A continuous decolorization system for xylose production and its usage method

Abstract

The present invention relates to the technical field of xylose production, and particularly relates to a continuous decolorization system for xylose production and its usage method. Three decolorization resin columns are provided and connected in series through series columns pipelines. Metering pumps are installed on the feed main pipe, alkali inlet main pipe, acid inlet main pipe, and elution main pipe. Automatic control valves are installed on the feed pipelines, discharge pipelines, and series columns pipelines of each decolorization resin column. The metering pumps and the automatic control valves are connected to a PLC control system. By controlling the opening and closing time and sequence of each metering pump and the automatic control valve, a cycle process of primary decolorization, regeneration, and secondary decolorization of a single decolorization resin column can be realized, and an orderly series connection between multiple decolorization resin columns can be achieved, realizing a continuous and stable decolorization process of the xylose solution by the entire system. The present invention can completely replace activated carbon, improve the working environment, reduce solid waste pollution, relieve the environmental protection pressure, and achieve automated continuous operation, reduce the labor intensity of personnel, and reduce production costs.

Description

Technical Field

[0001] The present invention relates to the technical field of xylose production, and specifically relates to a continuous decolorization system for xylose production and its usage method. Background Art

[0002] Xylose is the most abundant pentose in nature and widely exists in plant hemicellulose in the form of macromolecular xylan (condensed state); as a biodegradable natural material, xylose has broad application prospects in the fields of food, medicine, cosmetics, textile, and environmental protection.

[0003] Xylan can be degraded by acid or enzyme to obtain xylose. Currently, the xylose production process mainly uses corncob as the raw material, and after processes such as hydrolysis, neutralization, decolorization, separation, concentration, and crystallization, during which the suspension content in the xylose solution is very high and decolorization and purification are required. Currently, activated carbon is often used to decolorize and purify the xylose solution, but it consumes a large amount of activated carbon. On the one hand, 150 kg of activated carbon is consumed per ton of xylose, with a large workload and a harsh environment, which is not conducive to on-site management. On the other hand, the activated carbon decolorization process is a batch operation, with a large working intensity, low production efficiency, and serious resource waste, which is not conducive to cost savings.

[0004] Therefore, providing a continuous decolorization system for xylose production and its usage method that can completely replace activated carbon, improve the working environment, reduce solid waste pollution, continuously decolorize, and improve production efficiency is an urgent problem to be solved currently. Summary of the Invention

[0005] The purpose of the present invention is to provide a continuous decolorization system for xylose production and its usage method to achieve the purpose of completely replacing activated carbon, improving the working environment, reducing solid waste pollution, continuously decolorizing, and improving production efficiency.

[0006] To achieve the above purpose, the present invention adopts the following technical solution: A continuous decolorization system for xylose production includes three decolorization resin columns connected in series, and each decolorization resin column is respectively connected to a stock solution tank, a desorption liquid tank, a sewage tank, an alkali solution tank, an acid solution tank, a rinsing water tank, and a collection tank.

[0007] Further, each of the decolorization resin columns is connected to the stock solution tank through a feed pipeline and a feed main pipeline, connected to the desorption liquid tank through a discharge pipeline and a desorption liquid main pipeline, connected to the sewage tank through a discharge pipeline and a sewage main pipeline, connected to the alkali solution tank through a feed pipeline and an alkali inlet main pipeline, connected to the acid solution tank through a feed pipeline and an acid inlet main pipeline, connected to the rinsing water tank through a feed pipeline and a rinsing main pipeline, and connected to the collection tank through a discharge pipeline and a discharge main pipeline. The decolorization resin columns are connected in series through a series-column pipeline.

[0008] Further, metering pumps are installed on the main feed pipe, main alkali inlet pipe, main acid inlet pipe and main rinsing pipe, and automatic control valves are installed on the feed pipes, discharge pipes and column connection pipes of each decolorizing resin column.

[0009] Further, the metering pumps and automatic control valves are connected to the PLC control system.

