The invention relates to processes of producing sugars and/or fermentation products from pretreated cellulosic material comprising the steps of: preconditioning pretreated cellulosic material; hydrolyzing using a cellulolytic enzyme preparation; and fermenting sugars with a microorganism; wherein a solid-liquid separation step, resulting in a solid fraction and a liquid fraction, is carried out: after preconditioning, but before hydrolysis; or after hydrolysis, but before fermentation; wherein phenol oxidizing enzyme and hemicellulase are present or added during preconditioning; after preconditioning, but before hydrolysis; or during hydrolysis.

This specification describes a process of producing a monomeric sugar stream ligno-cellulosic biomass without enzymes or acid catalysts. This is accomplished by removing the water soluble C5 sugars from the ligno-cellulosic biomass feedstream, lowering the pH of the C5 solution with little or no addition of an acid, thermally treating the remaining ligno-cellulosic biomass, combining the thermally treated ligno-cellulosic biomass with the low pH C5 solution and then exposing the mixture to an elevated temperature greater than 80° C. for a time sufficient to hydrolyze at least some of the components of the ligno-cellulosic biomass. Preferably, the thermally treated ligno-cellulosic biomass is subjected to a fiber shives reduction step to reduce the amount of long fiber shives.

Provided are methods and compositions using activated carbon for optimizing purification and clarification of sugar streams produced from cellulosic or lignocellulosic biomass. Also provided are methods and compositions for decreasing one or more undesirable products during pretreatment.

A method produces a sugar liquid from a cellulosic biomass material, which sugar liquid has improved fermentability. The method produces a sugar liquid by: adding an alkali(s) to a concentrated cellulosic biomass sugar liquid to adjust the pH to not less than 7 to precipitate an insoluble substance(s) containing at least magnesium; and performing filtration through a microfiltration membrane to remove the insoluble substance(s), to obtain a sugar liquid as a permeate.

The invention relates to a method of processing lignocellulosic biomass comprising: providing lignocellulosic biomass feedstock; pretreating said biomass feedstock by continuous hydrothermal pretreatment in a pressurized reactor; measuring xylan number or lignin number in the output stream of pretreated biomass from the pretreatment reactor; and controlling the pretreatment reactor so as to maintain, in the output stream of pretreated biomass, a pre-determined level of measured xylan number or lignin number. The method allows for continuously controlling the digestibility of a lignocellulosic biomass during the step of pretreatment, and accordingly provides a continuous estimate of the severity of the pretreatment.

Related to are a device and a method for performing continuous carbonation and impurity removal for xylose mother liquor. The device includes an alkali addition unit, a continuous carbonating unit, a discharge controlling unit, a CO.sub.2 supply station, a vapor station and an after-carbonation tank, wherein the alkali addition unit is configured to add Ca(OH).sub.2 alkaline liquid into xylose mother liquor, the continuous carbonating unit is configured to introduce CO.sub.2 supplied from the CO.sub.2 supply station into the alkali-added xylose mother liquor to perform carbonation and mixing so as to remove impurities such as colloid and pigment in xylose mother liquor, the discharge controlling unit is configured to introduce CO.sub.2 supplied from the CO.sub.2 supply station and vapor transported from the vapor station into the carbonated xylose mother liquor so as to control and stabilize a pH value of the carbonated xylose mother liquor, and the after-carbonation tank is configured to collect and temporarily store the carbonated and impurity-removed xylose mother liquor so as to prepare for a next procedure. Further, a method using the device is disclosed. According to the device and the method, the pH of xylose mother liquor is continuously regulated and stabilized and continuous feeding and discharge are performed with highly automated device so as to achieve continuous and uninterrupted production, and thus facilitate improving the production efficiency.

A process for obtaining aqueous hydrolysates from solid material containing hemicellulose, cellulose and lignin, which process comprises hydrolysing at least part of the hemicellulose of the solid material with a first aqueous hydrochloric acid solution at a concentration of 15-40 wt %, yielding a remaining solid material and an aqueous first hydrolysate product solution. The aqueous first hydrolysate is displaced from the remaining solid material with a non-aqueous displacement fluid. Thereafter, at least part of the cellulose of the remaining solid material is hydrolysed with a second aqueous hydrochloric acid solution at a concentration of 40-51 wt %, yielding a residue and an aqueous second hydrolysate product solution.

In one aspect, the present invention provides methods for preparing a fermentation product. The methods include pre-treating a mixture of biomass and ionic liquid, wherein the ionic liquid comprises a choline cation and the biomass comprises polysaccharide and lignin. The methods further include forming hydrolysates from the introduction of glycoside hydrolase to the pre-treated mixture at conditions sufficient to produce a sugar composition mixture for fermentation steps. The present invention provides methods for loading biomass mixtures in a batch-fed process, wherein the biomass slurries can be loaded into water or a concentrated sugar composition for hydrolysate production. The methods can be performed in a one-pot process, wherein the ionic liquids are present in the mixtures throughout each step. Aspects of the invention provide compositions of sugar composition mixtures and fermentation product mixtures.

A wood-derived carbohydrate composition is disclosed. The wood-derived carbohydrate composition comprises monomeric C6 sugars and monomeric C5 sugars in a total amount of at least 80 weight-% based on the total dry matter content of the carbohydrate composition. The ratio of the monomeric C5 sugars to the monomeric C6 sugars is at most 0.15. Disclosed is also a method for producing a wood-derived carbohydrate composition.

The invention relates to a process for the preparation of a sugar and/or fermentation product from lignocellulosic material.