A method for preparing alcohol from licorice acidification waste liquid

Abstract

A method for preparing alcohol using glycyrrhizic acid waste liquid is disclosed, relating to the field of alcohol preparation. This invention treats the acidification waste liquid generated during the preparation of glycyrrhizic acid powder by separating most of the sulfates using a membrane separation device and concentrating the acidification waste liquid. Using this material as raw material, alcohol is prepared through cooking, saccharification, fermentation, and distillation. This method makes rational use of this resource and solves the problem of acidification waste liquid treatment during the production of glycyrrhizic acid powder, making it suitable for widespread promotion and application.

Description

Technical Field

[0001] This invention relates to the field of alcohol preparation, and more specifically to a method for preparing alcohol using licorice acidification waste liquid. Background Technology

[0002] Licorice is a perennial legume, and its roots and rhizomes are used medicinally. It is one of the four major medicinal materials under key supervision by the pharmaceutical industry. To date, my country is the world's largest consumer and exporter of licorice. my country uses over 200,000 tons of licorice annually, of which about 60% undergoes preliminary processing into glycyrrhizic acid powder. This powder is then further purified and sold worldwide. The annual wastewater generated from glycyrrhizic acid powder production exceeds 400,000 tons, containing over 8,000 tons of organic matter. Much of this organic matter is discharged after biodegradation, representing a waste of resources.

[0003] The process for preparing glycyrrhizic acid powder from licorice in its crude processing involves alkaline extraction and acid precipitation. This involves soaking pulverized licorice in alkaline water, separating the extracts after soaking, and typically extracting the licorice 3-5 times. The resulting extracts are then mixed, acid is added, and after settling, a precipitate forms – this precipitate is glycyrrhizic acid powder. This powder has a high glycyrrhizic acid content and can be sold as a crude processed product. The settled solution is generally called the acid-precipitating supernatant, and its typical treatment method is biodegradation to meet wastewater discharge standards before discharge. However, this method has several drawbacks:

[0004] 1. The extraction of glycyrrhizic acid powder requires a large amount of water, 8 to 10 times the amount of water, and 3 to 5 extractions. The amount of supernatant produced is very large, which puts great pressure on wastewater treatment and is costly.

[0005] 2. The supernatant mainly contains sugars (glucose, fructose, starch, sucrose, etc.), amino acids, etc., with a total sugar content of 40% to 50% and a protein content of 10% to 15%. Discharging it as waste liquid is a waste of resources.

[0006] With energy shortages and the need for sustainable development, finding new renewable energy sources has become an urgent issue. As a substitute for fossil fuels, fuel ethanol is easy to store and transport, and can be used as a vehicle fuel without changing existing refueling equipment and engine configurations. Therefore, the application scope and volume of ethanol are constantly expanding.

[0007] Currently, the main industrial method for producing fuel alcohol is through brewing yeast using sugar, primarily molasses and grains (wheat, corn) as raw materials. This method is costly and hampered by population growth and arable land loss. The supernatant from glycyrrhizic acid powder after acidification mainly consists of sugars and amino acids, meeting the requirements for raw materials in alcohol production. Therefore, providing a method for preparing alcohol using glycyrrhizic acidified waste liquid is particularly important. Summary of the Invention

[0008] To overcome the shortcomings of the prior art, the present invention provides a method for preparing alcohol using licorice acidification waste liquid. The present invention makes reasonable use of acidification waste liquid and solves the problem of acidification waste liquid treatment in the production process of glycyrrhizic acid powder.

[0009] To achieve the aforementioned inventive objectives, the present invention employs the following technical solution:

[0010] A method for preparing alcohol from licorice acidification waste liquid, the method specifically includes the following steps:

[0011] Step 1, Preprocessing:

[0012] The crushed licorice is soaked in alkaline water. After soaking, the extract is separated. The licorice is extracted 3 to 5 times. The extracts are mixed and acid is added to the mixed extract for acid fixation. After acid fixation, the supernatant is allowed to stand for 20 to 28 hours to remove insoluble substances and obtain a solution. The solution is filtered to obtain acidified waste liquid. The acidified waste liquid is concentrated under reduced pressure, and excess sulfate in the solution is separated to avoid the effect of excessive salt on yeast during fermentation.

