Camellia oil decolorization method based on modified palm wood-based activated carbon

Abstract

The invention discloses a camellia oil decolorizing method based on modified palm wood-based activated carbon, and belongs to the technical field of grease refining. According to the method, renewable palm wood (oil palm) is used as a raw material for preparing activated carbon, OPAC (oil palm wood-based activated carbon) is prepared, modification treatment is used for increasing the high specific surface area of the activated carbon with rich pore structures so as to increase the adsorption capacity of the activated carbon, the modified palm wood-based activated carbon is applied to the camellia oil decolorizing process, and the camellia oil decolorizing effect is improved. The method can effectively remove carotenoid, chlorophyll and impurities in the camellia oil, retains active components in the camellia oil, has the advantages of high decolorization efficiency, reusability of activated carbon, low cost, environmental friendliness and the like, and is suitable for industrial production and application.

Description

Technical Field

[0001] This invention relates to the field of oil refining technology, specifically to a method for decolorizing camellia oil based on modified palm wood-based activated carbon. Background Technology

[0002] Camellia oil is a high-quality edible vegetable oil, rich in polyunsaturated fatty acids, vitamin E, and other nutrients, possessing high nutritional value and health benefits. However, during the pressing or refining process, pigments (such as carotenoids and chlorophyll) and impurities may be introduced due to the raw materials themselves or the processing techniques, affecting the color and quality of the camellia oil and limiting its market application. Therefore, decolorization treatment is one of the key steps in improving the quality of camellia oil.

[0003] Currently, common methods for oil decolorization include adsorption decolorization, chemical decolorization, and membrane separation decolorization. Among them, adsorption decolorization is widely used due to its simple operation and good effect. Commonly used adsorbents include activated carbon and activated clay. Activated carbon has a large specific surface area and rich pore structure, and excellent adsorption performance. However, the selective adsorption capacity of ordinary activated carbon for pigments in camellia oil needs to be improved, and some activated carbons are expensive (Research on the Decolorization Effect of Several Decolorizing Agents on Rapeseed Oil, China Oils and Fats, Vol. 45, No. 1, 2020; Optimization of Decolorization Process for Cosmetic Grade Camellia Oil, Food Industry, 2021, 42 (01): 92-95), which limits its large-scale application in oil decolorization.

[0004] Palm wood, the woody part of palm trees, is widely available and inexpensive. Using it as a raw material to prepare activated carbon not only enables the resource utilization of waste but also reduces the production cost of activated carbon. However, the adsorption performance of raw palm wood-based activated carbon is often insufficient to meet the requirements of efficient decolorization. Modification treatment is needed to improve its surface chemical properties and pore structure, thereby enhancing its ability to adsorb pigments.

[0005] Based on this, the present invention provides a camellia oil decolorization method based on modified palm wood-based activated carbon. By performing composite modification on the palm wood-based activated carbon, its adsorption performance on pigments in camellia oil is enhanced, achieving efficient decolorization while reducing costs, and has good application prospects. Summary of the Invention

[0006] To address the existing technical problems, the present invention aims to provide a camellia oil decolorization method based on modified palm wood-based activated carbon. By performing composite modification on the palm wood-based activated carbon, its adsorption performance for pigments in camellia oil is enhanced, thereby achieving efficient decolorization.

[0007] To achieve the above objectives, the present invention adopts the following technical solution.

[0008] This invention provides a method for decolorizing camellia oil based on modified palm wood-based activated carbon, comprising the following steps: (1) Preparation of palm wood-based activated carbon: Palm wood waste is crushed, dried, carbonized and activated to obtain palm wood-based activated carbon; (2) Modification treatment of palm wood-based activated carbon: The palm wood-based activated carbon obtained in step (1) is placed in the modifier solution, stirred and reacted. After the reaction is completed, it is filtered, washed until neutral, and dried to obtain modified palm wood-based activated carbon. (3) Camellia oil decolorization: Heat the camellia oil, add the modified palm wood-based activated carbon obtained in step (2), stir to decolorize, filter and separate to obtain decolorized camellia oil.

[0009] Furthermore, in step (1), the drying temperature is 105-120℃ and the drying time is 2-4h.

[0010] Furthermore, in step (1), the carbonization process involves heating the temperature to 400-500℃ at a rate of 5-10℃ / min under a nitrogen atmosphere and holding it at that temperature for 2-3 hours.

[0011] Furthermore, in step (1), the activation treatment is carried out by steam activation at a temperature of 800-900℃ for 1-2 hours.

[0012] Furthermore, in step (2), the modifier solution is a mixed solution of nitric acid and phosphoric acid, wherein the mass fraction of nitric acid is 5%-10% and the mass fraction of phosphoric acid is 3%-5%.

[0013] Furthermore, in step (2), the liquid-solid ratio of the modifier solution to the palm wood-based activated carbon is 5:1-10:1 in mL / g.

[0014] Furthermore, in step (2), the temperature of the stirring reaction is 60-80℃ and the reaction time is 2-4h.

