Recycling method for processing white spirit lees

Abstract

The application discloses a recycling method, in particular to a recycling method for treating white spirit lees, and belongs to the technical field of recycling and treating waste in liquor beverage production. The recycling method can completely treat the white spirit lees and fully recycle and reuse the white spirit lees. The recycling method comprises the following steps: firstly, drying the white spirit lees; secondly, screening the dried white spirit lees into light waste and heavy residue; thirdly, packing and storing the heavy residue for other use; fourthly, carrying out anaerobic pyrolysis on the light waste and recycling solid residues, gas-liquid products and heat energy; and finally, purifying and discharging the gas-liquid products to complete the recycling treatment of the white spirit lees. When the heat energy is recycled, the non-condensable gas is combusted in an energy conversion device to produce high-temperature desalted water with a temperature of 80-90 DEG C, and the desalted water is collected and used.

Description

Technical Field

[0001] This invention relates to a recycling method, and more particularly to a recycling method for treating liquor lees, belonging to the field of recycling and treatment technology for waste from alcoholic beverage production. Background Technology

[0002] my country is a major producer and consumer of baijiu (Chinese liquor), producing approximately 7 million tons annually. For every ton of baijiu produced, 3-4 tons of brewing lees are generated, resulting in an annual baijiu lees production of about 30 million tons. Brewing lees mainly consist of water, rice husks, starch, protein, and organic acids, with a water content as high as 60%. They also contain small amounts of nitrogen, phosphorus, and potassium. The large-scale production of lees, if not properly disposed of promptly, easily leads to spoilage and deterioration if left to accumulate for extended periods. This not only wastes valuable resources but also pollutes the surrounding soil, vegetation, and water quality.

[0003] Currently, the main methods for handling trash in China are as follows:

[0004] 1. The biogas production rate of fermentation is low, and the biogas slurry and biogas residue produced in the process need to be treated again.

[0005] 2. Waste bio-fertilizer has a long processing cycle and requires the addition of about 30% other fertilizer substances during the process, resulting in low economic benefits and making it difficult to achieve large-scale promotion.

[0006] 3. Waste-generated biological feed occupies a large area, has low added value, and the waste liquid, waste gas, and dust generated during the process can easily cause secondary pollution.

[0007] The common problems with the above treatment methods are long processing cycles and large land areas, which are not conducive to the rapid and large-scale application of large quantities of baijiu (Chinese liquor) waste. Meanwhile, relevant research has confirmed that baijiu waste has a high calorific value, making it suitable for pyrolysis to achieve value-added utilization, rather than direct combustion. Currently, research on biomass pyrolysis technology is extensive both domestically and internationally, covering various aspects such as the composition of biomass, reaction processes, products, and factors influencing pyrolysis efficiency. Basic research is relatively thorough, but research on the resource utilization of specific biomass, such as baijiu waste, is lacking, especially for its efficient industrial-scale utilization. The gaseous products of biomass pyrolysis are a clean and efficient gaseous fuel, while the solid product, biochar, is considered to have broad application prospects due to its unique porous structure. The efficient utilization technology of baijiu waste has certain reference value and pioneering significance for the solid waste treatment and large-scale resource utilization of similar biomass wastes, and plays a positive role in promoting environmental protection, clean energy development, and social sustainable development.

[0008] Therefore, with the continuous production of large quantities of baijiu lees, and based on the characteristics of baijiu lees raw materials and the overall needs of the entire industry chain planning, how to efficiently and quickly reuse baijiu lees has become a key research direction in this field. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a method for recycling lees from baijiu brewing that can thoroughly treat and fully recycle the lees.

[0010] The technical solution adopted to solve the above-mentioned technical problems is: a method for reusing baijiu lees. The method first dries the lees, then screens the dried baijiu lees into light waste and heavy residue. Next, the heavy residue is packaged and stored for other uses. The light waste is subjected to anaerobic pyrolysis to recover solid residue, gaseous and liquid products, and heat energy. Finally, the gaseous and liquid products are purified before being discharged, completing the reuse of the baijiu lees.

[0011] The recovery of heat energy is achieved by burning the produced non-condensable gases in an energy conversion device to produce high-temperature demineralized water at a temperature of 80℃-90℃, which is then collected and used.

[0012] Furthermore, before drying the lees, they are first screened to remove stones, bamboo pieces, and other foreign matter such as pit mud.

[0013] The preferred method of the above scheme is to use cold-drawn stainless steel wire mesh for primary screening, with a wire diameter of 2mm-3mm and a screening rate of ≥97%.

