Industrial Skid Mount Chemical Dosing System

In physical oil refining, acid dosing, typically phosphoric acid, is used in the degumming process to convert non-hydratable phospholipids (NHPs) and other phosphatide complexes into hydratable ones, making them easier to remove via water washing or centrifugation. The acid dose is critical, with typical ranges being 0.1% to 1.0% of the oil by weight, and the goal is to significantly reduce the oil's phosphorus content and the risk of issues like gum formation in subsequent refining stages. 
Purpose of Acid Dosing

• Phospholipid Removal: 
  Acids like phosphoric acid are added to break down non-hydratable phospholipids (NHPs) into hydratable ones, which are then more effectively separated from the oil. 
• Metal Removal: 
  The acid helps to dissociate metal-phospholipid complexes, allowing the metals to precipitate out. 
• Improving Oil Purity: 
  By removing these undesirable components, the acid treatment leads to a significant reduction in phosphorus content and other impurities. 

Key Factors in Acid Dosing

• Acid Type and Concentration: 
  Phosphoric acid is common, but other acids such as citric acid can also be used. The concentration of the acid solution is also a key factor. 
• Temperature and Time: 
  The reaction between the acid and the oil occurs at elevated temperatures, often around 90°C, with a specific holding time to allow for complete reaction and agglomeration of the hydratable phospholipids. 
• Mixing: 
  Intensive mixing is essential to ensure thorough contact between the oil and the acidic solution, promoting an efficient reaction. 
• Dosage: 
  The amount of acid is carefully controlled. A dose of 0.1% to 1.0% phosphoric acid is a common range in the refining of products like palm oil. 

Process Steps

1. Heating: 
   The crude oil is heated to a suitable temperature, typically in the range of 60-90°C. 
2. Acid Addition: 
   The measured dose of acid solution is added to the heated oil. 
3. Mixing: 
   The mixture is then intensively mixed for a specific duration to facilitate the conversion of NHPs into hydratable forms. 
4. Separation: 
   Water is often added, and the mixture is mixed further to allow the hydratable phospholipids to agglomerate. The precipitated gums are then separated from the oil by centrifugation or gravity. 

1  

Bunge Loders Croklaan Oils Sdn Bhd