Method for extracting alcohol from by-products obtained after garlic oil production

Abstract

The invention provides a method for extracting alcohol by using a by-product after garlic oil production, which comprises a pretreatment step, a fermentation step, a distillation step and a refining step, and through the combination of crushing and high-temperature cooking, starch in the garlic by-product is fully gelatinized, the cell wall structure is destroyed, and the alcohol content is reduced; more importantly, infectious microbes possibly carried in the raw materials are effectively killed, and a solid foundation is laid for subsequent pure fermentation; amylase and saccharifying enzyme are selectively added for enzymolysis, so that macromolecular carbohydrates are further accurately degraded into fermentable sugars which can be directly utilized by yeast, the saccharification rate of the raw materials is remarkably improved, and a core guarantee is directly provided for improving the final ethanol yield. Through combination of normal pressure rectification and pressurized rectification, ethanol is separated and concentrated, and through deep processing units such as molecular sieve dehydration or blending and aging, diversified alcohol products from industrial fuel and medical disinfection to high-end drinking can be flexibly produced by the same basic process, so that the application range and the economic value are expanded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of garlic processing, in particular to a method for extracting alcohol from by-products after garlic oil production. BACKGROUND

[0002] A large amount of by-products such as garlic skin, garlic residue and broken pieces are produced in the process of food processing, condiment production and medicine extraction, which are collectively referred to as garlic by-products. At present, most of these by-products are not efficiently utilized, resulting in not only waste of resources but also environmental pollution. The garlic by-products contain a certain amount of carbohydrates such as starch and cellulose, which have the potential to be converted into energy or chemical products such as ethanol. If the garlic by-products can be used as non-grain raw materials for alcohol production, it can not only realize the resource utilization of waste, but also reduce the cost of alcohol production, which has significant economic and environmental benefits. However, the garlic by-products contain sulfur compounds such as allicin, which may inhibit the fermentation microorganisms, and the structure of their carbohydrates is different from that of traditional grain raw materials. Therefore, it is particularly important to develop a special method for garlic by-products that can effectively overcome the influence of inhibitors and efficiently convert carbohydrates into alcohol. SUMMARY

[0003] In view of this, the present application proposes a method for extracting alcohol from by-products after garlic oil production. Specifically, the method includes the following steps:

[0004] A method for extracting alcohol from by-products after garlic oil production, comprising the following steps:

[0005] Step one, pretreatment step, the by-products of garlic fuzi produced in the process of garlic oil production are pretreated, then the garlic fuzi is mixed with water to form a slurry, and the slurry is subjected to high-temperature cooking, the cooking temperature is 90-120℃, and the time is 30-90 minutes, so as to realize the gelatinization and sterilization of starch;

[0006] Step two, fermentation step, after the pretreated slurry is cooled to 25-35℃, alcohol active dry yeast or saccharomyces cerevisiae is inoculated, anaerobic fermentation is carried out in a sealed fermentation tank, the fermentation period is 48-96 hours, and the pH value is controlled to be 4.0-5.5 during the fermentation, so as to convert the carbohydrates in the garlic fuzi into ethanol;

[0007] Step three, distillation step, the fermented mature mash is subjected to solid-liquid separation, the liquid part obtained is introduced into a distillation column for distillation, the ethanol fraction is collected, and a crude alcohol product is obtained;

[0008] Step four, refining step, according to the purity requirements of the target product, the crude alcohol product is further rectified and dehydrated to improve the ethanol concentration.

[0009] Further, in the pretreatment step one, amylase and / or glucoamylase can be added to the slurry before or after cooking for enzymatic hydrolysis, the temperature is 50-65℃, and the time is 1-3 hours, so as to fully degrade the macromolecular starch in garlic powder into fermentable sugar, thereby improving the ethanol yield of the subsequent fermentation step.

[0010] Further, in the step two, the fermenter is equipped with a stirring device to perform intermittent or continuous stirring at a rate of 20-50 revolutions per minute, ensuring uniform fermentation system and promoting mass transfer efficiency, while the activity of yeast can be maintained by supplementing nitrogen source or phosphate nutrient during the fermentation process (about 10-15 days).

[0011] Further, in the step three, atmospheric distillation is used to preliminarily separate ethanol, obtaining an initial distillate with an ethanol volume fraction of 40%-60%, then the initial distillate is pumped into a rectifying column for pressurized rectification, finally obtaining a crude alcohol product with an ethanol volume fraction of not less than 95%.

[0012] Further, in the step four, when used for producing medical alcohol or anhydrous ethanol, it further includes a dehydration purification unit operation, specifically using molecular sieve adsorption method or pervaporation membrane method to deeply dehydrate the rectified ethanol, so that the water content is less than 0.5%, obtaining anhydrous ethanol with an ethanol volume fraction of greater than 99.5%.

