TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: Producing fuel or fuel precursor from lipid-containing biomass further comprises separating one or more organic chemical products from the aqueous phase; and heating the aqueous phase to temperatures of about 350 degrees C to about 500 degrees C, optionally in the presence of a catalyst. The aqueous slurry is heated to about 240 degrees C to about 300 degrees C for the purpose of selectively preparing the pyrazines in the aqueous phase. The solid phase is heated at about 300 degrees C or more. Solid phase is heated at about 400 to 900 degrees C or more, or at about 400 to 600 degrees C. The aqueous solution following separation of the solid phase, either with or without extraction or separation of any additional organic component, is heated to near critical or supercritical temperatures, optionally in the presence of a catalyst to prepare further organic materials. Aqueous solution following separation of the solid phase is steam distilled to separate pyrazines from lactams. The aqueous phase or the mixture of the solid phase and the aqueous phase is subjected to a solvent extraction step to separate residual organic phase from the aqueous phase; or the aqueous phase or the mixture of the solid phase and the aqueous phase is subjected to a sequence of solvent/aqueous extraction steps with sequential changes of pH to separate the classes of organic compounds. The solids separated from the liquid are pyrolyzed by heating at temperatures from 400 degrees C to about 600 degrees C for a period of about 1 minute to about 10 hours, preferably in the absence of oxygen, and the resultant liquids emitted are condensed and collected; or the solids separated from the liquid are treated hydrothermally at temperatures in excess of 300 degrees C for a period of about 1 minute to about 10 hours, and on subsequent cooling, the organic liquids are separated or extracted from the aqueous solution. Components dissolved or dispersed in water are recovered by adsorbing them onto a solid, including but not limited to a clay, treated or otherwise, a zeolite, an ion-exchange resin, charcoal, and aluminum oxide, and recovering the components either by heating them, or through ion exchange. Organic components are extracted with solvents insoluble in water, including but not limited to methylene chloride, hydrocarbons, esters such as ethyl or amyl acetate, ethers, and the solvents are removed by distillation, or hydrocarbon mixtures prepared by the method above. The pyrolysis product or hydrothermal product is distilled to separate hydrocarbons suitable for petrol from those suitable for diesel. Cations are either calcium or magnesium, and the final solid residue is used for agricultural or horticultural application. The pressure vessel is either batch or continuous, and may be stirred, fluid bed or fixed bed. Pyrolysis vessel may be batch or continuous, it may be ablative, fluid bed, stirred, or fixed bed. The aqueous slurry is heated for about 1 minute to about 12 hours; or the aqueous slurry is heated for a time period of about 5 minutes to about 60 minutes. Lipid containing biomass comprises about 2% to about 90% dry weight equivalent of the slurry. The metal base is a material that reacts with acid to form a salt and materials that are only mildly acid or are neutral. The metal base is an oxide or hydroxide. It is a Carbonate or a sulfide. Cation in the metal base is divalent, including but not restricted to magnesium, calcium, barium, strontium, zinc, cadmium, copper, nickel, cobalt, manganese, vanadyl, tin, lead and iron. Alternatively, the cation in the metal base is trivalent, including but not restricted to ferric, aluminum, chromic, scandium and rare earths. The lipid containing biomass is algae or microalgae. It is vegetable material either grown specifically for oil production or adventitious, including but not limited to plant oils such as olive, canola, jatropha, flax, soy, palm, coconut, or peanut oil, or wastes remaining after such oil pressing. It is of animal origin, including meat, fish, and bird processing wastes. It comprises waste lipid oils. EXAMPLE - No suitable example given.