Organic acid extracted from distiller's grains and huangshui and extraction method

Abstract

Provided in the present invention are an organic acid extracted from distiller's grains and Huangshui and an extraction method. The extraction method comprises: using distiller's grains as raw materials, and repeatedly eluting same with Huangshui to obtain a eluent; squeezing the eluted distiller's grains to obtain a squeezed fluid, and performing pressure filtration on the squeezed fluid to obtain a filtrate; uniformly mixing the eluent and the filtrate to obtain a mixture, performing ultrafiltration on the mixture to obtain an ultrafiltrate, and successively performing nanofiltration and reverse osmosis on the ultrafiltrate to obtain a reverse osmosis concentrate; and performing reduced-pressure low-temperature distillation on the reverse osmosis concentrate to yield a high-content organic acid solution, wherein the organic acid solution can be used as a feed acidifier, an industrial preservative, a pH regulator, etc. The efficiency of the method extracting the organic acid from the distiller's grains is 50% higher than that in the prior art, and the organic acid in Huangshui is fully utilized. By means of a multi-stage membrane treatment process, the present invention increases the concentration of the liquid to 15-20%, and simplifies the subsequent distillation process, so that only one step of reduced pressure distillation is required, and the concentration of the organic acid can reach 60-70% after distillation, thereby reducing energy consumption required for distillation.

Description

Organic acid extracted from distiller's grains and yellow water and extraction method thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of resource recycling, in particular to an organic acid extracted from distiller's grains and yellow water and an extraction method thereof. BACKGROUND

[0002] Distiller's grains are the main by-product of the liquor industry. According to statistics, China's liquor industry produces about 100 million tons of distiller's grains per year. Due to incomplete fermentation and other reasons, distiller's grains contain residual starch, sugars, proteins, amino acids, organic acids and other substances that have not been fully utilized. The acid substances in distiller's grains are abundant and highly available, with a total acid content of 2%-4%. A large amount of yellow water is produced in the traditional solid-state brewing process, mainly because only sugars and starches in the raw materials are utilized during brewing, while other substances such as cellulose, proteins, and phenols are dissolved in the water environment of the fermented grains and directly deposited at the bottom of the pool during fermentation. These substances, along with the liquid produced by fermentation and the water content of the fermented grains, form the yellow water in traditional brewing. Therefore, the organic matter concentration in the yellow water produced by traditional solid-state fermentation is relatively high.

[0003] The yellow water typically contains 1-2% residual starch, 0.3-0.7% residual sugar, 4-5% ethanol, as well as a large amount of organic acids, alcohols, aldehydes, antioxidant active substances, humus, autolytic substances of yeast cells, microbial cells and living cells, etc., and has high use value.

[0004] Currently, the main treatment method for distiller's grains is to use them as feed in the breeding industry. The utilization of brewing yellow water mainly includes pit maintenance, bottom pot distillation, and organic acid extraction. The deep resource utilization rate of distiller's grains and yellow water is low, and the added value of the products is low. Based on this, the present application provides a method for extracting organic acids from distiller's grains and yellow water.

[0005] SUMMARY

[0006] Based on the above description, the present application provides a method for extracting organic acids from distiller's grains and yellow water to solve the technical problem of low deep resource utilization rate and low added value of products.

[0007] The technical solution of the present application to solve the above technical problem is as follows:

[0008] In a first aspect, the present application provides a method for extracting organic acids from distiller's grains and yellow water, comprising:

[0009] Using distiller's grains as raw material, repeatedly washing with yellow water to obtain a washing liquid;

[0010] Squeezing the washed distiller's grains to obtain a squeezing liquid, and pressure filtering the squeezing liquid to obtain a pressure filtrate;

[0011] Mixing the leaching solution and the filter pressing solution to obtain a mixed solution, and performing ultrafiltration on the mixed solution to obtain an ultrafiltration clear solution, and performing nanofiltration and reverse osmosis on the ultrafiltration clear solution in sequence to obtain a reverse osmosis concentrated solution;

[0012] Performing reduced pressure and low temperature distillation on the reverse osmosis concentrated solution, and obtaining a high content organic acid solution after the total acid of the reverse osmosis concentrated solution is 60-70% after distillation.

