A preparation method for removing impurities by multi-stage filtration

Abstract

The present invention proposes a preparation method through multi-stage filtration and impurity removal, which belongs to the field of resistant dextrin processing. The filtration and impurity removal system of the present invention is designed for the material characteristics of the saccharification liquid produced by resistant dextrin, such as difficulty in filtering, too dark color, and damage to the membrane core caused by burnt and carbonized particles produced by dextrinization. The process includes dextrinization, liquefaction, saccharification, centrifugal separation, membrane filtration, drum filtration and carbon column decolorization, and a secondary filtration process is also added. The problem of difficulty in filtering saccharification liquid in the production process of resistant dextrin is solved, and at the same time, the material color of the decarbonization column decolorization system is reduced, and the load of the decolorization system is reduced. There is currently no related design in the production process of resistant dextrin. The present invention fills the gap in the saccharification liquid filtration process system in the production process of resistant dextrin.

Description

Technical Field

[0001] The invention belongs to the technical field of resistant dextrin processing, and particularly relates to a saccharification liquid filtering process in the processing technology. Background Art

[0002] Resistant dextrin is a dietary fiber produced by dextrinization reaction, industrial extraction and refining under acidic conditions using corn starch as raw material. Its low calorie content can inhibit the rapid rise of blood sugar levels after a meal, regulate the levels of cholesterol and triglycerides in serum, and reduce the content of medium and low-density fat in internal organs. It has the functions of moisturizing the intestines, promoting intestinal health, enhancing immunity, regulating blood sugar and blood lipids, and assisting weight loss. It is widely used in health products, beverages, baked goods, meal replacement foods, slimming products, special dietary foods, etc., and has broad development prospects in the food industry.

[0003] In the production process of resistant dextrin, the raw material corn starch undergoes molecular structure reorganization reaction under acidic and high temperature conditions to obtain a dextrinized starch mixture containing 58% resistant dextrin and 42% starch, and then undergoes subsequent slurry adjustment, liquefaction and saccharification treatment to obtain a 30% concentration of saccharified liquid. In the actual operation process, there are problems such as very poor protein flocculation effect, a small amount of starch converted into aged starch that cannot be hydrolyzed, and low filtration rate of saccharified liquid, which increases the difficulty of filtration.

[0004] The existing resistant dextrin production and filtration process has the following problems: large equipment investment, low flow rate and poor matching degree with equipment capacity, huge amount of diatomaceous earth, large carbon column decolorization load, and high cost:

[0005] At present, the production of resistant dextrin mostly adopts the combination of membrane filtration and drum filtration to filter the saccharification liquid. This process has certain defects. In order to ensure the conversion rate of resistant dextrin, the whiteness of dextrinized starch is usually controlled between 60-70. The color of the liquid material after dissolution is very dark, yellow-brown. Starch will produce a large number of black burnt carbonized particles under acidic and high temperature conditions. The carbonized particles cause the color of the material to deepen further. Finally, this high-color material enters the saccharification liquid filtration system.

[0006] From the perspective of decolorization, membrane filtration in the existing saccharification liquid filtration system has a good effect on reducing color. The membrane clear liquid with low color value directly enters the carbon column decolorization process for treatment, but the darker concentrated liquid after membrane concentration enters the drum filtration. The drum filtration has almost no effect on removing color substances. Therefore, most of the high-color substances are mixed with the membrane clear liquid after drum filtration and enter the carbon column decolorization process. That is: since the previous filtration process has extremely low effect on color removal, decolorization is mainly achieved by the carbon column decolorization process, resulting in an increase in the decolorization load of the carbon column and high decolorization costs.

[0007] From the perspective of filtration, the black burnt carbonized particles produced by starch during the dextrinization process will directly enter the membrane filtration, causing serious damage to the membrane core, reducing the online service life of the membrane core and increasing production costs. This problem has always been a problem that has plagued existing manufacturers of resistant dextrin.

[0008] The viscosity of the saccharified liquid produced in the existing resistant dextrin production process is high, which leads to a low filtration rate during the production process, which is about 10% of the filtration rate of other sugar products. The filtration rate of the concentrated liquid filtered by membrane through the drum is also too low, which causes huge consumption of diatomaceous earth and increases production costs. Furthermore, due to the low filtration rate of the saccharified liquid, the capacity of membrane filtration and drum filtration equipment is about 10 times that of other sugar products, and the investment in equipment has also increased by nearly 10 times accordingly. Due to the low flow rate but large equipment selection, the matching degree between flow rate and equipment is very low.

