Method and system for extracting soluble protein from alcohol-containing waste liquid and application

Abstract

The invention relates to the technical field of waste recycling, in particular to a method and system for extracting soluble protein in alcohol-containing waste liquid and application. The alcohol-containing waste liquid contains soluble protein and metabolite. The method comprises the following steps: distilling the alcohol-containing waste liquid to obtain distilled waste liquid; carrying out steam injection on the distillation waste liquid by using saturated steam to obtain a mixture containing denatured protein; performing denaturation treatment on the mixture containing the denatured protein to obtain waste liquid containing the denatured protein; and carrying out solid-liquid separation on the waste liquid containing the denatured protein to obtain the denatured soluble protein. According to the method, the recovery rate and the quality of soluble protein in the fine waste liquid can be effectively improved in a manner of combining steam injection and denaturation treatment.

Description

Technical Field

[0001] The present application relates to the technical field of waste recycling, and in particular to a method, system and application for extracting soluble protein from alcohol-containing waste liquid. Background Art

[0002] As alcohol is widely used in transportation fuel, chemical industry, food industry, daily chemicals, medicine and health, etc., the production activities of preparing alcohol base, extractant, solvent, detergent and surfactant products with alcohol as raw material occupy an important position in industrial production. However, due to complex reasons such as process route, investment, production scale, technological innovation, management, etc., most alcohol enterprises have a low comprehensive utilization rate of production raw materials, which makes the alcohol-containing waste liquid produced by alcohol enterprises one of the most serious pollution sources in the food industry and fermentation industry. Alcohol-containing waste liquid is high-concentration, high-temperature, high-suspended organic wastewater, mainly from distillation fermentation and alcohol lees discharged after mature mash. The direct degradation of these alcohol-containing waste liquids is difficult and the treatment cost is high. In addition, the comprehensive utilization of these alcohol-containing waste liquids is narrow and the economic benefits are poor; therefore, it is necessary to select a suitable pretreatment process method for treating this type of alcohol-containing waste liquid to reduce the difficulty of treating alcohol-containing waste liquid, so as to reduce the environmental pressure of alcohol enterprises and save production resources while creating considerable economic benefits. At present, most of the alcohol in alcohol-containing waste liquid can be recovered by distillation. However, the alcohol-containing waste liquid produced by the one-carbon biological fermentation to prepare ethanol based on carbon monoxide has a large viscosity and poor sedimentation property due to the small diameter of the ethanol Clostridium used in the one-carbon biological fermentation and a high protein content. In addition, after the alcohol is recovered by distillation, some soluble proteins still exist in the waste liquid and are not recovered. These soluble proteins will be dissolved or semi-dissolved in the waste liquid, and it is difficult to separate these soluble proteins by conventional methods. In addition, the mass concentration of these soluble proteins is very low. If these soluble proteins are to be recovered by drying, it will undoubtedly require a higher drying cost. In addition, the waste liquid in which the soluble proteins are dissolved has a high weight content of total suspended matter and other organic matter, and it is difficult to treat it directly as sewage.

[0003] At present, these soluble proteins can be extracted through protein extraction technology and processed as feed raw materials. The general process is to use centrifugation and drying technology. However, protein extraction technology is difficult to remove residual metabolites of soluble proteins, resulting in poor recovery rate of soluble proteins and poor quality of recovered protein products. Summary of the invention

[0004] The present application provides a method, system and application for extracting soluble protein from alcohol-containing waste liquid to solve the following technical problem: how to simultaneously improve the recovery rate and quality of soluble protein in alcohol-containing waste liquid.

[0005] In a first aspect, the present application provides a method for extracting soluble protein from alcohol-containing waste liquid, wherein the alcohol-containing waste liquid contains soluble protein and metabolites, and the method comprises:

[0006] distilling the alcohol-containing waste liquid to recover alcohol from the alcohol-containing waste liquid to obtain distilled waste liquid;

[0007] Using saturated steam to steam-spray the distillation waste liquid to preliminarily denature the soluble protein and dilute the metabolite, thereby obtaining a mixture containing denatured protein;

[0008] Denaturing the mixture containing denatured proteins to fully denature the soluble proteins, thereby obtaining a waste liquid containing denatured proteins;

[0009] The waste liquid containing denatured protein is subjected to solid-liquid separation to obtain denatured soluble protein.

[0010] Optionally, the temperature of the steam injection is 95° C. to 100° C., the pressure of the steam injection is 0.6 MPa to 0.8 MPa, and the time of the steam injection is 3 s to 5 s.

[0011] Optionally, the weight m1 of the saturated steam and the weight m2 of the distillation waste liquid satisfy the relationship: m1:m2=(1.5-8):(90-110).

