METHOD FOR PRODUCEING CRUDE JUICE FOR SUGAR PRODUCTION, METHOD FOR PRODUCEING SUGAR AND SUGAR PRODUCTION PLANT

Description

State of the art

[0001] The present invention relates to a method for producing raw juice for sugar production, wherein sugar beet pulp is fed into an extraction device designed as an extraction tower or diffusion trough, and sugar beet pulp residues and raw juice are withdrawn from the extraction device. The invention further relates to a method for producing sugar. A further object of the invention is a sugar production plant with an extraction device, for example an extraction tower or a diffusion trough, to which sugar beet pulp is fed and from which sugar beet pulp residues and raw juice can be withdrawn.

[0002] The production of raw juice is typically one of the first steps in industrial sugar production, carried out in the sugar production plant. The sugar beets delivered to the plant are usually washed to remove any adhering substances. The cleaned beets are then shredded into beet pulp. The actual production of the raw juice takes place in an extraction unit, to which the beet pulp is fed. Various types of extraction units exist, such as extraction towers or diffusion troughs. What they all have in common is that the beet pulp is subjected to hot water in a countercurrent process. The raw juice, which contains approximately 92% to 95% of the sucrose present in the beet pulp, along with some non-sugar components, is obtained through diffusion / extraction.The extraction process also produces sugar beet pulp residues, which are typically pressed into pellets and used as animal feed.

[0003] In industrial sugar production, particularly during the extraction process, careful adjustment and, if necessary, fine-tuning of process parameters is essential. Therefore, it is necessary to analyze the sugar beet pulp and / or sugar beet pulp residues and / or the extracted raw juice for their constituents. According to current best practices, samples are taken and analyzed in a laboratory. Sampling and subsequent laboratory analysis involve a certain turnaround time, which must be observed before the analysis results are available and any necessary actions, such as adjusting process parameters, can be taken.

[0004] WO 2020 / 027 731 A1 describes a separation process in which granulated sugar is separated from a thick-juice-granulated sugar mixture, i.e., magma or massecuite, by centrifugation. In this context, WO 2020 / 027 731 A1 proposes using an analytical method, such as near-infrared spectroscopy (NIRS), to derive a spectrum indicating the concentration of phenols or flavonoids in the thick-juice-granulated sugar mixture. Based on this information, suitable operating parameters for the centrifuge can be determined.

[0005] US Patent 6,630,672 B1 describes a method and system for online measurement of a stream from crushed sugar cane using near-infrared spectroscopy. Disclosure of the invention

[0006] Against this background, the object of the present invention is to enable the balancing of ingredients of the starting materials and / or products in the extraction process with less effort, in particular with less time and / or laboratory effort.

[0007] To solve the problem, a method for producing raw juice for the production of sugar with the features of claim 1 is proposed.

[0008] In the inventive method, several near-infrared spectroscopy devices are used to acquire measurement data concerning the sugar beet pulp fed to the extraction unit, the sugar beet pulp residues and raw juice removed from the extraction unit. These near-infrared spectroscopy devices enable the non-contact determination of the constituents of the sugar beet pulp, sugar beet pulp residues, and raw juice. Furthermore, the use of near-infrared spectroscopy devices offers the advantage that time-consuming sampling and analysis in a laboratory can be avoided. Instead, the inventive method makes it possible to determine the constituents during the ongoing production process without taking sugar beet pulp, sugar beet pulp residues, and / or raw juice.The near-infrared spectroscopy device(s) also enable the analysis and / or control of the extraction equipment and / or other equipment or process steps in the sugar production process.

[0009] Several near-infrared spectroscopy (NIRS) devices acquire measurement data from which conclusions can be drawn about the constituents of the sugar beet pulp, sugar beet pulp residues, and raw juice being analyzed. Each NIRS device utilizes a method in which the raw material or product under investigation is irradiated with electromagnetic radiation in the near-infrared range, for example, in a spectral range of 400 nm to 2,500 nm. This irradiation can excite molecular vibrations in the material under investigation. The electromagnetic radiation in the near-infrared range, e.g., in a spectral range of 400 nm to 2,500 nm, triggered by these molecular vibrations is detected and spectroscopically resolved. The type and / or quantity of constituents in the analyzed materials can be determined from the acquired spectra.

