Method and system for producing alcohol-free beer by using reverse osmosis membrane

Abstract

The invention discloses a method and system for producing alcohol-free beer by using a reverse osmosis membrane, and the method comprises the following steps: pre-concentration: introducing a preset volume of original beer into a reverse osmosis membrane system, and carrying out circulating filtration under the conditions of first pressure and first temperature to obtain a pre-concentrated beer liquid with a target concentration multiple and a first penetrating fluid; in the washing and filtering step, deoxygenated water is introduced into the pre-concentrated beer liquid while circulating filtration is carried out under the conditions of second pressure and first temperature, washing and filtering beer liquid with target alcohol content and second penetrating fluid are obtained, and the second pressure is lower than the first pressure; and blending: adding deoxidized water into the washed and filtered beer liquid so as to enable the washed and filtered beer liquid to reach a preset alcohol content, or adding original beer into the washed and filtered beer liquid added with the deoxidized water so as to blend the flavor of the product, thereby obtaining the finished product dealcoholized beer. According to the method, flavor substances in original beer can be reserved to the greatest extent, the dealcoholization efficiency is high, the consumed total deoxidized water is less, and the energy consumption of beer dealcoholization is reduced.

Description

A method and system for producing non-alcoholic beer using reverse osmosis membranes Technical Field

[0001] This invention relates to the field of non-alcoholic beer production technology, and in particular to a method and system for producing non-alcoholic beer using a reverse osmosis membrane. Background Technology

[0002] Non-alcoholic beer retains the flavor and color of regular beer, with an alcohol content generally less than or equal to 0.5 vol%. Non-alcoholic beer not only allows people to enjoy the delicious taste of beer but also reduces the health risks associated with regular beer. In recent years, with increased health awareness and improved living standards, non-alcoholic beer has become increasingly popular and possesses significant market potential.

[0003] Currently, there are two main methods for producing non-alcoholic beer industrially: restricted fermentation and physical dealcoholization. Restricted fermentation requires altering the original fermentation process, demanding high levels of process control and resulting in a higher content of non-fermentable residual sugars. The resulting non-alcoholic beer differs significantly in taste from regular beer, and the production cycle from saccharification to fermentation is long, generally at least 20 days. The most commonly used physical dealcoholization method is vacuum distillation. Vacuum distillation requires significant equipment investment and operates at high temperatures (40-60℃), which can damage the original flavor compounds in beer (such as proteins, vitamins, esters (e.g., ethyl acetate, isobutyl acetate, ethyl hexanoate, etc.), or acetic acid and some higher acids (e.g., isovaleric acid, hexanoic acid, octanoic acid, etc.); or n-propanol, isopropanol, or some higher alcohols (e.g., isoamyl alcohol, phenylethyl alcohol, etc.)). This significantly reduces the product's taste, color, and freshness, and vacuum distillation produces a certain cooked flavor that is difficult for consumers to accept. Therefore, effectively preserving the flavor compounds in beer during dealcoholization is crucial. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of significant loss of flavor substances, low dealcoholing efficiency, and high energy consumption in existing dealcoholized beer production processes. This invention provides a method and system for producing non-alcoholic beer using a reverse osmosis membrane, which can retain the original beer's flavor substances to the greatest extent, while achieving high dealcoholing efficiency, low total deoxygenated water consumption, and reduced energy consumption in beer dealcoholization.

[0005] For example, the flavor substances mentioned above include, but are not limited to: proteins, vitamins, esters (such as ethyl acetate, isobutyl acetate, ethyl hexanoate, etc.), or acetic acid and some higher acids (such as isovaleric acid, hexanoic acid, octanoic acid, etc.), or n-propanol, isopropanol and some higher alcohols (such as isopentanol, phenylethyl alcohol, etc.).

[0006] To address the aforementioned technical problems, embodiments of the present invention disclose a method and system for producing non-alcoholic beer using a reverse osmosis membrane. The method employs a "pre-concentration-washing-blending" approach, which can retain the flavor compounds in the original beer to the greatest extent possible. Furthermore, it has high dealcoholization efficiency, consumes less total deoxygenated water, and reduces energy consumption during the dealcoholization process.

[0007] Specifically, a method for producing non-alcoholic beer using a reverse osmosis membrane includes:

[0008] Pre-concentration involves passing a predetermined volume of raw beer into a reverse osmosis membrane system for circulation and filtration under first pressure and first temperature conditions to obtain pre-concentrated beer liquid and first permeate at the target concentration ratio.

[0009] Washing and filtration: Deoxygenated water is introduced into the pre-concentrated beer liquid, and at the same time, the liquid is circulated and filtered under a second pressure and a first temperature to obtain a washed beer liquid and a second permeate with the target alcohol content, wherein the second pressure is lower than the first pressure.

[0010] Blending involves adding deoxygenated water to the filtered beer liquid to achieve a preset alcohol content, or adding the original beer to the filtered beer liquid after adding deoxygenated water to adjust the product flavor, thereby obtaining the finished dealcoholized beer.

[0011] The first permeate and the second permeate are discharged from the reverse osmosis membrane system.

[0012] By adopting the above technical solution, the flavor substances in the original beer can be preserved to the greatest extent, and the de-alcoholization efficiency is high, the total deoxygenated water consumption is low, and the energy consumption of beer de-alcoholization is reduced.

[0013] The reverse osmosis membrane system will be explained first below:

[0014] A reverse osmosis membrane system includes a reverse osmosis membrane. Substances that permeate through the membrane are on the osmosis side, while those that do not are on the concentration side. The liquid on the concentration side is called concentrate, and the liquid on the osmosis side is called permeate. In this invention, the concentrate from the pre-concentration process is filtered multiple times to become pre-concentrated beer liquid, and the concentrate from the washing filtration process is filtered multiple times to become washed beer liquid. Furthermore, the permeate from the pre-concentration process is the aforementioned first permeate, and the permeate from the washing filtration process is the aforementioned second permeate.

[0015] Specifically, the first step is pre-concentration, in which a predetermined volume of raw beer is filtered under a first pressure and a first temperature, allowing small molecules such as water and ethanol to pass through the reverse osmosis membrane to the permeate side as the first permeate, while large molecules such as flavor substances are retained by the membrane to the concentration side. As filtration proceeds, the level of the raw beer drops. When the level of the raw beer drops to meet the target concentration ratio, the second step of washing and filtration is then carried out.

[0016] The main purpose of the first step is to increase the alcohol content in the concentrate on the concentration side, which is beneficial for increasing the de-alcoholization rate of alcohol during the second step of filtration. The reason for the increase in alcohol content in the concentrate on the concentration side is that, since water molecules are smaller than ethanol molecules, the permeation rate of water molecules is much higher than that of ethanol molecules during filtration. Therefore, the concentration of ethanol in the pre-concentrated beer gradually increases as the pre-concentration process proceeds.

[0017] Step 2: Washing and filtration. After the pre-concentration is completed, the pre-concentrated beer liquid left on the concentration side in the first step is filtered under the second pressure and the first temperature while deoxygenated water is added to obtain the washed beer liquid and the second permeate with the target alcohol content.

[0018] The main purpose of the second step is to maintain a constant concentration of substances other than ethanol during the de-alcoholization process, preventing increased permeation loss due to the increased concentration of these substances (such as flavor compounds). As the concentration of these substances increases, more of them dissolve within the membrane, leading to greater permeation and a lower rejection rate of the reverse osmosis membrane. This means that the concentration of substances permeating into the second permeate increases, resulting in greater loss of flavor compounds.

