It can be performed using a column fitted with a semipermeable gasket that pressurizes the column by retaining oxygen released by action of the hydrogen peroxide on a lignin-containing material.

A process to separate lignin from a lignocellulosic feedstock, said process comprising the steps of: providing said lignocellulosic feedstock; providing a composition comprising; an acid; a modifying agent selected from the group consisting of: sulfamic acid; imidazole; imidazole derivatives; taurine; a taurine derivative; a taurine-related compound; alkylsulfonic acid; arylsulfonic acid; triethanolamine; and combinations thereof; a peroxide salt; and a peroxide; exposing said lignocellulosic feedstock to said composition for a period of time sufficient to depolymerize substantially all of the lignin present in said lignocellulosic feedstock into lignin oligomers and lignin monomers;
wherein said process is carried out at atmospheric pressure.

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 modifying agent selected from the group consisting of: sulfamic acid; imidazole; N-alkylimidazole derivative; taurine; a taurine derivative; a taurine-related compound; alkylsulfonic acid; arylsulfonic acid; triethanolamine; and combinations thereof; a metal oxide; and a peroxide; adding an organic solvent to the resulting mixture; allowing a delignification reaction to occur for a period of time sufficient to remove at least 80% of the lignin present on said plant material.

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 capping agent; and a peroxide;
for a period of time sufficient to remove substantially all (at least 80%) of the lignin present on said plant material. Also disclosed are compositions to accomplish such delignification and processes using such.

An oxygen bleaching method of pulp includes the steps of: adding a solution formulated by a magnesium salt and an activator to an unbleached chemical pulp, stirring to be mixed well, and bleaching by introducing oxygen. The activators are nano zero-valent metals that are conventional, low-cost, and recyclable. These activators can activate low-concentration oxygen at low-temperature in neutral aqueous solution to efficiently generate peroxide anion radicals, so as to promote the generation of hydroperoxide anions and peroxide ions, achieving high efficient delignification. The whole process does not generate waste water, the oxygen consumption is only 50-85% of the original process, the yield is increased by 1.5-2.8% compared with the original system, the pulp brightness is increased to 28-32° SR, and the magnesium salt can be recycled and reused.

The present technology is directed to fluff pulps with improved odor control as well as methods of making such fluff pulps. A fluff pulp is provided that includes a bleached kraft fiber and a copper ion content from about 0.2 ppm to about 50 ppm by weight of the bleached kraft fiber. The bleached kraft fiber includes a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of more than about 3.5 meq/100 grams; an ISO brightness of at least 80; and a viscosity from about 2 cps to about 9 cps.

A method of producing high yield chemical cellulosic pulp includes: (a) chemically pulping wood chips to separate lignin and liberate cellulosic fibers from the wood chips to generate a cellulosic pulp; (b) washing and screening the pulp of step (a); (c) pre-treating the washed pulp with oxygen; (d) optionally washing the treated pulp of step (c); (e) bleaching the pre-treated pulp in an extended duration oxidative bleaching stage; (f) optionally washing the bleached pulp of step (e); and (g) optionally further oxidatively or reductively bleaching the bleached pulp in a shorter duration bleaching stage, wherein the bleached pulp is produced at a yield of greater than 60% based on the weight of the pulped wood chips (dry basis).

Bleached polyacrylic acid crosslinked cellulose fibers with reduced furfural content are disclosed. The reduced furfural content is accompanied by a strong reduction of malodor associated with crosslinked fibers. Methods of furfural reduction include treatment with hydrogen peroxide in the absence of alkaline or other bleaching agents subsequent to curing polyacrylic acid crosslinked cellulose fibers. Some embodiments of treated polyacrylic acid crosslinked cellulose fibers have a furfural content lower than 1.3 ppm. In some embodiments, the reduction of furfural content of the treated crosslinked fibers compared to untreated crosslinked fibers is at least 55%. in some embodiments, furfural content decreases with aging of the treated crosslinked fibers.