A process for purifying sugar syrup crystallization

Abstract

The present application relates to the technical field of sugar syrup processing, and discloses a purified sugar syrup crystallization process, which comprises the following steps: (1) after the sugar syrup is filtered and heated, it is delivered to a crystallization tank to obtain massecuite, the massecuite is sequentially subjected to crystal nucleation in a crystal nucleation tank and honey separation in a separator to obtain white granulated sugar and primary massecuite; (2) the primary massecuite is filtered by a filter, the filtrate is mixed with the white granulated sugar, the filtrate is mixed with the primary massecuite, and the mixture is heated and delivered to a second-stage crystallization tank; (3) the massecuite obtained by boiling in the second-stage crystallization tank is sequentially subjected to crystal nucleation in a crystal nucleation tank and honey separation in a separator to obtain secondary massecuite and secondary primary massecuite; and (4) the degree of the secondary primary massecuite is determined, and whether to continue to enter the third-stage crystallization is determined by comparing the degree of the secondary primary massecuite with a preset waste honey degree. The crystallization process of the purified sugar syrup is simple, low in energy consumption, high in sugar yield, low in color value, can greatly reduce the use of equipment, and can reduce the production cost.

Description

Technical Field

[0001] This invention relates to the field of syrup processing technology, and in particular to a process for purifying syrup crystallization. Background Technology

[0002] In the sugar production process, the sugar-making process of white granulated sugar generally includes raw material extraction, clarification, evaporation, sugar boiling, crystallization, molasses separation, and drying. Among them, the sugar paste A, sugar paste B, and sugar paste obtained in the sugar boiling process are crystallized and molasses separated into molasses and finished sugar. The purity of the molasses separated is not high. Generally, in order not to affect the product quality, only a part of the molasses A is boiled back into sugar paste A, and the other part is used as material for the subsequent sugar paste boiling process. This shifts the material to the later stage and reduces the recovery of sugar.

[0003] To improve sugar yield, existing technologies typically involve three and a half, or even four or five, crystallization processes. However, the more crystallization processes there are, the higher the energy consumption and the more equipment is involved, thus increasing production costs.

[0004] Therefore, how to provide a purified syrup crystallization process that is simple in procedure, has a high sugar yield, and reduces energy consumption is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a purified syrup crystallization process to solve the technical problems of low sugar yield, complicated process procedures, high energy consumption and high production cost in existing syrup crystallization processes.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A process for purifying syrup crystallization includes the following steps:

[0008] (1) After filtering the syrup, heat it and send it to a crystallization tank to cook it to obtain methyl syrup paste. The methyl syrup paste is then passed through a crystallization tank for crystallization and a separator for separation to obtain white granulated sugar and methyl syrup paste respectively.

[0009] (2) The honey is filtered through a filter, the filtered material is mixed with white sugar, the resulting filtrate is mixed with the honey, and the mixture is heated and then sent to a crystallization tank for two-stage crystallization.

[0010] (3) The ethyl sugar paste obtained by boiling in the crystallization tank of the two-stage crystallization is successively passed through the crystallization aid tank and the separator to obtain ethyl sugar and ethyl raw honey respectively.

[0011] (4) Measure the saturation of the raw saturation honey and determine whether to continue into the three-stage crystallization process by comparing the saturation of the raw saturation honey with the preset saturation of the waste honey.

[0012] Preferably, in the above-mentioned purified syrup crystallization process, the filtration in step (1) is filtration through a ceramic filter membrane and / or a chitosan-diatomaceous earth composite material.

[0013] More preferably, the filtration in step (1) is performed by sequentially passing the material through a ceramic filter membrane and a chitosan-diatomaceous earth composite material.

[0014] Preferably, in the above-mentioned purified syrup crystallization process, the ceramic filter membrane is an asymmetric ceramic membrane, and the ceramic filter membrane material is silicon carbide.

[0015] Preferably, in the above-mentioned purified syrup crystallization process, the preparation method of the chitosan-diatomaceous earth composite material is as follows: dissolve chitosan in acetic acid solution, stir at 25-30°C until completely dissolved, then add 8-10 times the mass of diatomaceous earth to chitosan, continue stirring until a uniform colloid is formed, dry at 110-120°C for 30-45 minutes, and pulverize.

[0016] A further preferred method for preparing the chitosan-diatomaceous earth composite material is as follows: dissolve chitosan in a 2% acetic acid solution, stir at 28°C until completely dissolved, then add 8 times the mass of diatomaceous earth to the chitosan, continue stirring until a uniform colloid is formed, dry at 115°C for 40 minutes, and grind into powder.