[0010] A method for using a continuous decolorization system for xylose production includes the following steps:

[0011] S1. Introduce the xylose solution after primary decolorization through the first decolorizing resin column into the secondary decolorization process of the second decolorizing resin column;

[0012] S2. Introduce the original xylose solution into the first decolorizing resin column for the primary decolorization process for the second decolorizing resin column after secondary decolorization in S1;

[0013] S3. Introduce the xylose solution after primary decolorization in S2 into the secondary decolorization process of the third decolorizing resin column;

[0014] S4. Introduce the original xylose solution into the third decolorizing resin column for the primary decolorization process for the third decolorizing resin column after secondary decolorization in S3;

[0015] S5. Introduce the xylose solution after primary decolorization in S4 into the secondary decolorization process of the first decolorizing resin column;

[0016] S6. Connect each metering pump and automatic control valve to the PLC control system to realize the continuous decolorization process of the original xylose solution.

[0017] Further, each decolorizing resin column after the secondary decolorization process enters the regeneration process.

[0018] Further, the regeneration process includes four stages: desorption, alkali washing, acidification and acid washing.

[0019] Further, the objects controlled by the PLC control system are the opening and closing times and sequences of each automatic control valve and metering pump.

[0020] Advantages of the present invention:

[0021] 1. The original xylose solution is adsorbed and decolorized by using decolorizing resin columns. In the process, through the technical solution of multi-stage adsorption and decolorization, the decolorization effect is good, and activated carbon can be completely replaced, achieving the purposes of improving the working environment, reducing solid waste pollution and alleviating the environmental protection pressure;

[0022] 2. By installing metering pumps and automatic control valves and connecting the metering pumps and automatic control valves to the PLC control system, the opening and closing times and sequences of the metering pumps and automatic control valves are controlled, the orderly series connection between multiple decolorizing resin columns is realized, the automatic continuous operation is achieved, and the purpose of reducing the labor intensity of personnel and lowering the production cost is achieved. Brief Description of the Drawings

[0023] Figure 1 is a schematic diagram of the decolorizing system of the present invention;

[0024] Figure 2 is a schematic diagram of the operating state of the decolorizing system of the present invention;

[0025] Figure 3 is a schematic diagram of the process state when the decolorizing resin column A of the present invention is in the regeneration treatment state, the decolorizing resin column B is in the primary decolorization state, and the decolorizing resin column C is in the secondary decolorization state;

[0026] Figure 4 is a schematic diagram of the process state when the decolorizing resin column A of the present invention is in the primary decolorization state, the decolorizing resin column B is in the secondary decolorization state, and the decolorizing resin column C is in the regeneration treatment state;

[0027] Figure 5 is a schematic diagram of the installation of each automatic control valve of the present invention.

[0028] The names corresponding to the marks in the figure:

[0029] 1. Decolorizing resin column A; 2. Decolorizing resin column B; 3. Decolorizing resin column C; 4. Stock solution tank; 5. Collection tank; 6. Desorption liquid tank; 7. Sewage tank; 8. Alkali solution tank; 9. Acid solution tank; 10. Flushing water tank; 11. Feed main pipe; 12. Series column pipeline; 13. Desorption liquid main pipe; 14. Sewage main pipe; 15. Inlet alkali main pipe; 16. Inlet acid main pipe; 17. Flushing main pipe; 18. Discharge main pipe; 19. Metering pump; 20. Feed pipeline; 21. Discharge pipeline; 22. Automatic control valve. Detailed Embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0031] As Figure 1As shown in the figure, in this embodiment, a decolorizing resin column A1, a decolorizing resin column B2, and a decolorizing resin column C3 are provided. The decolorizing resin column A1, the decolorizing resin column B2, and the decolorizing resin column C3 are connected in series through a series-column pipeline 12. The decolorizing resin column A1, the decolorizing resin column B2, and the decolorizing resin column C3 are respectively connected to a feed main pipe 11, a desorption liquid main pipe 13, a sewage main pipe 14, an alkali inlet main pipe 15, an acid inlet main pipe 16, a flushing main pipe 17, and a discharge main pipe 18. The feed main pipe 11 is connected to a stock solution tank 4, the desorption liquid main pipe 13 is connected to a desorption liquid tank 6, the sewage main pipe 14 is connected to a sewage tank 7, the alkali inlet main pipe 15 is connected to an alkali liquid tank 8, the acid inlet main pipe 16 is connected to an acid liquid tank 9, the flushing main pipe 17 is connected to a flushing water tank 10, and the discharge main pipe 18 is connected to a collection tank 5. Metering pumps 19 are installed on the feed main pipe 11, the alkali inlet main pipe 15, the acid inlet main pipe 16, and the flushing main pipe 17.

