NOVELTY - Semi-batchwise or semi-continuous production of biodiesel fuel, comprises optionally heat-supported, catalytic splitting of liquefied fats and/or biogenic oils into glycerol and fatty acids and esterifying the released fatty acids by an alcohol, preferably methanol, and/or an alcoholate, preferably methanolate, where: optionally after performing batchwise raw fat/-oil processing, mixing process upstream to the actual conversion process, optionally under addition of a mineral acid is brought together for splitting fat and/or oil, methanol and alkali methanolate and/or alkali methylate.    USE - The process is useful for the semi-batchwise or semi-continuous production of biodiesel fuel.    DETAILED DESCRIPTION - Semi-batchwise or semi-continuous production of biodiesel fuel, comprises optionally heat-supported, catalytic splitting of liquefied fats and/or biogenic oils into glycerol and fatty acids and esterifying the released fatty acids by an alcohol, preferably methanol, and/or an alcoholate, preferably methanolate, where: optionally after performing batchwise raw fat/-oil processing, mixing process upstream to the actual conversion process, optionally under addition of a mineral acid is brought together for splitting fat and/or oil, methanol and alkali methanolate and/or alkali methylate; the mixture is led to a continuous conversion- and optimization circulation process (900) of a conversion stage, where at least one main feeding and at least a main dissipation associated and parallely turned with the same are led to an adjustable circulation process stage, preferably by a circulation-shear reactor stage, pure circulation stage, circulation analysis stage, circulation filtration stage, circulation-ion exchange stage, circulation-distillation/rectification stage, circulation-cooling-heat-exchange stage and/or electrical, circulation-direct-heating stage, and a continually using optical analysis processor controlled, predetermined quality of biodiesel fuel is achieved; and then the splitted glycerol and the finished biodiesel fuel from the conversion- and optimization circulation process can be applied. An INDEPENDENT CLAIM is included for a device for semi-continuous production of biodiesel fuel, comprising optionally supply line of corresponding supply or waste disposal containers (101-107) from which the used, optionally heated and preferably with a mineral acid, supportably, batchwisely working raw fat/raw oil treatment and mixed container (91) and optionally of the same preparation mixture (silver) or with the mixture, optionally heated mixture of raw fat and/or oil, with methanol, methanolate and/or methylate providable with at least one circulation- and/or circulation pump (24) equipped with continuously processing conversion- and optimization-circulation plant (900); at least one feeding line from the raw fat/raw oil-conditioning and mixed container exhibiting and discharge line for splitted glycerol and produced biodiesel fuel, optionally with a heating system (18), main reaction container (90); and at least one inlet- and at least one outlet pipeline and circulation-processor (1-8, 19) arranged parallely to the main reaction container, preferably an intensive shear reactor.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a process for the production of biodiesel fuel.    Circulation-processor (1-8, 19)    Heating system (18)    Circulation pump (24)    Main reaction container (90)    Mixed container (91)    Waste disposal containers (101-107)    Continuous conversion- and optimization circulation process. (900)