Digestion of cellulosic biomass solids may be complicated by release of lignin therefrom. Methods and systems for processing a reaction product containing lignin-derived products, such as phenolics, can comprise hydrotreating the reaction product to convert the lignin-derived products to desired higher molecular weight compounds. The methods can further include separating the higher molecular weight compounds from unconverted products, such as unconverted phenolics, and recycling the unconverted phenolics for use as at least a portion of the digestion solvent and for further conversion to desired higher molecular weight compounds with additional hydrotreatment. The methods and systems can further include generating hydrogen with the further hydrotreatment.

The present invention relates to a process for lignin dissolution in which partial methylolation of lignin is carried out during the step of preparing a solution of lignin in an aqueous medium comprising alkali. The lignin prepared according to the process of the present invention can be used to manufacture lignin-based phenolic resins, which are particularly useful in the manufacture of laminates.

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.

The present invention relates to regulation of the p H of a liquefaction process. Presented is a method for treatment of a biomass feedstock wherein the biomass feedstock is subjected to liquefaction, at a p H of at most 4, by treatment with hot compressed liquid water (HCW) at subcritical and/or supercritical conditions to improve the conversion efficiency. The present invention is also directed to quenching of a liquefaction process according to above, preventing, minimizing or eliminating clogging and/or fouling of sticky biomass components in process equipment during processing as according to above, and to the use of additives in a biomass liquefaction process.

Described herein are processes for one-step delignification and hydrodeoxygenation of lignin fraction a biomass feedstock. The lignin feedstock is derived from by-products of paper production and biorefineries. Additionally described is a process for converting biomass-derived oxygenates to lower oxygen-content compounds and/or hydrocarbons in the liquid or vapor phase in a reactor system containing hydrogen and a catalyst comprised of a hydrogenation function and/or an oxophilic function and/or an acid function. Finally, also described herein is a process for converting biomass-derived oxygenates to lower oxygen-content compounds and/or hydrocarbons in the liquid or vapor phase in a reactor system containing hydrogen and a catalyst comprised of a hydrogenation function and/or an oxophilic function and/or an acid function.

Digestion of cellulosic biomass solids may be complicated by release of lignin therefrom. Methods and systems for processing a reaction product containing lignin-derived products, such as phenolics, can comprise hydrotreating the reaction product to convert the lignin-derived products to desired higher molecular weight compounds. The methods can further include separating the higher molecular weight compounds from unconverted products, such as unconverted phenolics, and recycling the unconverted phenolics for use as at least a portion of the digestion solvent and for further conversion to desired higher molecular weight compounds with additional hydrotreatment.

Lignin has a weight average molecular weight of at least 6,000 daltons and comprising (a) from 2% to 10% of a low molecular component having a weight average molecular weight (M.sub.w) of from 300 to 1500 daltons, and (b) from 10% to 50% of a high molecular weight component having a weight average molecular weight (M.sub.w) of at least 10,000 daltons; and exhibiting a T.sub.g of from 100° C. to 130° C. when measured by differential scanning calorimetry.

Provided is a method for producing a lignin degradation product that includes (1) a degradation step of degrading a raw material containing a plant biomass, in a mixed solvent of water and an aliphatic alcohol having from 4 to 10 carbon atoms, which separates into two phases at 0° C. or higher and 50° C. or lower, under the following conditions, and (2) after the degradation step, a liquid-liquid separation step of separating the lignin degradation product-containing organic phase from the solvent that has separated at the temperature for two-phase separation. The method produces a lignin degradation product at a high yield from lignin or a material containing lignin. Condition A: The concentration of the raw material to be in the mixed solvent is 1% by mass or more and 20% by mass or less. Condition B: The reaction temperature is 100° C. or higher and 350° C. or lower. Condition C: The reaction time is 0.1 hours or more and 10 hours or less.

A method for preparing dispersant using lignin degradation products includes preparation of lignin degradation products: degrading lignin which are used as raw materials using alkali through microwave-assisted activation at the presence of a metal oxide catalyst to obtain the lignin degradation products; and preparation of dispersant: preparing dispersant by molecularly reforming and chemically modifying the lignin degradation products obtained in the step of preparation of lignin degradation products.

The method is for separation of lignin from original black liquor (BL.sub.IN) that has a first precipitation phase (PR1/PR2) for precipitation of lignin by a first acidification using acidifier, CO.sub.2, at alkaline conditions, then separating a lignin cake with subsequent suspension of the lignin cake in a strong acid in order to leach out metals from the lignin followed by dewatering and obtaining a clean lignin product LP. Lignin germ particles (LG) are added to the original black liquor in the first precipitation stage, preferably between two phases in said precipitation stage, in order to increase lignin particle growth on such lignin germ particles instead of spontaneous nucleation of lignin particles in said original black liquor. This results in improved filterability in subsequent dewatering and lignin cake formation and hence an increased lignin yield.