[0013] On the basis of the above technical scheme, the application can also be improved as follows.

[0014] Further, during the leaching, the ratio of yellow water to distiller's grains is 1:1-3:1.

[0015] Further, the squeezing of the leached distiller's grains to obtain a squeezed solution specifically comprises:

[0016] Placing the leached distiller's grains into a screw press to perform squeezing;

[0017] The screw pressing pressure is 0.5-0.7 MPa, and the screw pressing screen mesh aperture is 0.3-0.5 mm.

[0018] Further, the filter pressing of the squeezed solution to obtain a filter pressing solution specifically comprises:

[0019] Conveying the squeezed solution into a plate-and-frame filter press to perform filter pressing;

[0020] The plate-and-frame filter pressing pressure is 0.7-1.2 MPa, and the filter cloth used in the plate-and-frame filter press has a gas permeability of 30-50 L / (m 2 ·s).

[0021] Further, the total acid content of the mixed solution obtained by uniformly mixing the leaching solution and the filter pressing solution is 3-4%.

[0022] Further, the ultrafiltration of the mixed solution to obtain an ultrafiltration clear solution, and the nanofiltration and reverse osmosis of the ultrafiltration clear solution to obtain a concentrated solution specifically comprise:

[0023] The mixed solution is subjected to ultrafiltration through an ultrafiltration membrane with a molecular weight of 2000-5000;

[0024] The ultrafiltration clear solution is subjected to nanofiltration through a nanofiltration membrane with a molecular weight of 100-300;

[0025] The nanofiltration clear solution is subjected to reverse osmosis through a reverse osmosis membrane with a molecular weight of 50-100 to obtain a concentrated solution containing organic acids.

[0026] Further, the reduced pressure and low temperature distillation of the reverse osmosis concentrated solution specifically comprises:

[0027] The reverse osmosis concentrated solution is removed of water by low-temperature distillation under reduced pressure, the concentration of organic acid is improved, the distillation temperature is 50-70 DEG C, and the vacuum degree is -0.1 to -0.12 MPa.

[0028] In a second aspect, the present application provides an organic acid extracted from vinasse and yellow water, which is extracted by the extraction method of any one of the first aspect.

[0029] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0030] The method for extracting organic acid from vinasse and yellow water provided by the present application extracts organic acid from yellow water without adding water, saves resources, and the spiral extrusion and plate and frame pressure filtration can provide a high-pressure environment to promote the sufficient dissolution of organic acid, which is 50% higher in extraction efficiency than the prior art for organic acid in vinasse, and the organic acid in yellow water is also fully utilized; and the method used is a method of concentrating and extracting organic acid by the way of ultrafiltration, nanofiltration, reverse osmosis and low-temperature distillation under reduced pressure, which can increase the concentration of the liquid to a higher level of 15-20% through a multi-stage membrane treatment process, simplify the subsequent distillation process, and only one step of reduced pressure distillation is needed, and the concentration of organic acid after distillation can reach 60-70%, while the energy consumption required during distillation is reduced compared with the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0031] Fig. 1 is a flowchart of the method for extracting organic acid from vinasse and yellow water provided by the present application. DETAILED DESCRIPTION

[0032] The technical concept of the present application is to provide a new method for processing and recycling vinasse and yellow water, and to extract organic acid from vinasse and yellow water to realize the processing and resource utilization of vinasse.

[0033] The present application will be further described in detail below with reference to specific examples, so that those skilled in the art can more clearly understand the present application. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application. Based on the specific examples in the present application, all other examples obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] In the embodiments of the present application, all raw material components are commercially available products well known to those skilled in the art unless otherwise specified; in the embodiments of the present application, the technical means used are conventional means well known to those skilled in the art unless otherwise specified.

