An object of the present invention is to provide a method for easily extracting and efficiently recovering xylan from wood.

A xylan-containing material is produced by a method comprising the steps of: (a) adding an acid and/or carbon dioxide to a black liquor discharged during a soda cooking step of wood chips including hardwood chips to adjust the pH of the black liquor to be in the range of 1 to 9, thereby giving a suspension; (b) dehydrating and washing an insoluble matter generated in the suspension to separately collect the insoluble matter; and (c) adding an organic solvent to the insoluble matter obtained at the step (b) to give a suspension, and separately collecting a xylan-containing material made of the insoluble matter present in the suspension by solid/liquid separation.

The present invention relates to the removal of hemicelluloses from paper-grade alkaline pulp thereby upgrading the pulp e.g. into dissolving-grade pulp using a combination of enzyme treatment, hot caustic extraction and optionally one or more bleaching steps.

A composition and method of preparing a composition is presented wherein the composition comprises cellulose platelets and the cellulose platelets comprise at least 60% cellulose by dry weight, less than 10% pectin by dry weight and at least 5% hemicellulose by dry weight. The composition can be concentrated to at least 25% by weight solids content by pressing under low pressure, whilst retaining the ability to be re suspended within an aqueous medium. The resulting aqueous medium obtains the desired properties of the composition, such as increased viscosity or increased dispersion of pigment particles, for example, to the same extent as the composition before pressing.

A composition and method of preparing a composition is presented wherein the composition comprises cellulose platelets and the cellulose platelets comprise at least 60% cellulose by dry weight, less than 10% pectin by dry weight and at least 5% hemicellulose by dry weight. The composition can be concentrated to at least 25% by weight solids content by pressing under low pressure, whilst retaining the ability to be re suspended within an aqueous medium. The resulting aqueous medium obtains the desired properties of the composition, such as increased viscosity or increased dispersion of pigment particles, for example, to the same extent as the composition before pressing.

A super strong and tough densified wood structure is formed by subjecting a cellulose-based natural wood material to a chemical treatment that partially removes lignin therefrom. The treated wood retains lumina of the natural wood, with cellulose nanofibers of cell walls being aligned. The treated wood is then pressed in a direction crossing the direction in which the lumina extend, such that the lumina collapse and any residual fluid within the wood is removed. As a result, the cell walls become entangled and hydrogen bonds are formed between adjacent cellulose nanofibers, thereby improving the strength and toughness of the wood among other mechanical properties. By further modifying, manipulating, or machining the densified wood, it can be adapted to various applications.

A method includes transferring at least one feed stream including calcium oxide calcium carbonate, water, and a fluidizing gas into a fluidized bed; contacting the calcium oxide with the water; based on contacting the calcium oxide with the water, initiating a hydrating reaction; producing, from the hydrating reaction, calcium hydroxide and heat; transferring a portion of the heat of the hydrating reaction to the calcium carbonate; and fluidizing the calcium oxide, calcium hydroxide, and the calcium carbonate into a first fluidization regime and a second fluidization regime. The first fluidization regime includes at least a portion of the calcium carbonate and at least a portion of the calcium oxide, and the second fluidization regime includes at least a portion of the calcium hydroxide and at least another portion of the calcium oxide. The first fluidization regime being different than the second fluidization regime.

A method includes transferring at least one feed stream including calcium oxide calcium carbonate, water, and a fluidizing gas into a fluidized bed; contacting the calcium oxide with the water; based on contacting the calcium oxide with the water, initiating a hydrating reaction; producing, from the hydrating reaction, calcium hydroxide and heat; transferring a portion of the heat of the hydrating reaction to the calcium carbonate; and fluidizing the calcium oxide, calcium hydroxide, and the calcium carbonate into a first fluidization regime and a second fluidization regime. The first fluidization regime includes at least a portion of the calcium carbonate and at least a portion of the calcium oxide, and the second fluidization regime includes at least a portion of the calcium hydroxide and at least another portion of the calcium oxide. The first fluidization regime being different than the second fluidization regime.

The present invention relates to a process for the production of treated pulp comprising the steps of: i. providing a fibre source material; ii. subjecting the fibre source material to pre-hydrolysis; iii. subjecting the pre-hydrolysed fibre source material to alkaline chemical pulping process, preferably kraft pulping, to obtain an alkaline pulp; iv. optionally adjusting the pH of the obtained pulp to above pH 9; v. subjecting the alkaline pulp to a bleaching sequence comprising contacting the pulp with ozone (Z) in alkaline conditions to obtain a treated pulp. The invention also relates to a treated pulp obtained, textile fibres produced from the treated pulp, textile products comprising the textile fibres and to the use of the treated pulp.

The present invention relates to a process for the production of treated pulp comprising the steps of: i. providing a fibre source material; ii. subjecting the fibre source material to pre-hydrolysis; iii. subjecting the pre-hydrolysed fibre source material to alkaline chemical pulping process, preferably kraft pulping, to obtain an alkaline pulp; iv. optionally adjusting the pH of the obtained pulp to above pH 9; v. subjecting the alkaline pulp to a bleaching sequence comprising contacting the pulp with ozone (Z) in alkaline conditions to obtain a treated pulp. The invention also relates to a treated pulp obtained, textile fibres produced from the treated pulp, textile products comprising the textile fibres and to the use of the treated pulp.

The invention relates to the chemical industry, namely to the production method of cellulose from all types of plant cellulose-containing raw material. The method includes raw material impregnation and hydrolysis in a hydrolysis solution, cellulose filtration, washing with water, filtration and drying, accompanied with the use of cycles that include heating of the material to a temperature of 115° C. or less, high-speed impulse action of vacuum with a pressure change in the range up to 5 mm Hg for a time of less than 10 seconds, followed by exposure under vacuum and vacuum relief.

Both solution of nitric or sulphuric acids, their mixture and alkaline solution can be used as hydrolysis solution.

Technical result of the claimed method consists in. reducing the duration of the cellulose hydrolysis process, reducing the temperature of the processes while obtaining the required chemical and structural homogeneity of the cellulose.