[0013] Step 2, steaming / boiling:

[0014] Add 10u / g to 15u / g of heat-resistant α-amylase and protease to the acidified waste liquid after vacuum concentration in the previous step for pre-cooking. The pre-cooking temperature is 50℃ to 60℃ and the pre-cooking time is 20min to 30min. After pre-cooking, heat to 95℃ to 105℃ and maintain for 90min to 120min to obtain liquefied mash.

[0015] Step 3, Saccharification:

[0016] After the liquefied mash is cooled to 50℃~65℃, it is put into the saccharification pot for saccharification to obtain saccharified mash, and then the saccharified mash is put into the fermentation tank;

[0017] Step 4: Activate the yeast:

[0018] Active dry yeast and process water are mixed in a predetermined ratio and then placed in a yeast activation tank for activation. The rehydration temperature is 30℃~35℃ and the activation time is 20min~30min. After activation, activated yeast is obtained. The activated yeast is pumped into an expansion tank and liquefied mash is added to the expansion tank for cultivation. After 6h~8h of cultivation, it is transferred to a fermentation tank. The inoculum is changed every 7~10 days.

[0019] Step 5: Fermentation

[0020] Activated yeast is added to the saccharified mash in the first fermentation tank at a mass concentration of 50mg / g to 70mg / g. After fermentation for 12 to 16 hours, 1 / 3 of the mash is transferred from the first fermentation tank to the second fermentation tank. Then, the first and second fermentation tanks are filled with material again for fermentation. After normal fermentation in the second fermentation tank for 12 to 16 hours, 1 / 3 of the mash is transferred to the third fermentation tank, which is then filled with material again for fermentation. This process is repeated to obtain mature mash, which has an alcohol concentration of ≥15% (v / v).

[0021] Step 6, Distillation:

[0022] Alcohol can be obtained by distilling the mature mash through conventional distillation.

[0023] In the method for preparing alcohol from licorice acidification waste liquid, the membrane used in the first step of membrane filtration is any one of nanofiltration 500, nanofiltration 1000, or reverse osmosis membrane.

[0024] In the method for preparing alcohol using licorice acidified waste liquid, the membrane pressure is set to 1-2 MPa during the first step of membrane filtration. When the solid content of the acidified waste liquid reaches 8%-12%, the membrane filtration is completed and the acidified waste liquid is collected.

[0025] In the method for preparing alcohol from licorice acidified waste liquid, in the first step, the acidified waste liquid is concentrated under reduced pressure at a concentration temperature of 60-80°C and a vacuum degree of -0.09--0.1 MPa until the solid content is 40%-50%.

[0026] In the method for preparing alcohol using licorice acidification waste liquid, the amount of saccharifying enzyme added in the third step of saccharification is 150u / g to 200u / g, the saccharification temperature is 50℃ to 65℃, and the saccharification time is 20min to 30min.

[0027] In the method for preparing alcohol using licorice acidification waste liquid, the weight ratio of active dry yeast to process water in the fourth step is 1:(15-25).

[0028] In the method for preparing alcohol using licorice acidification waste liquid, the weight ratio of activated yeast to liquefied mash in the fourth step is 1:(10-20).

[0029] By employing the technical solution described above, the present invention has the following advantages:

[0030] This invention treats the acidified waste liquid generated during the preparation of glycyrrhizic acid powder. Most of the sulfates are separated by a membrane separation device, and the acidified waste liquid is concentrated. Using this material as raw material, alcohol is prepared through cooking, saccharification, fermentation, and distillation. This invention makes rational use of this resource and solves the problem of acidified waste liquid treatment in the production of glycyrrhizic acid powder. It is suitable for widespread promotion and application. Detailed Implementation

[0031] The present invention can be explained in more detail through the following embodiments, but the present invention is not limited to the following embodiments;

[0032] The present invention discloses a method for preparing alcohol from licorice acidification waste liquid, the method specifically comprising the following steps:

[0033] Step 1, Preprocessing:

[0034] The pulverized licorice is soaked in alkaline water, and the extract is obtained after soaking. The licorice is extracted 3 to 5 times, and the resulting extracts are mixed. Then, acid is added to the mixed extract for acid fixation. After acid fixation, the supernatant is allowed to stand for 20 to 28 hours to remove insoluble substances and obtain a solution. The solution is then passed through a membrane device to obtain acidified waste liquid. The acidified waste liquid is concentrated under reduced pressure, and excess sulfate in the solution is separated to avoid the effect of excessive salt on yeast during fermentation.