[0019] The third step is blending. Deoxygenated water is added to the washed and filtered beer liquid obtained in step two to adjust the alcohol content of the beer, or the original beer is added to adjust the flavor of the beer to obtain the finished dealcoholized beer.

[0020] The main purpose of the third step is to control the alcohol content of the final product, the dealcoholized beer, and to maintain its taste and flavor. Additionally, adding the original beer can help recover some of the flavor compounds lost in the second step.

[0021] In this process, the ethanol content in the filtered beer liquid obtained in the second step needs to be slightly higher than the ethanol content in the finished dealcoholized beer, so as to leave room for adjusting the alcohol content in the third step. The aforementioned preset alcohol content is generally 0.5 vol%.

[0022] For example, suppose 100L of original beer is processed in the first step of pre-concentration to obtain 50L of pre-concentrated beer liquid; at the end of the second step of washing and filtering, the alcohol concentration of the filtered beer liquid with the target alcohol content should be less than 1% or less than 0.8%, so that when 50L of deoxygenated water is added in the third step of blending, the alcohol concentration of the finished dealcoholized beer will be less than the target 0.5%. At the same time, if a small amount of sake or fermentation liquid needs to be added in the third step to adjust the final taste and flavor, the ethanol content at the end of the second step needs to be even lower, because the addition of sake or fermentation liquid will increase the ethanol content.

[0023] It should be noted that the pre-concentration and filtration of this invention at low temperatures can prevent the thermal denaturation of flavor compounds in beer, thus preserving the original flavor of the finished dealcoholized beer. However, the temperature during pre-concentration and filtration should not be too low, for example, below 5°C, because excessively low temperatures will increase the loss of flavor compounds and slow down ethanol permeation, prolonging the beer dealcoholization time. Specifically, excessively low temperatures will increase the solubility of flavor compounds such as esters in the membrane, meaning that flavor compounds are more likely to dissolve in the membrane and diffuse away at excessively low temperatures. In addition, if the temperature is too low, the permeation rate of various substances, including ethanol, will decrease, reducing the permeation flux, thus greatly prolonging the dealcoholization time; the increased dealcoholization time also increases the interaction time between flavor compounds and the reverse osmosis membrane, further increasing the loss of flavor compounds. The aforementioned low-temperature environment is the first temperature environment described later.

[0024] In addition, the aforementioned first and second permeate solutions can be collected for subsequent recovery of ethanol and flavor compounds.

[0025] According to another specific embodiment of this application, during the washing and filtration process, the outflow volume of the second permeate is controlled to be equal to the volume of deoxygenated water added.

[0026] According to another specific embodiment of this application, the flow rate of the added deoxygenated water is controlled to be equal to the flow rate of the washed beer liquid permeating through the reverse osmosis membrane.

[0027] Using the above technical solution, during the washing and filtration process, it is necessary to control the outflow volume of the second permeate to be equal to the volume of deoxygenated water added. For example, if a total of 1L of water and ethanol flows out, then 1L of deoxygenated water should be added during washing and filtration to maintain the original liquid level. At the same time, the flow rate of deoxygenated water should be controlled to be equal to the flow rate of the beer liquid through the reverse osmosis membrane. Adding deoxygenated water too quickly will reduce the de-alcoholization efficiency, while adding deoxygenated water too slowly will increase the loss of flavor substances.

[0028] According to another specific embodiment of this application, the aforementioned first temperature range is 5~20℃, for example 8℃, 12℃, 16℃, etc. Furthermore, in the first step, the first pressure is controlled within the range of 20~50 bar, for example 35 bar, 28 bar, etc., while in the second step, the second pressure is controlled on average within the range of 5~30 bar.

[0029] Using the above technical solution, this application controls the loss of flavor substances by controlling the pressure and temperature at different stages. Increasing the pre-concentration operating pressure increases the permeation rate of various substances during the permeation process. However, the increase in the water permeation rate is greater than that of ethanol and flavor substances. Therefore, the retention rate of ethanol and other macromolecules increases with higher operating pressure. Thus, using a higher operating pressure for the first pre-concentration step facilitates rapid ethanol concentration and shortens the operation time; simultaneously, it helps retain macromolecules such as proteins and flavor substances, improving the taste of the final product, the dealcoholized beer.

[0030] It should be noted that although higher operating pressure is beneficial for increasing the permeation rate, the operating pressure used in the second washing step needs to be lower compared to the first pre-concentration step. This is because increasing the operating pressure in the second washing step will result in a greater increase in the water permeation rate than the ethanol permeation rate. Therefore, if a higher operating pressure is still used in the second washing step, the amount of deoxygenated water required to reach the target alcohol content will increase significantly. Simultaneously, using a higher operating pressure in the second washing step will greatly prolong the time required to reach the target alcohol content, leading to increased loss of flavor compounds. Therefore, the operating pressure in the second washing step should be appropriately lowered (i.e., the second pressure should be lower than the first pressure). This reduces the amount of deoxygenated water used during washing and shortens the dealcoholization time, which helps maintain the flavor compound content in the finished dealcoholized beer.

[0031] According to another specific embodiment of this application, the volume fraction of the preset alcohol content is ≤0.5 vol.

[0032] Using the above technical solution, an alcohol volume fraction of 0.5 vol% for dealcoholized beer is an alcohol content index for dealcoholized beer in the industry. Of course, this invention can be applied to the dealcoholization of other types of beer, that is, it is applicable to the production of beer with different alcohol contents, and is not limited to alcohol content ≤0.5 vol%.

[0033] According to another specific embodiment of this application, in the washing and filtration process, the second pressure segment is set as a first partial pressure, a second partial pressure, and a third partial pressure, and the washing and filtration is completed sequentially at the first partial pressure, the second partial pressure, the third partial pressure, and the first temperature; the range of the first partial pressure is 22~30 bar, the range of the second partial pressure is 14~22 bar, and the range of the third partial pressure is 5~14 bar.

[0034] Alternatively, in the washing and filtration process, the second pressure segment is set to a fourth partial pressure and a fifth partial pressure, and the washing and filtration is completed sequentially at the fourth partial pressure, the fifth partial pressure and the first temperature, wherein the range of the fourth partial pressure is 18~30 bar and the range of the fifth partial pressure is 5~18 bar.

[0035] For example, during filtration, the filter is sequentially subjected to a first partial pressure of 25 bar, a second partial pressure of 20 bar, and a third partial pressure of 10 bar, i.e., filtration is performed at these three pressures for a period of time; or, during filtration, the filter is sequentially subjected to a fourth partial pressure of 23 bar and a fifth partial pressure of 17 bar, i.e., filtration is performed at these two pressures for a period of time. Of course, other values ​​within the aforementioned pressure range are also acceptable, and this embodiment does not impose specific limitations on them.

[0036] By adopting the above technical solution, segmented pressure control helps to minimize the total amount of deoxygenated water used. As the filtration time increases, the alcohol concentration decreases. If the same operating pressure is maintained continuously, more water will permeate while less alcohol permeates, making alcohol removal increasingly difficult. Therefore, segmented pressure control, with the operating pressure gradually decreasing, allows for the use of less deoxygenated water to achieve the same amount of alcohol permeation, thus reducing the total amount of deoxygenated water used and consequently reducing the energy consumption of the de-alcoholization process.

[0037] According to another specific embodiment of this application, the target concentration factor is 1.2 to 4, for example 1.8, 2.2, etc.

