Method and apparatus for processing oil-containing seeds

Abstract

The process and apparatus are used for processing oilseeds. The seeds are first subjected to a primary pressing and then to a secondary pressing. Oil is extracted during at least one of the pressing processes. At the end of the secondary pressing, a press cake is produced. This press cake then undergoes hydrothermal treatment.

Description

[0001] The invention relates to a method for processing oil-containing seeds, in which the seeds are first subjected to a first pressing process and then to a second pressing process, in which oil is pressed out in at least one of the pressing processes and in which a press cake is produced at the end of the second pressing process.

[0002] The invention further relates to a device for processing oil-containing seeds, which has a seed feed, a first pressing stage and a subsequent second pressing stage.

[0003] Such processes and devices are used, for example, to produce edible oils. The pressing processes can be carried out, for example, at ambient temperature or with heated seeds.

[0004] In addition to mechanically pressing oil from the seeds, it is also possible to remove oil from the seeds using extraction agents.

[0005] Typically, according to the current state of the art, the main requirement is to extract as much oil as possible from the seeds and / or to achieve the best possible oil quality. The properties of the press cake resulting from the pressing process have so far been considered largely secondary.

[0006] When extracting oil from soybeans, the resulting press cake can be used as animal feed. In the past, producing high-quality feed of this kind required the use of an expander or extruder. Alternatively, a pre-pressing system followed by extraction is also a known method.

[0007] However, the existing methods and equipment for producing high-quality animal feed cannot yet meet all the requirements that would support both high throughput and economical process implementation.

[0008] The object of the present invention is to improve a method of the type mentioned in the introduction in such a way as to obtain press cake suitable for use as animal feed with high quality of feed.

[0009] This problem is solved by the combination of features of claim 1.

[0010] A further object of the present invention is to construct a device of the type mentioned in the introduction in such a way as to support the production of high-quality animal feed.

[0011] This problem is solved according to the invention by the combination of features of claim no. 10.

[0012] The invention is intended in particular for the processing of soybeans. The processing takes place as a two-stage pressing process followed by hydrothermal treatment of the resulting press cake. Optionally, the beans can be hulled and / or broken or ridged before processing.

[0013] Typically, the soybeans are conditioned before the first pressing. The resulting press cake is also conditioned and then fully pressed in the second pressing stage.

[0014] Preferably, the protein solubility, the so-called PDI value, in the final press cake is at least 15 to 20 percent. Furthermore, the final press cake should have a TIA (trypsin inhibitor activity) content of no more than three to four TIU / milligram.

[0015] Another advantage of the hydrothermal treatment carried out according to the invention is that the residual fat content in the final press cake can be reduced.

[0016] According to a preferred embodiment of the invention, the treatment duration during the hydrothermal treatment is optimized in combination with a specific moisture content and temperature. At the start of the hydrothermal treatment, the moisture content is at least 15% by weight. The residence time in the hydrothermal reactor is at least 20 minutes.

[0017] According to a preferred embodiment, the soybeans are conditioned such that the moisture content is 9 to 10 percent by weight and the temperature is 80 to 85 degrees Celsius.

[0018] According to another preferred embodiment, the conditioning of the press cakes is carried out such that the moisture content is 5 to 5.5 percent by weight and the temperature is 80 to 90 degrees Celsius.

[0019] According to another preferred embodiment, the residual fat content in the post-pressing cake is about 5 to 7 percent by weight, based on a moisture content of 10 percent by weight.