[0035] In specific implementation, the membrane used during membrane filtration is any one of nanofiltration 500, nanofiltration 1000, or reverse osmosis membrane;

[0036] Furthermore, the membrane pressure is set to 1-2 MPa during the membrane pass, and the membrane pass ends when the solid content of the acidified waste liquid reaches 8%-12%, at which point the acidified waste liquid is collected.

[0037] Furthermore, when the acidified waste liquid is concentrated under reduced pressure, the concentration temperature is 60-80℃, the vacuum degree is -0.09 to -0.1 MPa, and the concentration is carried out until the solid content is 40%-50%.

[0038] Step 2, steaming / boiling:

[0039] Add 10u / g to 15u / g of heat-resistant α-amylase and protease to the acidified waste liquid after vacuum concentration in the previous step for pre-cooking. The pre-cooking temperature is 50℃ to 60℃ and the pre-cooking time is 20min to 30min. After pre-cooking, heat to 95℃ to 105℃ and maintain for 90min to 120min to obtain liquefied mash.

[0040] Step 3, Saccharification:

[0041] After the liquefied mash is cooled to 50℃~65℃, it is put into the saccharification pot for saccharification to obtain saccharified mash. During the saccharification process, the amount of saccharifying enzyme added is 150u / g~200u / g, the saccharification temperature is 50℃~65℃, and the saccharification time is 20min~30min. Then the saccharified mash is put into the fermentation tank.

[0042] Step 4: Activate the yeast:

[0043] Active dry yeast and process water are mixed in a predetermined ratio and then placed in a yeast activation tank for activation. Specifically, the weight ratio of active dry yeast to process water is 1:(15-25), the rehydration temperature is 30℃-35℃, and the activation time is 20-30 minutes. After activation, activated yeast is obtained. The activated yeast is pumped into an expansion tank, and liquefied mash is added to the expansion tank for cultivation. Specifically, the weight ratio of activated yeast to liquefied mash is 1:(10-20). After 6-8 hours of cultivation, the yeast is transferred to a fermentation tank, and the yeast is replaced every 7-10 days.

[0044] Step 5: Fermentation

[0045] Activated yeast is added to the saccharified mash in the first fermentation tank at a mass concentration of 50mg / g to 70mg / g. After fermentation for 12 to 16 hours, 1 / 3 of the mash is transferred from the first fermentation tank to the second fermentation tank. Then, the first and second fermentation tanks are filled with material again for fermentation. After normal fermentation in the second fermentation tank for 12 to 16 hours, 1 / 3 of the mash is transferred to the third fermentation tank, which is then filled with material again for fermentation. This process is repeated to obtain mature mash, which has an alcohol concentration of ≥15% (v / v).

[0046] Step 6, Distillation:

[0047] Alcohol can be obtained by distilling the mature mash through conventional distillation.

[0048] Specific embodiments of the present invention are as follows:

[0049] Specific example 1:

[0050] Step 1, Preprocessing:

[0051] The pulverized licorice was soaked in alkaline water, and the extract was obtained after soaking. The licorice was extracted three times, and the resulting extracts were mixed. Acid was then added to the mixed extract for acid fixation. After acid fixation, the supernatant was allowed to stand for 20 hours to remove insoluble substances and obtain a solution. The solution was then passed through a nanofiltration membrane with a membrane pressure of 1 MPa. During the membrane filtration process, the solid content of the acidified waste liquid was measured. When the solid content of the acidified waste liquid reached 8%, the membrane filtration was stopped, and the acidified waste liquid was collected. The acidified waste liquid was concentrated under reduced pressure at 60°C with a vacuum degree of -0.09 MPa until the solid content reached 40%, at which point the concentration was stopped, yielding 500 L of concentrated solution.

[0052] The test data for the acidified waste liquid are shown in the table below:

[0053]

[0054] Step 2, steaming / boiling:

[0055] Add heat-resistant α-amylase and protease at a ratio of 10u / g to the 500L concentrate obtained in the previous step for pre-cooking. The pre-cooking temperature is 50℃ and the pre-cooking time is 30min. After pre-cooking, heat to 95℃ and maintain for 90min to obtain liquefied mash.

