Treatment process of wet spent grains
By filtration of wet wheat granules, semi-dried wheat granules and wheat granules water are obtained. The wheat granules water is used to generate biogas, which solves the problem of wet wheat granules not being effectively utilized, and achieves efficient utilization of resources and carbon emissions The decrease.
Patent Information
- Application Number
- CN202411634164.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-02-14
AI Technical Summary
The wet wheat granules produced during beer production have not been effectively utilized, resulting in waste of resources and increased carbon emissions.
By filtration of the wet wheat granules, semi-dried wheat granules and wheat granules water are obtained. Semi-dried wheat granules are sold as feed, and the wheat granules water enters the sewage treatment system to generate biogas.
It reduces carbon emissions in beer production, improves the economic value of wet wheat gravel, and improves sewage treatment efficiency.
Smart Images
Figure CN119432930A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of wet spent grains recycling, and in particular to a process for treating wet spent grains. Background Art
[0002] There are eight steps involved in beer brewing. The first step is raw material preparation, grinding the malt and mixing the ground malt with hot water. The second step is the saccharification process, heating the mixture to an appropriate temperature to promote the activity of enzymes, so that the enzymes break down starch into sugars to form sweet wort. The third step is filtering the saccharification liquid, filtering the saccharification liquid through a filter to remove dregs and solid particles to obtain a clear liquid. The fourth step is the boiling and hops adding step, boiling the saccharification liquid, and adding hops during the boiling process. The fifth step is the cooling and fermentation step, quickly cooling the boiled liquid to the fermentation temperature, adding yeast to the boiled liquid, and transferring it to a fermentation tank for fermentation. The sixth step is the maturation step, storing the beer in a low temperature environment to improve its taste and stability. The seventh step is filtration and carbonation, filtering to remove residual solid particles and suspended matter, and then injecting carbon dioxide to give the beer an appropriate carbon dioxide gas content. The eighth step is filling and packaging.
[0003] The beer production process consumes a lot of heat, and this heat mainly comes from the combustion of fossil fuels such as coal, oil, and natural gas. As the world faces huge pressure from carbon emissions, how to reduce carbon emissions in the beer production process has become an urgent problem to be solved.
[0004] Wet spent grains are a byproduct of beer production. During the beer brewing process, malt and other grain raw materials are saccharified, and the soluble substances are extracted for fermentation, while the insoluble substances are left to form spent grains. Spent grains are rich in nutrients and are a high-quality feed raw material for the breeding industry. Therefore, spent grains are usually sold as feed. At present, it is rare to use wet spent grains for other purposes, and there is no process for using wet spent grains to reduce carbon emissions. Summary of the invention
[0005] In view of the above-mentioned defects of the prior art, the present invention provides a processing process for wet spent grains, in which the wet spent grains are subjected to filter pressing treatment to obtain semi-dry spent grains and spent grains water, and the semi-dry spent grains are sold as feed; the spent grains water is introduced into a sewage treatment system to produce biogas, which is a green energy source. Reusing the biogas reduces the use of other energy sources and reduces carbon emissions in the beer production process.
[0006] In order to solve the above technical problems, the present invention provides a process for treating wet spent grains, comprising the following steps:
[0007] S1, sending the wet spent grains into the extrusion system through the conveying system, performing filter pressing treatment, and obtaining semi-dry spent grains and spent grains water;
[0008] S2. Send the spent grains water into the sewage treatment system to generate biogas.
[0009] As a preferred embodiment, the moisture content of the wet spent grains is 80%-95%.
[0010] As a preferred embodiment, the moisture content of the semi-dried spent grains is 50%-60%.
[0011] As a preferred embodiment, the COD of the spent grains water is 85000-95000 mg / L.
[0012] As a preferred embodiment, before the addition of the spent grains water, the average COD of the sewage in the sewage treatment system is no more than 2100 mg / L.
[0013] As a preferred embodiment, the conveying system is an auger conveyor.
[0014] As a preferred embodiment, the extrusion system is a screw press dehydrator.
[0015] As a more preferred embodiment, the extrusion system includes two pressing processes.
[0016] As a preferred embodiment, the sewage treatment system is a treatment system including anaerobic bacteria.
