NOVELTY - Installation comprises: a tank containing oils and/or fats to be treated connected by a supply pipe (2) to a first pump (3) for feeding the oils or fats; a tank (11) containing a light alcohol connected by a supply pipe to a second pump (5); a reactor (12) to which the first and second pumps feed the oils and/or fats and alcohol, and comprising a tubular reaction vessel; a heat exchanger for heating and cooling the reaction effluents; reaction effluent depressurization tank; and means for recovering excess alcohol.    USE - The installation is useful for producing fatty acid esters that are utilized as fuel (claimed) comprising biofuel and biodiesel and in chemical and cosmetic industry.    ADVANTAGE - The installation produces fatty acid ester without the presence of catalyst.    DETAILED DESCRIPTION - Installation for producing fatty acid esters usable as fuel, comprises: a tank containing oils and/or fats to be treated connected by a supply pipe (2) to a first pump (3) for feeding the oils or fats at a predetermined pressure; a tank (11) containing a light alcohol connected by a supply pipe to a second pump (5) for feeding the alcohol at the same predetermined pressure; a reactor (12) to which the first and second pumps feed the oils and/or fats and alcohol, and comprising a tubular reaction vessel with a winding or coil configuration having heating means associated with it for internally maintaining a supercritical temperature in relation to the alcohol used and a pressure provided by the first and second pumps for producing esterification and transesterification reactions of the oils and/or fats and alcohol without the presence of catalysts; a heat exchanger for heating and cooling the reaction effluents; a reaction effluent depressurization tank equipped with pressure/flow rate regulating valves for depressurization, connected to an end area of the reactor for the exit of the reaction effluents; and means for recovering the excess alcohol of the reaction which are associated with the depressurization tank, having an outlet for the produced esters and reaction by-products. The installation comprises means for stirring the reaction product at the reaction temperature and pressure in at least one segment of the tubular vessel covering a sector of the reactor before its end area for exit towards the mentioned depressurization tank. An INDEPENDENT CLAIM is also included for producing fatty acid esters usable as fuel from oils and/or fats and at least one alcohol comprising simultaneously performing esterification and transesterification reactions of a mixture of the oils and/or fats and alcohol inside a reactor made up of tubular vessel which has winding or coil configuration and operates at a pressure of 15-25 Mpa and at a supercritical temperature in relation to the alcohol of 280-325 degrees C and recovering the esters resulting from the reaction in a depressurization tank to which outlet of the mentioned reactor is connected, comprising stirring the reaction mixture inside the reactor operating under the pressure and temperature conditions of the reactor in a sector of the tubular vessel covering a segment of the reactor before its end area to favor the reaction.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the installation.    Supply pipe (2)    First pump (3)    Second pump (5)    Tank (11)    Reactor (12)