TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The inorganic material is in crystalline or quasi-crystalline form. It is an inert inorganic material. The inorganic material has catalytic properties. It is from clays, silicas, silica-aluminas, magnesia, magnesia-alumina, magnesia-silica, magnesia-silica-alumina, manganese compounds, calcium compounds, lime, transition metal hydroxides, metal oxides, metal hydroxyl salts, zeolites, cationic layered materials, anionic clays, layered double hydroxides, smectite clays, saponites, and/or sepiolites. Microcrystalline or quasi crystalline inorganic material is anionic clay, which is hydrotalcite. Preferred Parameter: The particles of inorganic material have an average particle size of 10 microns-100 nm, preferably 500-150 nm.    TECHNOLOGY FOCUS - METALLURGY - Preferred Material: The divalent metal is magnesium, calcium, or zinc. The trivalent metal is aluminum (Al) or iron. The cation is Al3+. The anion is aluminum oxide (Al2O42-).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The solvent comprises water, alcohol, carboxylic acid, and swelling agent, which is an acid or a base.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The polymeric material comprises biomass and cellulose and/or lignocellulose. Preferred Method: The step of modifying conditions comprises a change in temperature, a change in pH, and/or evaporation of solvent. The cellulose polymeric material is soaked with an aqueous solution of a divalent metal and a trivalent metal, e.g. metal salt, or an aqueous solution of a cation or anion of metal capable of forming particulate inorganic compound; and precipitation of crystalline inorganic material or precursor to particulate inorganic compound is initiated. The method comprises optionally aging to convert the precursor to the particulate inorganic compound; and co-grinding particles of the polymeric material and particles of the inorganic material. The polymeric material is treated with a swelling agent before contacting with the inorganic particulate compound or precursor. It is contacted with a suspension of colloidal particles followed by a treatment that allows the colloidal particles to coagulate. EXAMPLE - A suspension of partly dissolved sepiolite clay was produced by slurrying the clay with an aqueous solution of hydrochloric acid. Subsequently, the suspension was contacted and mixed with wood particles having a particle size distribution of 1-100 microns. The particles were soaked in the suspension for 60 minutes. The pH of the suspension was increased by adding sodium hydroxide. Thus, part of the dissolved sepiolite clay re-crystallized in the interior of the solid biomass. The presence of crystalline clay particles was confirmed with x-ray diffraction and microscopy. The polymeric material having embedded clay particles was gently heated at 180degreesC and autogenous pressure for 30 minutes. A bio-oil rich in oxygen-containing organic compounds was obtained.