[0012] Optionally, the mixture containing denatured proteins is subjected to denaturation treatment to fully denature the soluble proteins to obtain a waste liquid containing denatured proteins, comprising the steps of:

[0013] The mixture containing denatured protein is subjected to post-ripening treatment to obtain a primary waste liquid containing denatured protein;

[0014] Under the condition of a preset stirring speed, the primary waste liquid containing the denatured protein is subjected to a buffer storage treatment to obtain a waste liquid containing the denatured protein.

[0015] Optionally, the temperature of the post-ripening treatment is 95° C. to 100° C., and the time of the post-ripening treatment is 10 min to 60 min.

[0016] Optionally, the preset stirring speed is 30 r / min to 60 r / min, and the buffer storage treatment time is ≥ 60 min.

[0017] In a second aspect, the present application provides a system for extracting soluble proteins from alcohol-containing wastewater, the system being adapted to the method described in the first aspect, and the system comprising:

[0018] a distillation tower to recover alcohol from alcoholic wastewater;

[0019] The protein denaturation section comprises a steam injection unit, a post-ripening device and a buffer storage tank, wherein the feed port of the steam injection unit is connected to the discharge port of the distillation tower, the discharge port of the steam injection unit is connected to the feed port of the post-ripening device, and the discharge port of the post-ripening device is connected to the feed port of the buffer storage tank;

[0020] A centrifuge, wherein the feed port of the centrifuge is connected to the discharge port of the buffer storage tank.

[0021] Optionally, the steam injection unit includes a steam injector and a saturated steam delivery pipe, the discharge port of the saturated steam delivery pipe is connected to the air inlet of the steam injector, and the feed port of the steam injector is connected to the discharge port of the distillation tower.

[0022] Optionally, the steam injection unit also includes an automatic regulating valve, a temperature measuring instrument and a controller, the automatic regulating valve is arranged at the saturated steam inlet of the steam injector, the temperature measuring instrument is arranged at the outlet of the steam injector, and the controller is connected to the automatic regulating valve and the temperature measuring instrument through electrical signals respectively.

[0023] In a third aspect, the present application provides a protein feed, which comprises the denatured soluble protein obtained by the method described in the first aspect.

[0024] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0025] The embodiment of the present application provides a method for extracting soluble protein from alcohol-containing waste liquid. The method distills the alcohol-containing waste liquid to recover alcohol, and then uses saturated steam to steam-jet the distilled waste liquid. Based on the characteristics of high flow rate and high shear strength of the jet, the saturated steam and the distilled waste liquid are caused to collide with each other at high intensity in the mixing area of ​​the steam jet under the action of high flow rate and high shear strength, and the saturated steam and the distilled waste liquid are placed in a turbulent state. The saturated steam and the distilled waste liquid in the turbulent state will fully transfer mass and heat, so that the distilled waste liquid is heated to the denaturation temperature of the soluble protein in a short time, so that the soluble protein in the distilled waste liquid is denatured and a preliminarily denatured denatured protein is obtained. The preliminarily denatured denatured protein is further denatured to fully denature the denatured protein. , and fully denatured denatured proteins will form particles with larger diameters and larger densities. In the subsequent solid-liquid separation stage, these larger-density and larger-size denatured proteins will be fully separated from the solution, thereby improving the recovery rate of soluble proteins; in addition, in the outlet area of ​​steam injection, the distillation waste liquid and saturated steam will be atomized to form small droplets under the action of high shear intensity. On the one hand, these small droplets will fully transfer heat to each other, and on the other hand, these small droplets can be fully mixed to reduce the mass concentration of metabolites in the distillation waste liquid, thereby reducing the doping amount of soluble protein metabolites to improve the quality of soluble protein in alcohol-containing waste liquid; therefore, this method can effectively improve the recovery rate and quality of soluble protein in alcoholic waste liquid by combining steam injection and denaturation treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] Figure 1 A schematic flow chart of a method for extracting soluble protein from alcohol-containing waste liquid is provided for an embodiment of the present application;

[0029] Figure 2 A detailed schematic diagram of a method for extracting soluble protein from alcohol-containing wastewater is provided for the embodiment of the present application;

[0030] Figure 3 A schematic diagram of the logical structure of a system for extracting soluble protein from alcohol-containing wastewater provided in an embodiment of the present application;

[0031] Among them, 1-distillation tower, 2-steam injection unit, 21-steam ejector, 22-saturated steam delivery pipe, 23-automatic regulating valve, 24-temperature measuring instrument, 25-controller, 3-post-ripening device, 4-buffer storage tank, 5-centrifuge. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited number (fractional or integer) within the indicated range.

