Water-saving plant crude oil refining pretreatment method

Abstract

The invention belongs to the technical field of plant crude oil refining, and particularly relates to a water-saving plant crude oil refining pretreatment method. The invention relates to a water-saving plant crude oil refining pretreatment method, which is characterized by comprising the following steps: (1) taking plant crude oil, adding carbonate and CaCl2 or MgCl2, uniformly stirring, and reacting; and (2) centrifuging, and taking supernatant to obtain degummed crude plant oil. According to the method, the plant crude oil is degummed, the degumming rate is high, in the embodiment of the invention, the phosphorus content of the unrefined rice bran crude oil is 246.88 mg / kg, and the phosphorus content can be reduced to 99.54 mg / kg at the minimum after degumming. Compared with a hydration degumming method, the method has the biggest advantage of saving water, the rice bran crude oil is subjected to adsorption degumming through inorganic salt precipitation reaction, water resources are greatly saved, and the degumming cost is further reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of crude plant oil refining, and in particular relates to a water-saving crude plant oil refining pretreatment method. Background Art

[0002] The main method for pre-refining of crude vegetable oil is degumming. The main methods are as follows: Acid degumming: The commonly used method is to weigh the crude rice bran oil in a conical flask, add citric acid and stir at a uniform speed after heating, and then add distilled water for hydration. After the reaction, let it stand and centrifuge to obtain degummed oil. Acid degumming cannot reduce the phosphorus content in crude rice bran oil. It takes multiple acid degummings to reduce the crude oil to a level that meets physical refining requirements. Citric acid solution is used in the acid degumming process, and alkali solution needs to be added for neutralization in the subsequent refining process. This process increases the production steps and the addition of alkali solution will also reduce the final oil yield.

[0003] Hydration degumming: Take crude rice bran oil, stir it by magnetic heating, add water at the same temperature, wait for the colloid to flocculate, and centrifuge after the colloidal impurities and oil are obviously separated. Vacuum dehydrate and dry the upper layer of oil to obtain degummed oil. The degumming of crude rice bran oil is mainly to remove the phospholipids in the crude oil and reduce its phosphorus content, but hydration degumming can only simply remove hydrated phospholipids, and non-hydrated phospholipids cannot be effectively removed; and hydration degumming requires the use of a large amount of water resources. First, water resources themselves have a certain cost, and second, the sewage treatment brought about by the production process will increase the cost, which leads to high cost of this method in industrial production.

[0004] Enzymatic degumming: weigh the crude oil, add citric acid after heating and stir at a uniform speed, then add sodium hydroxide to adjust the pH of the system, and then add 2 mL PLA1 to degumming the rice bran crude oil, centrifuge, and obtain crude oil and oil foot. Most PLA1 enzymatic hydrolysis of phospholipids in vegetable oil requires at least 4 hours, and the degumming time is long; the temperature needs to be precisely controlled during the enzymatic degumming process, and the temperature is difficult to accurately control, which will cause temperature fluctuations during the reaction; in addition, due to the high price of enzymes, enzymatic degumming has not been widely promoted.

[0005] Therefore, it is necessary to improve the above method and invent a vegetable oil degumming method which is water-saving, has good degumming effect and is low in cost. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a vegetable oil degumming method which is water-saving, has good degumming effect and low cost. By adopting this method, the phosphorus content of crude oil can be reduced from 246.88 mg / kg to 99.54 mg / kg, thereby greatly improving the degumming rate.

[0007] The specific method of the present invention is as follows: (1) Take crude vegetable oil, add carbonate and CaCl2 / Mg2Cl2, stir evenly and react; (2) Centrifuge and take the supernatant to obtain the degummed crude vegetable oil.

[0008] The above carbonates are Na2CO3 or K2CO3.

[0009] Preferably, in (1), the crude vegetable oil is rice bran oil, and of course it can also be other vegetable oils, such as peanut oil, corn oil, soybean oil, etc. The above are only examples and are not exhaustive. After replacing the vegetable oil, the degumming principle of the present invention can also achieve excellent degumming effect.

[0010] Preferably, taking rice bran crude oil refining and degumming as an example, its degumming method is as follows: (1) Take 10 g of crude rice bran oil, add 1 mL of 1 M Na2CO3 and 400 μL of CaCl2, stir evenly, and react for 20 min; (2) Centrifuge at 7500 r / min for 3 min, retain the supernatant, and obtain the degummed rice bran crude oil.

