Waste cooking oil differs significantly from fresh vegetable oil, with more complex and higher levels of impurities including mechanical solids, free fatty acids, gums, metal ions, nitrogen compounds, and chlorides. Failure to effectively remove these impurities will severely impact the operational stability and catalyst life of downstream biofuel units.

Zhengzhou Ocean's waste oil pretreatment solution achieves efficient synergistic removal of multiple impurities through the system integration of two main sections: degumming/neutralization and adsorption/filtration.

1. Degumming and Neutralization Section: Primary Impurity Separation

The incoming raw oil first passes through a decanter centrifuge to remove large mechanical impurities. It then enters the heat exchange system for oil-to-oil heat exchange with the high-temperature finished oil, achieving energy savings. After heating to approximately 65°C, citric acid is added for degumming to convert non-hydratable phospholipids into hydratable phospholipids.

Liquid caustic soda is then added for neutralization, converting free fatty acids into soapstock. A centrifuge separates the soapstock from the neutral oil. The neutralized oil then passes through a water-washing centrifuge to remove residual soapstock and citric acid.

The entire acid, caustic, and water addition processes are online automatic proportioning systems, automatically adjusting based on flow meter signals to ensure reaction precision.

2. Adsorption and Filtration Section: Deep Purification

After neutralization and drying, the oil enters the adsorption section. The adsorbent (bleaching earth, etc.) is pneumatically conveyed to the adsorbent tank, then automatically added to the pre-mix tank by a dosing device in proportion. After thorough mixing, the mixture enters the adsorption tank for approximately 40 minutes, with steam agitation enhancing the adsorption reaction.

The oil-adsorbent mixture is then filtered through leaf filters for solid-liquid separation. The filters feature an automatic tank-switching design, completing the entire automatic operation of oil feeding, circulation, filtration, cake blowing, and slag discharge with one command, significantly reducing labor intensity.

The filtered oil then passes through a precision filter to remove residual adsorbent particles, and finally enters a buffer tank for moisture and volatile removal, producing finished pretreated oil.

3. System Integration Advantages:

· Full process automation: PLC/DCS centralized control with real-time monitoring of key parameters (temperature, pressure, flow, liquid level)

· Energy-saving design: Multi-stage oil-to-oil heat exchange for maximum heat recovery

· Low consumption: Precise chemical addition control reduces consumption of citric acid, caustic soda, and adsorbents

· High yield: Multi-stage soapstock and wash water recovery minimizes neutral oil loss

Ocean provides full-chain services from concept design to plant delivery, delivering proven turnkey solutions for waste oil pretreatment projects.