NOVELTY - Continuous treatment of biomass comprises: contacting the biomass with a first supercritical, near-critical or sub-critical fluid to form a solid matrix (109) and a first liquid fraction, in a pretreatment step; and contacting the solid matrix with a second supercritical or near-supercritical fluid to produce a second liquid fraction and insoluble lignin-containing fraction, in a hydrolysis step. The first supercritical, near-critical or sub-critical fluid, and second supercritical or near-critical fluid: comprise water and optionally carbon dioxide; and are free of 1-5C alcohols.    USE - The methods are useful for: continuous treatment of biomass; increasing the level of xylose produced from biomass; and increasing the level of glucose produced from lignocellulosic biomass (all claimed).    ADVANTAGE - The method converts biomass from renewable resources and/or waste materials to more valuable products.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) method (I) of increasing the level of xylose produced from biomass comprising: fractionating the biomass to form (a) a solid fraction comprising cellulose and insoluble lignin, and (b) a first liquid fraction at first temperature and at first pressure comprising soluble 5C saccharide comprising xylo-oligosaccharides and/or xylose; separating the solid fraction from the first liquid fraction at second pressure, where the first pressure and second pressure are same; adding an aqueous acid to the first liquid fraction to increase the level of the soluble 5C saccharide in the liquid fraction to form a second liquid fraction at a second temperature; and optionally, hydrolyzing the second liquid fraction to form xylose;    (2) a product produced by the method (I);    (3) a method (II) of increasing the level of glucose produced from lignocellulosic biomass (102) comprising: providing fractionated biomass comprising (c) a first solid fraction comprising cellulose and insoluble lignin, and (d) a first liquid fraction; mixing the solid fraction with water to form a slurry; pre-heating the slurry to a temperature less than critical point of water; contacting the slurry with a second reaction fluid to form a second solid fraction comprising insoluble lignin, and a second liquid fraction comprising a saccharide containing cello-oligosaccharides and/or glucose, where the second reaction fluid comprises water and optionally carbon dioxide, and the second reaction fluid has temperature and pressure above the critical point of water and of carbon dioxide; and reducing the temperature of the reaction mixture to a temperature below the critical point of water; and optionally, hydrolyzing the second liquid fraction to form glucose;    (4) a composition comprising: glucose (at least 63 wt.%); water; glycolaldehyde (less than 13 wt.%); and glycolic acid (less than 2 wt.%), where the glucose is extracted from biomass using supercritical fluid extraction; and    (5) an apparatus for continuous conversion of biomass comprising: a pretreatment reactor (101); and a hydrolysis reactor (110) associated with the pretreatment reactor.    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of method of converting lignocellulosic biomass to xylose, glucose, and lignin.    Pretreatment reactor (101)    Lignocellulosic biomass (102)    Solid matrix (109)    Hydrolysis reactor (110)    Lignin (116)