Physical Refining vs Chemical Refining: How Do You Choose the Right Process for Edible Oil?

A question I hear from almost every new investor

“Should we choose physical refining or chemical refining?”

When someone is planning an edible oil refinery, this is one of the first technical questions they will ask me.

It sounds like a simple question, but in reality, the answer is rarely black and white.

Over the years, I’ve learned that the best way to approach this decision is not to ask “Which process is better?” but rather:
“Which process is better for your oil, your market, and your long-term operation?”

Let me walk you through how we usually help customers think about this.

First, let's simplify what these two processes really mean

Without getting too technical, the key difference comes down to how free fatty acids (FFA) are removed from the oil.

In chemical refining, free fatty acids are neutralized using an alkaline solution. In physical refining, free fatty acids are removed through high-vacuum steam distillation during deodorization.

Both methods are widely used in the industry, and both can produce high-quality edible oil when the system is designed properly.

The real question is: Which one fits your raw material and production strategy better?

When chemical refining often makes more sense

From our experience, chemical refining is usually preferred when the crude oil contains higher levels of impurities, such as phospholipids or metals.

For example, some crude soybean oils or oils with less stable storage conditions may benefit from chemical refining because the process provides greater flexibility in handling variable feedstock quality.

Another advantage is that chemical refining can be more forgiving when raw oil quality fluctuates. For plants processing oil from multiple sources, this flexibility can be valuable.

However, the trade-off is that chemical refining typically involves higher chemical consumption and additional processing steps.

When physical refining becomes the better choice

Physical refining has become increasingly popular in modern large-scale plants, especially for oils like:

🔸 Palm oil

🔸 Palm kernel oil

🔸 Well-prepared sunflower oil

🔸 High-quality soybean oil

The reason is simple: When the crude oil is properly pre-treated, physical refining can offer several advantages.

In many projects we’ve worked on, physical refining allows customers to achieve:

🔸 Lower operating cost

🔸 Reduced chemical usage

🔸 Simpler process flow

🔸 Improved environmental performance

But there is one important condition: The pretreatment and degumming stages must be designed very carefully. Without proper pretreatment, physical refining can become unstable.

The decision is often more about raw material than technology
One thing I often explain to clients is that this decision should start with your raw material, not with the equipment.

Before recommending a process, we typically evaluate:

🔸 Crude oil quality

🔸 Phospholipid content

🔸 Metal and impurity levels

🔸 Expected variability in raw material supply

Once we understand these factors, the choice between physical and chemical refining usually becomes much clearer.

Energy efficiency and long-term operating cost

Another factor that investors sometimes overlook is long-term operating cost. In well-designed systems, physical refining often offers advantages in:

🔸 Lower chemical usage

🔸 Reduced wastewater generation

🔸 More streamlined operation

However, the deodorization system in physical refining requires very precise temperature and vacuum control. That's why process design and equipment quality become extremely important.

Why process design matters more than the process label

In reality, I've seen both physical and chemical refining plants perform extremely well — and I’ve also seen both perform poorly.

The difference rarely comes from the refining method itself. It usually comes from how well the entire process is engineered.

Experienced suppliers focus not just on selecting a process, but on optimizing the whole refining system, including:

🔸 Heat recovery

🔸 Vacuum stability

🔸 Automation and process control

This is where experienced turnkey providers, including companies like Myande Group, typically invest most of their engineering effort — ensuring the chosen refining method operates reliably under real plant conditions.

Questions I usually ask before recommending a process

When discussing refining technology with customers, I often start with a few simple questions:

🔸What type of crude oil will you process most of the time?

🔸How stable is the quality of your raw material supply?

🔸Are you prioritizing flexibility or operating efficiency?

🔸How important is wastewater and chemical reduction in your project?

Once these answers are clear, the technology choice becomes much more straightforward.

A practical way to think about the decision

If your crude oil quality is stable and pretreatment can be well controlled, physical refining often offers better long-term efficiency.

If your raw material varies significantly or contains higher impurities, chemical refining may provide greater operational stability.

In the end, the best refining process is not the one that looks best on paper — it's the one that works reliably every day in your plant.

Choosing between physical refining and chemical refining is not just a technical decision. It's a strategic one.

The right process will influence your operating cost, product quality, environmental footprint, and long-term profitability. That's why we always encourage investors to evaluate this choice carefully during the early engineering stage — because once the plant is built, changing the refining process later becomes much more difficult.

Frequently Asked Questions (FAQs)