The mixed oil-gas produced by waste plastic pyrolysis has a complex composition, containing light oil, heavy oil, oil-gas impurities, and condensable components. Without fine separation treatment, oil products tend to be mixed with excessive impurities, affecting subsequent use and storage. The multi-stage oil-gas separation process sorts oil-gas components step by step, achieving categorized collection and layered treatment to improve product orderliness. Based on the composition characteristics of pyrolysis oil-gas, Henan Yongle Group optimizes the multi-stage oil-gas separation structure of its plastic refining equipment, refining the oil-gas treatment workflow to make separation more thorough and improve resource recovery results.

Plastic refining equipment is equipped with a multi-stage oil-gas separation unit that performs gradient separation according to differences in boiling point and density of oil-gas components. After entering the separation system, the mixed oil-gas successively passes through three stages—primary settling, secondary splitting, and fine purification—gradually distinguishing different oil components, achieving natural separation of light and heavy oils, and reducing the mixing of different oil products.

The primary settling unit intercepts fine carbon powder, solid particles, and other impurities carried in the oil-gas, filtering solid impurities in advance to prevent particles from entering the condensation and oil storage stages, reducing oil impurity content at the source and simplifying later oil treatment.

The secondary splitting stage relies on temperature and flow rate control to distinguish light and heavy oil components, allowing high-boiling-point heavy oils and low-boiling-point light oils to precipitate independently into corresponding collection pipelines and storage areas, enabling categorized oil storage and facilitating targeted later use and sales.

The end-stage fine purification unit removes residual colloid and trace impurities from the oil, improving clarity and stability. Oil treated through multi-stage separation is less prone to stratification and sedimentation during storage, has a longer storage period, and suits various conventional industrial combustion and heating scenarios.

The refined multi-stage oil-gas separation process improves the resource recovery system of plastic refining equipment, making waste plastic pyrolysis products more orderly and stable in quality. The step-by-step, stage-by-stage purification model fits the demand for refined solid waste resource recovery and provides solid support for compliant, long-term project operation.