[0015] Furthermore, in step (2), the drying temperature is 80-100℃ and the drying time is 3-5h.

[0016] Furthermore, in step (3), the camellia oil is heated to a temperature of 60-85℃.

[0017] Furthermore, in step (3), the amount of modified palm wood-based activated carbon added is 2%-5% of the weight of camellia oil, and the stirring and decolorization time is 30-60 min.

[0018] Furthermore, in step (3), centrifugal filtration is used for filtration separation, and the modified palm wood-based activated carbon obtained after filtration can be reused after regeneration treatment.

[0019] Furthermore, the regeneration process involves washing the used modified palm wood-based activated carbon with deionized water until the washing liquid is colorless, then drying it at 110-120℃ for 2-3 hours, and then calcining it at 500-600℃ for 1-2 hours under a nitrogen atmosphere.

[0020] The beneficial effects of this invention are as follows: 1. This invention uses palm wood waste as raw material to prepare activated carbon, realizing the resource utilization of waste, reducing raw material costs, and conforming to the concept of green environmental protection.

[0021] 2. Through the composite modification treatment of nitric acid and phosphoric acid, the surface chemical properties and pore structure of palm wood-based activated carbon are improved, enhancing its selective adsorption capacity for pigments in camellia oil, resulting in high decolorization efficiency and effectively improving the color quality of camellia oil.

[0022] 3. Modified palm wood-based activated carbon has a high retention rate of active ingredients (such as vitamin E) in camellia oil during the decolorization process, thus ensuring the nutritional value of camellia oil.

[0023] 4. Modified palm wood-based activated carbon can be reused after regeneration, further reducing production costs and making it suitable for large-scale industrial applications. Attached Figure Description

[0024] Figure 1 The graph shows a comparison of the decolorization rate and vitamin E retention rate of the camellia oil prepared in Examples 1-3.

[0025] Figure 2 The image shows the color of camellia oil before and after decolorization with palm wood-based activated carbon in Example 1. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0027] Unless otherwise specified in the embodiments of this invention, the conditions shall be performed according to conventional conditions or conditions recommended by the manufacturer. All raw materials and reagents used, unless otherwise specified, are commercially available conventional products.

[0028] Example 1 (1) Preparation of palm wood-based activated carbon: Palm wood waste was crushed to a particle size of 2-5 mm and dried in an oven at 105℃ for 4 h; the dried palm wood powder was placed in a tube furnace and heated to 400℃ at a heating rate of 5℃ / min under a nitrogen atmosphere and held for 3 h for carbonization; after carbonization, water vapor was introduced and activated at 800℃ for 2 h, and then cooled to obtain palm wood-based activated carbon.

[0029] (2) Modification of activated carbon: Prepare a mixed modifier solution with 5% nitric acid and 3% phosphoric acid by mass. Add palm wood-based activated carbon to the modifier solution at a liquid-solid ratio of 5:1 (mL / g) and stir at 60℃ for 4h. After the reaction is completed, wash the activated carbon with deionized water until the filtrate is neutral, and then dry it in an 80℃ oven for 5h to obtain modified palm wood-based activated carbon.

[0030] (3) Decolorization of camellia oil: Camellia oil was heated to 60°C, and the modified palm wood-based activated carbon was added at 2% of the camellia oil mass. The mixture was stirred for 60 min to decolorize. After decolorization, the camellia oil was separated by plate and frame filtration to obtain the decolorized camellia oil. According to GB / T22460-2008, the decolorization rate of this method was 92.3% as determined by Luo Weipeng colorimeter. The retention rate of vitamin E in camellia oil was 90.5% as determined by high performance liquid chromatography (HPLC).

[0031] In this embodiment, the colors of the camellia oil before and after decolorization with palm wood-based activated carbon are shown in the figure. Figure 2 Example 2 (1) Preparation of palm wood-based activated carbon: Palm wood waste was crushed to a particle size of 2-5 mm and dried in an oven at 110℃ for 3 h; the dried palm wood powder was placed in a tube furnace and carbonized at a heating rate of 8℃ / min under a nitrogen atmosphere for 2.5 h; after carbonization, water vapor was introduced and activated at 850℃ for 1.5 h, and then cooled to obtain palm wood-based activated carbon.

[0032] (2) Modification of activated carbon: Prepare a mixed modifier solution with 8% nitric acid and 4% phosphoric acid by mass. Add palm wood-based activated carbon to the modifier solution at a liquid-solid ratio of 8:1 (mL / g) and stir at 70℃ for 3h. After the reaction is completed, wash the activated carbon with deionized water until the filtrate is neutral, and then dry it in a 90℃ oven for 4h to obtain modified palm wood-based activated carbon.

[0033] (3) Camellia oil decolorization: Camellia oil was heated to 70℃, and the modified palm wood-based activated carbon was added at 3.5% of the weight of the camellia oil. The mixture was stirred for 45 minutes for decolorization. After decolorization, the camellia oil was separated by centrifugation and filtration to obtain the decolorized camellia oil. According to GB / T22460-2008, the decolorization rate of this method was 95.1% and the vitamin E retention rate in the camellia oil was 92.3%, as determined by Luo Weipeng colorimeter.