[0034] In this document, the terms including "including" and "including" mean "including but not limited to". Relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone; where A and B can be singular or plural. "At least one" means one or more, and "plurality" means two or more; "at least one", "at least one of the following" or similar expressions, refers to any combination of these items, including any combination of single or plural items; for example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. "Parts" such as parts by weight and parts by mass indicate the proportional relationship between the components. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, if the mass ratio of substance A, substance B and substance C is 1:2:3, then substance A, substance B and substance C should correspond to the proportional numbers in the proportional formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0035] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this article can be purchased from the market or prepared by existing methods.

[0036] It should be noted that during the distillation process of the alcohol-containing waste liquid produced by the one-carbon biological fermentation to prepare ethanol based on carbon monoxide, the material residence time is generally less than 1 minute, and the temperature is relatively low (generally 70°C to 80°C), which makes the denaturation probability of the soluble protein in the alcohol-containing waste liquid during the distillation process lower, and the subsequent separation is more difficult; in addition, the density difference between the alcohol-containing waste liquid and water in the centrifugation stage is small, which makes it difficult to separate the soluble protein and the alcohol-containing waste liquid by centrifugation, which makes the weight content of the solid phase of the centrifuged concentrate low (generally 70g / L to 85g / L), which leads to a higher investment cost for the subsequent drying technology, and the operating cost of the technology is relatively high; in addition, some soluble proteins will remain in the clear liquid obtained by centrifugation, and the presence of soluble proteins will increase the difficulty of clear liquid treatment; in addition, the alcohol-containing waste liquid will also contain a large amount of residual metabolites, and these residual metabolites will make the soluble protein have a certain odor, affecting the application of the extracted soluble protein.

[0037] Therefore, how to simultaneously improve the recovery rate and quality of soluble proteins in alcohol-containing wastewater is a technical problem that urgently needs to be solved.

[0038] Figure 1 The present invention provides a schematic flow chart of a method for extracting soluble protein from alcohol-containing wastewater;

[0039] like Figure 1 As shown, the embodiment of the present application provides a method for extracting soluble protein from alcohol-containing waste liquid, wherein the alcohol-containing waste liquid contains soluble protein and metabolites, and the method comprises:

[0040] S1. distilling the alcohol-containing waste liquid to recover the alcohol in the alcohol-containing waste liquid to obtain a distilled waste liquid;

[0041] S2. steam-jetting the distillation waste liquid using saturated steam to preliminarily denature the soluble protein and dilute the metabolites to obtain a mixture containing denatured protein;

[0042] S3. subjecting the mixture containing the denatured protein to a denaturing treatment so that the soluble protein is fully denatured to obtain a waste liquid containing the denatured protein;

[0043] S4. The waste liquid containing the denatured protein is subjected to solid-liquid separation to obtain denatured soluble protein.

[0044] It should be noted that the denaturation treatment is mainly to fully denature the undenatured protein in the mixture containing denatured protein. The temperature of the denaturation treatment can be the same as the temperature of the steam injection, but the time of the denaturation treatment is much longer than the time of the steam injection to promote sufficient denaturation.

[0045] It should be noted that solid-liquid separation includes centrifugation. The centrifugal speed can be 3000r / min~6000r / min, and the centrifugal time can be 0.1min~3min. It can promote the full separation of denatured proteins with higher density and larger particle size from waste liquid, and can obtain denatured protein concentrate with higher solid content and centrifugal clear liquid with lower soluble protein content, thereby improving the recovery rate of soluble protein.

[0046] In some optional embodiments, the temperature of the steam injection is 95°C to 100°C, the pressure of the steam injection is 0.6MPa to 0.8MPa, and the time of the steam injection is 3s to 5s;

[0047] In these embodiments, the temperature of the steam injection can be 95°C to 100°C, and the pressure of the steam injection can be 0.6MPa to 0.8MPa, and the time of the steam injection can be 3s to 5s, so that the steam injection has sufficient temperature, sufficient time and sufficient intensity. The steam injection with sufficient process conditions can promote sufficient mass transfer and heat transfer between the saturated steam and the distillation waste liquid, so that the soluble protein in the distillation waste liquid can be fully denatured and denatured protein can be obtained, and at the same time, the doping amount of metabolites of the soluble protein can be reduced, thereby improving the recovery rate and quality of the soluble protein; in addition, in the outlet area of ​​the steam injection.

[0048] The temperature of the steam injection may be 95°C, 96°C, 97°C, 98°C, 99°C or 100°C.

[0049] The pressure of the steam injection may be 0.60 MPa, 0.61 MPa, 0.62 MPa, 0.63 MPa, 0.64 MPa, 0.65 MPa, 0.66 MPa, 0.67 MPa, 0.68 MPa, 0.69 MPa, 0.70 MPa, 0.71 MPa, 0.72 MPa, 0.73 MPa, 0.74 MPa, 0.75 MPa, 0.76 MPa, 0.77 MPa, 0.78 MPa, 0.79 MPa or 0.80 MPa.