[0035] As shown in Fig. 1, the present embodiment provides a method for extracting organic acid from vinasse and yellow water, which comprises the following steps:

[0036] Step S1: using distiller's grains as raw material, repeatedly washing with yellow water to obtain a washing liquid.

[0037] In the washing process, the ratio of yellow water to distiller's grains is 1:1 to 3:1.

[0038] Step S2: squeezing the washed distiller's grains to obtain a squeezing liquid, and pressure filtering the squeezing liquid to obtain a pressure filtered liquid.

[0039] Specifically, the washed distiller's grains are put into a screw press for squeezing, wherein the screw pressing pressure is 0.5-0.7 MPa, and the screw pressing screen mesh size is 0.3-0.5 mm.

[0040] The squeezing liquid is transported into a plate and frame filter press for pressure filtration, wherein the pressure during plate and frame pressure filtration is 0.7-1.2 MPa, and the air permeability of the filter cloth used in the plate and frame filter press is 30-50 L / (m 2 ·s).

[0041] Step S3: mixing the washing liquid and the pressure filtered liquid uniformly to obtain a mixed liquid, wherein the total acid content of the mixed liquid is 3-4%, and the mixed liquid is subjected to ultrafiltration to obtain an ultrafiltration clear liquid, and the ultrafiltration clear liquid is sequentially subjected to nanofiltration and reverse osmosis to obtain a reverse osmosis concentrated liquid.

[0042] Specifically,

[0043] The mixed liquid is subjected to ultrafiltration through an ultrafiltration membrane with a molecular weight of 2000-5000;

[0044] The ultrafiltration filtrate is subjected to nanofiltration through a nanofiltration membrane with a molecular weight of 100-300;

[0045] The nanofiltration clear liquid is subjected to reverse osmosis through a reverse osmosis membrane with a molecular weight of 50-100, to obtain a reverse osmosis concentrated liquid containing organic acids.

[0046] Step S4: subjecting the reverse osmosis concentrated liquid to reduced pressure and low temperature distillation, wherein the total acid content of the reverse osmosis concentrated liquid after distillation is 60-70%, and a high content organic acid solution is obtained, which can be used as a feed acidifier, an industrial preservative, or a pH regulator, etc.

[0047] Specifically, after the reverse osmosis concentrated liquid is subjected to reduced pressure and low temperature distillation, the water content is removed, and the concentration of organic acids is increased, wherein the distillation temperature is 50-70℃, and the vacuum degree is -0.1 to -0.12 MPa.

[0048] The following specific embodiments are used for specific introduction:

[0049] Example 1

[0050] The present embodiment provides a method for extracting organic acids from distiller's grains and yellow water, comprising the following steps:

[0051] Step S1: Take 10 kg of white liquor dregs and 10 kg of yellow water, repeatedly rinse the liquor dregs with the yellow water for 3 times, and obtain 9 kg of rinsing liquid.

[0052] Step S2: After rinsing, the liquor dregs are added into a screw extruder for extrusion, the screw extrusion pressure is 0.5 MPa, the screw extrusion screen aperture is 0.4 mm, and 5.3 kg of extrusion liquid is obtained; the extrusion liquid is subjected to plate and frame filter pressing, the plate and frame filter pressing pressure is 0.7 MPa, the air permeability of the filter cloth used in the plate and frame filter press is 40 L / (m 2 ·s), and 4.1 kg of filter pressing liquid is obtained.

[0053] Step S3: The total acid of the mixed liquid obtained by uniformly mixing the rinsing liquid and the filter pressing liquid is 3.14%; the mixed liquid is subjected to ultrafiltration through an ultrafiltration membrane with a molecular weight of 5000, and the ultrafiltration clear liquid is subjected to nanofiltration through a nanofiltration membrane with a molecular weight of 300; the nanofiltration clear liquid is subjected to reverse osmosis through a reverse osmosis membrane with a molecular weight of 100, and the total acid of the concentrated liquid obtained by reverse osmosis is 13.25%.

