Coconut oil pressing extraction line
Raw material pretreatment
Dried coconut selection and cleaning: Choosing high-quality dried coconut is the basis for oil extraction. High-quality copra should be mold-free, insect-free, and have a low moisture content (usually around 6-10%). Before pressing the oil, the dried coconut needs to be cleaned to remove impurities such as sand, coconut shell fragments, etc. Cleaning can be done through screening, winnowing, etc.
Crushing and grinding: In order to increase the oil yield, copra needs to be crushed and ground. Break the copra into smaller particles and grind it into a fine powder using a grinder. The degree of grinding should be moderate. If it is too coarse, it will lead to low oil yield. If it is too fine, it may affect subsequent filtration and other operations.
Oil extraction method
Mechanical pressing method: This is a traditional method of oil extraction. The ground copra powder is put into a screw press, and the rotation of the screw shaft exerts pressure on the copra powder so that the oil is squeezed out of the copra powder. The oil yield of this method is relatively stable, generally around 60-70%. During the pressing process, attention should be paid to controlling the pressure and temperature. The pressure is generally around 20 – 30MPa, and the temperature is maintained at 60 – 80°C to avoid deterioration of oil quality caused by excessive temperature.
Solvent extraction method (auxiliary): In some cases, in order to improve the oil yield, solvent extraction method can be used as an auxiliary method. A commonly used solvent is hexane. Soak the dried coconut powder in hexane to dissolve the oil and fat in the solvent, and then separate the solvent and oil through evaporation and other methods. However, this method requires strict control of the residual amount of solvent, because hexane is an organic solvent, and excessive residual amounts can cause harm to human health and the environment. The extraction method has a high oil yield, which can reach more than 90%, but the extracted oil needs further refining.