[0050] The steam injection time can be 3s, 4s or 5s.

[0051] In some optional embodiments, the weight m1 of the saturated steam and the weight m2 of the distillation waste liquid satisfy the relationship: m1:m2=(1.5-8):(90-110);

[0052] In these embodiments, the weight m1 of the saturated steam and the weight m2 of the distillation waste liquid can satisfy the relationship: m1:m2=(1.5~8):(90~110), so that the steam injection has a sufficient amount of saturated steam. The sufficient amount of saturated steam can not only fully transfer mass and heat with the distillation waste liquid to fully denature the soluble protein in the distillation waste liquid and obtain denatured protein, but also reduce the doping amount of metabolites of the soluble protein, thereby improving the recovery rate and quality of the soluble protein.

[0053] The weight m1 of the saturated steam may be 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5 or 8.0.

[0054] The weight m2 of the distillation waste liquid can be 90, 95, 100, 105 or 110.

[0055] Figure 2 The detailed flow chart of a method for extracting soluble protein from alcohol-containing waste liquid provided by the embodiment of the present application is exemplarily shown;

[0056] In some optional embodiments, such as Figure 2 As shown, the mixture containing denatured proteins is subjected to denaturation treatment to fully denature the soluble proteins to obtain a waste liquid containing denatured proteins, comprising the steps of:

[0057] S301. The mixture containing the denatured protein is subjected to a post-ripening treatment to obtain a primary waste liquid containing the denatured protein;

[0058] S302. Under the condition of a preset stirring speed, the primary waste liquid containing denatured protein is subjected to buffer storage treatment to obtain a waste liquid containing denatured protein;

[0059] In these embodiments, the mixture containing denatured proteins is subjected to post-ripening treatment and buffer storage treatment in sequence, which can promote the complete denaturation of the undenatured soluble proteins in the mixture, thereby obtaining a completely denatured waste liquid containing denatured proteins.

[0060] In some optional embodiments, the temperature of the post-ripening treatment is 95° C. to 100° C., and the time of the post-ripening treatment is 10 min to 60 min;

[0061] In these embodiments, the temperature of the post-ripening treatment can be 95°C to 100°C, and the time of the post-ripening treatment can be 10 minutes to 60 minutes, so that the post-ripening treatment has sufficient temperature and sufficient time. The post-ripening treatment with sufficient temperature and sufficient time can cause the uncompletely denatured soluble protein in the mixture containing the denatured protein to further denature, so as to facilitate the subsequent buffer storage treatment to obtain the waste liquid containing the denatured protein in which the soluble protein is completely denatured.

[0062] The temperature of the after-ripening treatment may be 95°C, 96°C, 97°C, 98°C, 99°C or 100°C.

[0063] The after-ripening treatment is carried out for 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min.

[0064] In some optional embodiments, the preset stirring speed is 30 r / min to 60 r / min, and the buffer storage treatment time is ≥ 60 min;

[0065] In these embodiments, the preset stirring speed can be 30r / min to 60r / min, and the buffer storage treatment time can be ≥60min, so that the buffer storage treatment is fully carried out to further promote the denaturation of soluble proteins in the primary waste liquid containing denatured proteins, and at the same time, the denatured proteins can be evenly dispersed in the waste liquid to obtain the waste liquid containing denatured proteins.

[0066] The preset stirring speed may be 30 r / min, 35 r / min, 40 r / min, 45 r / min, 50 r / min, 55 r / min or 60 r / min.

[0067] Figure 3 The present application embodiment provides a schematic diagram of the logical structure of a system for extracting soluble proteins from alcohol-containing wastewater;

[0068] Based on a general inventive concept, such as Figure 3 As shown, the embodiment of the present application provides a system for extracting soluble protein from alcohol-containing wastewater, the system is adapted to the method, and the system comprises:

[0069] A distillation tower 1, for recovering alcohol from alcohol-containing waste liquid;

[0070] The protein denaturation section includes a steam injection unit 2, a post-ripening device 3 and a buffer storage tank 4, wherein the feed port of the steam injection unit 2 is connected to the discharge port of the distillation tower 1, the discharge port of the steam injection unit 2 is connected to the feed port of the post-ripening device 3, and the discharge port of the post-ripening device 3 is connected to the feed port of the buffer storage tank 4;

[0071] A centrifuge 5 , wherein the feed port of the centrifuge 5 is connected to the discharge port of the buffer storage tank 4 .

[0072] It should be noted that a stirring device may be provided in the buffer storage tank 4, and the rotation speed of the stirring device may be 30 r / min to 60 r / min. The stirring device may be a vertical stirrer.