[0056] Step 3, Saccharification:

[0057] After the liquefied mash is cooled to 65°C, it is put into the saccharification pot for saccharification to obtain saccharified mash. The amount of saccharifying enzyme added during the saccharification process is 150u / g, the saccharification temperature is 65°C, and the saccharification time is 20min.

[0058] Step 4: Activate the yeast:

[0059] Active dry yeast was added to the yeast activation tank at a weight ratio of 1:25 to process water for activation. The rehydration temperature was 35℃ and the activation time was 20 minutes. After activation, the yeast was pumped into the expansion tank and liquefied mash was added to the expansion tank at a weight ratio of 1:10 to activated yeast. The culture time was 6 hours. The yeast was then transferred to the fermentation tank and the yeast culture was changed every 7 days.

[0060] Step 5: Fermentation

[0061] Activated dry yeast is added to the saccharified mash in the first fermentation tank at a mass concentration of 70 mg / g. After fermentation for 16 hours, 1 / 3 of the mash is transferred from the first fermentation tank to the second fermentation tank. Then, the first and second fermentation tanks are filled with the same amount of material. After normal fermentation in the second fermentation tank for 16 hours, 1 / 3 of the mash is transferred to the third fermentation tank, which is then filled with the same amount of material and fermented. This process is repeated to obtain mature mash, which has an alcohol content greater than or equal to 15% (v / v).

[0062] Step 6, Distillation:

[0063] The mature mash is distilled, and alcohol is obtained through conventional distillation, yielding 62L of alcohol. Specific Implementation Example 2:

[0065] Step 1, Preprocessing:

[0066] The pulverized licorice was soaked in alkaline water, and the extract was obtained after soaking. The licorice was extracted 5 times, and the resulting extracts were mixed. Acid was added to the mixed extract for acid fixation. After acid fixation, the supernatant was allowed to stand for 28 hours to remove insoluble substances. The solution was then filtered through a nanofiltration membrane with a membrane pressure of 2 MPa. The solid content of the acidified waste liquid was measured during the filtration process. When the solid content of the acidified waste liquid reached 12%, the filtration was stopped, and the acidified waste liquid was collected. The acidified waste liquid was concentrated under reduced pressure at 80°C with a vacuum degree of -0.09 to -0.1 MPa until the solid content reached 50%. Concentration was then stopped, yielding 1000 L of concentrate.

[0067] The test data for the acidified waste liquid are shown in the table below:

[0068]

[0069] Step 2, steaming / boiling:

[0070] Add heat-resistant α-amylase and protease to the 1000L acidified waste liquid obtained in the previous step at a rate of 15u / g for pre-cooking. The pre-cooking temperature is 60℃ and the pre-cooking time is 20min. After pre-cooking, heat to 105℃ and maintain for 120min to obtain liquefied mash.

[0071] Step 3, Saccharification:

[0072] After the liquefied mash is cooled to 50°C, it is put into the saccharification pot for saccharification to obtain saccharified mash. The amount of saccharifying enzyme added during the saccharification process is 200u / g, the saccharification temperature is 50°C, and the saccharification time is 30min.

[0073] Step 4: Activate the yeast:

[0074] Active dry yeast was added to the yeast activation tank at a weight ratio of 1:15 between active dry yeast and process water. The rehydration temperature was 30℃ and the activation time was 30 minutes. After activation, the yeast was pumped into the expansion tank and liquefied mash was added to the expansion tank. The weight ratio of activated yeast to liquefied mash was 1:20. The culture time was 8 hours. The yeast was then transferred to the fermentation tank and the yeast was replaced every 10 days.

[0075] Step 5: Fermentation

[0076] Activated dry yeast is added to the saccharified mash in the first fermentation tank at a mass concentration of 50 mg / g. After fermentation for 12 hours, 1 / 3 of the mash is transferred from the first fermentation tank to the second fermentation tank. Then, the first and second fermentation tanks are filled with the same amount of material. After normal fermentation in the second fermentation tank for 12 hours, 1 / 3 of the mash is transferred to the third fermentation tank, which is then filled with the same amount of material and fermented. This process is repeated to obtain mature mash, which has an alcohol content greater than or equal to 15% (v / v).

[0077] Step 6, Distillation:

[0078] The mature mash is distilled, and alcohol is obtained through conventional distillation, yielding 121L of alcohol.

