Oil is one of the raw materials of human food, and it is an indispensable substance for human life energy and body metabolism. Oils and fats are also industrial raw materials for daily chemicals, textile printing and dyeing, rubber and plastics, chemical coatings, and medicine. Oil processing steps include oil pretreatment, oil preparation, oil refining, and so on.
The following uses soybean as an example to describe the processing process:
Oil pretreatment includes metering, cleaning, crushing, softening, rolling and baking, etc .;
清理 Clean up
The purpose of oil cleaning is to remove impurities in the oil and include stones, soil, stems and leaves and other impurities. The main methods used are screening, wind separation, water separation, and combined cleaning methods.
破碎 2. Broken
The purpose of crushing is to increase the contact surface of oilseed heating during subsequent softening of the oil material, to facilitate the adjustment of moisture and material temperature, to prepare high-quality raw embryos, and to make the materials easily enter the gap between the rolls in the embryo rolling machine.
软化 3. soften
The softening of the oil is to properly adjust the moisture and temperature of the crushed or small particles of oil, especially for oils with low oil content and low water content, so that the oil has the best entry conditions required for the subsequent blank rolling process.
轧胚 4. Rolled embryo
The blank rolling is a process of rolling the prepared granular material into sheet-like ingredients by using a double-roller or multi-roller blank rolling machine.
烘胚 5. Baking embryo
Baking the embryo is to process the embryo material prepared by rolling the embryo, adding water, heating, drying and other treatments. Its role is to condense the oil, adjust the structure of the material embryo, and improve the quality of the oil.
Oil preparation includes four processes including soaking, wet meal evaporation, mixed oil treatment, and solvent recovery;
浸泡 1. soak
The raw material is immersed in a solvent, so that most of the fat is dissolved in the solvent to form a mixed oil.
湿粕蒸脱 2. Wet meal steamed off
The solid residue (wet meal) is immersed. In order to recover the solvent remaining in the wet meal, and also to obtain a better finished dry meal, the wet meal treatment of heating and solvent removal is required.
混合油处理 3.Mixed oil treatment
The mixed oil leached out contains a certain amount of solvent, and the solvent must be separated from the fat to obtain the leached crude oil. First, the mixed oil is filtered and settled to remove the powder and sticky substances. After using the difference in boiling point between the solvent and the oil, it is first heated and evaporated to vaporize most of the solvent, and the remaining oil is stripped (water steam distillation). , Distill out the residual solvent to obtain qualified leachable oil.
溶剂回收 4. Solvent recovery
During the leaching production process, the solvent gas, waste water and free gas volatilized in various equipment and pipes discharged from the mixed oil treatment and wet meal treatment processes are condensed and recovered. Minimize solvent loss during leaching production.
Oil refining includes degumming, deacidifying, decoloring, deodorizing and other processes;
That is, the process of removing gel-soluble impurities in the hair oil is mainly the presence of gelatinous substances such as phospholipids, which reduces the quality of fats and oils. The main methods are hydration degumming and acid degumming.
脱酸 2. Deacidification
It mainly removes free fatty acids in hair oil, as well as a small amount of gum, pigment and trace metal substances remaining in the oil. The methods mainly include alkali refining deacidification method and steam distillation deacidification method.
脱色 3. Discoloration
The decoloring agent with the function of adsorbing pigments is mixed into the pre-processed semi-finished oil and fat, and the separated decoloring agent is removed by filtration after the contact reaction is maintained for a certain time. Decolorizing agents usually use activated clay and activated carbon.
脱臭 4. Deodorization
The main function is to remove odors and odors from the oil. For example, the peculiar smell of oil, the odor of leaching out of crude oil, and the smell of clams caused by oxidation of fats and oils, etc. The specific method is a distillation method in which direct steam is injected into fats and oils under high vacuum and high temperature.