[0073] The system is implemented based on the above method. The specific steps of the method can refer to the above embodiment. Since the system adopts part or all of the technical solutions of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be repeated here.

[0074] In some optional embodiments, the steam injection unit 2 includes a steam injector 21 and a saturated steam delivery pipe 22, the discharge port of the saturated steam delivery pipe 22 is connected to the air inlet of the steam injector 21, and the feed port of the steam injector 21 is connected to the discharge port of the distillation tower 1;

[0075] In these embodiments, the steam injection unit 2 may include a steam injector 21 and a saturated steam delivery pipe 22, and the discharge port of the saturated steam delivery pipe 22 may be connected to the air inlet of the steam injector 21, and the feed port of the steam injector 21 may be connected to the discharge port of the distillation tower 1. Saturated steam is introduced through the saturated steam delivery pipe 22. On the one hand, the saturated steam can be used as a heat source to heat the distillation waste liquid. On the other hand, the saturated steam can also be used as a mixed medium to cause the soluble protein in the distillation waste liquid to undergo preliminary denaturation. At the same time, the metabolites of the distillation waste liquid are diluted by the saturated steam to improve the recovery rate and quality of the soluble protein.

[0076] In some optional embodiments, the steam injection unit 2 further includes an automatic regulating valve 23, a temperature measuring instrument 24 and a controller 25, wherein the automatic regulating valve 23 is provided at the saturated steam feed port of the steam injector 21, the temperature measuring instrument 24 is provided at the discharge port of the steam injector 21, and the controller 25 is connected to the automatic regulating valve 23 and the temperature measuring instrument 24 respectively through electrical signals;

[0077] In these embodiments, the steam injection unit 2 may further include an automatic regulating valve 23, a temperature measuring instrument 24 and a controller 25, and the automatic regulating valve 23 is arranged at the feed port of the steam injector 21, and the temperature measuring instrument 24 is arranged at the discharge port of the steam injector 21, and the controller 25 is respectively connected to the automatic regulating valve 23 and the temperature measuring instrument 24 through electrical signals, and the discharge temperature of the steam injector 21 is measured by the temperature measuring instrument 24, and then the controller 25 determines whether the discharge temperature is within 95°C to 100°C and controls the opening and closing degree of the automatic regulating valve 23 to control the feed amount of saturated steam per unit time, so that the entire temperature of the steam injection unit 2 can be controlled within 95°C to 100°C.

[0078] It should be noted that when the temperature measured by the temperature measuring instrument 24 is 0.5°C lower or higher than the upper and lower limits of 95°C to 100°C, the opening and closing degree of the automatic regulating valve 23 is adjusted by the controller 25, and the opening and closing degree is adjusted by 1% to 5% each time, and can be adjusted multiple times in a short time.

[0079] It should be noted that the controller can be embedded in the automatic regulating valve 23, for example, a regulating valve 23 with a pneumatic film actuator can be used. The regulating accuracy of the automatic regulating valve 23 is not less than ±1%.

[0080] Based on a general inventive concept, an embodiment of the present application provides a protein feed, which includes the denatured soluble protein obtained by the method.

[0081] The protein feed is realized based on the above method. The specific steps of the method can refer to the above embodiment. Since the protein feed adopts part or all of the technical solutions of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described one by one here.

[0082] In summary, the present invention provides a method for extracting soluble protein from alcohol-containing wastewater, which has the following advantages over traditional soluble protein extraction methods:

[0083] 1. Efficient mass and heat transfer: Through the high flow rate and high shear strength of steam injection, efficient mass and heat transfer between the distillation waste liquid and saturated steam is achieved, so that the distillation waste liquid is quickly heated to the denaturation temperature.

[0084] 2. High recovery rate: Completely denatured proteins form particles with larger diameter and higher density, which facilitates efficient separation in the solid-liquid separation stage and significantly improves the recovery rate of soluble proteins.

[0085] 3. High quality: Sufficient heat transfer and mixing during the atomization process reduce the mass concentration of metabolites in the distillation waste liquid and the amount of metabolite doping in the soluble protein, thereby improving the quality of the soluble protein.

