Abstract: Method for extraction of biomass with water in order to separate hemicelluloses from a fibrous structure. The biomass is impregnated under reduced pressure with the extraction fluid in order to prevent the degradation of the components to be extracted. During extraction the extract is circulated through the fiber matrix in order to remove unwanted components from the extract. The extract is reused for extracting untreated biomass in order to increase the consistency of the extract.

Abstract: This invention describes a method for the purification of a hemicellulose extract produced for example through hot water extraction. Such extracts often contain large amounts of colloidal material which primarily consists of lignin and other phenolic compounds. These colloidal particles clog equipment such as ultrafiltration membranes, which deem the use of such equipment almost impossible. The unwanted material is very tacky at temperatures between 70 and 120° C. which makes it possible to adsorb it onto a variety of materials. Further, by using an adsorbing material that is wholly or partly contaminated with chemically alike material the purification process is greatly enhanced.

Abstract: Increasing of the heating value of combustible biomass through hemicellulose extraction and subsequent press-drying is described. After hemicellulose extraction the remaining biomass is soft and easily press-dried to high dry content of up to 80%. The method involves the removal of most water binding hemicelluloses and retaining most of the lignin in the biomass. Lignin can either be retained in the biomass during the extraction or combining the lignin, which has been separated from the hemicellulose extract, with the extracted biomass.

Abstract: Method for extraction of biomass with water in order to separate hemicelluloses from a fibrous structure. The biomass is impregnated under reduced pressure with the extraction fluid in order to prevent the degradation of the components to be extracted. During extraction the extract is circulated through the fiber matrix in order to remove unwanted components from the extract. The extract is reused for extracting untreated biomass in order to increase the consistency of the extract.

Abstract: The invention relates to a method for removing lignin from lignocellulosic biomass. The method comprises feeding of lignocellulosic biomass and a first aqueous solution into a reactor vessel, the lignocellulosic biomass and the first aqueous solution forming a reaction mixture; reducing the pressure in the reactor vessel below 0.8 bar absolute pressure, preferably 0.5 bar absolute pressure, more preferably below 0.2 bar absolute pressure; keeping the reaction mixture in a predetermined extraction temperature, and adding at least one extraction chemical, such as base or acid, to the reaction vessel and extracting lignin from the biomass to the liquid phase of the reaction mixture.