[0017] Preferably, in the above-mentioned purified syrup crystallization process, the heating temperature in step (1) is 65-70°C;

[0018] More preferably, the heating temperature in step (1) is 65-68°C; even more preferably, it is 68°C.

[0019] Preferably, in the above-mentioned purified syrup crystallization process, step (1) also yields methyl methyl syrup, which is then completely refluxed into the crystallization tank and mixed with the methyl syrup paste.

[0020] Preferably, in the above-mentioned purified syrup crystallization process, the filter medium in step (2) includes, but is not limited to, filter cotton cake and diatomaceous earth, which can not only separate some of the white sugar in the raw honey, but also further remove impurities and reduce the color value of the white sugar.

[0021] Preferably, in the above-mentioned purified syrup crystallization process, the heating temperature in step (2) is 62-68°C;

[0022] More preferably, the heating temperature in step (2) is 65-68°C; even more preferably, it is 65°C.

[0023] Preferably, in the above-mentioned purified syrup crystallization process, all of the ethyl sugar obtained in step (3) is refluxed into a crystallization tank for a first-stage crystallization and mixed with the methyl sugar paste.

[0024] Preferably, in the above-mentioned purified syrup crystallization process, in step (4), the preset waste honey hammer degree is 50°Bx. If the hammer degree of the raw honey is greater than the preset waste honey hammer degree, the three-stage crystallization process is entered; if the hammer degree of the raw honey is not greater than the preset waste honey hammer degree, the crystallization ends and the raw honey is discharged as waste honey.

[0025] Preferably, in the above-mentioned purified syrup crystallization process, the three-stage crystallization process includes: the raw molasses enters the crystallization tank of the three-stage crystallization process, and the molasses paste obtained after boiling is successively passed through the crystallization aid tank and the molasses separator to obtain brown sugar and waste molasses;

[0026] More preferably, the brown sugar is refluxed into a first-stage crystallization tank and mixed with sugar paste A, and / or refluxed into a second-stage crystallization tank and mixed with sugar paste B, and / or discharged.

[0027] This invention provides a purified syrup crystallization process, which has the following advantages compared with the prior art:

[0028] The syrup of this invention is filtered before entering the crystallization tank, which can effectively remove impurities in the syrup and plays an extremely important role in improving the syrup yield and purity. The ceramic filter membrane is an asymmetric ceramic membrane with a pore size that decreases from bottom to top, ensuring high mechanical strength and large permeability, and achieving step-by-step filtration of the syrup with high filtration efficiency. The chitosan-diatomaceous earth composite material can effectively reduce syrup turbidity, improve syrup clarity, reduce syrup color value, and reduce syrup ash content, thereby improving the qualified rate and sugar yield of white sugar.

[0029] This invention heats the syrup entering the crystallization tank, which not only accelerates crystallization but also improves the yield of white sugar.

[0030] The crystallization process of the purified syrup of this invention is simple, has low energy consumption, high sugar yield, low color value, and can greatly reduce the use of equipment and reduce production costs. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] A process for purifying syrup crystallization includes the following steps:

[0034] (1) The syrup with a hammer weight of 65-68°Bx is filtered through a ceramic filter membrane and a chitosan-diatomaceous earth composite material, then heated to 68°C and fed into a crystallization tank to be cooked to obtain methyl sugar paste. The methyl sugar paste is then passed through a crystallization aid tank and a separator to separate the molasses, and then white granulated sugar and methyl molasses are obtained respectively.

[0035] Among them, the ceramic filter membrane is an asymmetric ceramic membrane, and the ceramic filter membrane material is silicon carbide; the preparation method of chitosan-diatomite composite material is as follows: dissolve chitosan in a 2% acetic acid solution, stir at 28°C until completely dissolved, then add 8 times the mass of chitosan and diatomite, continue stirring until a uniform colloid is formed, dry at 115°C for 40 minutes, grind and pulverize, and it is ready;

[0036] In step (1), methyl methyl ether was also obtained, and all of the methyl methyl ether was returned to the crystallization tank and mixed with methyl methyl ether paste;

[0037] (2) The raw honey is filtered through a filter with diatomaceous earth as the medium. The filtered material is mixed with white sugar. The resulting filtrate is mixed with the raw honey. The mixture is heated to 65°C and then sent to a crystallization tank for two-stage crystallization.

[0038] (3) The ethyl sugar paste obtained by boiling in the crystallization tank of the two-stage crystallization is successively passed through the crystallization aid tank and the separator to obtain ethyl sugar and ethyl raw honey respectively. All of the ethyl sugar is returned to the crystallization tank of the first-stage crystallization and mixed with methyl sugar paste.