[0086] In addition, the present application provides a system for extracting soluble protein from alcohol-containing wastewater. In addition to the advantages of the above method, the process of the system includes:

[0087] The distillation tower 1 is used to recover alcohol from alcohol-containing waste liquid; its connection mode is: the discharge port of the distillation tower 1 is connected to the feed port of the steam injection unit 2 of the protein denaturation part. The protein denaturation part includes the steam injection unit 2, which uses saturated steam to inject the distillation waste liquid at a high speed, so that it is fully mixed with the saturated steam at a high flow rate and high shear strength, so as to promote the initial denaturation of the soluble protein in the distillation waste liquid; its connection mode is: the feed port of the steam injection unit 2 is connected to the discharge port of the distillation tower 1, and the discharge port is connected to the feed port of the after-ripening device 3. The steam injection unit 2 includes a steam injector 21 (for injecting saturated steam and distillation waste liquid), a saturated steam delivery pipe 22 (for delivering saturated steam to the steam injector 21), an automatic regulating valve 23 (located at the saturated steam feed port of the steam injector 21, for adjusting the feed amount of saturated steam), a temperature measuring instrument 24 (located at the discharge port of the steam injector 21, for measuring the discharge temperature) and a controller 25 (connecting the automatic regulating valve 23 and the temperature measuring instrument 24 through an electrical signal, adjusting the opening and closing degree of the automatic regulating valve 23 according to the data of the temperature measuring instrument 24, and ensuring that the discharge temperature is within the range of 95°C to 100°C). The protein denaturation section also includes a post-ripening device 3, whose function is to further process the initially denatured soluble protein to make it completely denatured; its connection method is: the feed port of the post-ripening device 3 is connected to the discharge port of the steam injection unit 2, and the discharge port is connected to the feed port of the buffer storage tank 4. In addition, the protein denaturation part also includes a buffer storage tank 4, whose function is to store the waste liquid after denaturation treatment to prepare for the subsequent solid-liquid separation; its connection method is: the feed port of the centrifuge 5 is connected to the discharge port of the buffer storage tank 4.

[0088] Compared with the traditional alcohol waste liquid extraction system, this system has the following advantages:

[0089] 1. Efficient mass and heat transfer: The high flow rate and high shear strength of the steam injection unit 2 ensure efficient mass and heat transfer between the distillation waste liquid and the saturated steam, so that the distillation waste liquid quickly reaches the denaturation temperature.

[0090] 2. High recovery rate: The completely denatured soluble protein forms particles with larger diameter and higher density, which are easy to separate from the waste liquid during centrifugation, significantly improving the recovery rate of soluble protein.

[0091] 3. High quality: Through the atomization and mixing process of the steam injection unit 2, the mass concentration of metabolites in the distillation waste liquid is reduced, the amount of metabolite doping in the soluble protein is reduced, and the quality of the soluble protein is improved.

[0092] 4. Automatic control: The combination of the automatic regulating valve 23, the temperature measuring instrument 24 and the controller 25 ensures that the temperature of the entire system is controlled within the range of 95°C to 100°C, ensuring the stability and consistency of the denaturation process.

[0093] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples where specific conditions are not specified are usually measured in accordance with national standards / industry standards; if there are no corresponding national standards / industry standards, they are measured in accordance with common international standards, conventional conditions or conditions recommended by the manufacturer.

[0094] Example 1

[0095] like Figure 2 A method for extracting soluble protein from alcoholic wastewater, wherein the alcoholic wastewater contains soluble protein and metabolites, comprising:

[0096] S1. distilling the alcohol-containing waste liquid to recover alcohol from the alcohol-containing waste liquid to obtain a distilled waste liquid;

[0097] S2. steam-spraying the distillation waste liquid with saturated steam to preliminarily denature the soluble protein and dilute the metabolites to obtain a mixture containing denatured protein;

[0098] S301. The mixture containing the denatured protein is subjected to post-ripening treatment to obtain a primary waste liquid containing the denatured protein;

[0099] S302. Under the condition of a preset stirring speed, the primary waste liquid containing denatured protein is subjected to buffer storage treatment to obtain a waste liquid containing denatured protein;

[0100] S4. Separate the waste liquid containing denatured protein into solid-liquid state to obtain denatured soluble protein.

[0101] The temperature of the steam injection is 97°C, the pressure of the steam injection is 0.7 MPa, and the time of the steam injection is 4 s.

[0102] The weight m1 of saturated steam and the weight m2 of distillation waste liquid satisfy the relationship: m1:m2=8:90.

[0103] The temperature of the post-ripening treatment is 97°C, and the time of the post-ripening treatment is 30 minutes.

[0104] The preset stirring speed is 40r / min and the buffer storage treatment time is 60min.

[0105] Solid-liquid separation includes centrifugation, the centrifugal speed is 6000r / min, and the centrifugal time is 3min.

[0106] Example 2

[0107] Based on the contents disclosed in Example 1, the following modifications are further made:

[0108] The temperature of the steam injection is 95°C, the pressure of the steam injection is 0.8 MPa, and the time of the steam injection is 5 s.

[0109] The weight m1 of saturated steam and the weight m2 of distillation waste liquid satisfy the relationship: m1:m2=4:100.

[0110] The temperature of the post-ripening treatment is 95°C, and the time of the post-ripening treatment is 60 minutes.