[0020] The drawings schematically illustrate exemplary embodiments of the invention. They show: Fig. 1: An overview diagram of the process and the constructive design of the device Fig. 2a: a left-hand table section containing process data from a trial conducted at a customer's site 1 Fig. 2b: a right-hand table section to continue the table according to Fig. 2a Fig. 3a: a left-hand table section on samples and laboratory tests for customer 1 Fig. 3b: a right-hand table section as a continuation of the table according to Fig. 3a Fig. 4: a table on temperatures and residence times for a post-press cake Fig. 5: a table on the moisture and temperature of pre-pressed cakes Fig. 6: a table on the residual fat content in the press cake Fig. 7: Input values ​​for processing soybean seed Fig. 8: a table for documenting PDI and protein solubility Fig. 9: a table of data for urease and trypsin inhibitor activity Fig. 10: a table on the moisture dependence of urease activity Fig. 11: a table for systematization depending on the processing process Fig. 12: A graphic illustrating seed conditioning HAW and PDI protein solubility Fig. 13: A graph illustrating seed conditioning HAW and trypsin inhibitor activity Fig. 14: A graphic illustrating seed conditioning HAW and urease activity Fig. 15: a table illustrating the effect of direct steam on post-press cake Fig. 16: a schematic diagram of the construction of a heat pan Fig. 17a: A first table illustrating a comparison of a procedure implementation for customer 1 with potential alternatives Fig. 17b: a continuation of the table according to Fig. 17a

[0021] The seed to be processed, in particular soybean seeds or soybeans, is stored in a hopper (1) and fed from there to a conveyor (2). Typically, the conveyor (2) conveys the seed in a substantially horizontal direction. Downstream of the conveyor (2), a conveyor (3) is arranged, which typically conveys the seed vertically. A frequency-controlled metering screw, for example, can be used as conveyor (2). A bucket elevator, for example, can be used as conveyor (3).

[0022] Starting from the conveyor (3), the seed reaches a seed weighing unit (4). After passing the seed weighing unit (4), the seed reaches a conveyor (5), which preferably transports the material horizontally. A seed cleaning unit (6) is arranged downstream of the conveyor (5) in the direction of transport. A plate magnet (51) can be arranged upstream of the seed weighing unit (4).

[0023] Cleaned seeds leave the seed cleaning unit (6) and move towards a conveyor (7). Impurities separated from the seeds enter a receiving unit (8). Air from the seed cleaning unit (6) is cleaned of dust and hulls by a cyclone (52). The air is conveyed by a fan (53). A rotary valve (54) is located downstream of the cyclone (52).

[0024] According to the in Fig. In the illustrated embodiment 1, the conveyor (7) transports the cleaned seed to one or more conditioners (9). The embodiment shows the use of two conditioners (9), but depending on the application, more or fewer than two conditioners (9) can be used.

[0025] The material not supplied to the conditioners (9) by the conveyor (7) is conveyed via a conveyor (10) to an emptying point.

[0026] The material leaving the conditioners (9) is preferably transported horizontally via a conveyor (11). The conveyor (11) feeds the material to a conveyor (12), which preferably conveys the material vertically. From the conveyor (12), the material passes through a hopper (13) and a conveyor (14) into the area of ​​a pre-press (15). The hopper (13) may have an overflow function.

[0027] According to a preferred embodiment, a screw press (15) is used as the pre-press, in which a conveyor screw rotates within a housing. Typically, such a screw press is equipped with strainer bars for separating liquids, in particular for separating oil.

[0028] Liquid, in particular soybean oil, pressed from the pre-press (15) is fed to a conveyor (16). A press cake, in particular a pre-press cake, leaving the pre-press (15) is conveyed via a conveyor (17) to a conditioner (18). The material leaving the conditioner (18) is conveyed via a conveyor (19), which preferably conveys the material vertically, to a conveyor (20), which preferably conveys the material horizontally.

[0029] Starting from the conveyor (20), the material travels via conveyor (21) to secondary presses (22). Screw presses, which are constructed similarly to the primary press (15), can be used as secondary presses (22).

[0030] In the illustrated embodiment, two post-pressing units (22) are used, but depending on the application, more or fewer post-pressing units (22) can also be used.

[0031] The post-pressing units (22) feed the material to a conveyor (23), which preferably provides horizontal transport of the material.

[0032] Any remaining oil from the conveyor (23) is transferred to the conveyor (16). The material transported by the conveyor (23) is moistened by a spray device (24). Water is supplied to the spray device (24) from a reservoir (25). Typically, moistening takes place at ambient pressure and with cold water. The resulting moisture content can be measured and controlled. A target moisture content of 10% by weight in the press cake can be achieved.