[0039] (4) The saturation of the raw honey was measured to be 48°Bx, therefore the raw honey was discharged as waste honey.

[0040] Example 2

[0041] A process for purifying syrup crystallization includes the following steps:

[0042] (1) After filtering the syrup with a hammer weight of 65-68°Bx through a ceramic filter membrane, heat it to 70°C and then transfer it to a crystallization tank to cook it to obtain methyl sugar paste. The methyl sugar paste is then passed through a crystallization tank for crystallization and a separator for separation to obtain white granulated sugar and methyl raw honey respectively.

[0043] Among them, the ceramic filter membrane is an asymmetric ceramic membrane, and the ceramic filter membrane material is silicon carbide; in step (1), methyl ether syrup is also obtained, and all of the methyl ether syrup is returned to the crystallization tank and mixed with methyl ether syrup.

[0044] (2) The raw honey is filtered through a filter with a filter cake as the medium. The filtered material is mixed with white sugar. The resulting filtrate is mixed with the raw honey. The mixture is heated to 68°C and then sent to a crystallization tank for two-stage crystallization.

[0045] (3) The ethyl sugar paste obtained by boiling in the crystallization tank of the two-stage crystallization is successively passed through the crystallization aid tank and the separator to obtain ethyl sugar and ethyl raw honey respectively. All of the ethyl sugar is returned to the crystallization tank of the first-stage crystallization and mixed with methyl sugar paste.

[0046] (4) The saturation of raw honey was determined to be 55°Bx. Raw honey entered a three-stage crystallization tank. After boiling, the resulting sugar paste was passed through a crystallization aid tank and a separator to obtain brown sugar and waste honey. Part of the brown sugar was returned to the first-stage crystallization tank to mix with sugar paste, and the other part was returned to the second-stage crystallization tank to mix with sugar paste.

[0047] Example 3

[0048] A process for purifying syrup crystallization includes the following steps:

[0049] (1) The syrup with a hammer weight of 65-68°Bx is filtered through a chitosan-diatomaceous earth composite material and then heated to 66°C. It is then transported to a crystallization tank for cooking to obtain methyl sugar paste. The methyl sugar paste is then passed through a crystallization tank for crystallization and a separator for separation to obtain white granulated sugar and methyl molasses, respectively.

[0050] The preparation method of chitosan-diatomite composite material is as follows: dissolve chitosan in 2% acetic acid solution, stir at 25°C until completely dissolved, then add 10 times the mass of diatomite of chitosan, continue stirring until a uniform colloid is formed, dry at 120°C for 30 minutes, and pulverize.

[0051] In step (1), methyl methyl ether was also obtained, and all of the methyl methyl ether was returned to the crystallization tank and mixed with methyl methyl ether paste;

[0052] (2) The raw honey is filtered through a filter with diatomaceous earth as the medium. The filtered material is mixed with white sugar. The resulting filtrate is mixed with the raw honey. The mixture is heated to 63°C and then sent to a crystallization tank for two-stage crystallization.

[0053] (3) The ethyl sugar paste obtained by boiling in the crystallization tank of the two-stage crystallization is successively passed through the crystallization aid tank and the separator to obtain ethyl sugar and ethyl raw honey respectively. All the ethyl sugar is returned to the crystallization tank of the first-stage crystallization and mixed with methyl sugar paste.

[0054] (4) The saturation of the raw molasses was determined to be 56°Bx. The raw molasses entered the crystallization tank of the three-stage crystallization. After boiling, the resulting syrup was successively passed through the crystallization aid tank and the separator to obtain brown sugar and waste molasses. Both brown sugar and waste molasses were discharged.

[0055] Example 4

[0056] A process for purifying syrup crystallization includes the following steps:

[0057] (1) The syrup with a hammer weight of 65-68°Bx is filtered through a ceramic filter membrane and a chitosan-diatomaceous earth composite material, then heated to 65°C and fed into a crystallization tank to be cooked to obtain methyl sugar paste. The methyl sugar paste is then passed through a crystallization aid tank and a separator to separate the molasses, and then white granulated sugar and methyl raw molasses are obtained respectively.

[0058] Among them, the ceramic filter membrane is an asymmetric ceramic membrane, and the ceramic filter membrane material is silicon carbide; the preparation method of chitosan-diatomite composite material is as follows: dissolve chitosan in 2% acetic acid solution, stir at 30°C until completely dissolved, then add 9 times the mass of chitosan and diatomite, continue stirring until a uniform colloid is formed, dry at 110°C for 45 minutes, and pulverize.

