How we helped a customer turn standard fish-oil ethyl esters into premium 46/38 and 85%+ EPA/DHA products — with higher yield and lower urea consumption.
When a customer came to us with a clear target — process 300–350 tonnes per month of marine fish-oil ethyl esters (EE) at 16% EPA / 10% DHA and deliver food-grade 46/38 concentrate at 40+ tonnes per month, plus an 85%+ high-purity route.
We knew the answer wasn’t a single machine. It was process integration.
The Challenge
A 16/10 EE feed cannot reach 46/38 by short path molecular distillation alone with acceptable yield.
And a single harsh urea complexation pass can push concentration to 76–78% — but at a steep price: excessive urea consumption, heavy semi-finished losses, and poor overall yield.
Our Solution: 3 Distillations + 2 Complexations
Drawing on long-term industrial practice with this exact feedstock class, we engineered an integrated route built around three pillars:
1️⃣ Eight-Stage Molecular (Short-Path) Distillation Train — SPDUs
A continuous wiped-film SPD sequential distillation lines, operating from 20 mbar down to 0.001 mbar, with tuned temperature profiles per stage.
Semi-finished streams richer than 53% EPA+DHA are withdrawn at stages 4–6;
Streams below 55% are internally recycled and re-distilled to the optimal ratio for complexation.
By-product grades — 36/24, 33/22, 30/20, 18/12 — are recovered as valuable side draws.
Nothing is wasted.
2️⃣ Dual-Pass Urea Complexation with semi-Continuous Centrifuge Two complexation passes — first to ≥68%, second to ≈85% — with adduct crystals separated continuously in a food-grade centrifuge (SS316L).
Choosing two moderate passes over one severe pass is the economic heart of the design: dramatically less urea, dramatically better yield.
3️⃣ Urea Recovery Loop
Adduct cake from the centrifuge is dissolved, the entrained oil fraction is recovered — cutting operating cost and effluent load at the same time.
Ethanol solvent is recovered at >95%.
Why This Route Wins
| Route | Urea consumption | Product yield | 46/38 output |
|---|---|---|---|
| 1 complexation + 2 distillations (shortcut) | High | Low | Limited |
| 2 complexations + 3 distillations (our design) | Minimised | Maximised | 40+ t/month |
The Complete Package
Eight intermediate storage tanks (10 m³), urea complexation and water-washing kettles, alcohol recovery and dehydration condensers, mother-liquor and recovery tank farm, vacuum pump sets, chiller (150,000 kcal/h), and full PLC automation with recipe-driven pass profiles — all in SS316L product-contact / SS304 structure,
Food-grade execution, with complete documentation, FAT and on-site commissioning support.
The Bottom Line
Process targets are easy to promise and hard to deliver.
Delivering them economically is what separates an equipment list from an engineered solution.
This is what we do: we don’t just supply distillation stages — we integrate the distillation hall, the complexation workshop, and the recovery loop into one continuously operating plant.
📩 Planning a high-concentration Omega-3 project?
Send us your feed composition and target assays — we’ll engineer the route.