[0009] In addition, the drum clear liquid contains a certain amount of diatomaceous earth fine particles. During the processing, these diatomaceous earth fine particles will enter the carbon column decolorization process, thereby causing the activated carbon adsorption pores in the carbon column to be blocked, reducing the adsorption and decolorization capacity of the carbon column, and resulting in the need to increase the replacement frequency of the carbon column to ensure the decolorization quality, resulting in increased decolorization costs.

[0010] In addition, the fat, protein and other impurities in the sugar solution after drum filtration are higher than those after membrane filtration. They all enter the carbon column decolorization process, causing pollution to the activated carbon in the carbon column, resulting in reduced decolorization effect. In order to solve this problem, it is necessary to increase the replacement frequency of the carbon column, resulting in increased carbon column consumption and increased production costs.

[0011] Based on the above problems, there is an urgent need for a filtration and impurity removal process method with high filtration rate and cost saving. Summary of the invention

[0012] The filtering and impurity removal system of the present invention is designed to address the material characteristics of saccharified liquid produced by resistant dextrin, such as difficulty in filtering, excessively dark color, and damage to the membrane core caused by burnt and carbonized particles produced by dextrinization. It solves the problem of difficulty in filtering saccharified liquid in the production process of resistant dextrin, while reducing the material color of the decarbonization column decolorization system and the load of the decolorization system. There is currently no such design in the production process of resistant dextrin, which is an innovative technology in the industry and fills the gap in the saccharified liquid filtration process system in the production process of resistant dextrin.

[0013] A multi-stage filtration and impurity removal preparation method, in which the filtration and impurity removal process for the saccharified liquid is:

[0014] The saccharification liquid and the drum clear liquid after drum filtration are centrifuged together to separate the centrifugal concentrated phase, obtain the centrifugal clear liquid, and obtain aged starch, carbonized particles and waste diatomaceous earth;

[0015] The centrifuged clear liquid is filtered through a membrane to obtain a membrane clear liquid and a membrane concentrated liquid;

[0016] The membrane concentrate, aged starch, carbonized particles and waste diatomaceous earth are subjected to drum filtration to remove aged starch, carbonized particles and waste diatomaceous earth, to obtain drum clear liquid, and the drum clear liquid is mixed with the saccharification liquid stock solution and then subjected to secondary filtration;

[0017] The membrane clear liquid is subjected to a carbon column decolorization process to complete filtering and impurity removal.

[0018] Furthermore, in the preparation method, the saccharified liquid is obtained by:

[0019] The corn starch is subjected to dextrinization, liquefaction and saccharification to obtain saccharified liquid.

[0020] Furthermore, after membrane filtration, the membrane clear liquid accounts for 85%, and the membrane concentrated liquid accounts for 15%.

[0021] Furthermore, the saccharified liquid contains a dry matter concentration of 30%, a resistant dextrin content of 58%, and a disaccharide content of 42%.

[0022] Furthermore, the temperature of the saccharified liquid is 58-62°C.

[0023] Furthermore, the equipment used for the centrifugal separation is three-phase and can continuously input and output materials.

[0024] Furthermore, in the centrifugal separation process, the first phase separates the centrifugal concentrated phase, the second phase separates the aged starch, carbonized particles and waste diatomaceous earth, and the third phase separates the resistant dextrin and components below disaccharides.

[0025] Furthermore, the rotation speed of the centrifugal separation is 6000 rpm.

[0026] Beneficial Effects

[0027] The present invention solves the problem of process defects in saccharification liquid filtration during the production of resistant dextrin in the industry and proposes an innovative process path, namely, centrifugal separation filtration equipment, membrane filtration system and drum filtration system are designed simultaneously and used in conjunction with each other to achieve a complex filtration process method of multi-stage filtration.