[0059] In step (1), methyl ester molasses is also obtained. All of the methyl ester molasses is returned to the crystallization tank and mixed with methyl ester molasses paste.

[0060] (2) The raw honey is filtered through a filter with diatomaceous earth as the medium. The filtered material is mixed with white sugar. The resulting filtrate is mixed with the raw honey. The mixture is heated to 62°C and then sent to a crystallization tank for two-stage crystallization.

[0061] (3) The ethyl sugar paste obtained by boiling in the crystallization tank of the two-stage crystallization is successively passed through the crystallization aid tank and the separator to obtain ethyl sugar and ethyl raw honey respectively. All the ethyl sugar is returned to the crystallization tank of the first-stage crystallization and mixed with methyl sugar paste.

[0062] (4) The Brix of the raw honey was measured to be 48°Bx, and the raw honey was discharged as waste honey.

[0063] Comparative Example 1

[0064] Comparative Example 1 discloses a crystallization process for purified syrup. Comparative Example 1 is basically the same as Example 1, except that:

[0065] (1) The syrup is filtered through chitosan-diatomaceous earth composite material and ceramic filter membrane in sequence, then heated to 68°C and transported to crystallization tank for cooking to obtain methyl syrup paste. The methyl syrup paste is then passed through crystallization tank for crystallization and separated by separator to obtain white granulated sugar and methyl syrup paste respectively.

[0066] After processing in steps (1)-(3), the Brix of raw honey was measured to be 56°Bx. The raw honey entered the crystallization tank of the three-stage crystallization. After boiling, the resulting sugar paste was successively passed through the crystallization tank for crystallization and separated by the separator to obtain brown sugar and waste honey. Part of the brown sugar was returned to the crystallization tank of the first stage and mixed with the sugar paste of the first stage, while the other part was discharged.

[0067] Comparative Example 2

[0068] Comparative Example 2 discloses a crystallization process for purified syrup. Comparative Example 2 is basically the same as Example 1, except that:

[0069] (1) The syrup is filtered through a ceramic filter membrane and a chitosan-diatomaceous earth composite material in sequence, then heated to 72°C and transported to a crystallization tank for cooking to obtain methyl syrup paste. The methyl syrup paste is then passed through a crystallization tank for crystallization and a separator for separation to obtain white granulated sugar and methyl syrup paste respectively.

[0070] After processing in steps (1)-(3) of Comparative Example 2, the Brix of raw honey was measured to be 52°Bx. The raw honey was then placed in a three-stage crystallization tank. After boiling, the resulting sugar paste was passed through a crystallization aid tank and a separator to obtain brown sugar and waste honey. Part of the brown sugar was returned to the first-stage crystallization tank to be mixed with sugar paste, and the other part was returned to the second-stage crystallization tank to be mixed with sugar paste.

[0071] Comparative Example 3

[0072] Comparative Example 3 discloses a crystallization process for purified syrup. Comparative Example 3 is basically the same as Example 1, except that:

[0073] The preparation method of chitosan-diatomite composite material is as follows: dissolve chitosan in a 2% acetic acid solution and stir at 20°C until completely dissolved. Then add 8 times the mass of diatomite to the chitosan and continue stirring until a uniform colloid is formed. Dry at 105°C for 45 minutes and grind into powder.

[0074] After processing in steps (1)-(3), the Brix of the raw honey was measured to be 57°Bx. The raw honey was then placed in a three-stage crystallization tank. After boiling, the resulting syrup was passed through a crystallization aid tank and a separator to separate the honey, resulting in brown sugar and waste honey. The brown sugar was then discharged.

[0075] Comparative Example 4

[0076] Comparative Example 4 discloses a purification syrup crystallization process. Comparative Example 4 is basically the same as Example 1, except that:

[0077] (1) The syrup is heated to 68°C and then fed into a crystallizer to be cooked to obtain methyl syrup. The methyl syrup is then passed through a crystallizer for crystallization and a separator for separation to obtain white sugar and methyl syrup respectively.

[0078] After processing in steps (1)-(3), the Brix of the raw honey was measured to be 58°Bx. The raw honey was then placed in a three-stage crystallization tank. After boiling, the resulting syrup was passed through a crystallization aid tank and a separator to separate the honey, resulting in brown sugar and waste honey. The brown sugar was then discharged.

[0079] Comparative Example 5

[0080] Comparative Example 5 discloses a purification syrup crystallization process. Comparative Example 5 is basically the same as Example 1, except that:

[0081] (2) The raw honey is filtered through a filter with diatomaceous earth as the medium. The filtered material is mixed with white sugar. The resulting filtrate is mixed with the raw honey. The mixture is heated to 60°C and then sent to a crystallization tank for two-stage crystallization.

