Palm Oil Mill Process Flowchart & Mass Balance

Typical process flowchart of a Palm Oil Mill, followed by a step-by-step explanation based on real mill operations (60–90 TPH typical).

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🌴 Palm Oil Mill Process Flowchart (Overview)

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🔁 Main Process Flow (From FFB to CPO & Kernel)

Fresh Fruit Bunches (FFB)
        ↓
     Weighbridge
        ↓
     Loading Ramp
        ↓
      Sterilizer
        ↓
     Thresher
        ↓
   Digester
        ↓
     Screw Press
        ↓
 ┌───────────────┐
 │               │
Oil Line       Press Cake
 │               │
 ↓               ↓
Vibrating     Depericarper
Screen            ↓
 │            Nut & Fibre
 ↓               ↓
Sand Trap     Nut Silo
 │               ↓
 ↓            Ripple Mill
Crude Oil         ↓
Clarification  Kernel Dryer
 │               ↓
 ↓            Kernel Storage
CPO Storage

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🧩 Detailed Explanation (Engineer’s View)

1️⃣ Weighbridge

• Weigh incoming FFB

• Data used for:

  • Yield calculation

  • Supplier payment

  • OER & KER tracking

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2️⃣ Loading Ramp

• Temporary holding area

• Important controls:

  • FIFO (First In First Out)

  • Minimise FFB waiting time
    👉 Long waiting = high FFA

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3️⃣ Sterilization (Heart of the Mill)

Purpose:

• Stop enzyme activity (reduce FFA)

• Loosen fruits from bunch

• Soften mesocarp for pressing

Typical conditions:

• Steam pressure: 2.8–3.0 bar

• Time: 85–95 minutes

⚠️ Poor sterilization = poor oil extraction

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4️⃣ Threshing

• Rotating drum

• Separates fruitlets from bunch stalk

Outputs:

• Empty Fruit Bunch (EFB)

• Loose fruits → Digester

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5️⃣ Digestion

• Steam-heated vertical digester

• Mash fruitlets

• Break oil cells

Control points:

• Temperature

• Retention time

• Knife condition

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6️⃣ Screw Press

• Press out crude oil

• Output:

  • Press liquor (oil + water + solids)

  • Press cake (fibre + nuts)

Press efficiency directly affects OER

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🛢️ OIL LINE

7️⃣ Vibrating Screen

• Remove coarse fibre

• Protect downstream equipment

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8️⃣ Sand Trap / Desander

• Remove sand & heavy solids

• Prevent pump & separator wear

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9️⃣ Clarification Station

• Settling tank / clarifier

• Oil-water separation

Then:

• Purifier (centrifuge)

• Vacuum dryer

Final product:
👉 Crude Palm Oil (CPO) → Storage Tank

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🌰 KERNEL LINE

🔟 Depericarper

• Separate fibre from nut

• Fibre → boiler fuel

• Nut → nut silo

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1️⃣1️⃣ Nut Cracking (Ripple Mill)

• Crack shell

• Release kernel

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1️⃣2️⃣ Kernel Separation

• Clay bath / hydrocyclone

• Separate shell & kernel

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1️⃣3️⃣ Kernel Drying & Storage

• Reduce moisture to ~7%

• Stored for sale or kernel crushing plant

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🔥 Utility Systems (Supporting Process)

Not shown in flowchart but critical:

• Boiler → steam for sterilizer & power

• Turbine / Generator → electricity

• Water treatment plant

• Effluent (POME) treatment

• Workshop & maintenance

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📌 Key Performance Indicators (Engineers Monitor)

• OER (%)

• KER (%)

• Steam consumption (kg/ton FFB)

• Power consumption (kWh/ton FFB)

• Boiler efficiency

• Downtime

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Final Note (From Experience)

A palm oil mill looks simple on paper, but losses happen between every step:

• Poor sterilization

• Press inefficiency

• Oil losses in sludge & fibre

• Kernel breakage

👉 Good engineers don’t just run machines — they control losses.

A mass balance diagram is what really helps engineers see losses, not just machines.

Below is a simple, practical palm oil mill mass balance diagram based on 1,000 kg FFB (easy to scale up to any capacity).

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🌴 Palm Oil Mill Mass Balance Diagram (Typical)

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🔢 Standard Mass Balance (Per 1,000 kg FFB)

Fresh Fruit Bunches (1,000 kg)
│
├── Crude Palm Oil (CPO)     → 200 – 230 kg  (OER 20–23%)
│
├── Palm Kernel              → 45 – 55 kg   (KER 4.5–5.5%)
│
├── Empty Fruit Bunch (EFB)  → 220 – 230 kg
│
├── Fibre                    → 130 – 150 kg
│
├── Shell                    → 55 – 70 kg
│
├── Palm Oil Mill Effluent   → 550 – 650 kg
│
└── Losses (oil, moisture)   → balance

👉 Values vary by fruit quality, sterilization, press efficiency, and clarification performance.

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📊 Breakdown by Process Section

1️⃣ Sterilization & Threshing

Input:

• FFB: 1,000 kg

Output:

• Loose fruits: ~770–780 kg

• EFB: ~220–230 kg

📌 Loss risk:

• Oil remaining in EFB

• Overcooked / undercooked sterilization

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2️⃣ Pressing Section

Input:

• Digested fruits

Output:

• Press liquor (oil + water + solids)

• Press cake:

  • Fibre: ~140 kg

  • Nut: ~110 kg

📌 Loss risk:

• Oil trapped in fibre (>5% is bad)

• Poor press cone & screw condition

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3️⃣ Clarification Section

Input:

• Press liquor

Output:

• CPO: ~210 kg

• Sludge / wastewater: major part of POME

📌 Loss risk:

• Oil in sludge (>1% is high)

• Poor temperature control

• Separator inefficiency

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4️⃣ Kernel Recovery Section

Input:

• Nut (~110 kg)

Output:

• Kernel: ~50 kg

• Shell: ~60 kg

📌 Loss risk:

• Broken kernel

• Kernel lost with shell

• Poor hydrocyclone density control

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⚖️ Simple Mass Balance Formula (Engineer Use)

Oil Extraction Ratio (OER)

OER (%) = (CPO produced / FFB processed) × 100

Kernel Extraction Ratio (KER)

KER (%) = (Kernel produced / FFB processed) × 100

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🚨 Where Engineers SHOULD Focus (Real Mill Reality)

Section	Typical Loss	Target
EFB	Oil on bunch	<0.6%
Fibre	Oil content	<5.0%
Sludge	Oil loss	<1.0%
Kernel	Broken kernel	<5%

💡 0.1% oil loss = big money when running 60–90 TPH.

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🧠 Why Mass Balance Is Powerful

• Detect hidden losses

• Compare shift vs shift

• Identify bad machines vs bad operation

• Support management decisions with numbers

A mill with good machines but poor mass balance control still loses profit.

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📌 Engineer’s Tip (From Experience)

Don’t chase production first.
👉 Chase losses — production will follow.