[0014] Furthermore, when drying the slag, steam with parameters of 0.5MPa-0.7MPa and 160℃-180℃ is used as a heat source to reduce the moisture content of the slag from 60% to 10%-15% through indirect heat exchange, thus completing the drying process.

[0015] The preferred method for the above scheme is to use a paddle-type or tube-type heat exchanger for indirect heat exchange, with an evaporation intensity of not less than 8 kg / m². 2 The slag drying time is 20-30 minutes, and the steam-water mixture generated after steam heat exchange at 95℃-100℃ is collected and utilized.

[0016] Furthermore, when screening the dried baijiu lees, a planar reciprocating rotary screening device is used with a screening aperture of 2.5mm-3.5mm to screen the dried baijiu lees into rice husks on the screen and sorghum-type fermentation residues on the screen.

[0017] The preferred method of the above scheme is that when rice husks are subjected to oxygen-deficient pyrolysis, the pyrolysis energy source is electricity or natural gas, the heating method is indirect heating, and the pyrolysis products are pyrolysis gas and distiller's grains biochar.

[0018] Furthermore, when using electricity or natural gas for indirect heating to pyrolyze rice husks, the pyrolysis temperature is 700℃-800℃, the heating time is 20-30 minutes, and the process is carried out in stages under different temperature controls. The specific process is as follows.

[0019] The material lifting device drives the material to circulate from the bottom to the top of the pyrolysis unit, where a pyrolysis reaction occurs under low-oxygen conditions of 380℃-450℃, releasing non-condensable gases; under low-oxygen conditions of 450℃-800℃, the solid material is converted into distiller's grains biochar.

[0020] The produced non-condensable gases are burned in an energy conversion unit to provide energy, while the high-temperature demineralized water produced at 80℃-90℃ is collected and used.

[0021] After being cooled, the biochar is placed in a temporary storage bin, where it is indirectly cooled using demineralized water. The heated demineralized water is then collected.

[0022] The beneficial effects of this invention are as follows: The technical solution provided in this application first dries the waste, then screens the dried baijiu lees into light waste and heavy residue. The heavy residue is then packaged and stored for other uses. The light waste undergoes anaerobic pyrolysis to recover solid residues, gas-liquid products, and heat energy. Finally, the gas-liquid products are purified and discharged, completing the reuse of the baijiu lees. In particular, the heat energy recovery is achieved by burning the produced non-condensable gas in an energy conversion device to produce high-temperature desalinated water at 80℃-90℃, which is then collected and used. Thus, by first classifying the waste and then processing and reusing it according to its different components, especially the recovery of solid residues, gas-liquid products, and heat energy after pyrolysis of the light waste, a more thorough treatment and reuse of brewing waste is achieved. This solves the technical problems of long processing cycles and large land areas in the prior art, which are not conducive to the rapid large-scale application of baijiu lees produced in large quantities. The recycling and reuse are more thorough, enabling rapid large-scale application. Attached Figure Description

[0023] Figure 1 This is a process flow diagram of the method for reusing baijiu lees according to the present invention. Detailed Implementation

[0024] like Figure 1As shown, in order to solve the problems of subsequent processing and reuse of baijiu brewing lees in existing technologies, this invention provides a reuse method for baijiu lees that can thoroughly process and fully recover baijiu brewing lees. The reuse method first dries the lees, then screens the dried baijiu lees into light waste and heavy residue. Next, the heavy residue is packaged and stored for other uses. The light waste is subjected to anaerobic pyrolysis to recover solid residues, gas-liquid products, and heat energy. Finally, the gas-liquid products are purified and discharged to complete the reuse of the baijiu lees. The heat energy recovery is achieved by burning the produced non-condensable gases in an energy conversion device to produce high-temperature desalinated water at a temperature of 80℃-90℃, which is then collected and used. The technical solution provided in this application first dries the waste, then screens the dried baijiu lees into light waste and heavy residue. The heavy residue is then packaged and stored for other uses. The light waste undergoes anaerobic pyrolysis to recover solid residues, gaseous and liquid products, and heat energy. Finally, the gaseous and liquid products are purified and discharged, completing the reuse of the baijiu lees. In particular, the heat energy recovery is achieved by burning the produced non-condensable gases in an energy conversion device to produce high-temperature desalinated water at 80℃-90℃, which is then collected and used. This method, by first classifying the waste and then processing and reusing it according to its different components, especially the recovery of solid residues, gaseous and liquid products, and heat energy after pyrolysis of the light waste, achieves a more thorough treatment and reuse of brewing waste. It solves the technical problems of existing technologies, such as long processing cycles, large land areas, and unfavorable conditions for the rapid large-scale application of baijiu lees produced in large quantities. The more thorough recycling and reuse enables rapid large-scale application.