[0010] The sugar beet pulp and / or sugar beet pulp residues and / or the raw juice can be detected with the respective near-infrared spectroscopy device without further treatment. Removal of the sugar beet pulp and / or sugar beet pulp residues from the production flow and / or processing is not required.

[0011] With regard to the raw juice, it can be advantageous to arrange the third near-infrared spectroscopy device in a bypass line into which the raw juice is introduced, thus creating a stagnant sample of raw juice for acquiring the third measurement data. Acquiring the third measurement data from the liquid raw juice can be done with improved reproducibility if it remains stationary. After the measurement of the stagnant raw juice has been carried out, it can be returned to the production flow.

[0012] Preferably, the measurement data acquired with the respective near-infrared spectroscopy device can be obtained through multiple measurements from different directions. For this purpose, the respective near-infrared spectroscopy device can be provided with several detectors arranged in different orientations relative to the material under investigation. Such non-contact measurement from multiple directions allows the constituents to be determined with increased accuracy from the respective measurement data.

[0013] According to the invention, an optical imaging device is used to determine one or more geometric properties of the sugar beet pulp, in particular its length and / or width and / or cross-sectional area. The additional optically detectable properties of the sugar beet pulp determined can improve the analysis and / or monitoring of the extraction process. The optical imaging device is preferably directed at the same area of ​​the production flow as the first near-infrared spectroscopy device, so that the initial measurement data from the near-infrared spectroscopy device and the properties determined by the optical imaging device relate to identical sugar beet pulp.

[0014] Preferably, the sugar beet pulp residues extracted from the extraction device are pressed, producing residual water, and fourth measurement data concerning the residual water produced during the pressing of the sugar beet pulp residues are recorded using a fourth near-infrared spectroscopy device.

[0015] Particularly preferred is the fourth near-infrared spectroscopy device arranged in a bypass line into which the residual water is introduced, thus creating stagnant residual water for the acquisition of the fourth measurement data. The acquisition of the fourth measurement data can be performed with improved reproducibility on the stagnant residual water. After the measurement has been carried out on the stagnant residual water, it can be drained from the bypass line.

[0016] It is particularly advantageous if the sugar beet pulp residues extracted from the extraction device are pressed, producing residual water, and fifth measurement data concerning the pressed sugar beet pulp residues obtained during pressing are recorded using a fifth near-infrared spectroscopy device.

[0017] The method according to the invention provides that at least one process parameter of the extraction device is set depending on the first measurement data and the geometric properties of the sugar beet pulp, and depending on the second and / or third measurement data. By setting the process parameters depending on the measurement data acquired by several near-infrared spectroscopy devices and the properties determined by the optical imaging device, the process parameters of the extraction device can be adjusted with low latency. The process parameter can, for example, be an extraction time, which specifies the duration for which the sugar beet pulp remains in the extraction device, and / or an extraction temperature, which specifies the temperature at which the extraction device is operated.Alternatively or additionally, the process parameter can be the amount of fresh water supplied to the extraction unit and / or the fill level in the extraction unit. For example, the yield of the extraction process can be determined based on the first and / or second and / or third measurement data, whereby if the yield decreases, the amount of fresh water in the extraction unit and / or the extraction temperature is increased.