[0028] In the preparation method of the present invention, the design concept of the single material flow direction in the existing conventional preparation method is changed, and the drum clear liquid after drum filtration is returned to the centrifugal separation process for re-separation filtration and membrane filtration to achieve secondary filtration. The membrane clear liquid after the secondary filtration enters the carbon column for decolorization. Compared with the prior art in which the drum clear liquid is directly subjected to carbon column decolorization, the materials entering the carbon column for decolorization are all treated by membrane filtration, which effectively avoids the problem of clogging of the activated carbon adsorption pores caused by residual fine diatomaceous earth particles, burnt carbonized particles, fats, proteins and other impurities entering the carbon column, thereby improving the efficiency of carbon column decolorization and greatly reducing equipment investment and production variable costs.

[0029] In the present invention, all filtrates enter the carbon column decolorization process through membrane filtration, and at the same time, the drum clear liquid is subjected to centrifugal separation filtration to remove residual impurities and diatomaceous earth particles in the sugar solution, thereby solving the problem of damage to the membrane core by the material after drum filtration and the problem of being unable to return to the membrane filtration for secondary filtration.

[0030] In the present invention, after the centrifugal separation process, the protein, fat and other impurities in the saccharified liquid are removed, the filtration speed of the drum filtration and the membrane filtration is improved, and the equipment investment, the amount of diatomaceous earth used and the power consumption are reduced. At the same time, the burnt carbonized particles in the saccharified liquid are removed, which also avoids the damage to the membrane core, increases the online service life of the membrane core, and thus reduces the production cost.

[0031] The preparation method of the present invention is suitable for improving the existing saccharification liquid filtration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a process flow chart of multi-stage filtration and impurity removal according to the present invention;

[0033] Figure 2 This is the process flow chart of the existing filtration and impurity removal process. DETAILED DESCRIPTION

[0034] Example 1. A multi-stage filtration and impurity removal preparation method.

[0035] like Figure 1As shown, after dextrinization, slurry adjustment, liquefaction and saccharification, corn starch is obtained to obtain a saccharification liquid with a dry matter concentration of 30%, a temperature of 58-62°C, a resistant dextrin content of about 58% and a content of about 42% below disaccharides. The saccharification liquid containing fat, protein, burnt carbonized particles produced in the dextrinization process and other impurities is sent to a three-phase and continuously feeding and discharging centrifugal separation and filtration equipment for centrifugal separation, and the centrifugal separation speed is about 6000 rpm. Based on the different specific gravities of various components in the saccharification liquid, the different components are separated by the action of centrifugal force, and the centrifugal concentrated phase composed of fat, protein and other impurities in the saccharification liquid is separated as the first phase; unhydrolyzed aged starch, burnt carbonized particles, residual diatomaceous earth particles, etc. are separated as the second phase; the centrifugal clear night composed of resistant dextrin and components below disaccharides in the saccharification liquid is separated as the third phase. The separated first phase fat and protein residues are directly discharged, and the separated second phase unhydrolyzed aged starch, burnt carbonized particles, residual diatomaceous earth particles and other substances are mixed with the membrane filtration concentrate and enter the drum filtration for further treatment. After being processed by the centrifuge, most of the substances in the saccharified liquid that affect the filtration rate are removed, thereby increasing the rate of membrane filtration and drum filtration. The centrifuged clear liquid enters the membrane filtration system. The membrane core adopts an organic roll membrane for cross-flow filtration. The saccharified liquid passed through the membrane unit is divided into 15% membrane concentrate and 85% membrane clear liquid. The membrane clear liquid goes directly to the carbon column decolorization system. The membrane concentrate is mixed with the aged starch and burnt carbonized particles of the centrifuge and enters the drum filtration system for further treatment. The drum clear liquid is mixed with the saccharified liquid stock and enters the centrifugal separation equipment again according to the method. Figure 1 The process path returns to membrane filtration for secondary filtration. The residues produced by drum filtration are directly discharged from the system. According to this process flow, all materials decolorized by the decarbonization column are processed by the membrane filtration system, which prevents impurities such as fine diatomaceous earth particles, burnt carbonized particles and proteins from entering the carbon system, improves the material quality of the decarbonization column decolorization system, reduces the load of the carbon column decolorization system, and solves the problem that the material after drum filtration cannot be returned to the membrane filtration system for secondary filtration under the original process due to the damage of the membrane core by diatomaceous earth in the material.

