The invention discloses a high acid-value
grease depickling novel technology. The technology of the invention applies advanced molecular
distillation technique to high acid-value
grease depickling and can separate the
grease from the
fatty acid better on the basis of not damaging the original compositions of the
raw material so as to reduce the oil acid-value; furthermore, the depickling effect can be improved by multi-stage serial connection and the
continuous operation can be carried out. The acidified oil is dehydrated by fine
filtration, saturated NaCl
water washing and film braising and is pumped into a first-stage molecular distiller by a first-stage delivery pump so as to distil part of
fatty acid; the distilled residue in the first-stage is taken as the
raw material of the second-stage molecular distiller and pumped into the second-stage molecular distiller by a second-stage delivery pump so as to distil the residual
fatty acid; the distilled residue is taken as the
raw material of the third-stage; the circulation is repeatedly to the required N-stage; wherein, N is more than or equal to 2 and less than or equal to 5; the best
stage number is 3 or 2. The technology of the invention has the advantages that the fatty acid is separated; meanwhile, the raw material composition of the grease is not damaged; the distilled high-quality fatty acid has extremely high application value by the further disposal; furthermore, multi-stage molecular distilling is beneficial to the
continuous operation so as to complement the shortages of single-stage separation capability, thus providing beneficial conditions for the industrialization in large scale.