The invention relates to a method for producing normal paraffin by hydrogenating
fatty acid ester, mainly solves the problems of narrow application range, low added values and the like of
first generation biodiesel (
fatty acid methyl ester), and develops the application range of animal and
vegetable oil (fatty
glyceride). The method for producing normal paraffin by hydrogenating
fatty acid ester comprises the following steps: mixing
fatty acid ester with
hydrogen, sequentially introducing the obtained mixture to enter a
fixed bed prehydrogenation reactor and a
hydrodeoxygenation reactor in order to remove most
oxygen-containing groups in the above
raw material, carrying out gas-liquid separation on crude products, fractioning, and introducing the fractioned product to an additional purifying unit to carry out deep hydrotreatment in order to produce highly pure normal paraffin with the
oxygen content of below 0.5ppm. The method adopting the above technical scheme well solves the problems, can be used in the industrial production of normal paraffin through hydrogenating
fatty acid ester, and has the advantages of low reaction pressure, low
hydrogen / oil ratio, low
hydrogen consumption, large apparatus load, high product purity and good product quality.