[0018] An advantageous embodiment of the method involves cutting sugar beet slices from sugar beets using a cutting machine, and adjusting a process parameter of the cutting machine based on the first, second, and / or third measurement data and / or, if applicable, the geometric properties of the sugar beet slices. Adjusting the process parameters based on the measurement data acquired by one or more near-infrared spectroscopy devices and / or the properties determined by the optical imaging device allows for low-latency adjustment of the cutting machine's process parameters.For example, it can be detected that a geometric property, such as length, width, cross-sectional area, or specific surface area, is smaller than a predefined minimum value, and a process parameter of the cutting machine can be modified to produce larger sugar beet slices. Alternatively, it can be detected that the geometric property is larger than a predefined maximum value, and a process parameter of the cutting machine can be modified to produce smaller sugar beet slices. The geometric property can be determined as a measure of the distribution of length, width, cross-sectional area, or surface area. It is particularly suitable if the geometric property of the sugar beet slices is determined as a length distribution or a distribution of specific surface area.Uniformly long sugar beet pulp leads to good extraction results because it offers a large surface area and, due to its length, ensures good flow of the water and pulp mixture. Short sugar beet pulp, while also having a large surface area, hinders the transfer of substances during the separation of the pulp and juice, for example, in the bottom sieves of an extraction tower. A high proportion of only partially cut sugar beets, such as in the form of slices, results in a smaller surface area and therefore poorer mass transfer. Uniformly long sugar beet pulp allows for better pressing in the pulp presses, thus reducing energy consumption and improving the recovery of residual sugar from the pulp.

[0019] Furthermore, to solve the aforementioned problem, a method for producing sugar is proposed, wherein raw juice is produced according to a method described above and sugar is produced from the raw juice in subsequent process steps.

[0020] The process for producing sugar offers the same advantages that have already been described in connection with the process for producing raw juice.

[0021] According to an advantageous embodiment of the sugar production process, at least one process parameter of one of the subsequent process steps is adjusted based on the first, second, and / or third measurement data and / or, if applicable, the geometric properties of the sugar beet pulp. Adjusting the process parameters based on the measurement data acquired by one or more of the near-infrared spectroscopy devices and / or the properties determined by the optical imaging device allows for low-latency adjustment of the process parameters of one of the subsequent process steps.

[0022] Preferably, the subsequent process step is a liming step, a carbonation step, a filtration step, a thickening step, a crystallization step, or a separation step. In the liming step, process parameters such as the amount of lime milk added, the composition or concentration of the lime milk, a pH value, or the amount of precipitated calcium carbonate added can be used. precipitated calcium carbonate, (abbreviated PCC) or sludge juice recirculation can be set. In the thickening step and / or crystallization step, a temperature or residence time, for example, can be set as a process parameter.

[0023] In addition to the advantageous embodiments explained above, the advantageous embodiments and features described in connection with the process for producing raw juice can also be applied to the process for producing sugar, either alone or in combination.

[0024] The invention further relates to a sugar production plant with the features of claim 12.

[0025] The same advantages can be achieved with the sugar production plant as have already been described in connection with the process for producing sugar.

[0026] The sugar production plant according to the invention comprises an optical imaging device for determining one or more geometric properties of the beet pulp, in particular length and / or width and / or cross-sectional area. The additional determination of optically detectable properties of the sugar beet pulp allows for further improvement of the analysis and / or monitoring of the extraction process. The optical imaging device is preferably directed at the same area of ​​the production flow as the first near-infrared spectroscopy device, so that the first measurement data from the near-infrared spectroscopy device and the properties determined by the optical imaging device relate to identical sugar beet pulp.

[0027] A preferred embodiment of the invention provides that the sugar production plant includes a cutting machine for cutting sugar beet slices from sugar beets, wherein the optical image acquisition device is arranged in the output area of ​​the cutting machine. This makes it possible to analyze the sugar beet slices cut by the cutting machine and to adjust the operating mode of the cutting machine depending on this analysis.

[0028] In addition to the advantageous designs explained above, the advantageous designs and features described in connection with the processes explained above can also be applied to the sugar production plant, either alone or in combination.

[0029] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of a preferred embodiment with reference to the drawings. The drawings merely illustrate an exemplary embodiment of the invention, which does not limit the inventive concept. Brief description of the characters

[0030] The Fig. 1 shows a process for the production of sugar according to an embodiment of the invention.

[0031] The Fig. 2 shows a method for producing raw juice according to an embodiment of the invention. Embodiments of the invention

[0032] In the various figures, identical parts are always marked with the same reference symbols and are therefore usually only named or mentioned once.

[0033] The in Fig. 1The flowchart shown illustrates an embodiment of a process according to the invention for the production of sugar, which is carried out in a sugar production plant. The sugar beets delivered to the sugar production plant are preferably first cleaned, i.e., freed from adhering substances such as soil, sand, or leaves. In a first process step of cutting 1, the sugar beets are cut into pieces by a cutting machine to obtain sugar beet pulp 11.