[0025] Accordingly, to improve the processing quality of each step in the reuse process and achieve the best processing and recycling effect, this application first performs a preliminary screening on the waste residue before drying to remove stones, bamboo pieces, and pit mud-like foreign matter. The preliminary screening uses cold-drawn stainless steel wire mesh with a wire diameter of 2mm-3mm and a screening rate ≥97%. During the drying process, steam with parameters of 0.5MPa-0.7MPa and 160℃-180℃ is used as a heat source to indirectly reduce the moisture content of the waste residue from 60% to 10%-15%. More specifically, the indirect heat exchange uses a paddle-type or tube-type heat exchanger with an evaporation intensity of not less than 8kg / m². 2The drying time for the lees is 20-30 minutes, and the steam-water mixture generated at 95-100℃ after steam heat exchange is collected and utilized. Similarly, when screening the dried lees, a planar reciprocating rotary screening device with a screening aperture of 2.5mm-3.5mm is used to screen the dried lees into rice husks on the screen and sorghum-like fermentation residues on the screen.

[0026] Furthermore, in the oxygen-deficient pyrolysis of rice husks, the energy source is electricity or natural gas, the heating method is indirect, and the pyrolysis products are pyrolysis gas and distiller's grains biochar. More specifically, when using electricity or natural gas for indirect heating to pyrolyze rice husks, the pyrolysis temperature is 700℃-800℃, the heating time is 20-30 minutes, and it is carried out in stages under different temperature controls. The specific process is as follows.

[0027] The material lifting device drives the material to circulate from the bottom to the top of the pyrolysis unit, where a pyrolysis reaction occurs under low-oxygen conditions of 380℃-450℃, releasing non-condensable gases; under low-oxygen conditions of 450℃-800℃, the solid material is converted into distiller's grains biochar.

[0028] The produced non-condensable gases are burned in an energy conversion unit to provide energy, while the high-temperature demineralized water produced at 80℃-90℃ is collected and used.

[0029] After being cooled, the biochar is placed in a temporary storage bin, where it is indirectly cooled using demineralized water. The heated demineralized water is then collected.

[0030] In summary, the recycling method provided in this application for treating brewing lees addresses the issue of large-volume production of baijiu lees by reducing its volume. By employing efficient utilization technology, approximately 40% of the high-value portion is screened, with the undersize material used as high-protein feed, and the remaining portion utilized for energy and resource recovery. This effectively avoids the problems of high carbon emissions and difficult flue gas treatment associated with traditional direct combustion biomass technology.

[0031] The technology for drying baijiu lees uses indirect steam heat exchange, continuous drying, and continuous feeding and discharging. It solves the problems of long drying cycles, large area requirements, and easy contamination of raw materials caused by biological drying, sunroom drying, and flue gas drying. The drying time is only about 30 minutes, which improves the drying efficiency of baijiu lees in industrial production.

[0032] The segmented pyrolysis unit is used in conjunction with raw materials with low density (approximately 0.18 T / m³). 3 Taking advantage of the characteristics of ), a segmented continuous pyrolysis device is adopted, and the pyrolysis time is only about 30 minutes. At the same time, the heating area is increased to avoid the problem of insufficient pyrolysis. Through segmented pyrolysis temperature control, gas is produced first and then carbonization is carried out, which improves energy efficiency.

[0033] The technology for efficient utilization of baijiu lees is effectively coupled with the baijiu production park. The high-temperature demineralized water produced by this technology can be used in the park's boilers; the biochar produced can be used for planting crops such as sorghum; and the high-protein feed produced can be sold externally, thereby increasing the economic value of the technical solution.

[0034] Compared with other methods of utilizing baijiu lees, such as producing baijiu lees organic fertilizer, the processing cycle is 50-60 days. However, this efficient method only takes about 90 minutes from the time the baijiu lees enter the system to the production of biochar. It effectively solves the problems of long processing cycle and large land area required for baijiu lees, while avoiding environmental hazards such as leachate and odorous substances generated during the process.

[0035] The technical solution of this application will be further described below through specific embodiments:

[0036] To solve the above-mentioned technical problems, the technical solution adopted in this application is as follows:

[0037] A method for reusing baijiu lees mainly includes: baijiu lees drying technology, screening technology, segmented pyrolysis technology, and energy recovery technology.