[0082] After being processed in steps (1)-(3), the Brix of the raw honey was measured to be 52°Bx. The raw honey was then placed in a three-stage crystallization tank. After being boiled, the resulting syrup was passed through a crystallization aid tank and a separator to separate the honey, resulting in brown sugar and waste honey. Part of the brown sugar was returned to the two-stage crystallization tank to mix with the syrup, and the other part was discharged.

[0083] The present invention conducted relevant quality tests on the white granulated sugar prepared in Examples 1-4 and Comparative Examples 1-5. The test results are shown in Table 1.

[0084] Table 1 Results of Quality Test for White Sugar

[0085]

[0086]

[0087] The above results indicate that both ceramic filter membranes and chitosan-diatomaceous earth composite materials significantly improve the quality of granulated sugar. The optimization effect is most pronounced when the sugar is treated sequentially with a ceramic filter membrane followed by the chitosan-diatomaceous earth composite material, achieving a superior grade. However, when the sugar is treated sequentially with the chitosan-diatomaceous earth composite material followed by a ceramic filter membrane, the improvement in quality is not significantly different from that achieved with either the chitosan-diatomaceous earth composite material alone or the ceramic filter membrane alone. Therefore, considering cost, the sequential treatment with the chitosan-diatomaceous earth composite material followed by the ceramic filter membrane is discarded. Furthermore, the preparation of the chitosan-diatomaceous earth composite material also has a significant impact on the quality of granulated sugar.

[0088] If the heating temperature exceeds 70℃ during the heating process before the syrup enters the first crystallization step, or if the heating temperature is below 60℃ during the heating process before the raw honey enters the second crystallization step, the sucrose content of the white sugar will decrease, the reducing sugar content in the white sugar will increase, and the electrical conductivity and ash content will also increase accordingly. The resulting white sugar can only meet the second-grade standard.

[0089] In summary, the white granulated sugar prepared by the purification syrup crystallization process of this invention can meet the first-grade standard or even the superior standard specified in GB / T317-2018, and can minimize the crystallization process, reduce energy consumption and production costs.

[0090] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The solutions disclosed in the embodiments are described simply because they correspond to the methods disclosed in the embodiments; relevant parts can be found in the method section.

[0091] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A process for purifying syrup crystallization, characterized in that, Includes the following steps: (1) After filtering the syrup, heat it and send it to a crystallization tank to cook it to obtain methyl syrup paste. The methyl syrup paste is then passed through a crystallization tank for crystallization and a separator for separation to obtain white granulated sugar and methyl syrup paste respectively. (2) The honey is filtered through a filter, the filtered material is mixed with white sugar, the resulting filtrate is mixed with the honey, and the mixture is heated and then sent to a crystallization tank for two-stage crystallization. (3) The ethyl sugar paste obtained by boiling in the crystallization tank of the two-stage crystallization is successively passed through the crystallization aid tank and the separator to obtain ethyl sugar and ethyl raw honey respectively. (4) Measure the arginine content of the raw arginine and determine whether to continue to the three-stage crystallization process by comparing the arginine content of the raw arginine with the preset waste arginine content. The filtration in step (1) is filtration through a ceramic filter membrane and / or a chitosan-diatomaceous earth composite material, and the heating temperature is 65-70℃; In step (1), methyl methyl ether is also obtained, and all of the methyl methyl ether is returned to the crystallization tank and mixed with methyl methyl ether paste; The heating temperature mentioned in step (2) is 62-68℃; The ethyl sugar obtained in step (3) is all refluxed into a crystallization tank for crystallization and mixed with the methyl sugar paste; In step (4), the preset waste honey hammer degree is 50°Bx. If the hammer degree of the raw honey is greater than the preset waste honey hammer degree, the three-stage crystallization process is entered; if the hammer degree of the raw honey is not greater than the preset waste honey hammer degree, the crystallization process ends. The preparation method of the chitosan-diatomite composite material is as follows: dissolve chitosan in acetic acid solution, stir at 25-30℃ until completely dissolved, then add 8-10 times the mass of diatomite, continue stirring until a uniform colloid is formed, dry at 110-120℃ for 30-45 minutes, and pulverize.

2. The purified syrup crystallization process according to claim 1, characterized in that, The ceramic filter membrane is an asymmetric ceramic membrane, and the material of the ceramic filter membrane is silicon carbide.

3. The purified syrup crystallization process according to claim 1, characterized in that, The filter media mentioned in step (2) include filter cake and diatomaceous earth.

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