The invention discloses a method for preparing
biomass fuel from nanometer materials under catalytic
cracking. The method comprises the following steps: performing
dehydration treatment on such
raw material oil as swill-cooked dirty oil, acidic oil, waste animal and vegetable
grease, and separating to remove water and impurities; pumping the dehydrated
grease into a tubular
heating furnace by a high-temperature
oil pump so as to gasify the
grease to form a grease vapor and heavy oil mixture, separating the heavy oil by a catalytic fractionating
tower at the bottom of the
tower, performing catalytic
cracking reaction on the pure grease vapor by a catalyst layer, reducing the molecular weight of the grease, removing groups, such as carboxyl and glycerinum, from the grease molecules, and generating
hydrocarbon-type oil, liquefied gas and
combustible gas; performing preliminary purification on the diesel part of the
hydrocarbon-type oil by a steam stripping method and then performing deacidifying stable coalescence treatment; and adsorbing by an adsorbent and separating to obtain
biodiesel and
biogasoline. The method provided by the invention has the characteristics of high universality, easily available material, excellent property, wide application, simple process, high quality consistency, high additional value and low cost.