[0038] 1. Primary screening

[0039] It primarily removes foreign matter from raw materials, such as stones, bamboo pieces, and pit mud. The screen is made of cold-drawn stainless steel wire mesh with a wire diameter of 2mm-3mm and a screening rate of ≥97%.

[0040] 2. Drying of Baijiu lees

[0041] This will reduce the moisture content of baijiu lees from 60% to 10%-15%.

[0042] Drying heat source: Steam parameters are (0.5-0.7) MPa, (160-180)℃, using indirect heat exchange methods such as paddle type or tube type, with an evaporation intensity of not less than 8 kg / m². 2 The drying time is 20-30 minutes. The steam-water mixture produced after steam heat exchange, with a temperature of approximately 100℃, is collected and utilized.

[0043] 3. Secondary screening

[0044] The dried baijiu mash is sieved. The material that passes through the sieve is rice husk, which is collected and used in the subsequent pyrolysis process. The material that passes through the sieve is mainly the residue of raw materials such as sorghum left over from fermentation, which is collected, packaged, and stored for use as high-protein feed.

[0045] The screening device adopts a planar reciprocating rotary motion, with a screening aperture of 2.5mm-3.5mm.

[0046] 4. Pyrolysis

[0047] The rice husks left on the sieve undergo oxygen-deficient pyrolysis. The pyrolysis energy source is electricity or natural gas, which provides indirect heating. The pyrolysis products are pyrolysis gas and distiller's grains biochar.

[0048] Different temperature controls are used in different stages, with pyrolysis temperature of 700℃-800℃ and heating time of 20min-30min.

[0049] The lifting device circulates the material from the bottom to the top of the pyrolysis unit, where a pyrolysis reaction occurs under low-oxygen conditions of 380℃-450℃, releasing non-condensable gases. Under low-oxygen conditions of 450℃-800℃, the solid material is converted into distiller's grains biochar. The produced non-condensable pyrolysis gas enters the energy conversion unit for combustion to provide energy, and the resulting high-temperature demineralized water (80℃-90℃) is collected for use. The biochar is cooled and then enters a temporary storage silo, where it is indirectly cooled using demineralized water. The heated demineralized water is then collected.

[0050] 5. Energy usage

[0051] The sources of usable energy in the method are: the steam-water mixture produced in the drying process, the high-temperature desalinated water produced by the pyrolysis gas combustion heat exchange, and the high-temperature desalinated water produced in the cooling process of the distiller's grains biochar. By systematically recovering this desalinated water, it can be used for boiler water in the liquor production park, thus achieving energy recovery.

[0052] 6. Gas purification

[0053] In this method, the gas is purified in stages according to its characteristics. The gas produced in the screening and drying stages is mainly dust and water vapor, which is discharged after dust removal and deodorization. The flue gas produced in the pyrolysis stage and the pyrolysis gas combustion stage is treated for desulfurization and denitrification and discharged in compliance with standards.

[0054] Example 1

[0055] The lees were taken from a liquor factory in Sichuan. Analysis and testing showed that the raw material had a moisture content of 59.8%, a fiber content of 31.84%, and a protein content of 8.54%.

[0056] Fresh baijiu mash was dried using a paddle dryer with steam parameters of 0.6 MPa / 170℃ for 28 minutes, reducing the moisture content to 13% and the protein content to 18.6%. The dried mash was then sieved through a high-resolution sieve (3.0 mm aperture) to obtain: rice husk weight percentage of 21.8% and protein content of 10.93%; the undersize was high-protein feed weight percentage of 78.2% and protein content of 20.5%.

[0057] The rice husks left on the sieve are processed through a pyrolysis gasification device at a temperature of 700-800℃ for 30 minutes, producing pyrolysis gas and biochar, with a biochar yield of 30%. The pyrolysis gas is burned to produce high-temperature water, which is then transported to the energy center for boiler use.

[0058] After the flue gas was treated by spraying, desulfurization and denitrification, no particulate matter, sulfur dioxide and nitrogen oxides were detected.

[0059] Example 2

[0060] The lees were taken from a liquor factory in Sichuan. Analysis and testing showed that the raw material had a moisture content of 62.3%, a fiber content of 28.16%, and a protein content of 11.62%.