[0038] By adopting the above technical solution, appropriately increasing the concentration ratio of the first-step pre-concentration, for example, within 4 times, can reduce the amount of deoxygenated water used in the second-step filtration process and reduce the loss of flavor substances, thus increasing the content of flavor substances in the finished dealcoholized beer. However, the concentration ratio cannot be too high; otherwise, a large amount of deoxygenated water will need to be added for blending, affecting the product's taste. For example, if 100L of original beer is pre-concentrated to obtain 40L of pre-concentrated beer liquid, and if only 20L of pre-concentrated beer liquid is obtained, then too much deoxygenated water needs to be added in the third-step blending, resulting in a bland taste in the finished dealcoholized beer.

[0039] This application also discloses a system for producing non-alcoholic beer, which utilizes any of the aforementioned methods for producing non-alcoholic beer using reverse osmosis membranes. The system for producing non-alcoholic beer includes:

[0040] The buffer tank includes: a first inlet pipe equipped with a second valve, a second inlet pipe equipped with a third valve, a third inlet pipe equipped with a fourth valve, and a first outlet pipe equipped with a fourth valve.

[0041] The deoxygenated water tank is connected to the second inlet pipe, and the third valve is used to control the amount and rate of addition of deoxygenated water.

[0042] The reverse osmosis membrane system is provided with a membrane housing containing multiple membrane elements connected in series or parallel, including a permeate outlet pipe, a concentrate outlet pipe, and a beer inlet pipe. The concentrate outlet pipe is connected to the third inlet pipe to achieve circulating filtration.

[0043] The cooler includes an inlet end and an outlet end, the inlet end being connected to the first outlet pipe, and the outlet end being connected to the beer liquid inflow pipe of the reverse osmosis membrane system;

[0044] A high-pressure pump is located between the first outlet pipe and the inlet end.

[0045] According to another specific embodiment of this application, the system for producing non-alcoholic beer further includes a first valve, and the first valve, the fourth valve, and the high-pressure pump are connected by a tee.

[0046] According to another specific embodiment of this application, the high-pressure pump includes: a first high-pressure pump and a second high-pressure pump, the first valve, the fourth valve and the first high-pressure pump are connected by a tee, the first high-pressure pump and the second high-pressure pump are connected in series, and the pressure range of the second high-pressure pump is greater than the pressure range of the first high-pressure pump.

[0047] Using the above technical solution, the entire dealcoholization process of the system for producing non-alcoholic beer in this application is as follows:

[0048] 1) Feeding: Close the first, third, and fourth valves and open the second valve to introduce the raw beer to be dealcoholized into the buffer tank. Once the beer volume in the buffer tank reaches the preset value, close the second valve to stop feeding. The first valve controls the outflow of the finished dealcoholized beer; the third valve is opened when deoxygenated water needs to be added during the filtration process; the fourth valve is closed until the raw beer volume in the buffer tank reaches the preset value for pre-concentration, at which point it is opened again. Closing the fourth valve during feeding also prevents the raw beer from entering the reverse osmosis system.

[0049] 2) Pre-concentration: The raw beer is repeatedly circulated and filtered between a buffer tank and a reverse osmosis membrane system to obtain pre-concentrated beer and first permeate at the target concentration ratio. This process requires opening the fourth valve and starting the first and second high-pressure pumps. The raw beer in the buffer tank is first pumped from the inlet into the cooler, and then from the outlet into the reverse osmosis membrane system. Under high pressure, water and ethanol permeate through the reverse osmosis membrane into the permeate side, becoming the first permeate. The concentrate that does not permeate remains on the concentration side and is then transported back to the buffer tank. The first and second high-pressure pumps then pump the concentrate from the concentration side back into the cooler and reverse osmosis membrane system for circulation and de-alcoholization until the liquid level in the buffer tank drops to the preset volume. The liquid remaining in the buffer tank is the pre-concentrated beer. The first step of pre-concentration ends when the pre-concentrated beer meets the target concentration ratio.

[0050] For example, in the above process, the outlet pressure range of the second high-pressure pump is controlled at 20~50 bar, and the cooler cools the original beer to 5~20°C, such as 8°C, 12°C, 16°C, etc. The temperature is controlled within this range in multiple cycles, and the final concentration ratio of the original beer is 1.2~4 times, such as 1.8, 2.2, etc. This concentration ratio is the ratio of the volume of the original beer to the volume of the pre-concentrated beer liquid obtained after the pre-concentration.

[0051] 3) Washing and filtration: This process works similarly to the first step of pre-concentration, except that deoxygenated water is added while the concentrate is being circulated and filtered. This process requires opening the third valve to introduce deoxygenated water from the deoxygenated water tank into the buffer tank. The rate at which the deoxygenated water is added is controlled to be equal to the permeation rate of the second permeate (i.e., the rate at which it permeates the reverse osmosis membrane). Simultaneously, the outflow volume of the second permeate is controlled to be equal to the volume of deoxygenated water added; that is, the amount of second permeate flowing out is equal to the amount of deoxygenated water entering, maintaining a constant liquid level in the buffer tank. Circulation and filtration continue until the alcohol content of the washed beer in the buffer tank decreases to a preset value (i.e., the target alcohol content), at which point filtration stops. For example, in this process, the outlet pressure of the second high-pressure pump is controlled at 5~30 bar, and the cooling temperature of the cooler is controlled within the range of 5~20°C.

[0052] 4) Blending: Close the first, second, and fourth valves, and open the third valve to introduce deoxygenated water into the buffer tank to blend the filtered beer obtained after the washing process until the alcohol content in the buffer tank is ≤0.5 vol%. The beer remaining in the buffer tank at this point is the finished dealcoholized beer. If the taste of the finished dealcoholized beer remaining in the buffer tank is unsatisfactory, open the second valve again to introduce a small amount of the original beer (e.g., sake or fermentation liquid) into the buffer tank for further blending. This ensures that the alcohol content in the buffer tank is ≤0.5 vol% while increasing the content of flavor compounds, thus improving the product's taste. The beer remaining in the buffer tank at this point is the finished dealcoholized beer with improved taste.

[0053] If blending with original beer is required, the alcohol content in the buffer tank after adding deoxygenated water needs to be further reduced from 0.5 vol%, to 0.3 vol% or 0.4 vol%. This is because the original beer typically contains around 5 vol% alcohol, and adding it will increase the alcohol content in the buffer tank. Therefore, to ensure the final product's alcohol content is ≤0.5 vol%, the alcohol content in the buffer tank needs to be further reduced from 0.5 vol% after adding deoxygenated water. Then, close the second and third valves, open the fourth and first valves, and finally remove the finished dealcoholized beer from the buffer tank.

[0054] According to another specific embodiment of this application, the membrane core includes: a spiral wound polyamide reverse osmosis composite membrane, or a cellulose acetate reverse osmosis membrane, or a nanofiltration membrane.

[0055] By employing the above technical solution and using a reverse osmosis membrane as the filtration medium, large molecules can be retained to the maximum extent on the concentration side during the filtration of water and ethanol. Specifically, the reverse osmosis membrane used in the membrane core of this invention is not limited to spiral-wound polyamide composite membranes; other types of reverse osmosis membranes can also be used, such as cellulose acetate membranes, or a separate nanofiltration membrane module can be used. Nanofiltration membranes have larger pores than reverse osmosis membranes, resulting in faster filtration and a correspondingly lower rejection rate for large molecules and flavor compounds. Provided that the requirements for alcohol content and taste of the final product are met, nanofiltration membranes can also be used in this system, as their de-alcoholization principle is the same as that of reverse osmosis membranes.

[0056] For example, a separate nanofiltration membrane module can also be used. For instance, multiple nanofiltration membrane cores can be placed in a membrane housing, and multiple membrane housings can be connected in parallel or in series for filtration. This method can also be applied to this invention, and the specific parameters can be adapted according to the actual original beer parameters.