[0079] By applying this invention, the following prior art problems are solved:

[0080] 1. The problem of wastewater treatment in the preparation of glycyrrhizic acid powder has been solved. The substances in the solution are separated from the water by membrane concentration, and the organic matter in the solution is recovered. The water produced does not contain organic matter and can be directly discharged after pH neutralization.

[0081] 2. It realizes resource utilization. The organic matter in the supernatant of acidification is mostly sugar and protein, which are the main substances for alcohol production. It is prepared into alcohol through steps such as cooking, saccharification, fermentation and distillation, making full use of resources.

[0082] The parts of this invention not described in detail are prior art.

[0083] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A method for preparing alcohol from licorice acidification waste liquid, characterized in that: The method specifically includes the following steps: Step 1, Preprocessing: The crushed licorice is soaked in alkaline water. After soaking, the extract is separated. The licorice is extracted 3 to 5 times. The extracts are mixed and acid is added to the mixed extract for acid fixation. After acid fixation, the supernatant is allowed to stand for 20 to 28 hours to remove insoluble substances and obtain a solution. The solution is filtered to obtain acidified waste liquid. The acidified waste liquid is concentrated under reduced pressure, and excess sulfate in the solution is separated to avoid the effect of excessive salt on yeast during fermentation. Step 2, steaming / boiling: Add 10u / g to 15u / g of heat-resistant α-amylase and protease to the acidified waste liquid after vacuum concentration in the previous step for pre-cooking. The pre-cooking temperature is 50℃ to 60℃ and the pre-cooking time is 20min to 30min. After pre-cooking, heat to 95℃ to 105℃ and maintain for 90min to 120min to obtain liquefied mash. Step 3, Saccharification: After the liquefied mash is cooled to 50℃~65℃, it is put into the saccharification pot for saccharification to obtain saccharified mash, and then the saccharified mash is put into the fermentation tank; Step 4: Activate the yeast: Active dry yeast and process water are mixed in a predetermined ratio and then placed in a yeast activation tank for activation. The rehydration temperature is 30℃~35℃ and the activation time is 20min~30min. After activation, activated yeast is obtained. The activated yeast is pumped into an expansion tank and liquefied mash is added to the expansion tank for cultivation. After 6h~8h of cultivation, it is transferred to a fermentation tank. The inoculum is changed every 7~10 days. Step 5: Fermentation Activated yeast is added to the saccharified mash in the first fermentation tank at a mass concentration of 50mg / g to 70mg / g. After fermentation for 12 to 16 hours, 1 / 3 of the mash is transferred from the first fermentation tank to the second fermentation tank. Then, the first and second fermentation tanks are filled with material again for fermentation. After normal fermentation in the second fermentation tank for 12 to 16 hours, 1 / 3 of the mash is transferred to the third fermentation tank, which is then filled with material again for fermentation. This process is repeated to obtain mature mash, which has an alcohol concentration of ≥15% (v / v). Step 6, Distillation: Alcohol can be obtained by distilling the mature mash through conventional distillation.

2. The method for preparing alcohol from licorice acidification waste liquid according to claim 1, characterized in that: The membrane used in the first step is any one of nanofiltration 500, nanofiltration 1000, or reverse osmosis membrane.

3. The method for preparing alcohol from licorice acidification waste liquid according to claim 1, characterized in that: In the first step, the membrane pressure is set to 1-2 MPa during membrane filtration. When the solid content of the acidified waste liquid reaches 8%-12%, the membrane filtration ends and the acidified waste liquid is collected.

4. The method for preparing alcohol from licorice acidification waste liquid according to claim 1, characterized in that: In the first step, when the acidified waste liquid is concentrated under reduced pressure, the concentration temperature is 60-80℃, the vacuum degree is -0.09--0.1Mpa, and the concentration is carried out until the solid content is 40%-50%.

5. The method for preparing alcohol from licorice acidification waste liquid according to claim 1, characterized in that: In the third step of saccharification, the amount of saccharifying enzyme added is 150u / g to 200u / g, the saccharification temperature is 50℃ to 65℃, and the saccharification time is 20min to 30min.

6. The method for preparing alcohol from licorice acidification waste liquid according to claim 1, characterized in that: In the fourth step, the weight ratio of active dry yeast to process water is 1:(15-25).

7. The method for preparing alcohol from licorice acidification waste liquid according to claim 1, characterized in that: In the fourth step, the weight ratio of activated yeast to liquefied mash is 1:(10-20).

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