[0032] As Figure 2 shown, a continuous xylose decolorization system forms a cycle among the decolorizing resin column A1, the decolorizing resin column B2, and the decolorizing resin column C3. Each column independently undergoes a cycle process of primary decolorization - desorption - alkali washing - acidification - acid washing - secondary decolorization. Meanwhile, xylose stock solution is supplemented during primary decolorization, and a finished product is obtained after secondary decolorization. The xylose stock solution goes to the decolorizing resin column B2 for secondary decolorization to obtain a finished product after primary decolorization by the decolorizing resin column A1. After completing the secondary decolorization process, the decolorizing resin column B2 supplements the xylose stock solution for primary decolorization and then goes to the decolorizing resin column C3 for secondary decolorization to obtain a finished product. At this time, the decolorizing resin column A1 has completed the regeneration process of desorption - alkali washing - acidification - acid washing. Therefore, after completing the secondary decolorization process, the decolorizing resin column C3 supplements the xylose stock solution for primary decolorization and then goes to the decolorizing resin column A1 for secondary decolorization to obtain a finished product, thus realizing the continuous cyclic operation of the entire system.

[0033] As Figures 1 - 5 shown, each decolorizing resin column is connected to the feed main pipe 11, the alkali inlet main pipe 15, the acid inlet main pipe 16, and the flushing main pipe 17 through a feed pipeline 20, and is connected to the desorption liquid main pipe 13, the sewage main pipe 14, and the discharge main pipe 18 through a discharge pipeline 21. Automatic control valves 22 are installed on the feed pipeline 20 and the discharge pipeline 21. By connecting the metering pumps 19 and the automatic control valves 22 to a PLC control system and controlling the opening and closing time and sequence of each metering pump 19 and automatic control valve 22, the above-mentioned in-column cycle and inter-column cycle processes are realized.

[0034] The principle of the present invention is:

[0035] Based on the fact that the decolorization and impurity removal of xylose stock solution by activated carbon will generate a large amount of solid waste and cause environmental pollution, it is necessary to develop an economical, environmentally friendly, and efficient means for decolorization and impurity removal of xylose stock solution.

[0036] Based on the adsorption principle of the adsorption decolorization resin column, impurities in the crude xylose solution are adsorbed and removed for decolorization. However, the impurity removal effect of a single adsorption resin column is not ideal. To achieve a better effect, repeated adsorption operations are required. During the operation, the decolorized resin column needs to be regenerated. Using a single resin column greatly prolongs the time of the entire technological process, resulting in low production efficiency and unable to meet the actual production requirements. For example, in a Chinese invention patent (202011167017.8), a method for continuous decolorization and desalination of xylose mother liquor is disclosed.

[0037] A method of connecting multiple decolorization resin columns in series is adopted, and the in-column and inter-column circulation of each decolorization resin column is realized through a PLC control system. The in-column circulation is a cyclic process of primary decolorization - desorption - alkali washing - acidification - acid washing - secondary decolorization. The inter-column circulation is to supplement the crude xylose solution after secondary decolorization for primary decolorization, and after primary decolorization, it goes to the next column for secondary decolorization. The entire decolorization system has stable operation control, good regeneration effect of the decolorization resin column, good decolorization effect of the crude xylose solution, ensuring product quality while greatly improving production efficiency, which is beneficial to the low-cost, low-pollution and high-efficiency production operation of the enterprise.

[0038] The control technology of PLC in this invention application is a mature existing technology, which is not difficult to understand for those skilled in the art and will not be elaborated here.

[0039] Example 1

[0040] This example is the decolorization process of the first-concentrated xylose solution, which will be described in conjunction with the attached Figure 4 The feed liquid to be treated is the xylose solution after the first concentration, with a refractive index of 32% and a light transmittance of 1%. The feed flow rate is controlled at 5m 3 / h, and the flow direction of the feed liquid is feed main pipe - decolorization resin column A1 (primary decolorization) - series column pipeline - decolorization resin column B2 (secondary decolorization) - discharge main pipe - collection tank.

[0041] After detection, the final discharged product has a refractive index of 32% and a light transmittance of 70%, indicating a good decolorization effect.