[0057] For example, the membrane housing in the reverse osmosis membrane system has a barrel-shaped structure. The barrel-shaped structure facilitates the stacking of membrane cores and can guide the beer to flow in the direction of the membrane housing's extension, which helps to increase the efficiency of reverse osmosis membrane filtration.

[0058] According to another specific embodiment of this application, a recovery device is also included, which is connected to the permeate outlet pipe to recover ethanol and flavoring substances from the first and second permeates discharged from the reverse osmosis membrane system.

[0059] By adopting the above technical solution, since the first permeate discharged during the pre-concentration process and the second permeate discharged during the washing and filtration process contain a large amount of alcohol and a small amount of macromolecular substances and flavor substances, the energy consumption of beer dealcoholization can be reduced by recovering the ethanol and a small amount of flavor substances through the recovery device.

[0060] For example, ethanol and flavor substances can be recovered by means of "pervaporation", "adsorption-desorption" or "(reduced pressure) distillation", etc. The specific operation can be referred to the existing "pervaporation", "adsorption-desorption" or "(reduced pressure) distillation" process, and this application does not impose any specific restrictions on it.

[0061] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0062] Figure 1 shows a schematic diagram of a system for producing non-alcoholic beer using a reverse osmosis membrane according to an embodiment of the present invention;

[0063] Figure 2 shows a flowchart of a method for producing non-alcoholic beer using a reverse osmosis membrane according to an embodiment of the present invention.

[0064] In the picture:

[0065] S100 Step 1; S200 Step 2; S300 Step 3;

[0066] 10 Buffer tank; 20 Deoxygenated water tank; 30 Reverse osmosis system; 41 First high-pressure pump; 42 Second high-pressure pump; 50 Cooler;

[0067] 101 First valve; 102 Second valve; 103 Third valve; 104 Fourth valve;

[0068] 201 First inlet pipe; 202 Second inlet pipe; 203 Third inlet pipe; 204 First outlet pipe;

[0069] 301 Permeate outlet pipe; 302 Concentrate outlet pipe;

[0070] 501 Import end; 502 Export end;

[0071] 60 Recycling Unit. Detailed Implementation

[0072] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0073] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0074] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0075] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0076] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0077] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0078] Existing methods for producing dealcoholized beer suffer from significant loss of flavor compounds, slow dealcoholization efficiency, and high energy consumption. This invention provides a method for producing non-alcoholic beer using reverse osmosis membranes. This method maximizes the retention of flavor compounds in the original beer, while achieving high dealcoholization efficiency, low total deoxygenated water consumption, and reduced energy consumption. Reverse osmosis membrane separation offers advantages such as small footprint, modular operation, and energy efficiency. Furthermore, reverse osmosis dealcoholization can be performed at low temperatures, preventing thermal denaturation of flavor compounds and preserving the original flavor of the finished dealcoholized beer. This provides a unique advantage in the production of non-alcoholic beer.

[0079] For example, the flavor substances mentioned above include, but are not limited to: proteins, vitamins, esters (such as ethyl acetate, isobutyl acetate, ethyl hexanoate, etc.), or acetic acid and some higher acids (such as isovaleric acid, hexanoic acid, octanoic acid, etc.), or n-propanol, isopropanol and some higher alcohols (such as isopentanol, phenylethyl alcohol, etc.).

[0080] Specifically, to solve the above-mentioned technical problems, the embodiments of the present invention disclose a method and system for producing non-alcoholic beer using reverse osmosis membranes. The method adopts the "pre-concentration-washing-blending" approach, which can retain the flavor substances in the original beer to the greatest extent, and has high dealcoholization efficiency, consumes less total deoxygenated water, and reduces the energy consumption of the dealcoholization process.

[0081] This application discloses a system for producing non-alcoholic beer. Referring to FIG1, the system includes:

[0082] The buffer tank 10 includes: a first inlet pipe 201 with a second valve 102, a second inlet pipe 202 with a third valve 103, a third inlet pipe 203 with a third valve 103, and a first outlet pipe 204 with a fourth valve 104.

[0083] The deoxygenated water tank 20 is connected to the second inlet pipe 202, and the third valve 103 is used to control the amount and rate of addition of deoxygenated water.

[0084] The reverse osmosis membrane system is equipped with a membrane housing containing multiple membrane elements connected in series or in parallel, including a beer liquid inlet pipe (connected to the outlet end 502 below), a permeate outlet pipe 301, and a concentrate outlet pipe 302. The concentrate outlet pipe 302 is connected to a third inlet pipe 203 to achieve circulation filtration.

[0085] Cooler 50 includes an inlet end 501 and an outlet end 502. The inlet end 501 is connected to the first outlet pipe 204, and the outlet end 502 is connected to the beer inlet pipe of the reverse osmosis membrane system, for introducing beer into the reverse osmosis membrane system.

[0086] A high-pressure pump is installed in the pipeline between the first outlet pipe 204 and the inlet end 501.

[0087] It should be noted that a reverse osmosis membrane system includes a reverse osmosis membrane. Substances that permeate through the reverse osmosis membrane are on the osmosis side, while those that do not are on the concentration side. The liquid on the concentration side is called concentrate, and the liquid on the osmosis side is called permeate. In this invention, the concentrate from the pre-concentration process is filtered multiple times to become pre-concentrated beer liquid, and the concentrate from the washing filtration process is filtered multiple times to become washed beer liquid. Furthermore, the permeate from the pre-concentration process is the aforementioned first permeate, and the permeate from the washing filtration process is the aforementioned second permeate.

[0088] In addition, the aforementioned system for producing non-alcoholic beer also includes a first valve 101. The first valve 101, the fourth valve 104, and the high-pressure pump are connected via a tee. The first valve 101 is used to discharge the finished dealcoholized beer. Furthermore, the high-pressure pump includes a first high-pressure pump 41 and a second high-pressure pump 42, which are connected in series. The pressure range of the second high-pressure pump 42 is greater than that of the first high-pressure pump 41. The first valve 101, the fourth valve 104, and the first high-pressure pump 41 are connected via a tee (e.g., a tee fitting).

[0089] The dealcoholization process of the above-mentioned system for producing non-alcoholic beer is as follows:

[0090] 1) Feeding: Close the first valve 101, the third valve 103, and the fourth valve 104, and open the second valve 102 to introduce the raw beer to be de-alcoholized into the buffer tank 10. When the beer volume in the buffer tank 10 reaches the preset value, close the second valve 102 to stop feeding. The first valve 101 controls the outflow of the finished de-alcoholized beer; the third valve 103 is opened when deoxygenated water needs to be added during the filtration process; the fourth valve 104 is closed until the raw beer volume in the buffer tank 10 reaches the preset value for pre-concentration, at which point it is opened again. Closing the fourth valve during feeding also prevents the raw beer from entering the reverse osmosis system 30.

[0091] It should be noted that the preset value in the aforementioned "when the beer volume in the buffer tank 10 reaches the preset value, close the second valve 102" is related to the actual volume of the original beer introduced into the buffer tank 10, the alcohol content of the dealcoholized beer, and the target concentration ratio, etc. This embodiment does not impose specific limitations on this.