[0054] Step S4: 0.25 L of the reverse osmosis concentrated liquid is subjected to low-temperature evaporation under reduced pressure, the evaporation temperature is 70°C, the vacuum degree is -0.12 MPa, and after evaporation, the concentrated liquid is 0.045 L and the total acid is 70.08%. The low-temperature evaporation concentrated liquid is processed to prepare a high-content organic acid solution.

[0055] Example 2

[0056] The method for extracting organic acid from liquor dregs and yellow water provided in this embodiment comprises the following steps

[0057] Step S1: Take 10 kg of white liquor dregs and 20 kg of yellow water, repeatedly rinse the liquor dregs with the yellow water for 2 times, and obtain 18.5 kg of rinsing liquid.

[0058] Step S2: After rinsing, the liquor dregs are added into a screw extruder for extrusion, the screw extrusion pressure is 0.6 MPa, the screw extrusion screen aperture is 0.3 mm, and 5.6 kg of extrusion liquid is obtained; the extrusion liquid is subjected to plate and frame filter pressing, the plate and frame filter pressing pressure is 1 MPa, the air permeability of the filter cloth used in the plate and frame filter press is 50 L / (m 2 ·s), and 4.5 kg of filter pressing liquid is obtained.

[0059] Step S3: The total acid of the mixed liquid obtained by uniformly mixing the rinsing liquid and the filter pressing liquid is 3.87%; the mixed liquid is subjected to ultrafiltration through an ultrafiltration membrane with a molecular weight of 2000, and the ultrafiltration clear liquid is subjected to nanofiltration through a nanofiltration membrane with a molecular weight of 100; the nanofiltration clear liquid is subjected to reverse osmosis through a reverse osmosis membrane with a molecular weight of 50, and the total acid of the concentrated liquid obtained by reverse osmosis is 11.96%.

[0060] Step S4: 0.25L reverse osmosis concentrated liquid was subjected to low-temperature distillation under reduced pressure, the distillation temperature was 50℃, the vacuum degree was-0.1MPa, after distillation, the concentrated liquid was 0.048L, and the total acid was 59.81%. The low-temperature evaporation concentrated liquid was processed to prepare a high-content organic acid solution.

[0061] Example 3

[0062] The method for extracting organic acid from distiller's grains and yellow water provided by the embodiment comprises the following steps

[0063] Step S1: 10kg of white spirit grains and 30kg of yellow water were used to repeatedly spray the distiller's grains once, and 28.5kg of spraying liquid was obtained.

[0064] Step S2: After spraying, the distiller's grains were added into a spiral extruder for extrusion, the spiral extrusion pressure was 0.7MPa, the spiral extrusion screen aperture was 0.5mm, and 6kg of extruded liquid was obtained. The extruded liquid was subjected to plate-and-frame filter pressing, the plate-and-frame filter pressing pressure was 1.2MPa, the filter cloth used in the plate-and-frame filter press had a gas permeability of 30L / (m 2 ·s), and 4.7kg of filter pressing liquid was obtained.

[0065] Step S3: the total acid of the mixed liquid obtained by uniformly mixing the spraying liquid and the filter pressing liquid was 3.57%; the mixed liquid was subjected to ultrafiltration through an ultrafiltration membrane with a molecular weight of 3000; the ultrafiltration clear liquid was subjected to nanofiltration through a nanofiltration membrane with a molecular weight of 200; and the nanofiltration clear liquid was subjected to reverse osmosis through a reverse osmosis membrane with a molecular weight of 80, and the total acid of the concentrated liquid obtained by reverse osmosis was 12.45%.

[0066] Step S4: 0.25L reverse osmosis concentrated liquid was subjected to low-temperature distillation under reduced pressure, the distillation temperature was 65℃, the vacuum degree was-0.11MPa, after distillation, the concentrated liquid was 0.046L, and the total acid was 67.23%. The low-temperature evaporation concentrated liquid was processed to prepare a high-content organic acid solution.

