a method and installation for energy densification of a material to obtain pyrolytic oils for energy . the method includes preconditioning the material by heating and drying to raise the material temperature close to 100 ° c . and a relative humidity not exceeding about 10 %; pyrolyzing the material that is subsequently caused to flow through a substantially hermetic reactor containing at least one transfer screw or vibrating tube heated by the joule effect , the material heated progressively in the range of 300 ° c . to 850 ° c ., the electrical power passing through the transfer screw or the vibrating tube for providing heating regulated as a function of the material in order to obtain the desired temperature level during the transit time of the material through the reactor ; extracting pyrolysis gas from a high portion of the reactor for rapid recondensation in a vertical condenser ; and recovering pyrolytic oils from a low portion of the vertical condenser .