[0092] 2) Pre-concentration: The original beer is repeatedly circulated and filtered between the buffer tank 10 and the reverse osmosis membrane system to obtain pre-concentrated beer and first permeate at the target concentration ratio. This process requires opening the fourth valve 104 and starting the first high-pressure pump 41 and the second high-pressure pump 42. The original beer in the buffer tank 10 is first pumped into the cooler 50 from the inlet end 501, and then enters the reverse osmosis membrane system from the outlet end 502. Under high pressure, water and ethanol permeate through the membrane and enter the permeate side to become the first permeate. The unpermeated concentrate remains on the concentration side and is transported back to the buffer tank 10. The first high-pressure pump 41 and the second high-pressure pump 42 pump the concentrate from the concentration side back into the cooler 50 and the reverse osmosis membrane system for circulation and de-alcoholization until the liquid level in the buffer tank 10 drops to the preset volume. The liquid remaining in the buffer tank is the pre-concentrated beer. The first step S100 pre-concentration ends when the pre-concentrated beer meets the target concentration ratio.

[0093] For example, in the above process, the outlet pressure range of the second high-pressure pump 42 is controlled at 20~50 bar, and the cooler 50 cools the original beer to 5~20°C, such as 8°C, 12°C, 16°C, etc. The temperature is controlled within this range in multiple cycles, and the final concentration ratio of the original beer is 1.2~4 times, such as 1.8, 2.2, etc. This concentration ratio is the ratio of the volume of the original beer to the volume of the pre-concentrated beer liquid obtained after the pre-concentration.

[0094] It should be noted that the preset volume in the aforementioned "until the liquid level in the buffer tank 10 drops to the preset volume" is related to the volume of the original beer introduced into the buffer tank 10, the alcohol content of the dealcoholized beer, and the target concentration ratio, etc. This embodiment does not make specific limitations on this.

[0095] 3) Washing and filtration: The working principle of this process is similar to the first step, S100 pre-concentration, except that deoxygenated water is added to the concentrate while it is being circulated and filtered. This process requires opening the third valve 103 to introduce deoxygenated water from the deoxygenated water tank 20 into the buffer tank 10. The rate at which the deoxygenated water is added is controlled to be equal to the permeate rate of the second permeate (i.e., the rate at which it permeates the reverse osmosis membrane). Simultaneously, the outflow volume of the second permeate is controlled to be equal to the volume of deoxygenated water added; that is, the amount of deoxygenated water added equals the amount of permeate flowing out, to maintain a constant liquid level in the buffer tank 10. Circulation and filtration continue until the alcohol content of the washed beer in the buffer tank 10 decreases to a preset value (i.e., the target alcohol content), at which point filtration stops. During this process, the outlet pressure of the second high-pressure pump 42 is controlled at 5~30 bar, and the cooling temperature of the cooler 50 is controlled within the range of 5~20℃.

[0096] It should be noted that the preset value in the aforementioned "stop filtration when the alcohol content in the buffer tank 10 decreases to the preset value" is related to the volume of the original beer introduced into the buffer tank 10, the alcohol content of the dealcoholized beer, and the concentration ratio of the beer. It needs to be set according to actual adaptability. This embodiment does not impose specific restrictions on this.

[0097] 4) Blending: Close the first valve 101, the second valve 102, and the fourth valve 104, and open the third valve 103 to introduce deoxygenated water into the buffer tank 10 to blend the washed and filtered beer liquid obtained after the washing and filtering process until the alcohol content in the buffer tank 10 is ≤0.5 vol%. At this point, the beer liquid remaining in the buffer tank is the finished dealcoholized beer.

[0098] If the finished dealcoholized beer remaining in the buffer tank has an unsatisfactory taste, a second valve is opened to introduce a small amount of the original beer into the buffer tank for further blending. This ensures that the alcohol content in the buffer tank is ≤0.5 vol%, while simultaneously increasing the content of flavor compounds and other substances to improve the product's taste. At this point, the beer liquid remaining in the buffer tank is the finished dealcoholized beer.

[0099] For example, if the beer's taste is unsatisfactory and it needs to be blended with the original beer, the alcohol content in the buffer tank after adding deoxygenated water needs to be further reduced from 0.5 vol%, which could be 0.3 vol% or 0.4 vol%. This is because the original beer typically contains about 5 vol% alcohol, and adding more original beer will increase the alcohol content of the liquid in the buffer tank. Therefore, to ensure that the final product's alcohol content is ≤0.5 vol%, the alcohol content in the buffer tank after adding deoxygenated water needs to be further reduced from 0.5 vol%. Then, the second valve 102 and the third valve 103 are closed, and the fourth valve 104 and the first valve 101 are opened. Finally, the finished dealcoholized beer is removed from the buffer tank 10.

[0100] According to another specific embodiment of this application, the aforementioned membrane core includes: a spiral wound polyamide reverse osmosis composite membrane, or a cellulose acetate reverse osmosis membrane, or a nanofiltration membrane.

[0101] By employing the above technical solution and using a reverse osmosis membrane as the filtration medium, large molecules can be retained to the maximum extent on the concentration side during the filtration of water and ethanol. Specifically, the reverse osmosis membrane used in the membrane core of this invention is not limited to spiral-wound polyamide composite membranes; other types of reverse osmosis membranes can also be used, such as cellulose acetate membranes, or a separate nanofiltration membrane module can be used. Nanofiltration membranes have larger pores than reverse osmosis membranes, resulting in faster filtration and a correspondingly lower rejection rate for large molecules, flavor compounds, etc. Provided that the requirements for alcohol content and taste of the final product are met, nanofiltration membranes can also be used in this system, as their de-alcoholization principle is the same as that of reverse osmosis membranes.

[0102] For example, a separate nanofiltration membrane module can also be used. For instance, multiple nanofiltration membrane cores can be placed in a membrane housing, and multiple membrane housings can be connected in parallel or in series for filtration. This method can also be applied to this invention, and the specific parameters can be adapted according to the actual original beer parameters.

[0103] For example, the membrane housing in the aforementioned reverse osmosis membrane system can be a barrel-shaped structure. The barrel-shaped structure facilitates the stacking of membrane cores and can guide the beer to flow in the direction of the membrane housing's extension, which helps to increase the efficiency of reverse osmosis membrane filtration.

[0104] According to another specific embodiment of this application, a recovery device 60 is also included, which is connected to the permeate outlet pipe 301 to recover ethanol and flavoring substances from the first and second permeates discharged from the reverse osmosis membrane system.

[0105] By adopting the above technical solution, since the first permeate discharged during the pre-concentration process and the second permeate discharged during the washing and filtration process contain a large amount of alcohol and a small amount of macromolecular substances and flavor substances, the ethanol and a small amount of flavor substances in them can be recovered by the recovery device 60, which can reduce the energy consumption of beer dealcoholization.

[0106] For example, ethanol and flavor substances can be recovered by means of "pervaporation", "adsorption-desorption" or "(reduced pressure) distillation", etc. The specific operation can be referred to the existing "pervaporation", "adsorption-desorption" or "(reduced pressure) distillation" process, and this application does not impose any specific restrictions on it.

[0107] Referring to Figure 2, the present invention also discloses a method for producing non-alcoholic beer using a reverse osmosis membrane, comprising:

[0108] Pre-concentration involves passing a predetermined volume of raw beer into a reverse osmosis membrane system for circulation and filtration under first pressure and first temperature conditions to obtain pre-concentrated beer liquid and first permeate at the target concentration ratio.

[0109] Washing and filtration: Deoxygenated water is introduced into the pre-concentrated beer liquid and circulated for filtration under the second pressure and the first temperature to obtain the washed beer liquid and the second permeate with the target alcohol content. The second pressure is lower than the first pressure.

[0110] Blending involves adding deoxygenated water to the filtered beer liquid or adding a small amount of original beer to the filtered beer liquid after adding deoxygenated water to adjust the flavor of the final product and obtain the finished dealcoholized beer.