[0011] The beneficial effects of the present invention are: (1) The method of the present invention is used to degumming crude vegetable oil, and the degumming rate is high. In the embodiment of the present application, the phosphorus content of unrefined crude rice bran oil is 246.88 mg / kg, which can be reduced to 99.54 mg / kg after degumming; (2) Compared with the hydration degumming method, the method of the present invention has the greatest advantage of saving water. The present invention utilizes inorganic salt precipitation reaction to adsorb and degumming crude rice bran oil, which greatly saves water resources and further reduces the cost of degumming. (3) The method of the present invention also has a significant effect on decolorizing and reducing turbidity of crude vegetable oil, and is suitable for large-scale production applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The effect of different concentrations of CaCl2 on the phosphorus content of crude oil; Figure 2 The effect of different concentrations of CaCl2 on the decolorization rate of crude oil; Figure 3 To compare the degumming effects of different raw material combinations; Figure 4 The effect of K2CO3 and different concentrations of CaCl2 on the turbidity of crude rice bran oil; Figure 5 The actual photos show the effect of K2CO3 combined with different concentrations of CaCl2 on the turbidity of crude rice bran oil; Figure 6The effect of Na2CO3 and different concentrations of MgCl2 on the turbidity of crude rice bran oil; Figure 7 The actual photos show the effect of Na2CO3 and different concentrations of MgCl2 on the turbidity of crude rice bran oil; Figure 8 The effect of NaHCO3 and different concentrations of CaCl2 on the turbidity of crude rice bran oil; Fig. 9 These are actual photos of the effect of NaHCO3 combined with different concentrations of CaCl2 on the turbidity of crude rice bran oil. DETAILED DESCRIPTION

[0013] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0014] Example 1 Accurately weigh 10g of crude oil and put it in a 50mL stoppered conical flask, add 1M Na2CO3 and CaCl2 to the oil, continue to stir evenly and react for 20 minutes, then centrifuge at 7500r / min for 3 minutes, and take the supernatant to obtain the degummed oil.

[0015] Example 2 Accurately weigh 10 g of crude oil and put it into a stoppered conical flask, add 100 mM K2CO3 and CaCl2 to the oil, continue to stir evenly and react for 20 minutes, then centrifuge at 7500 r / min for 3 minutes, and take the supernatant to obtain the degummed oil.

[0016] Example 3 Accurately weigh 10g of crude oil and put it into a stoppered conical flask, add 100mM Na2CO3 and MgCl2 to the oil, continue to stir evenly and react for 20min, then centrifuge at 7500r / min for 3min, and take the supernatant to obtain the degummed oil.

[0017] Example 4 Accurately weigh 10g of crude oil and put it into a stoppered conical flask, add 1M NaHCO3 and CaCl2 to the oil, continue to stir evenly and react for 20 minutes, then centrifuge at 7500r / min for 3 minutes, and take the supernatant to obtain the degummed oil.

[0018] Example 5 5.1 The inventors investigated the effect of CaCl2 concentration on the phosphorus content of crude oil during the experiment. The specific experiment is as follows: Referring to the method of Example 1, 1M Na2CO3 (added in an amount of 1 ml) and CaCl2 (added in amounts of 200 μL, 400 μL, 600 μL, 800 μL, 1000 μL, and 1200 μL, respectively) were reacted at ratios of 5:1, 5:2, 5:3, 5:4, 5:5, and 5:6, and the results were detected. The detection method was as follows: GB / T 5537-2008 was used to detect the effect of CaCl2 concentration on the phosphorus content of crude oil.

[0019] The results are shown in Table 1 and Figure 1 As shown: Table 1 Effect of CaCl2 concentration on phosphorus content in crude oil <![CDATA[CaCl 2]]> 0μL 200μL 400μL 600μL 800μL 1000μL 1200μL Phosphorus content mg / kg 246.88 160.35 137.36 166.98 151.39 196.21 207.13 From the above table and Figure 1 It can be seen that when the volume ratio of Na2CO3 to CaCl2 is 5:2, the phosphorus content in the crude oil after degumming is the lowest. When the concentration of CaCl2 is further increased, the phosphorus content in the crude oil will increase instead.

[0020] 5.2 Effect of CaCl2 concentration on crude oil decolorization Referring to the method of Example 1, Na2CO3 (100 μL) with a concentration of 100 mM and CaCl2 (added in amounts of 20 μL, 40 μL, 60 μL, 80 μL, 100 μL, and 120 μL, respectively) were reacted at a ratio of 5:1, 5:2, 5:3, 5:4, 5:5, and 5:6, and the decolorization rate was calculated as follows: Decolorization rate (%) = (A0-A1) / A0×100%, Where: A0—absorbance of crude rice bran oil before bleaching; A1—absorbance of crude rice bran oil after bleaching; The results are attached Figure 2 As shown in Table 2: Table 2 Effect of CaCl2 concentration on crude oil decolorization rate <![CDATA[CaCl 2]]> 0μL 20μL 40μL 60μL 80μL 100μL 120μL Decolorization rate% 0 11.84 38.48 36.15 27.695 42.075 38.69 From the table above, it can be seen that when the concentration is 100mM, the decolorization effect is best when the amount of CaCl2 added is 100μL. At this time, the volume ratio of Na2CO3 to CaCl2 is 5:5.