[0033] The spray device (24) serves in particular to cool the press cakes transported in the area of ​​the conveyor (23). The material leaving the conveyor (23) is fed via a conveyor (26) to a pelletizing device (27). Before cooling, the press cakes have a temperature of approximately 150 degrees Celsius. Cooling preferably takes place within five minutes to a temperature of preferably approximately 100 degrees Celsius. The conveyor (26) preferably transports the material vertically. The conveyor (26) can be implemented as a bucket elevator.

[0034] In the pelletizing unit (27), the press cake preferably undergoes hydrothermal treatment. The material leaving the pelletizing unit (27) is conveyed via a conveyor (28), partly to a conveyor (29) and partly to a cake cooler (30). From the conveyor (29), the material then proceeds to a cake storage area (31).

[0035] Gaseous components, mist, or dust separated in the area of ​​the conveying device (23) are fed to a cyclone (32). Solids separated by the cyclone (32) are conveyed via a conveyor (33) to the area of ​​the conveyor (29).

[0036] Gaseous components, mist, or dust separated in the cake cooler (30) are fed to a cyclone (34), which in turn feeds separated solids to the conveyor (33). Gaseous components separated in the cyclone (32) are conveyed via a blower (35) to a tank (36). Gases separated by the cyclone (34) can also be fed to the tank (36) via a blower (37). Alternatively, a scrubber (36) can be used to clean the gas instead of the tank (36).

[0037] The oil leaving the conveyor (16) enters the area of ​​a separator (38). The separator (38) serves in particular to separate suspended solids from the extracted oil.

[0038] The oil leaving the separator (38) enters a collection tank (39). From the collection tank (39), the oil flows to pumps (40), preferably filter press pumps. The residual fat content in the press cake can be approximately 6% by weight.

[0039] The pumps (40) transport the oil to an oil filter (41). On the outlet side, the oil filter (41) is connected to a collection container (42) and an oil reservoir (43).

[0040] Starting from the oil reservoir (43), the oil can be fed to a heat exchanger (45) via oil transfer pumps (44). From the heat exchanger (45), the oil flows to an oil storage tank (46). The oil is cooled in the heat exchanger (45) using cooling water drawn from a supply (47). After leaving the heat exchanger (45), the cooling water is transported to a drain (48). A compressed air supply (49) and a saturated steam supply (50) are provided to support the operation of the system.

[0041] In addition to the hydrothermal treatment of the press cake already described after leaving the second pressing stage, it is optionally possible to carry out one or more further hydrothermal treatments of the seed or pre-press cake. For example, it is possible to perform a hydrothermal treatment of the soybeans or pre-press cake in the area of ​​one or more of the conditioners (9, 18).

[0042] According to an exemplary process flow, the plant according to the invention processes a quantity of approximately 100 tons of soybeans per day. With regard to the aforementioned residual fat content, it proves advantageous to operate one or more of the secondary presses (22) at a speed of 30 to 40 revolutions per minute of the screw press used.

[0043] According to a preferred embodiment, the hydrothermal treatment is carried out at ambient pressure and with a saturated water vapor atmosphere. Immediately following the hydrothermal treatment, the press cakes are preferably cooled with cold air.

[0044] In Fig. 2a and Fig. Figure 2b illustrates data from an experiment in which seed conditioning was performed to a moisture content of 9 to 10% by weight and a temperature of 80 to 85°C. Cake conditioning was performed to a moisture content of 5 to 5.5% by weight and a temperature of 80 to 90°C. During the experiment, after stable operating conditions were established, samples were taken of seed from the silo, seed from the seed conditioner, pre-press cake, press, pre-press cake from the cake conditioner, post-press cake from the press, post-press cake from the cake cooler, and post-press cake from the retention tank.

[0045] In Fig. 3a and Fig. Section 3b documents the laboratory tests already available. No measurements are currently available for the fields marked in dark.

[0046] Fig. Figure 4a illustrates the relationship between temperature and residence time. A post-press cake is moistened to a moisture content of approximately 10% by weight. The residence tank is not heated. After leaving the residence tank, the samples are cooled to ambient temperature. A portion of the samples is then transferred to a hydrothermal reactor. This reactor contains a saturated water vapor atmosphere at ambient pressure. After leaving the hydrothermal reactor, the samples are cooled with cold air.