[0034] In a subsequent step of the extraction process (2), or juice extraction, following cutting (1), the sugar beet pulp is leached of water in an extraction unit. Optionally, the sugar beet pulp can first be preheated, for example, to a temperature of 60 °C to 80 °C, to make the cell walls more permeable. The actual extraction process (2) takes place in a countercurrent flow, in which the sugar beet pulp is conveyed or guided through the extraction unit in the opposite direction to hot water. The product of extraction (2) is raw juice (14), which contains almost all the sugar contained in the sugar beets, in addition to sugar beet pulp residue. Details of extraction (2) are described below in connection with... Fig. 2 explained.

[0035] In a liming step 3, lime in the form of lime milk is added to the raw juice 14. The lime binds non-sugar substances contained in the raw juice 14. Acids are neutralized and the pH value is raised.

[0036] In the subsequent carbonation step (4), carbon dioxide is introduced into the mixture of raw juice and lime milk. Calcium and other non-sugar substances are bound and precipitate as lime (calcium carbonate). In the following filtration step (5), the lime is then separated, leaving the thin juice. The liming steps (3), carbonation (4), and filtration (5) are collectively referred to as juice purification. These steps can optionally be repeated several times in this sequence, for example, twice, to improve the purification result.

[0037] This is followed by the thickening process step 6, in which the thin juice is thickened in a mostly multi-stage heating process to obtain the thick juice.

[0038] In a crystallization step 7, the thick juice is crystallized with sugar at moderate or high temperature and reduced pressure, for example at approximately 70 °C. Crystallization 7 preferably comprises several successive crystallization steps. A mixture of thick juice and crystalline sugar, also known as magma, is obtained.

[0039] Finally, in a separation step 8, for example in a centrifuge, the granulated sugar is separated.

[0040] In the procedure according to Fig. 1 An extraction step 2 according to the invention is used, which is described below with reference to the illustration in Fig. 2 This will be explained.

[0041] In extraction step 2, an extraction unit 20 is used, which is designed as an extraction tower or diffusion trough. In the extraction unit 20, the sugar beet pulp 11, cut by the cutting machine 10, are subjected to hot water 12 in a countercurrent process to extract the raw juice 14 from the sugar beet pulp 11. Extracted sugar beet pulp residue 13 remains. This residue is pressed in a press 30 to dry. The residual water 15 obtained during pressing is heated and supplied to the extraction unit 20 together with fresh water 12.

[0042] To facilitate the analysis of the constituents of the starting materials and / or products during the extraction process with less effort, special measures are taken in extraction step 2. A first near-infrared spectroscopy device 21 is used to acquire initial measurement data concerning the sugar beet pulp 11. An optical imaging device 25 determines, particularly simultaneously, one or more geometric properties of the sugar beet pulp 11, especially its length and / or width and / or cross-sectional area. Both the first near-infrared spectroscopy device 21 and the optical imaging device 25 are located in the output area of ​​the cutting machine 10. A second near-infrared spectroscopy device 22 acquires further measurement data concerning the sugar beet pulp residue 13 removed from the extraction unit 20.And a third near-infrared spectroscopy device 23 records third measurement data concerning the raw juice 14.

[0043] The third near-infrared spectroscopy device 23 is arranged in a bypass line into which the raw juice 14 is introduced, and a stagnant raw juice is produced to acquire the third measurement data. After the measurement data has been acquired, the raw juice 14 is returned to the production flow and fed to the juice purification stage (process steps 3, 4, 5).

[0044] The extraction step after Fig. 2 additionally includes a fourth near-infrared spectroscopy device 24, with which fourth measurement data concerning the residual water 15 produced when pressing the sugar beet pulp residues 13 are recorded.

[0045] The measurement data from the near-infrared spectroscopy devices 21, 22, 23, 24 can, for example, indicate the detection of the following constituents or their concentrations: sucrose, fructose, glucose, lactic acid, oxalic acid, oxalates, nitrates, nitrites, pectins, dextrans, nitrogen. The optical imaging device can additionally determine information about the color of the material under investigation, for example, in the Lab color space.

