NOVELTY - The system has chambers (R201-1-R201-5) that are respectively arranged one below the other in common housing. The chambers are provided with agitator units (R201-1a,R201-3a), and are provided with an inlet for oil to be transesterified and device for adding additional catalyst for completing reaction of unreacted triglycerides. An outlet chamber of chamber (R201-5) is provided with an outlet for crude biodiesel.    USE - Biodiesel production system.    ADVANTAGE - The structure of the biodiesel production system can be compact. The bio-diesel can be produced efficiently. The process oil temperature can be maintained even during shut down so that the maintenance and cleaning of process equipment can be achieved without the need for ramp up time or additional power consuming device such as electric heater. The crude oil which is pre-treated with phosphoric acid and water can be sent to the reactor so that the removing of impurities can be achieved.    DETAILED DESCRIPTION - A portion of the chamber (R201-1) is extended over the whole width of the reactor and separator unit (R201), the chamber (R201-3) is extended over the whole width of the reactor and separator unit, the chamber (R201-2,R201-4) are arranged side-by- side. The chamber (R201-5) is arranged within the chamber (R201-1) and adjacent to the chamber (R201-4) and having a width corresponding to the width of the chamber (R201-4). A mixer is provided for adding phosphoric acid for neutralisation of the biodiesel. A blending tank is provided for completing neutralisation reaction. An ion exchange purification vessel, where residual glycerin, soaps, free fatty acids, unreacted oil, waxes, salts, water and methanol are removed. A polishing filter is provided to remove any remaining particulate impurities where the biodiesel exits the system to a collection tank. The twin chamber vessel is provided with a mixing unit for agitating the content of the first and second chambers including common shaft rotatably driven by the mixing motor and passing partially into each of the chambers of the twin vessel and first and second stirring elements. An oil expeller is provided for extracting crude oil from raw feedstock. A de-gumming process reactor is provided for removing one of gums, metal compounds and other impurities from the crude oil. The reactor and separator unit or vessel for transesterification of the crude oil to methyl esters and for removing glycerin from the methyl esters. A blending tank is provided for completing neutralisation reaction. An INDEPENDENT CLAIM is included for continuous method of producing bio-diesel in bio-diesel system, which involves using methanol and sodium hydroxide (NaOH) as a catalyst to transesterify oil. The oil is reacted with methanol by mixing with estimated stoichiometric amount for transesterifying the oil in the presence of 2 to 10% by weight NaOH catalyst, based on the weight of the methanol in a first chamber of a reactor. A second chamber of the reactor glycerin is separated from the resulting fatty acid methyl ester mixture which is reacted for a second time with about 8 to about 15 % of the amount of mixture containing 2 to 10% by weight NaOH in methanol in a third reaction chamber. A fourth chamber of the reactor residual glycerin is separated from the resulting more enriched fatty acid methyl ester mixture to obtain crude biodiesel. The temperature in the process is about 60C and the pressure is at or slightly above up to about 5% or about 10% or about 15%, based on the absolute pressure, above ambient pressure.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the reactor and separator unit.    Separator unit (R201)    Chambers (R201-1-R201-5)    Agitator units (R201-1a,R201-3a)