[0111] In this process, the first and second permeate are discharged from the reverse osmosis membrane system. As described above, the first step S100, pre-concentration, involves filtering a predetermined volume of raw beer at a first pressure and a first temperature, allowing small molecules such as water and ethanol to pass through the reverse osmosis membrane to the permeate side as the first permeate, while flavor compounds and large molecules are retained by the membrane to the concentration side. As filtration proceeds, the level of the raw beer decreases. Once the level of the raw beer has decreased to meet the target concentration ratio, the second step S200, washing filtration, is then performed.

[0112] The main purpose of step S100 is to increase the alcohol content in the concentrate on the concentration side, which is beneficial for improving the de-alcoholization rate of alcohol during the washing and filtration process in step S200. The reason for the increase in alcohol content in the concentrate on the concentration side is that, since water molecules are smaller than ethanol molecules, the permeation rate of water molecules is much higher than that of ethanol molecules during filtration. Therefore, the concentration of ethanol in the pre-concentrated beer gradually increases as the pre-concentration process proceeds.

[0113] Step 2 S200: Washing and filtering. After the pre-concentration is completed, the pre-concentrated beer liquid left on the concentration side in Step 1 S100 is filtered under the second pressure and the first temperature while deoxygenated water is added to obtain the washed beer liquid and the second permeate with the target alcohol content.

[0114] The main purpose of the second step, S200, is to maintain a constant concentration of substances other than ethanol during the de-alcoholization process, preventing increased permeation loss due to the increased concentration of these substances (such as flavor compounds). As the concentration of these substances increases, more of them dissolve in the membrane, leading to greater permeation and a lower rejection rate of the reverse osmosis membrane. This results in an increased concentration of substances permeating into the second permeate, causing further loss of flavor compounds.

[0115] In this step, it is necessary to control the outflow volume of the second permeate to be equal to the volume of deoxygenated water added. For example, if the total outflow of water and ethanol is 1L, then 1L of deoxygenated water should be added during filtration to maintain the original liquid level. At the same time, the flow rate of deoxygenated water should be controlled to be equal to the flow rate of the filtered beer liquid through the reverse osmosis membrane. Adding deoxygenated water too quickly will reduce the de-alcoholization efficiency, while adding it too slowly will increase the loss of flavor substances.

[0116] The third step, S300, involves adding deoxygenated water or the original beer to the washed and filtered beer liquid obtained in step two to adjust the alcohol content or flavor of the beer, thus obtaining the finished dealcoholized beer.

[0117] The main purpose of step S300 is to control the alcohol content of the final product, the dealcoholized beer, and to maintain its taste and flavor. It also helps to recover some of the flavor compounds lost in step S200.

[0118] Specifically, the ethanol content in the filtered beer liquid obtained in step S200 needs to be slightly higher than that in the finished dealcoholized beer to allow for adjustment of alcohol content in step S300. The aforementioned preset alcohol content is generally 0.5 vol%.

[0119] For example, suppose 100L of raw beer is processed in the first step S100 pre-concentration to obtain 50L of pre-concentrated beer liquid; at the end of the second step S200 washing and filtering, the alcohol concentration of the filtered beer liquid with the target alcohol content is less than 1% or less than 0.8%, so that when 50L of deoxygenated water is added in the third step S300 blending, the alcohol concentration of the finished dealcoholized beer will be less than the target 0.5%. At the same time, because a small amount of sake or fermentation liquid is added in the third step S300 to adjust the final taste and flavor, the ethanol content at the end of the second step S200 needs to be even lower.

[0120] It should be noted that the pre-concentration and filtration of this invention at low temperatures can prevent the thermal denaturation of flavor compounds in beer, thus preserving the original flavor of the finished dealcoholized beer. However, the temperature during pre-concentration and filtration should not be too low, for example, below 5°C, because excessively low temperatures will increase the loss of flavor compounds and slow down ethanol permeation, prolonging the beer dealcoholization time. Specifically, excessively low temperatures will increase the solubility of flavor compounds such as esters in the membrane, meaning that flavor compounds are more likely to dissolve in the membrane and diffuse away at excessively low temperatures. In addition, if the temperature is too low, the permeation rate of various substances, including ethanol, will decrease, reducing the permeation flux, thus greatly prolonging the dealcoholization time; the increased dealcoholization time also increases the interaction time between flavor compounds and the reverse osmosis membrane, further increasing the loss of flavor compounds. The aforementioned low-temperature environment is the first temperature environment described later.

[0121] In addition, the aforementioned first and second permeate solutions can be collected for subsequent recovery of ethanol and flavor compounds.

[0122] According to another specific embodiment of this application, the aforementioned first temperature range is 5~20℃, for example 8℃, 12℃, 16℃, etc. Furthermore, in the first step S100, the first pressure is controlled within the range of 20~50 bar, for example 35 bar, 28 bar, etc., while in the second step S200, the second pressure is controlled on average within the range of 5~30 bar.

[0123] Using the above technical solution, this application controls the loss of flavor substances by controlling the pressure and temperature at different stages. Because increasing the pre-concentration operating pressure increases the permeation rate of various substances during the permeation process, but the increase in water permeation rate is greater than that of ethanol and flavor substances. Therefore, the retention rate of ethanol and other macromolecular substances increases with higher operating pressure. Thus, using a higher operating pressure for the first step, S100 pre-concentration, is beneficial for rapid ethanol concentration and shortens the operation time; it also helps retain macromolecular substances such as proteins and flavor substances, improving the taste of the final product, the dealcoholized beer.

[0124] It should be noted that although higher operating pressure is beneficial for increasing the permeation rate, the operating pressure used in the second step, S200 washing and filtration, needs to be lower compared to the first step, S100 pre-concentration. This is because increasing the operating pressure in the second step, S200 washing and filtration, would increase the water permeation rate more significantly than the ethanol permeation rate. Therefore, if the second step, S200 washing and filtration, still uses a higher operating pressure, the amount of deoxygenated water required to reach the target alcohol content will increase substantially. Simultaneously, using a higher operating pressure in the second step, S200 washing and filtration, would greatly prolong the time required to reach the target alcohol content. Increased washing and filtration time leads to greater loss of flavor compounds. Therefore, the operating pressure in the second step, S200 washing and filtration, should be appropriately lowered (i.e., the second pressure should be lower than the first pressure). This reduces the amount of deoxygenated water used during washing and filtration and shortens the dealcoholization time, which helps maintain the content of flavor compounds in the finished dealcoholized beer.

[0125] According to another specific embodiment of this application, the volume fraction of the preset alcohol content is ≤0.5 vol.

[0126] Using the above technical solution, an alcohol volume fraction of 0.5 vol% for dealcoholized beer is an alcohol content index for dealcoholized beer in the industry. Of course, this invention can be applied to the dealcoholization of other types of beer, that is, it is applicable to the production of beer with different alcohol contents, and is not limited to alcohol content ≤0.5 vol%.

[0127] According to another specific embodiment of this application, during the washing and filtration process, the second pressure segment is set as a first partial pressure, a second partial pressure, and a third partial pressure, and the washing and filtration are completed sequentially at the first partial pressure, the second partial pressure, the third partial pressure, and the first temperature; the range of the first partial pressure is 22~30 bar, the range of the second partial pressure is 14~22 bar, and the range of the third partial pressure is 5~14 bar.

[0128] Alternatively, the second pressure segment can be set as the fourth and fifth partial pressures. During the washing and filtration process, the washing and filtration is completed sequentially at the fourth partial pressure, the fifth partial pressure, and the first temperature. The range of the fourth partial pressure is 18~30 bar, and the range of the fifth partial pressure is 5~18 bar.