[0061] Fresh baijiu mash was dried using a paddle dryer with steam parameters of 0.6 MPa / 170℃ for 30 minutes, reducing the moisture content to 12% and the protein content to 27.12%. The dried mash was then sieved through a high-resolution sieve (3.0 mm aperture) to obtain: rice husk weight percentage of 25.5% and protein content of 9.75%; the undersize was high-protein feed weight percentage of 74.5% and protein content of 31.2%.

[0062] The rice husks left on the sieve are processed through a pyrolysis gasification device at a temperature of 700-800℃ for 30 minutes, producing pyrolysis gas and biochar. The biochar yield from distiller's grains is 29.6%. The pyrolysis gas is burned to produce high-temperature water, which is then transported to the energy center for boiler use.

[0063] After the flue gas was treated by spraying, desulfurization and denitrification, no particulate matter, sulfur dioxide and nitrogen oxides were detected.

[0064] Example 3

[0065] The lees were taken from a liquor factory in Sichuan. Analysis and testing showed that the raw material had a moisture content of 59.8%, a fiber content of 31.84%, and a protein content of 8.54%.

[0066] Fresh baijiu mash was dried using a paddle dryer with steam parameters of 0.6 MPa / 170℃ for 30 minutes, reducing the moisture content to 12% and the protein content to 18.8%. The dried mash was then sieved through a high-resolution sieve (2.5 mm aperture) to obtain: rice husk weight percentage of 25.6% and protein content of 11.93%; the undersize was high-protein feed weight percentage of 74.4% and protein content of 21.2%.

[0067] The rice husks left on the sieve are processed through a pyrolysis gasification device at a temperature of 700-800℃ for 32 minutes, producing pyrolysis gas and biochar, with a biochar yield of 28%. The pyrolysis gas is burned to produce high-temperature water, which is then transported to the energy center for boiler use.

[0068] After the flue gas was treated by spraying, desulfurization and denitrification, no particulate matter, sulfur dioxide and nitrogen oxides were detected.

Claims

1. A method for reusing lees from liquor processing, characterized in that: First, the lees are dried. Then, the dried lees are screened into light waste and heavy residue. The heavy residue is packaged and stored for other uses. The light waste is subjected to anaerobic pyrolysis to recover solid residue, gas-liquid products and heat energy. Finally, the gas-liquid products are purified and discharged to complete the reuse of lees. In the process of drying the slag, steam with parameters of 0.5MPa~0.7MPa and 160℃~180℃ is used as a heat source to reduce the moisture content of the slag from 60% to 10%~15% through indirect heat exchange. The indirect heat exchange employs a paddle-type or tube-type heat exchange device, with an evaporation intensity of not less than 8 kg / m². 2 The slag drying time is 20 min to 30 min, and the steam-water mixture generated after steam heat exchange at 95℃ to 100℃ is collected and utilized. In the process of oxygen-deficient pyrolysis of lightweight waste rice husks, the energy source is electricity or natural gas, the heating method is indirect, and the pyrolysis products are pyrolysis gas and distiller's grains biochar. The pyrolysis temperature is 700℃~800℃, the heating time is 20min~30min, and the process is carried out in stages under different temperature controls. The specific process is as follows: The lifting device drives the material to circulate from the bottom to the top of the pyrolysis device. The pyrolysis reaction occurs under low oxygen conditions of 380℃~450℃, releasing non-condensable gases. Under low oxygen conditions of 450℃~800℃, the solid material generates distiller's grains biochar. The non-condensable gas produced enters the energy conversion device for combustion to supply energy, and the high-temperature demineralized water produced at 80℃~90℃ is collected and used. The biochar is cooled and then enters the temporary storage bin, where it is indirectly cooled by demineralized water. The heated demineralized water is then collected. The recovery of heat energy is achieved by burning the produced non-condensable gases in an energy conversion device to produce high-temperature demineralized water at a temperature of 80℃~90℃, which is then collected and used.

2. The method for reusing baijiu lees according to claim 1, characterized in that: Before drying the lees, they are first screened to remove stones, bamboo pieces, and other foreign objects such as pit mud.

3. The method for reusing baijiu lees according to claim 2, characterized in that: The primary screening uses cold-drawn stainless steel wire mesh with a wire diameter of 2mm to 3mm and a screening rate of ≥97%.

4. The method for recycling baijiu lees according to any one of claims 1 to 3, characterized in that: When screening the dried baijiu lees, a planar reciprocating rotary screening device is used with a screening aperture of 2.5mm to 3.5mm. The dried baijiu lees are screened to separate the rice husks on the screen and the fermented residues of sorghum and other raw materials on the screen.

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