[0111] The preset stirring speed is 60r / min, and the buffer storage treatment time is 60min.

[0112] Solid-liquid separation includes centrifugation, the centrifugal speed is 4500r / min, and the centrifugal time is 1min.

[0113] Example 3

[0114] Based on the contents disclosed in Example 1, the following modifications are further made:

[0115] The temperature of the steam injection is 100°C, the pressure of the steam injection is 0.6 MPa, and the time of the steam injection is 3 s.

[0116] The weight m1 of saturated steam and the weight m2 of distillation waste liquid satisfy the relationship: m1:m2=8:100.

[0117] The temperature of the post-ripening treatment is 100°C, and the time of the post-ripening treatment is 10 minutes.

[0118] The preset stirring speed is 30r / min and the buffer storage treatment time is 60min.

[0119] Solid-liquid separation includes centrifugation, the centrifugal speed is 3000r / min, and the centrifugal time is 0.5min.

[0120] Example 4

[0121] Based on the method disclosed in Example 1, an adapted system is further designed:

[0122] like Figure 3 As shown, a system for extracting soluble protein from alcohol-containing wastewater comprises:

[0123] A distillation tower 1, for recovering alcohol from alcohol-containing waste liquid;

[0124] The protein denaturation section includes a steam injection unit 2, a post-ripening device 3 and a buffer storage tank 4, wherein the feed port of the steam injection unit 2 is connected to the discharge port of the distillation tower 1, the discharge port of the steam injection unit 2 is connected to the feed port of the post-ripening device 3, and the discharge port of the post-ripening device 3 is connected to the feed port of the buffer storage tank 4;

[0125] The centrifuge 5 has a feed port connected to a discharge port of the buffer storage tank 4 .

[0126] The steam injection unit 2 includes a steam injector 21 and a saturated steam delivery pipe 22 . The discharge port of the saturated steam delivery pipe 22 is connected to the air inlet of the steam injector 21 , and the feed port of the steam injector 21 is connected to the discharge port of the distillation tower 1 .

[0127] The steam injection unit 2 also includes an automatic regulating valve 23, a temperature measuring instrument 24 and a controller 25. The automatic regulating valve 23 is arranged at the saturated steam feed port of the steam injector 21, the temperature measuring instrument 24 is arranged at the discharge port of the steam injector 21, and the controller 25 is connected to the automatic regulating valve 23 and the temperature measuring instrument 24 through electrical signals respectively.

[0128] Comparative Example 1

[0129] Based on the disclosure of Example 1, the following modifications are further made:

[0130] Without using steam injection, saturated steam is directly introduced into the distillation waste liquid.

[0131] Comparative Example 2

[0132] Based on the disclosure of Example 1, the following modifications are further made:

[0133] The temperature of the steam injection is 90°C, the time of the steam injection is 8s, and the corresponding temperature of the post-ripening treatment is 90°C.

[0134] Comparative Example 3

[0135] Based on the disclosure of Example 1, the following modifications are further made:

[0136] The temperature of the steam injection is 110°C, the time of the steam injection is 2s, and the corresponding temperature of the post-ripening treatment is 110°C.

[0137] Comparative Example 4

[0138] Based on the disclosure of Example 1, the following modifications are further made:

[0139] The pressure of steam injection was 0.4 MPa.

[0140] Comparative Example 5

[0141] Based on the disclosure of Example 1, the following modifications are further made:

[0142] The pressure of steam injection was 1.0 MPa.

[0143] Related experiments and effect data:

[0144] The solid weight content of the denatured soluble protein obtained in each embodiment and comparative example and the solid weight content of the clear liquid after solid-liquid separation were measured by spectrophotometer, and the denaturation rate of the soluble protein was also measured. The results are shown in Table 1.

[0145] Table 1 The solid weight content of the denatured soluble protein and the solid weight content of the separated clear liquid in each embodiment and comparative example

[0146]

[0147] As can be seen from Table 1, the embodiment of the present application provides a method for extracting soluble protein from alcohol-containing waste liquid. This method, through the combination of steam injection and denaturation treatment, not only effectively improves the recovery rate of soluble protein in alcohol-containing waste liquid, so that the solid weight content of the denatured protein finally separated is ≥100 g / L, but also significantly improves the quality of soluble protein and reduces the solid weight content of the separated clear liquid to ≤0.2 g / L, which shows that this method has important application value.

[0148] In addition, although Comparative Example 1 has a higher solid weight content of denatured soluble protein and a higher denaturation rate of soluble protein, its steam consumption is relatively high, and it is difficult to obtain a better result at a lower cost.

[0149] In addition, comparative example 3 uses a relatively high steam injection temperature. Although it can improve the recovery rate of soluble protein in alcohol-containing waste liquid, the denatured protein is deeply denatured and is difficult to be applied to feed protein.