[0036] Example 2. The color of the carbon column feed in the multi-stage filtration and impurity removal process system and the existing process.

[0037] Comparative Example: The existing method for preparing resistant dextrin uses a combination of membrane filtration and drum filtration to filter the saccharified liquid, such as Figure 2 As shown, corn starch is subjected to dextrinization, slurry adjustment, liquefaction and saccharification to obtain saccharified liquid, and the saccharified liquid is filtered through a membrane to obtain a membrane clear liquid and a concentrated liquid. The membrane clear liquid directly enters the carbon column for decolorization, and the concentrated liquid enters the rotary drum filtration system to discharge waste diatomaceous earth, fat, protein and other impurities, and the rotary drum clear liquid is obtained to enter the carbon column for decolorization.

[0038] The same amount of saccharified liquid was filtered and impurities removed in the two systems of the comparative example and Example 1 at the same time, and the color of the material entering the carbon column for decolorization was counted, and the results are shown in Table 1. Using the preparation method of Example 1, the color of the material entering the carbon column for decolorization was reduced from the original 5.9 to 5.0, which was reduced by 15.5%, compared with the preparation method of the comparative example. That is, the same decolorization effect was achieved and the amount of activated carbon used was greatly saved.

[0039] Table 1: Color comparison table of comparative examples and examples

[0040]

[0041] Example 3. Comparison of investment between the preparation method of the present invention and the existing preparation method described in the comparative example.

[0042] Comparing the investment amounts of the filtration and impurity removal process systems in the comparative example and in Example 1, the results are shown in Table 2.

[0043] Table 2: Comparative Example and Example 1 Investment Comparison Table

[0044] Equipment investment Traditional crafts Process of the present invention Savings (10,000 yuan) Centrifuge increase 0 200 -200 Membrane filtration system 934 500 434 Drum filtration system 220 100 120 Carbon column decolorization system 480 320 160 Total (ten thousand yuan) 1634 1120 514

[0045] As shown in Table 2, compared with the prior art, the equipment required for the preparation method of the present invention has an additional centrifuge equipment, and the investment is increased by 2 million yuan; after adding the equipment, the filtration rate is improved, so that the subsequent membrane filtration system is reduced from the original 6 groups to 3 groups, and the number of membrane cores is reduced from the original 168 to 84, which can still achieve a good filtration effect, and the investment in the membrane filtration system is reduced by 4.34 million yuan; the number of drum filters is changed from 2 units with a filtration area of ​​70 square meters / unit to 1 unit with a filtration area of ​​50 square meters / unit, and the investment in the drum system is reduced by 1.2 million yuan; since the material entering the carbon column decolorization system is filtered twice, its color is significantly reduced compared with the color entering the carbon column decolorization in Comparative Example 1, which also reduces the number of carbon columns from the original 3 columns to 2 columns, and still achieves a good filtration effect. After the number of carbon columns is reduced, the total amount of activated carbon loaded is reduced from 300 cubic meters to 200 cubic meters, and the investment in the carbon column decolorization system is reduced by nearly 1.6 million yuan.

[0046] Through the above comparison, the equipment for implementing the preparation method described in Example 1, after adding the centrifugal separation equipment, the other filtering equipment are reduced, so that the total investment of all equipment can be reduced from 16.34 million yuan of the original process to 11.20 million yuan, with an overall investment saving of nearly 5.14 million yuan.

[0047] Example 4. Comparison of production costs between the preparation method of Example 1 and the preparation method described in the comparative example.

[0048] The same amount of saccharified liquid was processed by the two preparation methods of the comparative example and Example 1 at the same time, and the production costs of the two preparation processes were statistically analyzed. The results are shown in Table 3.

[0049] Table 3: Comparative Example and Example 1 Production Cost Comparison Table

[0050]

[0051]

[0052] As shown in Table 3, due to the reduction of the required heavy carbon column of the carbon column decolorization system, the amount of activated carbon used was significantly reduced: the use of activated carbon was reduced by 23.47%, saving 105.6 tons of activated carbon throughout the year, and the cost of activated carbon was reduced by 1.853 million yuan / year.

