菜籽油 · Rapeseed / Canola Oil Press process guide for hydraulic pressing
Align pretreatment, pressing route, and oil quality expectations before comparing press sizes.
Rapeseed guidance must distinguish traditional high-erucic flavor oil from canola RBD cooking oil, then walk through cleaning, flaking, cooking, hot pressing, and refining as one connected system.
38–46% oil content, hot-press on 300/325 series
Rapeseed yields well under hot pressing. The 300/325 hot-press series (100 kg/barrel, 30–40 min/barrel) is the standard match. Pre-cooking at 100–110 °C activates oil release and reduces residual oil in cake to ≤7%.
Erucic acid: traditional ~50% vs canola <2%
Traditional rapeseed is hot-pressed for high-erucic flavor oil (Chinese cuisine, frying). Canola is bred for low erucic acid and is the global commodity cooking oil. The two products use the same press but require different sales channels.
Glucosinolates in cake control feed value
Rapeseed/canola cake contains 32–38% protein, attractive for animal feed. Glucosinolate content limits inclusion rate in monogastric (pig, poultry) diets. Canola cake is far more feed-friendly than traditional rapeseed cake.
Refining is standard, not optional
Crude rapeseed oil is dark green-brown with phospholipids, FFA, and pigments. Full degumming + alkali neutralization + bleaching + deodorization (RBD) is required for retail bottling, except in niche flavor-oil markets.
Process map
From raw material to crude oil
The press is one node inside a seed-specific process. When upstream prep is weak, downstream yield and filtration become unpredictable.
Verify variety (traditional vs canola) and clean the seed
Variety identification is critical. Vibrating screen + destoner + magnetic separator removes stones, metal, and debris. Moisture target 7–9%. Mixing varieties on one line without changeover compromises both products.
Flake or roll the seed for surface area
Roller mill flakes the seed to 0.3–0.5 mm thickness, exposing oil cells for the cooker. Proper flaking is essential for hot-press yield; under-flaked seed gives high residual oil in cake.
Cook at 100–110 °C, 8–12% moisture, 20–30 min
Steam-jacketed cooker conditions flaked seed. Moisture and temperature combined trigger oil release and develop the characteristic nutty aroma in traditional rapeseed oil. Canola conditioning is similar but slightly cooler if the goal is a milder oil.
Hot-press on 300/325 at 100 kg/barrel, 30–40 min/barrel
Two-barrel cycle including loading is ~1.5 h. Residual oil in cake ≤7%. Cake is discharged for animal-feed milling (canola) or fertilizer (traditional). Crude oil flows to settling.
Refine: degum + neutralize + bleach + deodorize (RBD)
Hot-water + phosphoric acid degumming removes phospholipids. Alkali neutralization with NaOH removes FFA. Bleaching earth removes pigments and trace metals. Vacuum deodorization at 240–260 °C strips off-flavors and reduces FFA below 0.05%.
Control points
Variables that matter before pressure is applied
Traditional rapeseed and canola are not the same crop
Traditional rapeseed contains ~50% erucic acid and is hot-pressed for the strong nutty flavor prized in Chinese cooking. Canola was bred to <2% erucic acid plus low glucosinolates and is sold as a neutral, refined cooking oil. The variety chosen at intake decides everything downstream.
Hot pressing plus refining is the dominant route
Most rapeseed plants run a 300/325 hot-press line followed by degumming, alkali neutralization, bleaching, and deodorization. Cold-pressed rapeseed exists for premium niches but is a minority of installed capacity.
Operator checkpoints
Batch-to-batch consistency comes from material grading, stable moisture, and a clear rule for when to recondition instead of forcing a cycle.
Quality discipline
Practical checkpoints before you promise oil quality
- Traditional rapeseed and canola are different products. Verify the variety at intake — mixing them on one line without changeover compromises both flavor oil and refined oil quality.
- Pre-cooking at 100–110 °C is essential for hot-press yield and characteristic flavor. Cooker capacity must match press throughput, not be sized as an afterthought.
- Crude rapeseed oil always needs refining for retail. Plan the RBD train (degum + neutralize + bleach + deodorize) alongside the press, not as a future addition.
- Canola cake (low glucosinolate) is feed-grade up to 15% in pig/poultry diets. Traditional rapeseed cake is best for ruminants or fertilizer due to higher glucosinolates.
- Hot-press cycle is 30-40 min/barrel on 300/325 series. Plan daily output from this cycle plus loading/unloading time, not from a brochure throughput number.
Quote prep
Information that speeds up engineering discussion
- Variety: traditional high-erucic rapeseed or low-erucic canola.
- Daily seed input and target shift output, in tons of seed processed.
- Hot-press or cold-press route, and whether the line includes pre-cooking.
- Whether full RBD refining is in scope or the project ends at crude oil.
- Cake market plan: canola feed (with glucosinolate spec) or traditional cake for ruminants/fertilizer.
- Bottling format: PET retail, glass for flavor oil, drums for foodservice.
Questions to confirm next
What is the difference between rapeseed oil and canola oil?
Which press model fits rapeseed?
Can rapeseed cake be sold as animal feed?
Keep the engineering path moving
These next topics sharpen process, layout, and utility scope
Ready to size a line for your oilseed?
Share feed condition, pretreatment depth, shift output, post-press destination, and utility limits. We use that to narrow the scope to the pressing section, clarification loop, and real factory boundary.