[0150] In addition, the pressure used in Comparative Example 4 is relatively low, which makes it difficult to effectively mix the saturated steam and the distillation waste liquid, or the mixing is insufficient, resulting in difficulty in fully denaturing the soluble protein in the distillation waste liquid.

[0151] In addition, the pressure used in Example 5 is relatively high, which makes the pressurization process of saturated steam more stringent. Although the final parameters are good, the requirements for equipment are high, and a large number of high-pressure equipment are required, which increases the production cost of the final overall method; in addition, excessively high steam pressure will aggravate the contamination and blockage of the steam ejector by denatured protein, affecting the continuous and stable operation time of the saturated steam.

[0152] In summary, the embodiment of the present application provides a method for extracting soluble protein from alcohol-containing waste liquid. This method can effectively improve the recovery rate and quality of soluble protein in alcohol waste liquid by combining steam injection and denaturation treatment.

[0153] In addition, an embodiment of the present application provides a system for extracting soluble proteins from alcohol-containing waste liquid. The system achieves efficient extraction and high-quality recovery of soluble proteins from alcohol-containing waste liquid through efficient design and automated control, and has important application value.

[0154] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown in the present application, but will conform to the widest range consistent with the principles and novel features applied for by the present application.

Claims

1. A method for extracting soluble protein from alcoholic waste liquid, wherein the alcoholic waste liquid contains soluble protein and metabolites, the method comprising: distilling the alcohol-containing waste liquid to recover alcohol from the alcohol-containing waste liquid to obtain distilled waste liquid; Using saturated steam to steam-spray the distillation waste liquid to preliminarily denature the soluble protein and dilute the metabolite, thereby obtaining a mixture containing denatured protein; Denaturing the mixture containing denatured proteins to fully denature the soluble proteins, thereby obtaining a waste liquid containing denatured proteins; The waste liquid containing denatured protein is subjected to solid-liquid separation to obtain denatured soluble protein.

2. According to the method of claim 1, the temperature of the steam injection is 95°C to 100°C, the pressure of the steam injection is 0.6MPa to 0.8MPa, and the time of the steam injection is 3s to 5s.

3. According to the method of claim 1, the weight m1 of the saturated steam and the weight m2 of the distillation waste liquid satisfy the relationship: m1:m2=(1.5-8):(90-110).

4. The method according to claim 1, wherein the mixture containing denatured proteins is subjected to denaturation treatment to fully denature the soluble proteins to obtain a waste liquid containing denatured proteins, comprising the steps of: The mixture containing denatured protein is subjected to post-ripening treatment to obtain a primary waste liquid containing denatured protein; Under the condition of a preset stirring speed, the primary waste liquid containing the denatured protein is subjected to a buffer storage treatment to obtain a waste liquid containing the denatured protein.

5. The method according to claim 4, wherein the temperature of the post-ripening treatment is 95°C to 100°C, and the time of the post-ripening treatment is 10 min to 60 min.

6. The method according to claim 4, wherein the preset stirring speed is 30 r / min to 60 r / min, and the buffer storage treatment time is ≥ 60 min.

7. A system for extracting soluble protein from alcohol-containing wastewater, the system being adapted to the method according to any one of claims 1 to 6, the system comprising: A distillation tower (1) for recovering alcohol from alcohol-containing waste liquid; The protein denaturation section comprises a steam injection unit (2), a post-ripening vessel (3) and a buffer storage tank (4), wherein the feed port of the steam injection unit (2) is connected to the discharge port of the distillation tower (1), the discharge port of the steam injection unit (2) is connected to the feed port of the post-ripening vessel (3), and the discharge port of the post-ripening vessel (3) is connected to the feed port of the buffer storage tank (4); A centrifuge (5), wherein the feed port of the centrifuge (5) is connected to the discharge port of the buffer storage tank (4).

8. According to the system of claim 7, the steam injection unit (2) comprises a steam injector (21) and a saturated steam delivery pipe (22), the discharge port of the saturated steam delivery pipe (22) is connected to the air inlet of the steam injector (21), and the feed port of the steam injector (21) is connected to the discharge port of the distillation tower (1).

9. According to the system of claim 8, the steam injection unit (2) further comprises an automatic regulating valve (23), a temperature measuring instrument (24) and a controller (25), wherein the automatic regulating valve (23) is arranged at the saturated steam feed port of the steam injector (21), the temperature measuring instrument (24) is arranged at the discharge port of the steam injector (21), and the controller (25) is connected to the automatic regulating valve (23) and the temperature measuring instrument (24) respectively through electrical signals.

10. A protein feed, comprising the denatured soluble protein obtained by the method according to any one of claims 1 to 6.

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