[0021] 5.3 Investigating the degumming effect of different raw material combinations The versatility of this method was verified according to the following reaction formulas: Group I: CaCl2+K2CO3→CaCO3↓+2KCl, K2CO3: 100mM, 100μL; CaCl2 volume: 40μL; Group II: MgCl2+Na2CO3→MgCO3↓+2NaCl, Na2CO3: 100mM, 100μL; MgCl2 volume: 40μL; Group III: CaCl2+2NaHCO3→CaCO3↓+H2O+CO2↑, NaHCO3 is: 1M, 80μL; CaCl2 volume is 40μL.

[0022] Taking phosphorus content as the standard, the specific test results are shown in Table 3 and Appendix Figure 3 As shown: Table 3 Dephosphorization effect under different raw material combinations Phosphorus content (mg / kg) Comparison 249.22 Group I 99.55 Group II 174.77 Group III 192.70 From the attached Figure 3 It can be seen that the use of inorganic salt precipitation reaction in different groups to degumming crude vegetable oil will have certain effects, among which CaCl2+K2CO3 has the best effect.

[0023] 5.4 Effect of different concentrations of CaCl2 on the turbidity of crude rice bran oil The results are shown in Table 4 and Appendix. Figure 4 As shown, the photo comparison is as attached Figure 5 As shown: Table 4 Effect of different concentrations of CaCl2 on the turbidity of crude rice bran oil <![CDATA[CaCl2]]> 0μL 20μL 40μL 60μL 80μL 100μL Turbidity (NTU) 32.42 9.74 12.35 12.21 10.62 19.05 From the table above, we can see that the decolorization rate is best at 5:1. Figure 5 The results show that the turbidity (transparency) of crude oil changes significantly when observed with the naked eye. The best decolorization effect is achieved when the concentration is 100mM and the amount of CaCl2 added is 20μL.

[0024] 5.5 Effect of different concentrations of MgCl2 on the turbidity of crude rice bran oil The concentration of 100mM Na2CO3 (added in 100μL) and MgCl2 (added in 20μL, 40μL, 60μL, 80μL, respectively) were reacted at a ratio of 5:1, 5:2, 5:3, 5:4, and the specific results are shown in Table 5 and Appendix. Figure 6 , 7 As shown: Table 5 Effect of different concentrations of MgCl2 on the turbidity of crude rice bran oil <![CDATA[MgCl2]]> 0μL 20μL 40μL 60μL 80μL Turbidity (NTU) 32.42 15.32 12.17 12.25 11.6 From the above table, it can be concluded that the decolorization rate is best at 5:4. Figure 7 In the experiment, it can be observed that the turbidity (transparency) of the crude oil has obvious and clear changes.

[0025] 5.6 Effect of different concentrations of CaCl2 on the turbidity of crude rice bran oil The concentration of 1M NaHCO3 (added in an amount of 100 μL) and CaCl2 (added in an amount of 20 μL, 40 μL, 60 μL, 80 μL, respectively) were reacted at a ratio of 5:1, 5:2, 5:3, 5:4, as shown in Table 6 and Appendix. Figure 8 , 9 As shown: Table 6 Effect of different concentrations of CaCl2 on the turbidity of crude rice bran oil <![CDATA[CaCl2]]> 0μL 20μL 40μL 60μL 80μL Turbidity (NTU) 32.42 18.67 23.13 19.00 15.24 It can be seen from the above table that when the volume ratio of NaHCO3 to MgCl2 is 5:4, the decolorization rate is the best. Fig. 9 It can be observed with the naked eye that the turbidity (transparency) of the crude oil has obvious and clear changes.

Claims

1. A water-saving crude plant oil refining pretreatment method, characterized in that: The following steps are involved: (1) Take crude vegetable oil, add carbonate and CaCl2 or MgCl2, stir evenly and react; (2) Centrifuge and take the supernatant to obtain the degummed crude vegetable oil.

2. A water-saving crude plant oil refining pretreatment method as claimed in claim 1, characterized in that: In (1), the crude vegetable oil is rice bran oil.

3. A water-saving crude plant oil refining pretreatment method as claimed in claim 1, characterized in that: (1) The carbonate is Na2CO3 or K2CO3, the concentration of carbonate is 0.9~1.1M, and the volume ratio of carbonate to CaCl2 / MgCl2 is 5:1.8~2.

2.

4. A water-saving crude plant oil refining pretreatment method as claimed in claim 3, characterized in that: (1), the volume-to-weight ratio of carbonate to crude vegetable oil is 1 mL: 9-11 g.

5. A water-saving crude plant oil refining pretreatment method as claimed in claim 3, characterized in that: (1) and stir the reaction for 15-25 min.

6. A water-saving crude plant oil refining pretreatment method as claimed in claim 1, characterized in that: (2) The centrifugal speed is 7000~8000r / min and the centrifugal time is 2~4min.

7. A water-saving crude vegetable oil refining pretreatment method as claimed in claim 1, comprising the following steps: (1) Take 10 g of crude rice bran oil, add 1 mL of 1 M Na2CO3 and 400 μL of CaCl2, stir evenly, and react for 20 min; (2) Centrifuge at 7500 r / min for 3 min, retain the supernatant, and obtain the degummed rice bran crude oil.

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