[0067] In summary, combined with Examples 1 to 3, it can be seen that the method for extracting organic acid from distiller's grains and yellow water provided by the embodiment of the present application uses yellow water to extract organic acid, does not need to add water, saves resources, and the spiral extrusion and plate-and-frame filter pressing can provide a high-pressure environment to promote the sufficient dissolution of organic acid, which is 50% higher in extraction efficiency of organic acid in distiller's grains than the prior art, and the organic acid in yellow water is also fully utilized; and the method used is a way of concentrating and extracting organic acid through mixed liquid ultrafiltration, nanofiltration, reverse osmosis and reduced-pressure low-temperature distillation, which can increase the concentration of the liquid to a higher level through a multi-stage membrane treatment process, can reach 15-20%, simplifies the subsequent distillation process, and only needs one step of reduced-pressure distillation, and the organic acid concentration after distillation can reach 60-70%, and the energy consumption required during distillation is reduced compared with the prior art.

[0068] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for extracting organic acids using distiller's grains and yellow water, characterized in that, include: The leachate is obtained by repeatedly rinsing the lees with yellow water. The washed lees are squeezed to obtain a squeeze liquid, and the squeeze liquid is then filtered to obtain a filtrate. The eluent and the filtrate are mixed evenly to obtain a mixture, and the mixture is subjected to ultrafiltration to obtain an ultrafiltrate. The ultrafiltrate is then subjected to nanofiltration and reverse osmosis to obtain a reverse osmosis concentrate. The reverse osmosis concentrate is subjected to low-pressure, low-temperature distillation. After distillation, the total acid content of the reverse osmosis concentrate is 60-70%, thus obtaining a high-content organic acid solution.

2. The method for extracting organic acids from distiller's grains and yellow water according to claim 1, characterized in that, During rinsing, the ratio of yellow water to lees is 1:1 to 3:

1.

3. The method for extracting organic acids from distiller's grains and yellow water according to claim 2, characterized in that, The process of pressing the washed lees to obtain the press liquid specifically includes: The rinsed lees are put into a screw press and pressed. The screw extrusion pressure is 0.5–0.7 MPa, and the screw extrusion screen aperture is 0.3–0.5 mm.

4. The method for extracting organic acids from distiller's grains and yellow water according to claim 3, characterized in that, The step of pressing and filtering the squeezed liquid to obtain the filtrate specifically includes: The extruded liquid is fed into a plate and frame filter press for filtration. The pressure during plate and frame filter press operation is 0.7–1.2 MPa, and the air permeability of the filter cloth used in the plate and frame filter press is 30–50 L / (m²). 2 ·s).

5. The method for extracting organic acids from distiller's grains and yellow water according to claim 1, characterized in that, The total acid content of the mixture obtained by uniformly mixing the eluent and the filtrate is 3-4%.

6. The method for extracting organic acids from distiller's grains and yellow water according to claim 1, characterized in that, The process of ultrafiltration of the mixture to obtain ultrafiltrate, followed by nanofiltration and reverse osmosis of the ultrafiltrate to obtain reverse osmosis concentrate, specifically includes: The mixture is ultrafiltered through an ultrafiltration membrane with a molecular weight of 2000-5000. The filtrate after ultrafiltration is then subjected to nanofiltration through a nanofiltration membrane with a molecular weight of 100-300. The clarified liquid after nanofiltration is then subjected to reverse osmosis through a reverse osmosis membrane with a molecular weight of 50-100 to obtain a reverse osmosis concentrate containing organic acids.

7. The method for extracting organic acids from distiller's grains and yellow water according to claim 1, characterized in that, The reverse osmosis concentrate is subjected to reduced pressure and low-temperature distillation, specifically including: The reverse osmosis concentrate is subjected to vacuum low-temperature distillation to remove water and increase the concentration of organic acids. The distillation temperature is 50-70℃ and the vacuum degree is -0.1 to -0.12MPa.

8. An organic acid extracted using distiller's grains and yellow water, characterized in that, The organic acid is obtained by the extraction method according to any one of claims 1 to 7.

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