[0017] As a preferred embodiment, the biogas heat generated per ton of spent grains water is 1089.13 MJ.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] (1) The wet spent grains treatment process of the present invention obtains semi-dry spent grains and spent grains water by filter pressing the wet spent grains, and the spent grains water is used to produce green biogas, which is beneficial to reducing carbon emissions from corporate production; at the same time, the spent grains water is added to a sewage treatment system with an average COD of no more than 2100 mg / L, which can significantly improve the carbon-nitrogen ratio of the sewage, stabilize the water quality of the external drainage, and further improve the water reuse rate of the treated sewage.
[0020] (2) The wet spent grains treatment process of the present invention converts the wet spent grains into semi-dry spent grains and spent grains water, and the spent grains water enters the sewage treatment system to prepare biogas, thereby overcoming the environmental pollution and raw material waste problems caused by the spent grains water in the wet spent grains being directly discharged in the subsequent feed factory treatment.
[0021] (3) The wet spent grains treatment process of the present invention can obtain semi-dried spent grains and sell them as feed. The spent grains water can be used to prepare biogas, thereby increasing the economic value of the wet spent grains.
[0022] (4) The wet spent grains treatment process of the present invention generates biogas by passing spent grains water into a sewage treatment system. The biogas generated from each ton of spent grains water can provide 1089.13 MJ of energy for use by the brewery, thereby reducing the energy consumption of the brewery. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a process diagram of the treatment of wet spent grains of the present invention.
[0024] Figure 2 This is a test report on generating biogas heat by using the wet spent grains treatment process of the present invention.
[0025] Among them: 1-first extrusion system, 2-second extrusion system, 3-conveying system, 4-transmission section, 5-compression section and 6-discharging section. DETAILED DESCRIPTION
[0026] In order to make the technical means, creative features, objectives and effects of the invention easier to understand, the invention is further described below with reference to specific illustrations. However, the invention is not limited to the following implementation cases.
[0027] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.
[0028] There are eight steps involved in beer brewing. The first step is raw material preparation, grinding the malt and mixing the ground malt with hot water. The second step is the saccharification process, heating the mixture to an appropriate temperature to promote the activity of enzymes, so that the enzymes break down starch into sugars to form sweet wort. The third step is filtering the saccharification liquid, filtering the saccharification liquid through a filter to remove dregs and solid particles to obtain a clear liquid. The fourth step is the boiling and hops adding step, boiling the saccharification liquid, and adding hops during the boiling process. The fifth step is the cooling and fermentation step, quickly cooling the boiled liquid to the fermentation temperature, adding yeast to the boiled liquid, and transferring it to a fermentation tank for fermentation. The sixth step is the maturation step, storing the beer in a low temperature environment to improve its taste and stability. The seventh step is filtration and carbonation, filtering to remove residual solid particles and suspended matter, and then injecting carbon dioxide to give the beer an appropriate carbon dioxide gas content. The eighth step is filling and packaging.
[0029] The saccharification and boiling steps in beer production both consume a lot of energy. How to recycle heat and reduce carbon emissions has become an urgent problem to be solved.
[0030] Wet spent grains are a byproduct of beer production. In the beer brewing process, malt and other grain raw materials are saccharified, and the soluble substances are extracted for fermentation, while the insoluble substances are left to form spent grains. For every 100 kg of raw malt, about 30 kg of wet spent grains can be produced. Spends contain husks, leaf buds, insoluble proteins, hemicellulose, fat and a small amount of undecomposed starch.
[0031] Because spent grains are rich in nutrients, they are a high-quality feed raw material for the breeding industry, and spent grains are usually sold as feed. The inventors of this application found through analysis of wet spent grains that the moisture content and COD content of wet spent grains are very high. If the wet spent grains with high COD content are converted into spent grains water with high COD content, it is expected to be used for biogas production; in addition, as the loss of extract in breweries is controlled lower and lower, the COD content of drainage water during beer production is also getting lower and lower, with an average value of about 2100 mg / L. After entering the anaerobic sewage treatment system, it is easy to cause granular sludge to deflocculate and become flocculent sludge, affecting sewage treatment efficiency. Therefore, the inventors proposed a new idea of using wet spent grains as raw materials, preparing biogas through spent grains water obtained by squeezing, and at the same time improving sewage treatment efficiency.
[0032] The inventor of the present application produces semi-dry spent grains and spent grains water after filter pressing the wet spent grains. The semi-dry spent grains are sent to the feed factory without affecting the use of the feed factory; the spent grains water is sent to the sewage treatment system. Since the total COD content of the wet spent grains is very high, the COD content of the spent grains water after filter pressing treatment is as high as 90,000 mg / L. Sending the spent grains water to the sewage treatment workshop can produce a large amount of biogas, which can be reused as green energy to reduce carbon emissions in the beer production process.
