This invention discloses a method for low-temperature pressing purification and dewaxing of
Torreya grandis kernels, comprising at least the following steps: S5.1 Pre-preparation of a
composite filter layer: After pre-cooling the filter chamber of a vacuum
filtration device, a filter screen and a filter membrane are laid in sequence, and
nitrogen is introduced to remove impurities; S5.2 Gradient negative pressure
filtration: The initially dewaxed oil is injected into the filter chamber at low temperature, first pre-filtered at -0.05MPa to -0.06MPa for 10 minutes, then deep filtered at -0.08MPa to -0.09MPa for 20 to 30 minutes to retain trace
wax crystals; S5.3
Nitrogen purging to remove water: The dewaxed oil is introduced into a low-temperature
oil storage tank, and
nitrogen is continued to be introduced to remove water and prevent oxidation; S5.4 Finished product fine
filtration: The dewaxed oil is slowly heated and then finely filtered through a filter screen to obtain
Torreya grandis finished oil. Gradient negative pressure filtration retains trace
wax crystals in
Torreya grandis oil. This invention employs a gradient negative pressure dewaxing step, which ensures sufficient driving force to accelerate the filtration speed and utilizes the formed
filter cake layer as a secondary filtration medium to efficiently retain
trace amounts of residual
wax crystals. This approach ensures a high dewaxing rate while shortening the filtration time and improving production efficiency.