[0129] For example, during filtration, the filter is sequentially subjected to a first partial pressure of 25 bar, a second partial pressure of 20 bar, and a third partial pressure of 10 bar, i.e., filtration is performed at these three pressures for a period of time; or, during filtration, the filter is sequentially subjected to a fourth partial pressure of 23 bar and a fifth partial pressure of 17 bar, i.e., filtration is performed at these two pressures for a period of time. Of course, other values ​​within the aforementioned pressure range are also acceptable, and this embodiment does not impose specific limitations on them.

[0130] By adopting the above technical solution, segmented pressure control helps to minimize the total amount of deoxygenated water used. As the filtration time increases, the alcohol concentration decreases. If the same operating pressure is maintained continuously, more water will permeate while less alcohol permeates, making alcohol removal increasingly difficult. Therefore, segmented pressure control, with the operating pressure gradually decreasing, allows for the use of less deoxygenated water to achieve the same amount of alcohol permeation, thus reducing the total amount of deoxygenated water used and consequently reducing the energy consumption of the de-alcoholization process.

[0131] According to another specific embodiment of this application, the target is condensed to 1.2~4, for example 1.8, 2.2, etc.

[0132] By adopting the above technical solution, appropriately increasing the concentration ratio of the first step S100 pre-concentration, for example, within 4 times, can reduce the amount of deoxygenated water used in the second step S200 filtration process and reduce the loss of flavor substances, thus increasing the content of flavor substances in the finished dealcoholized beer. However, the concentration ratio cannot be too high; otherwise, a large amount of deoxygenated water will need to be added for blending, affecting the product's taste. For example, if 100L of original beer is pre-concentrated to obtain 40L of pre-concentrated beer liquid, and only 20L of pre-concentrated beer liquid is obtained, then too much deoxygenated water needs to be added in the third step S300, resulting in a bland taste in the finished dealcoholized beer.

[0133] To make the above description of the present invention more apparent and understandable, several preferred embodiments of the dealcoholization process are described in detail below.

[0134] Example 1: Comparison of parameters of finished dealcoholized beer obtained under different dealcoholization processes.

[0135] 400L of German wheat beer (brand: Fresh Beer 30km) was dealcoholized by direct washing and filtration at 25 bar pressure, consuming 20hl (hectoliters) of deoxygenated water. At the end of the washing and filtration process, the alcohol concentration in the resulting beer was 1.51 vol%. However, when using the "pre-concentration + washing and blending" method provided in this application to dealcoholize 400L of German wheat beer (brand: Fresh Beer 30km), pre-concentration was performed at a concentration ratio of 1.68 and a pressure of 25 bar, followed by washing and filtration at 25 bar. When 18hl (hectoliters) of deoxygenated water was used, the alcohol concentration in the washed beer became 1.19 vol.

[0136] The specific comparison parameters are shown in Table 1 below:

[0137] Table 1. Comparison of relevant parameters for processing the same volume of original beer using different methods.

[0138]

[0139] As can be seen from the above comparison, under the same operating pressure, the "concentration + washing and filtration + blending" method of producing non-alcoholic beer using reverse osmosis membranes proposed in this application can improve the ethanol removal rate and reduce the amount of deoxygenated water used.

[0140] Example 2: The effect of different operating temperatures on the parameters of the finished dealcoholized beer.

[0141] 400L of German wheat beer (brand: Fresh Beer 30km) was pre-concentrated under operating conditions of 16℃, 30 bar, and a concentration ratio of 1.43. Then, the pressure range of the second step, S200 filtration, was controlled between 12 and 20 bar, and 20hl (100 liters) of deoxygenated water was used for filtration. After filtration, the beer entered the blending process. The final product, a dealcoholic beer, had an alcohol content of 0.33 vol%, an original wort concentration of 4.8°P, and a color of 8.8 EBC. Under the same conditions, but with the operating temperature reduced to 11℃, the resulting dealcoholic beer had an alcohol content of 0.42 vol%, an original wort concentration of 4.9°P, and a color of 8.9 EBC. All these indicators are superior to those obtained at the 16℃ operating temperature.

[0142] It should be noted that when the operating temperature is reduced from 16℃ to 11℃, the total time for dehydrogenation is extended from 5.4 hours to 6 hours.

[0143] The specific comparison parameters are shown in Table 2 below:

[0144] Table 2 Comparison of the effects of different operating temperatures on the parameters of the finished dealcoholized beer

[0145]

[0146] As shown in the table above, the lower the operating temperature, the longer the de-alcoholization time. This confirms what was mentioned earlier: if the operating temperature is too low, the permeation rate of various substances, including ethanol, will decrease, the permeation flux will decrease, and the de-alcoholization time will be greatly extended.

[0147] Example 3: The effect of different operating pressures on de-alcoholization during the pre-concentration process.

[0148] 400L of German wheat beer (brand: Fresh Beer 30km) was de-alcoholized at an operating temperature of 13℃ and a concentration ratio of 1.33. When the first step of S100 pre-concentration was carried out at a pressure of 26 bar, the alcohol content of the pre-concentrated beer obtained at the end of the pre-concentration was 5.03 vol%, and the actual residual sugar concentration was 6.21 wt%. The entire de-alcoholization process required 28 hl (hectoliters) of deoxygenated water. The final de-alcoholized beer had an ethanol content of 0.48 vol% and an average loss rate of 30% of flavor substances.

[0149] In addition, 370L of German wheat beer (brand: Fresh Beer 30km) was de-alcoholized at an operating temperature of 15℃ and an concentration ratio of 1.48. When the first step of S100 pre-concentration was carried out at a pressure of 30 bar, the alcohol content of the pre-concentrated beer obtained at the end of the pre-concentration was 5.27 vol% and the actual residual sugar concentration was 6.57 wt%. The entire de-alcoholization process required 20 hl (hectoliters) of deoxygenated water. The final de-alcoholized beer had an alcohol content of 0.42 vol% and an average loss rate of 28% of flavor substances.

[0150] As can be seen from the above, the use of higher pressure in the first step of S100 pre-concentration is beneficial to concentrate ethanol to a higher concentration value, increase the actual residual sugar concentration, reduce the amount of deoxygenated water used in the subsequent washing and filtration process, and reduce the loss of flavor substances throughout the process.

[0151] Example 4: The effect of the washing and filtration operating pressure being lower than the pre-concentration pressure on de-alcoholization.

[0152] Although high pressure is beneficial to increase the permeation rate, the second step S200 washing filter should use a lower pressure compared to the first step S100 pre-concentration. The average operating pressure range of the second step S200 washing filter in this invention is between 5 and 30 bar.

[0153] For example, when processing 400L of German wheat beer (brand: Fresh Beer 30km), if the first step, S100 pre-concentration, is performed at an operating pressure of 28 bar to concentrate the original beer to 165L, and the second step, S200 filtration, is performed at an operating pressure of 35 bar, that is, the second pressure is greater than the first pressure. When the amount of deoxygenated water used is 20hl (hectoliters), the alcohol concentration in the beer is 1.17 vol. However, if the first step, S100 pre-concentration, is performed at an operating pressure of 26 bar to concentrate the beer to 300L, and the pressure range of the second step, S200 filtration, is controlled within 16~20 bar, that is, the second pressure is less than the first pressure. When the amount of deoxygenated water used is 20hl (hectoliters), the alcohol concentration in the beer is reduced to 0.9 vol.

[0154] As can be seen from the above, the pressure of the second step S200 washing filter (i.e., the second pressure) is lower than the pressure of the first step S100 pre-concentration (i.e., the first pressure), which is conducive to rapid de-alcoholization and shortens the operation time; at the same time, it reduces the loss of macromolecular substances such as proteins and flavor substances, and improves the taste of the final de-alcoholized beer.