[0042] Example 2

[0043] This example is the regeneration process after the decolorization resin column fails, which will be described in conjunction with the attached Figure 3 The decolorization resin column A1 is sequentially switched among the states of desorption, alkali washing, acidification, and acid washing.

[0044] First, 5% NaOH is introduced into the decolorization column A in the regeneration stage, and the flow rate is controlled at 5m 3 / h, the pigment adsorbed by the resin is desorbed with an alkali solution, and the resulting desorption solution is collected for other uses. When the alkali concentration at the outlet reaches 3%, the desorption is completed. Then, rinsing water is passed through to wash away the residual alkali solution. Subsequently, a 1.5% HCl solution is passed through the decolorizing resin column A for acidification treatment. When the outlet becomes acidic, the acidification is completed. Finally, rinsing water is used to wash away the residual acid, and the acid washing is completed when the outlet pH is 2.0 - 3.0, ending the entire regeneration process.

[0045] The present invention is not limited to the above - mentioned optimal implementation mode. Any person can obtain other various forms of products under the inspiration of the present invention. However, no matter what changes are made in its shape or structure, as long as it has a technical solution identical or similar to that of this application, it falls within the protection scope of the present invention.

Claims

1. A method for using a continuous decolorization system for xylose production, characterized in that, It includes the following steps: S1. Introduce the xylose solution after primary decolorization through the first decolorizing resin column into the secondary decolorization process of the second decolorizing resin column; S2. Introduce the original xylose solution into the first decolorizing resin column for the primary decolorization process of the second decolorizing resin column after secondary decolorization in S1; S3. Introduce the xylose solution after primary decolorization in S2 into the secondary decolorization process of the third decolorizing resin column; S4. Introduce the original xylose solution into the first decolorizing resin column for the primary decolorization process of the third decolorizing resin column after secondary decolorization in S3; S5. Introduce the xylose solution after primary decolorization in S4 into the secondary decolorization process of the first decolorizing resin column; S6. Connect each metering pump (19) and automatic control valve (22) to the PLC control system to realize the continuous decolorization process of the original xylose solution.

2. The usage method of a continuous decolorization system for xylose production according to claim 1, characterized in that: Each decolorizing resin column after the secondary decolorization process enters the regeneration process.

3. The usage method of a continuous decolorization system for xylose production according to claim 2, characterized in that: The regeneration process includes four stages: desorption, alkali washing, acidification, and acid washing.

4. The method for using a continuous decolorization system for xylose production according to claim 1, characterized in that: The objects controlled by the PLC control system are the switching times and sequences of each automatic control valve (22) and metering pump (19).

5. The continuous decolorization system for xylose production involved in the usage method according to any one of claims 1-4, characterized in that: It includes three decolorizing resin columns connected in series, and each decolorizing resin column is respectively connected to the original liquid tank (4), desorption liquid tank (6), sewage tank (7), alkali liquid tank (8), acid liquid tank (9), flushing water tank (10), and collection tank (5).

6. The continuous decolorization system for xylose production according to claim 5, characterized in that: Each decolorizing resin column is connected to the original liquid tank (4) through the feed pipeline (20) and the main feed pipeline (11), connected to the desorption liquid tank (6) through the discharge pipeline (21) and the main desorption liquid pipeline (13), connected to the sewage tank (7) through the discharge pipeline (21) and the main sewage pipeline (14), connected to the alkali liquid tank (8) through the feed pipeline (20) and the main alkali inlet pipeline (15), connected to the acid liquid tank (9) through the feed pipeline (20) and the main acid inlet pipeline (16), connected to the flushing water tank (10) through the feed pipeline (20) and the main flushing pipeline (17), connected to the collection tank (5) through the discharge pipeline (21) and the main discharge pipeline (18), and the decolorizing resin columns are connected in series through the series-column pipeline (12).

7. The continuous decolorization system for xylose production according to claim 6, wherein: Metering pumps (19) are installed on the main feed pipeline (11), main alkali inlet pipeline (15), main acid inlet pipeline (16), and main flushing pipeline (17), and automatic control valves (22) are installed on the feed pipeline (20), discharge pipeline (21), and series-column pipeline (12) of each decolorizing resin column.

8. The continuous decolorization system for xylose production according to claim 7, characterized in that: The metering pump (19) and the automatic control valve (22) are connected to the PLC control system.

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