[0033] The present application provides a process for treating wet spent grains, comprising the following steps:
[0034] S1, sending the wet spent grains into the extrusion system through the conveying system 3, performing filter pressing treatment, and obtaining semi-dry spent grains and spent grains water.
[0035] Among them, the moisture content of wet spent grains is 80%-95%; the moisture content of semi-dry spent grains is 50%-60%, and the COD of spent grains water is 85000mg / L-95000mg / L.
[0036] Among them, the conveying system 3 is an auger conveyor, and the extrusion system is a screw press dehydrator.
[0037] The wet spent grain processing process of the present application includes two extrusion systems, namely a first extrusion system 1 and a second extrusion system 2. The first extrusion system 1 and the second extrusion system 2 use the same equipment, which are both screw press dehydrators.
[0038] like Figure 1 The wet spent grains in spent grains tank 1# and spent grains tank 2# first enter the first extrusion system 1, and after being extruded by the first extrusion system 1, enter the second extrusion system 2 through the conveying system 3. After two extrusions, the wet spent grains are converted into semi-dry spent grains for use in feed factories.
[0039] The extrusion system uses a spiral auger for dehydration. The spiral auger is divided into three sections: a transmission section 4, a compression section 5 and a discharge section 6. The transmission section 4 ensures that the material enters the equipment smoothly. The spiral blade pitch of the compression section 5 (the front section pitch is 270mm, and the rear section pitch is 250mm) and the spiral inner diameter gradually decrease, so that the transmission space gradually decreases. Due to the gradual reduction of the transmission space, a gradually increasing pressure is exerted on the material, forcing the material volume to shrink and squeeze out the water; when the material enters the discharge section 6 of the spiral auger, the spiral auger will exert an axial thrust on the material to push it out of the discharge port.
[0040] When the wet spent grains enter the first extrusion system 1, water needs to be added to flush the wet spent grains. The amount of water used is about 15 t / h (tons / hour). The flushing process allows the wet spent grains to quickly and completely enter the first extrusion system 1. After being extruded by the first extrusion system 1, the wet spent grains enter the second extrusion system 2 under the transportation of the conveying system 3. In the process of entering the second extrusion system 2, water still needs to be added for flushing, and its function is the same as that of entering the first extrusion system 1.
[0041] After being squeezed by the first squeezing system 1 and the second squeezing system 2, the wet spent grains are converted into semi-dried spent grains. At this time, the moisture content of the semi-dried spent grains is 50%-60%. In the process of using the squeezing system for filtration, it is found that the moisture content of the semi-dried spent grains is not as low as possible. When the moisture content of the semi-dried spent grains is 60%, the auger works normally and there is no blockage problem; but when the moisture content of the semi-dried spent grains is 50% or 55%, the auger is blocked, affecting normal operation. For the convenience of use, the moisture content of the semi-dried spent grains is controlled at 60%, and the COD of the spent grains water obtained is about 90,000 mg / L.
[0042] S2. Send the spent grains water into the sewage treatment system to generate biogas.
[0043] The sewage treatment system here is an anaerobic sewage treatment system. An anaerobic sewage treatment system is a sewage treatment method in which organic matter in sewage is decomposed, metabolized, and digested by anaerobic bacteria under anaerobic conditions, so that the organic matter content in sewage is greatly reduced and biogas is produced at the same time. There is no special limitation on the anaerobic sewage treatment system used in this application, and a common anaerobic sewage treatment system in the art can be used.
[0044] When the anaerobic sewage treatment system is in use, when the COD of sewage is low, the granular sludge anaerobic bacteria that do not get enough nutrients are prone to deflocculation, turning into flocculent sludge, affecting the efficiency of pollutant removal. This application filters the wet malt grains into malt grain water, and the COD of malt grain water is as high as 90,000 mg / L. The malt grain water is added to the sewage treatment system with low COD. On the one hand, it solves the problem of granular sludge deflocculation and ensures the normal treatment of sewage. On the other hand, it is also convenient to produce a large amount of biogas, which can be reused in the beer production process to reduce carbon emissions.
[0045] Example 1
[0046] A process for treating wet spent grains comprises the following steps:
[0047] S1. 100t (ton) of wet spent grains are sent to the extrusion system through the conveying system 3 for filter pressing. During the filter pressing process, 15HL (hectoliter) of water is added for flushing to obtain 85t of semi-dry spent grains and 30t of spent grain water, and the COD of the spent grain water is 90000mg / L.
