NOVELTY - Processing (I) biomass materials, comprises hydrothermally treating the biomass materials to produce a combined char and oil fraction and an aqueous fraction; separating the combined oil and char fraction from the aqueous fraction; and separating the combined oil and char fraction to create a separate oil fraction and a separate char fraction.    USE - The process is useful for processing biomass materials, low cellulosic biomass and algal biomass (claimed) to convert into biofuels.    ADVANTAGE - The process provides: oil product comprising lipids and lipid-derived materials for conversion to biofuels, in high yield, within the char and easily recoverable from it; extracted char product that has an energy content equivalent to natural bituminous coal; and aqueous product that contains most of the nitrogen, phosphorus and potassium originally present in the biomass substrate for recycling as a plant nutrient solution. The process converts recoverable oil into char during hydrothermal process, especially with the highly unsaturated fatty acids, and the char can absorb almost all of the fatty acids present and that the major fraction of the fatty acids could be so easily separated from the char. The process recycles the important nutrient, thus reduces production cost, and greenhouse gas footprint due to lower demand for fossil fuel-derived nitrogen fertilizer.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) processing (II) a low cellulosic biomass, comprising hydrothermally treating the low cellulosic biomass materials to produce a combined char and oil fraction and an aqueous fraction, separating the combined oil and char fraction from the aqueous liquid fraction by filtration, extracting a separate oil fraction from the combined oil and char fraction by use of an organic solvent forming a separate char fraction and a separate liquid oil and solvent solution, and distilling the liquid oil and solvent solution into separate oil and solvent fractions; and    (2) processing (III) an algal biomass, comprising hydrothermally treating the algal biomass to produce a combined char and oil fraction and an aqueous fraction, separating the combined oil and char fraction from the aqueous liquid fraction by filtration, extracting a separate oil fraction from the combined oil and char fraction by use of organic solvent forming a separate char fraction and a separate liquid oil and solvent solution, and separating the liquid oil and solvent solution into separate oil and solvent fractions by distillation.