How to filter and purify waste oil?

Waste oil filtration and purification is a process of removing impurities, moisture and harmful substances from it by physical or chemical methods to restore or approach the performance of new oil. Common purification methods include:

1. Physical filtration:

Sedimentation method: Use gravity to make impurities and moisture settle naturally, suitable for preliminary separation.

Filtration method: Use oil filter or filter paper to remove solid particles. Common equipment includes plate and frame oil filter, vacuum oil filter, etc.

Centrifugal separation method: Separate impurities and moisture through centrifugal force generated by high-speed rotation, suitable for treating waste oil with high water content.

2. Chemical treatment:

Acid washing method: Use acidic substances such as sulfuric acid to remove colloids and asphaltene, but it may corrode equipment and produce waste acid.

Alkaline washing method: Use alkaline substances such as sodium hydroxide to neutralize acidic substances, but it may produce waste alkali liquid.

Adsorption method: Use adsorbents such as activated white clay and silica gel to remove colloids, pigments, etc., suitable for treating severely deteriorated waste oil.

3. Other methods:

Vacuum dehydration method: Heating waste oil in a vacuum environment to evaporate water, suitable for treating oil products with high water content.

Electrostatic oil purification method: Using electrostatic field to adsorb charged impurities, suitable for treating oil products with trace impurities.

The following factors should be considered when choosing a purification method:

Waste oil type and degree of contamination: Different types of waste oil and degree of contamination affect the choice of method.

Purification requirements: ｓｅｌｅｃｔ a suitable purification process according to the requirements of oil use.

Cost and environmental protection: Comprehensively consider the treatment cost and environmental protection requirements.

General steps for waste oil purification:

1. Pretreatment: Sedimentation or filtration to remove large particles of impurities.

2. Deep purification: ｓｅｌｅｃｔ a suitable method according to the condition of the waste oil to further remove impurities and water.

3. Post-treatment: Adjust the performance of the oil, such as adding additives.

Waste oil purification is an important measure for resource reuse and environmental protection. Reasonable selection of purification methods can effectively restore oil performance and reduce environmental pollution.