[0046] The measurement data from the near-infrared spectroscopy devices 21, 22, 23, 24, as well as the geometric properties of the sugar beet pulp 11, are used to adjust one or more process parameters of the extraction device 20. For example, an extraction time and / or an extraction duration can be set depending on the measurement data. Specifically, an extraction time and / or an extraction duration can be set based on the first measurement data, i.e., the constituents or composition of the sugar beet pulp 11. Additionally or alternatively, it is possible to adjust the extraction time and / or an extraction duration based on the second measurement data concerning the sugar beet pulp residues 13 and / or the third measurement data concerning the raw juice 14, so that the processing of the sugar beet pulp 11 following the measured material can be modified.

[0047] The acquired measurement data from the near-infrared spectroscopy devices 21, 22, 23, 24, as well as the geometric properties of the sugar beet pulp 11, are also used to control and / or adjust the cutting machine 10 used in the cutting step 1. For example, the knife quality and / or the pulp size of the sugar beet pulp 11 obtained during cutting 1 can be adjusted depending on a geometric property of the sugar beet pulp 11, such as its length and / or width and / or cross-sectional area. Furthermore, process parameters of one or more of the subsequent process steps 3, 4, 5, 6, 7, or 8 can be adjusted depending on the first measurement data and / or the second measurement data and / or the third measurement data and / or the geometric properties of the sugar beet pulp.Adjusting the process parameters based on the measurement data acquired by one or more of the near-infrared spectroscopy device(s) and / or the properties determined by the optical image acquisition device allows for low-latency adjustment of process parameters in one of the subsequent process steps.

[0048] The method and system described above enable the analysis of the constituents of the starting materials and / or products in the extraction process with less effort, particularly with less time and / or laboratory work. This allows for improved control of the processes in sugar production.

[0049] The extraction process can be balanced as the difference between the sugar content of the reactants and products, i.e., as sugar content (reactants) - sugar content (products), or by the yield, i.e., the sugar content in the raw juice 14 relative to the sugar content in the sugar beet pulp 11.

[0050] To achieve the most precise control of the extraction process, knowledge of the sugar content of the sugar beet pulp residue 13 (wet pulp) extracted from the extraction unit 20 is desirable. However, due to the relatively high moisture content of this sugar beet pulp residue 13, determining the sugar content using the second near-infrared spectroscopy device is difficult. Pressing the sugar beet pulp residue 13 in the press 30 can remedy this. The residual water obtained during pressing is measured with the fourth near-infrared spectroscopy device 24, and the pressed sugar beet pulp obtained from pressing is measured with a fifth near-infrared spectroscopy device.Therefore, the sugar content in the residual water and in the pressed sugar beet pulp residues can be determined, and the sugar content in the sugar beet pulp residues 13 (wet pulp) drawn from the extraction unit 20 can be inferred. With this knowledge, the extraction process can be balanced. Reference symbol list

[0051] 1. Process step "Cutting" 2. Process step "Extraction" 3. Process step "Liming" 4. Process step "Carbonization" 5. Process step "Filtration" 6. Process step "Concentration" 7. Process step "Crystallization" 8. Process step "Separation" 10 Cutting machine 11 Sugar beet pulp 12 Water 13 Sugar beet pulp residue 14 Raw juice 15 Residual water 20 Extraction device 21 Near-infrared spectroscopy device 22 Near-infrared spectroscopy device 23 Near-infrared spectroscopy device 24 Near-infrared spectroscopy device 25 Optical image acquisition device 30 Press

Claims

1. Process for the production of raw juice (14) for the production of sugar, wherein sugar beet pulp (11) is fed to an extraction device (20) designed as an extraction tower or diffusion trough and sugar beet pulp residues (13) and raw juice (14) are withdrawn from the extraction device (20), characterized in that a first near-infrared spectroscopy device (21) is used to record first measurement data relating to the sugar beet pulp (11) which is fed to the extraction device (20), and one or more geometric properties of the sugar beet pulp (11) are determined using an optical image acquisition device (25), and a second near-infrared spectroscopy device (22) is used to record second measurement data relating to the sugar beet pulp residues (13) which are extracted from the extraction device (20) and / or a third near-infrared spectroscopy device (23) is used to record third measurement data relating to the raw juice (14) which is drawn off from the extraction device (20), at least one process parameter of the extraction device (20) being set as a function of the first measurement data and of the geometric properties of the sugar beet pulp (11) and as a function of the second measurement data and / or third measurement data.

