The invention herein disclosed and claimed is a process for refining fiber from lignocellulosic biomass. The process provides refined fiber and agriculturally amenable co-products, with a virtually waste-free systems design.

Provided are cost-effective methods and systems for producing a low molecular weight reactive lignin from a lignocellulosic biomass. The process is rapid and the reactive lignin is easily separated from carbohydrates and other components of the biomass at low cost. This clean lignin product has a very low molecular weight, good hydroxyl content, and low ash and sulfur, making it valuable to many applications.

Provided are cost-effective methods and systems for producing a low molecular weight reactive lignin from a lignocellulosic biomass. The process is rapid and the reactive lignin is easily separated from carbohydrates and other components of the biomass at low cost. This clean lignin product has a very low molecular weight, good hydroxyl content, and low ash and sulfur, making it valuable to many applications.

Methods and systems for preparing non-wood agricultural feedstock material for use as a pulp, and making a paper product therefrom. The method includes providing non-wood agricultural feedstock material (e.g., corn stover) that includes agricultural fibers, chemically pulping the agricultural fibers at a low temperature of less than 100° C., refining the agricultural fibers (either before or after cooking), and introducing the produced agricultural fiber pulp into a papermaking machine to make liner, medium, tissue, towel, cardstock or other paper product (e.g., tubes, cores, chipboard, grayboard, or other rigid container board). The agricultural pulp fibers can also be introduced into a molded pulp products manufacturing machine, to make egg cartons, molded paper plates, molded single use packaging, or the like.

Methods and systems for preparing non-wood agricultural feedstock material for use as a pulp, and making a paper product therefrom. The method includes providing non-wood agricultural feedstock material (e.g., corn stover) that includes agricultural fibers, chemically pulping the agricultural fibers at a low temperature of less than 100° C., refining the agricultural fibers (either before or after cooking), and introducing the produced agricultural fiber pulp into a papermaking machine to make liner, medium, tissue, towel, cardstock or other paper product (e.g., tubes, cores, chipboard, grayboard, or other rigid container board). The agricultural pulp fibers can also be introduced into a molded pulp products manufacturing machine, to make egg cartons, molded paper plates, molded single use packaging, or the like.

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 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 digestion accelerator which is safe and has a high digestion acceleration effect is provided. The digestion accelerator according to the present invention contains tannin or a polyphenol compound that is a hydrolysate of the tannin, a salt of the polyphenol compound, or ester of the polyphenol compound.