[0048] S2. Send the spent grains water into the sewage treatment system. At this time, the COD of the sewage treatment system increases from 2100mg / L to 3200mg / L, and biogas is produced.
[0049] The generated biogas is entrusted to a third-party testing agency to test its calorific value. The test results are as follows: Figure 2 As shown. Figure 2 It can be seen that the calorific value of biogas is 29.5-32.74MJ / m 3 .
[0050] Example 2
[0051] There are two ways to dispose of wet spent grains. One is to sell the wet spent grains directly as feed (Plan A); the other is to sell the semi-dry spent grains after filtering the wet spent grains as feed, and use the spent grains water to produce biogas (Plan B). The comparison is shown in Table 1.
[0052] Table 1
[0053]
[0054] Table 1 shows the results of different treatment methods of wet spent grains produced by a factory of Budweiser. Plan A is to sell the wet spent grains directly, with a profit of 400 yuan per ton of spent grains. Plan B is to convert the wet spent grains into semi-dry spent grains and spent grain water, with a profit of 434.63 yuan per ton of spent grains, which has a relatively high added value. In addition, when the total amount of wet spent grains is 11,944.54 tons, 132,296.98 m3 of biogas can be generated. 3 .
[0055] Biogas is a green energy source. Producing biogas through spent grains water is beneficial to reducing carbon emissions from corporate production. At the same time, because spent grains water contains rich carbon sources, it provides nutrients to the microorganisms in the sewage treatment system, improves the health of the microorganisms, and ensures the stability of the outflowing water quality after microbial treatment. In addition, the carbon source provided by spent grains water increases the sewage treatment capacity of the sewage treatment system, and the treated sewage enters the grey water system, which can reduce the problem of filter blockage and improve the grey water treatment capacity and the grey water reuse rate.
[0056] In summary, the treatment process of wet spent grains of the present invention obtains semi-dry spent grains and spent grains water by filter pressing the wet spent grains. The spent grains water enters the sewage treatment system to produce green biogas, which is beneficial to reducing the carbon emissions of enterprise production. At the same time, the spent grains water enters the sewage treatment system, which can also improve the carbon-nitrogen ratio of the sewage, stabilize the water quality of the external drainage, and further improve the reuse rate of the reclaimed water.
[0057] The wet spent grain treatment process of the present application converts the organic matter in spent grain water obtained by squeezing the wet spent grain into biogas, which is a renewable energy source composed of methane and carbon dioxide. In the anaerobic sewage treatment system, microorganisms decompose organic matter to produce biogas, which can be used to provide energy for the production process, replacing traditional fossil fuels, reducing fuel costs, reducing carbon emissions, and improving resource utilization efficiency, opening up a new path for the sustainable development of the beer industry. Beer production is expected to move towards a greener and more environmentally friendly direction.
[0058] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.
Claims
1. A process for treating wet spent grains, characterized in that: The steps include: S1, sending the wet spent grains into the extrusion system through the conveying system, performing filter pressing treatment, and obtaining semi-dry spent grains and spent grains water; S2. Send the spent grains water into the sewage treatment system to generate biogas.
2. The process for treating wet spent grains according to claim 1, characterized in that: The moisture content of the wet spent grains is 80%-95%.
3. The process for treating wet spent grains according to claim 1, characterized in that: The moisture content of the semi-dried spent grains is 50%-60%.
4. The process for treating wet spent grains according to claim 1, characterized in that: The COD of the spent grains water is 85000-95000 mg / L.
5. The process for treating wet spent grains according to claim 1, characterized in that: Before adding the spent grains water, the average COD of the sewage in the sewage treatment system is no more than 2100 mg / L.
6. The process for treating wet spent grains according to claim 1, characterized in that: The conveying system is an auger conveyor.
7. The process for treating wet spent grains according to claim 1, characterized in that: The extrusion system is a screw press dehydrator.
8. The process for treating wet spent grains according to claim 7, characterized in that: The extrusion system includes two pressing processes.
9. The process for treating wet spent grains according to claim 1, characterized in that: The sewage treatment system is a treatment system including anaerobic bacteria.
10. The process for treating wet spent grains according to claim 1, characterized in that: The biogas heat generated by each ton of spent grains is 1089.13MJ.