[0053] Diatomaceous earth saving: In the preparation method described in Example 1, centrifugal separation is used to effectively remove substances such as fat, protein and aged starch that cause filtering difficulties. At the same time, centrifugal separation also increases the subsequent filtration flow rate, so that the drum filtration rate is increased by 83.33% compared with the control example. The increase in filtration rate greatly reduces the use of diatomaceous earth, and the use of each piece is reduced by about 1,000 tons. The cost of the 1,000 tons of diatomaceous earth is 2.22 million yuan.

[0054] Water saving: Since the color of the material entering the carbon column for decolorization is low, the decolorization effect of the carbon column is improved, and the number of carbon columns and the amount of carbon released in the corresponding carbon column decolorization process are reduced. At the same time, during the preparation process, the number of carbon pressing times is reduced from 4 times a day to 2 times a day; after the filtration effect is improved, the frequency of drum pre-coating is reduced from 2 times a day to once every 3 days, and the use of desalted water is reduced by 61.9%, a reduction of 11,555 tons per year. Converted into cost, the cost of desalted water is reduced by 31,000 yuan / year.

[0055] Savings on membrane core: Due to the use of centrifugal separation and secondary filtration, the membrane damage caused by the burnt and carbonized particles produced by dextrinization entering the membrane filtration system is effectively avoided. Therefore, the service life of the membrane core is significantly extended from the original 2 years to more than 4 years, saving 50%, and saving an average of 420,000 yuan in membrane core costs each year.

[0056] Reduced power consumption: In the preparation method of Example 1, the installed power of the entire production system is reduced by 85KW compared with the comparative example, and the power consumption per unit product is reduced by 2.27%, corresponding to a power consumption of 68KWH / ton, saving 408,000 yuan / year in power consumption.

[0057] Equipment depreciation savings: The materials after centrifugal separation improve the filtration efficiency of the membrane filtration system and the drum filtration system. Therefore, the equipment capacity selection is reduced compared with the original process, the investment is reduced by 5.14 million yuan compared with the original process system, the equipment depreciation cost is reduced by 31.46%, and the equipment depreciation savings are 343,000 yuan / year.

[0058] Combining all the above savings, the production cost of the preparation method described in Example 1 is saved by 5.275 million yuan per year compared with the comparative example, and the economic benefits are considerable.

Claims

1. A preparation method for removing impurities by multi-stage filtration, characterized in that: In the preparation method, the filtration and impurity removal process for the saccharified liquid is as follows: The saccharification liquid and the drum clear liquid after drum filtration are centrifuged together to separate the centrifugal concentrated phase, obtain the centrifugal clear liquid, and obtain aged starch, carbonized particles and waste diatomaceous earth; The centrifuged clear liquid is filtered through a membrane to obtain a membrane clear liquid and a membrane concentrated liquid; The membrane concentrate, aged starch, carbonized particles and waste diatomaceous earth are subjected to drum filtration to remove aged starch, carbonized particles and waste diatomaceous earth, to obtain drum clear liquid, and the drum clear liquid is mixed with the saccharification liquid stock solution and then subjected to secondary filtration; The membrane clear liquid is subjected to a carbon column decolorization process to complete filtering and impurity removal.

2. The preparation method according to claim 1, characterized in that: In the preparation method, the process of obtaining the saccharified liquid is as follows: The corn starch is subjected to dextrinization, liquefaction and saccharification to obtain saccharified liquid.

3. The preparation method according to claim 1 or 2, characterized in that: After membrane filtration, the membrane clear liquid accounts for 85%, and the membrane concentrated liquid accounts for 15%.

4. The preparation method according to claim 1 or 2, characterized in that: The saccharified liquid contains 30% dry matter concentration, 58% resistant dextrin content and 42% disaccharide and lower content.

5. The preparation method according to claim 1 or 2, characterized in that: The temperature of the saccharified liquid is 58-62°C.

6. The preparation method according to claim 1 or 2, characterized in that: The equipment used for the centrifugal separation is three-phase and can continuously feed and discharge materials.

7. The preparation method according to claim 6, characterized in that: In the centrifugal separation process, the first phase separates the centrifugal concentrated phase, the second phase separates the aged starch, carbonized particles and waste diatomaceous earth, and the third phase separates the resistant dextrin and components below disaccharides.

8. The preparation method according to claim 1 or 2, characterized in that: The rotation speed of the centrifugal separation is 6000 rpm.

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