No.4 solvent is purified from liquefied petroleum gas. Its main composition is propane and butane. The boiling point below 0℃. Leaching process is in a certain process (0.1~0.7Mpa for liquid state) and room temperature, achieving oil extraction
at room temperature. The solvent of leaching meal and oil is removed under low temperature and vacuum station. The solvent is cyclic after liquefaction.
No.4 solvent has low boiling point, pure components and low residual solvent after leaching. Leaching process is low temperature, good selectivity with few impurities such as pigment and phospholipids. So the products quality is high.
Subcritical extraction equipment, No.4 solvent leaching equipment, is an innovation and has a huge economic benefits and profound social signification. It can not only reduce the cost of processing, but also creates the condition for the extraction of valuable oil and development and utilization of plant protein. In the aspect of environmental protection, subcritical extraction equipment will has brought fundamental changes in the development of the oil industry.