The present invention relates to a method for preparing fructose or xylulose from biomass comprising glucose or xylose, and a method for separating a mixture of glucose and fructose and a mixture of xylose and xylulose.

Disclosed herein are embodiments of a method for producing furfural from a hemicellulose source material. Also disclosed are embodiments of a system for carrying out the method. In particular embodiments, the method can be carried out without adding an extraneous mineral acid to facilitate pentose production from the hemicellulose source material and thus byproducts produced by the method can be used as animal feed.

A hardwood-derived carbohydrate composition is disclosed. The hardwood-derived carbohydrate composition comprises monomeric sugars in an amount of 50-80 weight-% based on the total dry matter content of the carbohydrate composition, wherein the monomeric sugars include monomeric glucose and monomeric xylose, the amount of monomeric xylose in the carbohydrate composition being 40-60 weight-% based on the total dry matter content of the carbohydrate composition, and the weight ratio of monomeric glucose to monomeric xylose being 0.067-0.2. Disclosed is also a method for producing a wood-derived carbohydrate composition.

This disclosure describes processes for using a single cellulosic feedstock or a combination of two or more different cellulosic feedstocks with a starch component to produce a fermented product. The process includes separating the components of the cellulosic feedstocks with fractionation, pretreating a component with wet fractionation with chemicals, hydrolysis and fermenta-tion of the pretreated feedstock(s) to produce cellulosic biofuel. The process may include combining the cellulosic feedstock(s) with other components to a cook and/or a fermentation process, distilling and dehydrating the combined components to produce the biofuel. The process may also include producing a whole stillage stream from the feedstock(s) and mechanically processing the whole stillage stream to produce a high-value protein animal feed.

A method of completely dissolving lignocellulosic biomass. The method includes the steps of dissolving a sample of biomass in an aqueous solution of strong acid and an amine-thiol to yield a first solution. A method for measuring lignin concentration in biomass via absorbance of the first solution at a wavelength of about 283 nm by comparing the measured absorbance to a standard curve of absorbance values made from solutions of known lignin concentration.

A homogeneous catalyst is provided comprising one or more metals; and at least two metal coordinating ligands wherein the homogeneous catalyst is a multi-ligand metal complex adapted for use with an oxidant in an oxidation reaction to catalytically pretreat lignocellulosic biomass. In one embodiment, the homogenous catalyst is copper (II) 2, 2′ bipyridine ethylenediamine (Cu(bpy)en). Related methods are also disclosed.

The invention relates to a process for the preparation of a fermentation product from lignocellulosic material, comprising the following steps: a) optionally, pre-treatment of the lignocellulosic material, b) optionally, washing of the optionally pretreated lignocellulosic material, c) enzymatic hydrolysis of the optionally washed and/or optionally pretreated lignocellulosic material using an enzyme composition comprising at least two cellulases and whereby the enzyme composition at least comprises LPMO, and optionally purifying the hydrolysed lignocellulosic material, d) fermentation of the hydrolysed lignocellulosic material to produce a fermentation product, and e) optionally, recovery of a fermentation product, wherein oxygen is consumed in amounts corresponding to between 20 and 5000 mmol molecular oxygen per kg glucan present in the lignocellulosic material, the oxygen is added after the pretreatment and before and/or during the enzymatic hydrolysis of the lignocellulosic material, preferably in an amount corresponding to at least 30 mmol molecular oxygen per kg glucan present in the lignocellulosic material, more preferably in an amount corresponding to at least 40 mmol molecular oxygen per kg glucan present in the lignocellulosic material, and most preferably in an amount corresponding to at least 50 mmol molecular oxygen per kg glucan present in the lignocellulosic material is consumed.

Lignocellulosic biomass can be fractionated for the purpose of increasing cellulose purity in the pulp, increasing native lignin content of the isolated lignin, and improving cellulose hydrolysis, by performing the steps of: (a) extracting the biomass with an extracting liquid comprising at least 20 wt % of a first organic solvent at a temperature below 100° C.; (b) treating the extracted biomass with a treatment liquid comprising a second organic solvent selected from lower alcohols, ethers and ketones, optionally water and optionally an acid, at a temperature between 120° C. and 280° C., and, optionally: (c) subjecting a cellulose-enriched product stream resulting from step (b) to enzymatic hydrolysis. The first and second organic solvent may be different or the same; in particular they comprise ethanol or acetone.

The present disclosure provides methods for generating sugars from a cellulosic biomass. The methods combine treatment of the biomass using a high-shear milling device and saccharification of the biomass to partially hydrolyze the biomass. The biomass can be saccharified either after or simultaneously with the high-shear milling treatement. The partially hydrolyzed biomass is then separated into a solids stream with saccharification enzymes, and a liquid stream with sugars. The solids stream and associated enzymes are further incubated under saccharification conditions to produce additional sugars, or are recycled and added to fresh biomass, which is saccharified under high-shear milling conditions. The methods result in improved conversion of cellulosic biomass to glucose.

A process for production of sugars from biomass derived from guayule plants includes placing a certain amount of the biomass in contact with a certain amount of water and with at least one organic acid. The sugars thus obtained may advantageously be used as sources of carbon in fermentation processes for the production of alcohols, lipids, diols, or in chemical synthesis processes for the production of other intermediates or chemicals.