On August 15, 2023, a Russian company ordered Huatai Group's 200T rapeseed and sunflower seed pre-pressing, and the 150T cake extraction project was shipped. 

Investors of oil equipment know that the first step in oil refining is the pretreatment of oilseeds, followed by the extracting stage and refining process. Oilseed pretreatment is to clean up impurities such as mud, metal, stems and leaves contained in the oilseeds, and separate out mixed impurities such as mixed seeds and shrunken seeds. Oilseeds inevitably contain some impurities such as stones, mud, stems and leaves, hemp ropes and other impurities during harvesting, drying, transportation and storage. Although the initial selection has been made, some impurities will still be carried during transportation to the oil mill. The content is generally around 1%-6%, these impurities are extremely unfavorable to oil production and need to be cleaned up.

Impurities contained in oilseeds are mainly divided into three categories: inorganic impurities, organic impurities and oily impurities. Inorganic impurities are mainly dust, sand, stones, tiles, metals, etc.; organic impurities are mainly stems and leaves, shells, Artemisia annua, hemp ropes, various grains, etc.; oily impurities are mainly diseased and insect-damaged grains, false grains and different oilseeds. The purpose of cleaning is to clean up various impurities from the oilseeds input for processing. It has the following practical significance for oil production.

1. It can improve the oil yield.

Most impurities do not contain oil and fat. If they are not removed before pressing or extracting, they will adsorb a corresponding amount of oil and fat and remain in the cake, reducing the oil yield. If there is too much mud and ash in the oilseeds, it will reduce the plasticity of the material embryo, make it loose, unable to withstand greater pressure, and cause blockage or sticky oil in the oil passage, affecting the oil yield. Therefore, removing impurities can improve the oil yield.

2. It can improve the quality of oil and cake

Organic impurities such as soil, plant stems and leaves, and shells contained in oilseeds will deepen the color of crude oil, increase sedimentation, and increase refining consumption. As for cakes and meal, some can be used as raw materials for food and chemical products. If they contain too many impurities, it will reduce their value. Some impurities are even harmful to humans and animals. For example, even if a small amount of Tung seed is mixed in rapeseed or a small amount of castor seeds is mixed in sunflower seeds, the crude oil and cake cannot be eaten or used as feed. With the rapid development of the food industry and other industries, people’s requirements for improving the quality of oil and cake are getting higher and higher. Therefore, removing impurities from oilseeds has become increasingly important.

3、It can reduce equipment wear and tear

Impurities such as mud, stones, and metals have a strong frictional effect on the equipment, which quickly wears out various parts and greatly shortens their service life. Hard impurities such as metals and stones are more harmful to equipment with high operating speed and pressure and can easily damage the parts. Therefore, cleaning impurities will reduce equipment wear and extend its service life.

4、It can avoid production accidents

When metal impurities enter equipment with high operating speed and pressure (such as shelling machines, rolling machines, and oil presses), they will damage the equipment and cause accidents. Long fiber impurities such as hemp ropes and Artemisia annua in oilseeds are easy to wrap around the rotating shaft of the operating equipment, affecting the process effect, increasing power consumption, and even blocking the inlet and outlet of the equipment, causing production accidents or equipment failures. Therefore, removing these impurities is conducive to ensuring smooth production.

5、It can increase the processing capacity of equipment.

Impurities occupy a corresponding volume in oilseeds. The more impurities in oilseeds, the larger the volume occupied, especially stems and shells. Removing impurities from oilseeds can reduce the burden on equipment and increase its processing capacity.

6、It can improve production conditions.

Dust contained in oilseeds will cause workshop dust during transportation and processing, which is harmful to workers’ health, causes environmental pollution, and may even cause explosions when serious. Cleaning impurities can create a good sanitary environment, ensure workers’ physical health and happy mood, stabilize production, and improve product quality.

Extraction is one of the common processing methods in the edible oil processing industry. Projects that use extraction usually have a large output, such as projects with a daily output of more than 30 tons, which are more suitable for extraction oil. Common projects that use extraction equipment include soybean oil, rapeseed oil, cottonseed oil, rice bran oil and other extraction oil projects.

The process of extraction oil can be divided into two types: direct extraction and pre-pressing extraction. The choice of process is determined by the oil content of the oilseeds. For oilseeds with low oil content, such as soybeans and rice bran, direct extraction process can maximize the extraction of oil. If it is an oilseed with high oil content, such as rapeseed and peanuts, pre-pressing and extracting can be used. First, 80%~89% of the oil is squeezed out with an oil press machine, and then the pressed cake is crushed and sent to the extracting equipment to extract the remaining oil.

Regardless of which extracting process is used, the advantages of extraction are very obvious: high oil yield, low residual oil rate (less than 1%), and high quality cake that is conducive to secondary utilization.

The types of equipment required for a complete set of extraction equipment production lines are many. From raw materials to finished oil, it can be divided into three stages:

1、Raw material pretreatment:

The purpose of this stage is to clean, remove stones, crush, steam and fry, extrude and other operations on the raw materials. Different equipment is required according to different raw material varieties. For example, for rice bran extracting, the extruding extracting process is usually used, which can better change the structure of rice bran and make it more conducive to extraction oil. This part requires different equipment according to different raw materials. Commonly used equipment includes: vibration cleaning and stone removal machine, crusher, rolling mill, extruding machine, steaming and frying pot, etc.

2、Oil extraction：

In this stage, the extraction equipment uses solvents to fully contact with the pretreated oilseeds to extract oil and form mixed oil. Then use the solvent with different boiling points from the oil to evaporate, distill, condense and recover it to separate crude oil from solvent. The crude oil enters the next process and the solvent is recovered for reuse. The complete set of extraction equipment consists of a cake extraction system, a wet meal steaming and drying system, a mixed oil evaporation system, and a solvent recovery system.

3、Crude oil refining:

Extraction oil must be equipped with refined oil equipment, not only because of the impurities contained in the oil, but also because the extracted crude oil will contain a small amount of solvent residue, which is harmful to the human body after consumption. It needs to be controlled within a reasonable range through refining equipment.

Refining equipment generally includes five main processes: degumming, deacidification, dehydration, decolorization, and deodorization. Because some oils need to be dewaxed, such as rice bran oil, camellia seed oil, walnut oil, etc., a dewaxing equipment needs to be configured after deodorization. After the above “six removal” process, the refined oil is filled and sealed after passing the inspection, which is the edible oil sold in supermarkets.

The production line of extraction equipment is a relatively large investment project. The quality and safety requirements of the equipment are relatively high. Therefore, customers should compare and investigate more when choosing manufacturers to choose manufacturers that are suitable for themselves and have more guarantees in terms of scheme design, equipment quality, and after-sales service.