[0034] Example 3 (1) Preparation of palm wood-based activated carbon: Palm wood waste was crushed to a particle size of 2-5 mm and dried in an oven at 120℃ for 2 h; the dried palm wood powder was placed in a tube furnace and heated to 500℃ at a heating rate of 10℃ / min under a nitrogen atmosphere and held for 2 h for carbonization; after carbonization, water vapor was introduced and activated at 900℃ for 1 h, and palm wood-based activated carbon was obtained after cooling.

[0035] (2) Modification of activated carbon: Prepare a mixed modifier solution with 10% nitric acid and 5% phosphoric acid by mass. Add palm wood-based activated carbon to the modifier solution at a liquid-to-solid ratio of 10:1 (mL / g) and stir at 80°C for 2 hours. After the reaction is completed, wash the activated carbon with deionized water until the filtrate is neutral. Then dry it in an oven at 100°C for 3 hours to obtain modified palm wood-based activated carbon.

[0036] (3) Camellia oil decolorization: Camellia oil was heated to 85°C, and the modified palm wood-based activated carbon was added at 5% of the mass of the camellia oil. The mixture was stirred for 30 minutes for decolorization. After decolorization, the camellia oil was separated by plate and frame filtration to obtain the decolorized camellia oil. According to GB / T22460-2008, the decolorization rate of this method was 94.7% and the vitamin E retention rate in the camellia oil was 89.8%, as determined by Luo Weipeng colorimeter.

[0037] Figure 1 The diagram shows a comparison of the decolorization rate and vitamin E retention rate of the camellia oil prepared in Examples 1-3.

[0038] Comparative Examples Unmodified palm wood-based activated carbon was used to treat the camellia oil following the decolorization steps in Example 2, with the activated carbon added at 3.5% of the camellia oil mass. According to GB / T22460-2008, the decolorization rate was 78.2% and the vitamin E retention rate in the camellia oil was 88.6%, as determined by a Luo Weipeng colorimeter.

[0039] Compared with the comparative examples, the present invention significantly improves the decolorization rate of camellia oil by modifying palm wood-based activated carbon, while better preserving the active ingredients in camellia oil, indicating that the method of the present invention has obvious advantages.

[0040] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for decolorizing camellia oil based on modified palm wood-based activated carbon, characterized in that, Includes the following steps: (1) Preparation of palm wood-based activated carbon: Palm wood waste is crushed, dried, carbonized and activated to obtain palm wood-based activated carbon; (2) Modification treatment of palm wood-based activated carbon: The palm wood-based activated carbon obtained in step (1) is placed in the modifier solution, stirred and reacted. After the reaction is completed, it is filtered, washed until neutral, and dried to obtain modified palm wood-based activated carbon. (3) Camellia oil decolorization: Heat the camellia oil, add the modified palm wood-based activated carbon obtained in step (2), stir to decolorize, filter and separate to obtain decolorized camellia oil.

2. The camellia oil decolorization method according to claim 1, characterized in that, In step (1), the drying temperature is 105-120℃ and the drying time is 2-4h; the carbonization treatment is carried out in a nitrogen atmosphere, with the temperature increased to 400-500℃ at a rate of 5-10℃ / min and held for 2-3h; the activation treatment is carried out by steam activation, with the activation temperature at 800-900℃ and the activation time at 1-2h.

3. The camellia oil decolorization method according to claim 1, characterized in that, In step (2), the modifier solution is a mixed solution of nitric acid and phosphoric acid, wherein the mass fraction of nitric acid is 5%-10% and the mass fraction of phosphoric acid is 3%-5%.

4. The camellia oil decolorization method according to claim 1, characterized in that, In step (2), the liquid-solid ratio of the modifier solution to the palm wood-based activated carbon is 5:1-10:1 in mL / g.

5. The camellia oil decolorization method according to claim 1, characterized in that, In step (2), the temperature of the stirring reaction is 60-80℃ and the reaction time is 2-4h.

6. The camellia oil decolorization method according to claim 1, characterized in that, In step (2), the drying temperature is 80-100℃ and the drying time is 3-5h.

7. The camellia oil decolorization method according to claim 1, characterized in that, In step (3), the camellia oil is heated to a temperature of 60-85℃.

8. The camellia oil decolorization method according to claim 1, characterized in that, In step (3), the amount of modified palm wood-based activated carbon added is 2%-5% of the weight of camellia oil, and the stirring and decolorization time is 30-60 min.

9. The camellia oil decolorization method according to claim 1, characterized in that, In step (3), the filtration separation is carried out by centrifugal filtration, and the modified palm wood-based activated carbon obtained after filtration can be reused after regeneration treatment.

10. The camellia oil decolorization method according to claim 9, characterized in that, The regeneration process involves washing the used modified palm wood-based activated carbon with deionized water until the washing liquid is colorless, then drying it at 110-120℃ for 2-3 hours, and then calcining it at 500-600℃ for 1-2 hours under a nitrogen atmosphere.

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