Effect of crude oil quality on refining loss
1. Content of suspended impurities in crude oil
The suspended impurities in crude oil not only directly cause refining loss, but also affect the effect of hydration degumming and alkali refining deacidification. Due to the existence of suspended impurities, it is easy to cause emulsification during hydration alkali refining, which reduces the separation effect of oil and oil foot or soap foot, increases the amount of neutral oil entrained by oil foot or soap foot, and increases the additional loss. Therefore, measures should be taken to reduce the impurity content of crude oil, such as increasing or improving the oil residue separation process of crude oil, extracting the evaporated meal of mixed oil, etc.
2. Colloid content in crude oil
Colloidal impurities have influence on degumming, deacidification, decolorization and even deodorization. High colloidal content leads to high loss of degumming. Due to the emulsifying property of colloid, the additional loss is bound to increase. Especially when the content of non hydrated phospholipids is high, it must be removed from the oil by auxiliary agents such as phosphoric acid and alkali, which not only increases the use of auxiliary agents, but also increases the extra loss of oil.
The effect of colloidal impurities on Deacidification is mainly due to its strong surface activity, which makes it easy to produce lasting emulsification in alkali refining. The reaction between colloidal impurities and alkali increases the amount of excess alkali.
In the decolorization process, the phosphorus content in the oil will increase the use of activated clay, increase the entrainment loss, reduce the filtration efficiency and affect the output. Due to the high phosphorus content, the deodorization effect is affected, and the color of the finished product is deepened and easy to return to color.
In the process of oil preparation, the content of non hydrated phospholipids can be effectively reduced and the refining effect of oil can be greatly improved by using such technologies as expansion, wet heat treatment and inactivation of phospholipase.
3. Pigment in crude oil
Pigment in oil can be divided into natural pigment and processing pigment. Natural pigment is mainly chlorophyll, carotenoid and other pigments. Processing pigment is a new pigment produced in the process of oil storage, transportation and processing. It is mainly the degradation product of protein, carbohydrate and phospholipid in fission oil, or the pigment produced by oxidation and isomerization of oil and other lipids. The processing pigment is more difficult to remove than the natural pigment. In order to remove the processing pigment, more clay or other adsorbents should be added, or the method of thermal decolorization should be used. These will undoubtedly increase the refining consumption of oil. Therefore, effective measures should be taken in the process of storage, transportation and processing to minimize the production of such processing pigments. For example, to prevent the heating and red change of oil.
4. Influence of acid value and odor component content in crude oil
The concentration of odor components in oil has a direct impact on the deodorization loss and deodorization effect of oil. There is a certain relationship between the content of odor components in oil and the content of fatty acids. The content of free fatty acids decreases, and the content of odor components also decreases. When the content of free fatty acids decreases to 0.01% - 0.03%, the odor can be qualified by sensory identification. The high content of acid value and odor components in the oil not only increases the refining loss, but also increases the consumption of direct steam, more heat input, longer deodorization time and more splash loss. Therefore, the main goal of deodorization loss control is to take effective measures to reduce the formation of odor components according to the source of odor components.