2. Method according to claim 1, characterized in that the third near-infrared spectroscopy device (23) is arranged in a bypass line into which the raw juice is introduced and a standing raw juice is produced for recording the third measurement data.

3. Method according to any of the preceding claims, characterized in that the measurement data acquired with the respective near-infrared spectroscopy device (21, 22, 23) are obtained by several measurements from different directions.

4. Method according to any of the preceding claims, characterized in that a length and / or a width and / or a cross-sectional area is determined with the optical image acquisition device (25).

5. Method according to any of the preceding claims, characterized in that the sugar beet pulp extracted from the extraction device is pressed, residual water being produced and fourth measurement data relating to the residual water produced during pressing of the sugar beet pulp residues being recorded by means of a fourth near-infrared spectroscopy device, in particular the fourth near-infrared spectroscopy device being arranged in a bypass line into which the residual water is introduced and standing residual water being produced for recording the fourth measurement data.

6. Method according to any of the preceding claims, characterized in that the at least one process parameter is an extraction time, which indicates the duration for which the sugar beet pulp remains in the extraction device, and / or is an extraction temperature, which indicates the temperature at which the extraction device is operated.

7. Method according to any one of claims 1 to 5, characterized in that the at least one process parameter is a quantity of fresh water supplied to the extraction device and / or a filling level in the extraction device.

8. Method according to any of the preceding claims, characterized in that the sugar beet pulp (11) is cut from sugar beet using a cutting machine (10) and a process parameter of the cutting machine (10) is set as a function of the first measurement data and / or the second measurement data and / or third measurement data and / or, if applicable, the geometric properties of the sugar beet pulp (11).

9. Method for producing sugar, wherein raw juice (14) is produced according to a method according to any of the preceding claims and sugar is produced from the raw juice (14) in subsequent process steps.

10. Method according to claim 9, characterized in that at least one process parameter of one of the subsequent process steps is set as a function of the first measurement data and / or the second measurement data and / or the third measurement data and / or, if applicable, the geometric properties of the sugar beet pulp (11).

11. Method according to claim 10, characterized in that the subsequent process step is a liming step (3) or a carbonation step (4) or a filtration step (5) or a thickening step (6) or a crystallization step (7) or a separation step (8).

12. Sugar production plant with an extraction device (20) designed as an extraction tower or diffusion trough, to which sugar beet pulp (11) can be fed and from which sugar beet pulp residues (13) and raw juice (14) can be extracted, characterized by a first near-infrared spectroscopy device (21) for recording first measurement data relating to sugar beet pulp (11) which are fed to the extraction device (20), and an optical image acquisition device (25) for determining one or more geometric properties of the beet pulp (11), and a second near-infrared spectroscopy device (22) for acquiring second measurement data relating to sugar beet pulp residues (13) extracted from the extraction device (20) and / or a third near-infrared spectroscopy device (23) for acquiring third measurement data relating to the raw juice (14) which is extracted from the extraction device (20), the extraction device (20) being set up to adjust at least one process parameter of the extraction device (20) as a function of the first measurement data and of the geometric properties of the sugar beet pulp (11) and as a function of the second measurement data and / or third measurement data.

13. Sugar production plant according to claim 12, characterized in that the respective near-infrared spectroscopy device (21, 22, 23) comprises a plurality of detectors which are arranged in different orientations relative to the material under investigation.

14. Sugar production plant according to one of claims 12 or 13, characterized in that the optical image acquisition device (25) is set up to determine a length and / or a width and / or a cross-sectional area.

15. Sugar production plant according to claim 14, characterized by a cutting machine (10) for cutting the sugar beet pulp (11) from sugar beet, wherein the optical image capturing device (25) is arranged in the output area of the cutting machine (10).