[0155] For example, since the second step S200 filtration takes a relatively long time, it is advisable to adopt a segmented filtration process with segmented pressure control and a gradually decreasing pressure. This helps to minimize the total amount of deoxygenated water used. It is understood that as the filtration process progresses, the alcohol concentration decreases. If the same pressure is continuously applied, relatively more water will permeate while less alcohol will permeate. Therefore, using staged pressure reduction allows the second step S200 filtration to achieve the same amount of alcohol permeation with less deoxygenated water.

[0156] Specifically, in the second step of the S200 filter washing process, the operating pressure can be divided into three segments, such as the first partial pressure, the second partial pressure, and the third partial pressure. The range of the first partial pressure is 22~30 bar, the range of the second partial pressure is 14~22 bar, and the range of the third partial pressure is 5~14 bar.

[0157] Alternatively, the operating pressure can be divided into two segments, such as the fourth and fifth partial pressures. The pressure range of the fourth partial pressure is 18 to 30 bar, and the pressure range of the fifth partial pressure is 5 to 18 bar.

[0158] Example 5: The effect of different concentration ratios on de-alcoholization.

[0159] The concentration ratio of the present invention (i.e., the ratio of the original beer volume to the volume of the finished dealcoholized beer after concentration) is specifically between 1.2 and 4 times.

[0160] 400L of German wheat beer (brand: Fresh Beer 30km) was de-alcoholized at an operating temperature of 16℃. The operating pressure of the first step S100 pre-concentration (i.e., the first pressure mentioned above) was 30 bar. When the concentration ratio was 1.43, the pressure range of the second step S200 washing filter (i.e., the second pressure mentioned above) was 12~20 bar. A total of 20hl (hectoliters) of deoxygenated water was required for washing and filtration. The final blended non-alcoholic beer had an alcohol content of 0.33 vol% and an original wort concentration of 4.8°P. The average loss rate of flavor substances, including esters and higher alcohols, was 39%.

[0161] Under the same conditions, when the concentration factor of the first step S100 pre-concentration is increased to 2 times, the total amount of deoxygenated water required in the dealcoholization process is 12hl (100 liters). The final product dealcoholized beer has an alcohol content of 0.49 vol% and an original wort concentration of 6.0°P. The average loss rate of flavor substances, including esters and higher alcohols, is 31%.

[0162] The specific comparison parameters are shown in Table 3 below:

[0163] Table 3. Comparison of parameters after dealcoholization treatment at different concentration ratios

[0164]

[0165] As shown in the table above, increasing the concentration factor of the first step S100 pre-concentration can reduce the amount of deoxygenated water used in the dealcoholization process, which is beneficial to maintaining the content of flavor substances in the finished dealcoholized beer and increasing the original wort concentration in the finished dealcoholized beer.

[0166] It should be noted that the concentration ratio mentioned above cannot be too high, otherwise more deoxygenated water will need to be added for blending, which will affect the taste of the final product, the dealcoholized beer. The concentration ratio in this application can be any value between 1.2 and 4. For example, the concentration ratio in this application can be 1.5, 2, 2.5, 3, 3.5, etc.

[0167] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A method for producing non-alcoholic beer using a reverse osmosis membrane, characterized in that, include: Pre-concentration involves passing a predetermined volume of raw beer into a reverse osmosis membrane system for circulation and filtration under first pressure and first temperature conditions to obtain pre-concentrated beer liquid and first permeate at the target concentration ratio. Washing and filtration: Deoxygenated water is introduced into the pre-concentrated beer liquid, and simultaneously, the liquid is circulated and filtered under a second pressure and a first temperature to obtain a washed beer liquid with the target alcohol content and a second permeate, wherein the second pressure is lower than the first pressure; Blending: Deoxygenated water is added to the washed beer liquid to bring it to a preset alcohol content, or the original beer is added to the washed beer liquid after the addition of deoxygenated water to blend the product flavor, thereby obtaining the finished dealcoholized beer; wherein, the first permeate and the second permeate are discharged from the reverse osmosis membrane system.

2. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 1, characterized in that, During the washing and filtration process, the outflow volume of the second permeate is controlled to be equal to the volume of deoxygenated water added.

3. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 2, characterized in that, The flow rate of the added deoxygenated water is controlled to be equal to the flow rate of the washed beer liquid permeating through the reverse osmosis membrane.

4. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 1, characterized in that, The first pressure ranges from 20 to 50 bar; the first temperature ranges from 5 to 20°C.

5. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 1, characterized in that, The average range of the second pressure is 5~30 bar.

6. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 1, characterized in that, The preset alcohol content has a volume fraction of ≤0.5 vol.

7. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 5, characterized in that, During the washing and filtration process, the second pressure segment is set as a first partial pressure, a second partial pressure, and a third partial pressure, and the washing and filtration is completed sequentially under the first partial pressure, the second partial pressure, and the third partial pressure; the range of the first partial pressure is 22~30 bar, the range of the second partial pressure is 14~22 bar, and the range of the third partial pressure is 5~14 bar.

8. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 5, characterized in that, During the washing and filtration process, the second pressure segment is set to a fourth partial pressure and a fifth partial pressure, and the washing and filtration is completed sequentially under the fourth partial pressure and the fifth partial pressure; the range of the fourth partial pressure is 18~30 bar, and the range of the fifth partial pressure is 5~18 bar.

9. The method for producing non-alcoholic beer using a reverse osmosis membrane according to claim 1, characterized in that, The target concentration factor is 1.2 to 4.

10. A system for producing non-alcoholic beer, characterized in that, The method for producing non-alcoholic beer using a reverse osmosis membrane according to any one of claims 1-9, wherein the system for producing non-alcoholic beer comprises: a buffer tank, including: a first inlet pipe with a second valve, a second inlet pipe with a third valve, a third inlet pipe, and a first outlet pipe with a fourth valve; a deoxygenated water tank connected to the second inlet pipe, wherein the third valve is used to control the amount and rate of addition of deoxygenated water; a reverse osmosis membrane system, comprising a membrane housing containing multiple membrane elements connected in series or parallel, including a permeate outlet pipe, a concentrate outlet pipe, and a beer inlet pipe, wherein the concentrate outlet pipe is connected to the third inlet pipe to achieve circulating filtration; a cooler, including an inlet end and an outlet end, wherein the inlet end is connected to the first outlet pipe, and the outlet end is connected to the beer inlet pipe of the reverse osmosis membrane system; and a high-pressure pump disposed between the first outlet pipe and the inlet end.

11. The system for producing non-alcoholic beer according to claim 10, characterized in that, It also includes a first valve, and the first valve, the fourth valve, and the high-pressure pump are connected by a tee.

12. The system for producing non-alcoholic beer according to claim 11, characterized in that, The high-pressure pump includes a first high-pressure pump and a second high-pressure pump. The first valve, the fourth valve, and the first high-pressure pump are connected by a tee. The first high-pressure pump and the second high-pressure pump are connected in series. The pressure range of the second high-pressure pump is greater than that of the first high-pressure pump.

13. The system for producing non-alcoholic beer according to claim 10, characterized in that, The membrane core includes: a spiral-wound polyamide reverse osmosis composite membrane, or a cellulose acetate reverse osmosis membrane, or a nanofiltration membrane.

14. The system for producing non-alcoholic beer according to claim 10, characterized in that, It also includes a recovery device connected to the permeate outlet pipe to recover ethanol and flavoring substances from the first and second permeates discharged from the reverse osmosis membrane system.

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