[0047] Fig. Figure 5 shows the relationship between moisture and temperature in a pre-pressed cake that was dried to six percent residual moisture.

[0048] Fig. Figure 6 illustrates the residual fat content in a press cake after a two-stage pressing process. A reduction of the residual fat content to approximately 5 to 7 percent by weight can be achieved by conditioning the pre-press cake to a moisture content of 5 to 5.5 percent. Measurement data for the fields highlighted in dark in the table are not yet available.

[0049] Fig. Figure 7 illustrates target values ​​for PDI, urease, and trypsin inhibitor activity. Measurement data for the dark-marked fields are not yet available.

[0050] Fig. Figure 8 illustrates PDI and protein solubility in the area of ​​the post-press cake.

[0051] Fig. Figure 9 illustrates the urease and trypsin inhibitor activity.

[0052] Fig. 10 documents the moisture dependence of urease activity.

[0053] Fig. 11 documents different measurement data depending on the selected processing method.

[0054] The graphic in Fig. Figure 12 illustrates a comparison of the experimental procedure with state-of-the-art seed conditioning of soybeans.

[0055] Fig. Figure 13 illustrates seed conditioning HAW and trypsin inhibitor activity.

[0056] Illustrated in a similar way Fig. 14 the seed conditioning HAW as well as the urease activity.

[0057] Fig. Section 15 illustrates in tabular form data on hydrothermal treatment at different stages of the processing process.

[0058] Fig. Figure 16 shows a heating pan for carrying out the hydrothermal treatment of the seed. In a first process step, the seed remains in an upper region of the heating pan at a temperature of approximately 100 °C. Preferably, a high moisture content is present during this process phase. After the first processing step, the moisture content of the seed is reduced in the area of ​​steam-heated bottoms of the heating pan.

[0059] In Fig. 17a and in Fig. Section 17b documents a comparison of the procedure implementation for customer 1 with alternative procedure implementations.

[0060] A comparison of the different processes shows that although the process according to the invention leads to increased investment costs and increased energy consumption, the resulting process product has significant advantages over the process products manufactured according to the prior art.

Claims

[1] Process for processing oilseed, wherein the seed is first subjected to a first pressing process and then to a second pressing process, wherein oil is extracted in at least one of the pressing processes and wherein a press cake is produced at the end of the second pressing process, characterized by that a hydrothermal treatment of the press cake is carried out. [2] Method according to claim 1, characterized by that soybeans are being processed. [3] Method according to claim 1 or 2, characterized by , that a mechanical pressing is carried out. [4] Method according to any one of claims 1 to 3, characterized by that at least one pressing operation is carried out using a screw press. [5] Method according to any one of claims 1 to 4, characterized by that pre-conditioning of the material to be pressed is carried out before reaching the first pressing stage. [6] Method according to any one of claims 1 to 5, characterized by , that conditioning of the material to be pressed is carried out between the first and second pressing stages. [7] Method according to any one of claims 1 to 6, characterized by , that conditioning is carried out with regard to the temperature of the material. [8] Method according to any one of claims 1 to 7, characterized by , that conditioning is carried out with regard to the moisture content of the material. [9] Method according to any one of claims 1 to 8, characterized by that the hydrothermal treatment is carried out at ambient pressure. [10] Device for processing oil-containing seeds, comprising a seed feeder, a first pressing stage and a subsequent second pressing stage, characterized by , that a hydrothermal treatment facility is arranged following the second pressing stage. [11] Device according to claim 10, characterized bythat at least one conditioner is used. [12] Device according to claim 10 or 11, characterized by that a water supply is used. [13] Device according to any one of claims 10 to 13, characterized by that a measuring device is used to detect the moisture content of the material. [14] Device according to one of claims 10 to 13, wherein a water supply is provided with a control. [15] Method according to any one of claims 10 to 14, characterized by that the water supply is designed as a nozzle at least in certain areas.

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