This document discusses different techniques for oil extraction from oilseeds, including expellers and extruders. It notes that India produces 33 million tonnes of oilseeds annually but loses around 6% to inefficient processing. Traditional animal-powered expellers recover only 15% oil from the seed cake, while modern mechanical expellers and solvent extraction plants recover 6-8% and less than 1% respectively. The document then examines single screw extruders and expanders for oil extraction. It finds that extruders using short heating times can extract 50-75% of oil in one pass while maintaining high protein levels and inactivating trypsin inhibitors in the seed cake. Integral extrusion expelling units that combine extrusion and pressing show

1. Application of Expanders and
Extruders for Oil Seed Processing
Dr. R. T. Patil
Fmr Director
Central Institute of Post Harvest
Engineering & Technology, Ludhiana

2. Oil Extraction
•Oil Seed Production of India is 33 million tonnes,
losses are to about 6%.
•Oil from by products
–Rice Bran
–Maize Germ
–Millet bran
•Oilseed processing is a major segment, an activity
largely concentrated in the cottage industry.
• 2.5 lakh ghanis and kolus which are animal operated
oil expellers (cake has 15% fat)
•50,000 mechanical oil expellers (Cake 6-8%)
•15,500 oil mills (Cake 5-6%)
•725 solvent extraction plants (Cake/Meal <1%)
•300 oil refineries and
•over 175 hydrogenated vegetable oil plants.

3. Oil Expelling Techniques

4. SINGLE SCREW EXTRUDER

5. Extruder Expelled Product Quality
The high temperature-short time extrusion
cooking process eliminates the prolonged
heating and holding of raw material in
conventional expelling. Under the
experimental conditions, press cake with
50% protein, 6% residual oil and 90%
inactivation of trypsin inhibitors was
obtained

7. Extruder Expelling Process
• Coarsely ground whole soybeans at 10 to
14% moisture are extrusion cooked to get
extrudate in a semi-fluid state.
• The dwell time within the extruder was less
than 30 seconds, and the temperature was
raised to about 135 C.
• The semi-fluid extrudate is immediately
pressed in a conventional screw press
• High quality oil and press cake is obtained
Oil recovery of above 70-75% was obtained
in single pass expelling

8. • Capacity 100 kg /h
• Oil recovery 65 – 70 % in
single pass
• Good quality MFSF (Protein
48 %, Fat 6-8 %, TI
Inactivation up to 70 %)
•Development of commercial
unit ( 250 kg /h) in progress
in collaboration with a
manufacturer
Integral Extrusion Expelling Unit

9. EXPANDER - EXTRACTION

11. Oil Recovery during Expansion
The flaked and heated rapeseed at 44% oil content, is fed
directly into the expander. Live steam is injected about
halfway down the barrel and 15-20% oil is expressed
leaving 25-30% oil in collets.
The oil recovered is 3-5% solids level, less than 0.3%
moisture level, and is of the same, or better, quality as
pre-press oil.
The expander operates at lower temperature than a
prepress, and most of the heat is supplied through
injected steam rather than shaft friction.
The maximum temperature reaches at 110-115°C at a
point 150 mm upstream of the die openings.
Oil flows from material at 87-115"C, average oil
temperature being 85-95°C.

12. Thank You
Contact: ramabhau@gmail.com
Mob. No. 8964030701