The Engineering Challenge
Edible oil refining (crude palm oil, soybean, and canola) requires precise chemical neutralization to remove Free Fatty Acids (FFA), followed by bleaching and high-vacuum deodorization. In manual or semi-automated plants, crude oil variations lead to over-dosing of caustic soda (producing neutral oil saponification and high oil yield loss) or under-dosing (failing finished product FFA specifications).
Furthermore, processing areas require stringent adherence to hazardous atmosphere regulations (ATEX/HazLoc) due to solvent recovery stages, demanding explosion-proof containment and intrinsically safe control architecture.
Technical Architecture & Automation Scope
MBH Solutions designed and commissioned a closed-loop chemical conditioning skid and supervisory SCADA platform engineered specifically for continuous refining lines:
- Coriolis Mass-Based Stoichiometric Dosing: Integrated Endress+Hauser Promass flowmeters measuring incoming crude mass flow and density, instantly calculating exact stoichiometric requirements for phosphoric acid (degumming) and sodium hydroxide (neutralization).
- ATEX Purged Enclosures (Ex p): Engineered pressurized control panels with automatic inert gas purge cycles and continuous internal pressure monitoring for hazardous plant sectors.
- High-Viscosity Fluid Handling: Equipped centrifugal and progressive cavity pumps with Danfoss VLT AutomationDrives, dynamically modulating pump speeds to prevent shear stress and thermal degradation.
- Deodorizer Vacuum & Thermal Loops: Automated multi-stage steam ejector vacuum control and high-temperature thermal oil heating loops to ensure stable strip-temperature maintenance within ±1.0°C.
Performance Metrics & Operational Results
| Process Parameter | Volumetric / Manual Dosing | Automated Coriolis Closed-Loop |
|---|---|---|
| Chemical Dosing Precision | ±2.5% volumetric deviation | ±0.2% mass-based accuracy |
| Neutral Oil Loss (Saponification) | 1.45–1.80% above theoretical | < 0.65% above theoretical |
| Finished Product FFA Stability | Variable (0.06% to 0.12%) | Consistent < 0.045% FFA target |
| Steam & Thermal Energy Efficiency | Manual throttle valve drift | 12.5% thermal energy savings |
Frequently Asked Engineering Questions
Why are Coriolis mass flow meters critical in edible oil chemical dosing?
Because vegetable oils undergo significant viscosity and density shifts across seasonal temperature swings, volumetric flow sensors deliver fluctuating readings. Coriolis mass flow meters measure pure mass throughput (kg/h) independent of fluid viscosity, ensuring consistent chemical reaction ratios and preventing oil loss.
How are explosion-proof safety requirements addressed in solvent extraction zones?
In hexane extraction and chemical preparation areas, we deploy ATEX Zone 1/2 certified purged and pressurized enclosures (Ex p) paired with intrinsically safe galvanic barriers (Ex i) on all field transmitter wiring. This guarantees that neither electrical sparks nor component overheating can trigger ignition.