TECHNOLOGY FOCUS - BIOLOGY - Preferred Process: The aqueous suspension of algal biomass derived from the growth of unicellular algae (microalgae) in industrial wastewater is thickened to obtain algal biomass containing dry material with concentration of 2-40 weight%, preferably 4-25 weight% with respect to total weight of aqueous suspension of algal biomass. The ratio of concentration of dry material in aqueous suspension of algal biomass with respect to volume of organic solvent is 1:1-1:80 or 1:3-1:70. The organic phase comprising lipids and organic solvent is subjected to evaporation process in order to recover organic solvent for reuse, and then lipids are extracted. The lipids are subjected to esterification in presence of 1-4C alcohol and acid catalyst to produce glycerol and alkyl esters (biodiesel). Alternately, the lipids are subjected to hydrogenation/deoxygenation in presence of hydrogen and catalyst to produce green diesel. Alternately, the organic phase comprising lipids and organic solvent is directly subjected to esterification or hydrogenation/deoxygenation. The semi-solid phase comprising residue of algal biomass is subjected to pyrolysis to obtain pyrolytic oils. After removal of organic solvent, the semi-solid phase comprising residue of algal biomass is subjected to anaerobic digestion by microorganisms in absence of oxygen to obtain biogas.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Solvents: The organic solvent immiscible in water is chosen from aliphatic hydrocarbons with boiling point of more than 100 degrees C chosen from n-octane, nonane and decane, aromatic hydrocarbons chosen from xylene isomers, toluene, benzene and chlorobenzene, and refinery cuts comprising mixtures of aliphatic hydrocarbons having boiling point of more than 100 degrees C, mixtures of aromatic hydrocarbons and mixtures of aliphatic and aromatic hydrocarbons, preferably n-octane and/or xylene. The organic solvent partially immiscible in water is esters chosen from ethyl acetate, isopropyl acetate and n-butyl acetate, or ketones with boiling point of more than 100 degrees C chosen from pentanone and hexanone, preferably ethyl acetate. Preferred Conditions: When the organic solvent having boiling temperature of more than 100 degrees C is used, the evaporation of water and lipid extraction are carried out at 100 degrees C under atmospheric pressure for 30 minutes to 5 hours. When the organic solvent having low boiling azeotrope with respect to water is used, the evaporation of water and lipid extraction are carried out at boiling temperature of low boiling azeotrope, under atmospheric pressure for 30 minutes to 5 hours, preferably 1.5-3.5 hours.