[0013] Further, in the step four, when used for producing edible alcohol, it further includes a blending and post-treatment unit operation, specifically blending the edible grade base alcohol obtained by distillation with treated pure water, adjusting the ethanol concentration to the target alcohol degree, and can be aged or added with flavoring substances meeting food safety requirements to improve the flavor according to needs.

[0014] The above technical solution has the following beneficial effects:

[0015] Through high-temperature cooking, not only is the starch in the by-products after garlic oil fully gelatinized, and the cell wall structure is destroyed, but more importantly, the miscellaneous bacteria that may exist in the raw materials are effectively killed, laying a solid foundation for subsequent pure culture fermentation; while selectively adding amylase and glucoamylase for enzymatic hydrolysis further precisely degrades macromolecular carbohydrates into fermentable sugars that can be directly utilized by yeast, significantly improving the saccharification rate of raw materials and directly providing the core guarantee for increasing the final ethanol yield. After entering the fermentation step, by precisely controlling the temperature, pH value and supplemented with gentle mechanical stirring, an optimal metabolic environment is created for yeast. This dynamic regulation not only promotes the uniform contact between the bacterial cells and the substrate and strengthens the mass transfer efficiency, but also effectively alleviates the potential inhibition of sulfur-containing compounds in garlic itself on yeast activity, ensuring the stable and efficient progress of the fermentation process, so as to maximize the conversion of carbohydrates into the target product ethanol. The subsequent distillation and refining steps are flexibly and precisely designed according to the product use. Through the combination of atmospheric and pressurized rectification, ethanol is efficiently separated and concentrated. And deep processing units such as molecular sieve dehydration or blending and aging enable the same basic process to flexibly produce diversified alcohol products from industrial fuels, medical disinfection to high-end drinking, expanding the application scope and economic value of the technology. It not only solves the safety problems of traditional reaction kettles, but also solves the environmental pollution caused by waste materials. Further improving economic benefits. Detailed implementation manners

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] Example 1:

[0018] A method for extracting alcohol from the by-products after garlic oil production, comprising the following steps:

[0019] Step 1, pretreatment step: Pretreat the garlic dregs, which are the by-products during garlic processing, to obtain garlic puree with uniform particle size. Subsequently, mix the garlic puree with water to form a slurry, and perform high-temperature cooking on the slurry at a cooking temperature of 90-120°C for 30-90 minutes to achieve starch gelatinization and sterilization;

[0020] Step 2, fermentation step: After cooling the pretreated slurry to 25-35°C, inoculate alcohol active dry yeast or Saccharomyces cerevisiae strains, and perform anaerobic fermentation in a closed fermentation tank for a fermentation period of 48-96 hours. During this period, control the pH value to be 4.0-5.5 to convert the carbohydrates in the garlic dregs into ethanol;

[0021] Step 3, distillation step: the fermented mash is separated into solid and liquid components. The liquid portion is introduced into a distillation column for distillation, and the ethanol fraction is collected to obtain crude alcohol product.

[0022] Step four, refining step: According to the purity requirements of the target product, the crude alcohol product is further distilled and dehydrated to increase the ethanol concentration.

[0023] In the first pretreatment step, amylase and / or saccharifying enzyme can be added to the slurry before or after cooking for enzymatic hydrolysis. The hydrolysis temperature is 50-65℃ and the time is 1-3 hours to fully degrade the macromolecular starch in the garlic cloves into fermentable sugars, thereby increasing the ethanol yield in the subsequent fermentation steps. In the second step, the fermentation tank is equipped with a stirring device to intermittently or continuously stir at a rate of 20-50 revolutions per minute to ensure the uniformity of the fermentation system and promote mass transfer efficiency. At the same time, the activity of yeast can be maintained by supplementing nitrogen sources or phosphate nutrients during the fermentation process.

[0024] In step three, ethanol is initially separated by atmospheric distillation to obtain a primary distillate with an ethanol volume fraction of 40%-60%. This primary distillate is then pumped into a distillation column for pressurized distillation to finally obtain a crude alcohol product with an ethanol volume fraction of not less than 95%. In step four, when used for the production of medical alcohol or anhydrous ethanol, a dehydration and purification unit operation is also included. Specifically, molecular sieve adsorption or pervaporation membrane method is used to deeply dehydrate the distilled ethanol to reduce its water content to less than 0.5%, resulting in anhydrous ethanol with an ethanol volume fraction greater than 99.5%. In step four, when used for the production of edible alcohol, a blending and post-processing unit operation is also included. Specifically, the edible-grade base alcohol obtained by distillation is blended with treated pure water to adjust the ethanol concentration to the target alcohol content. It can also be aged or flavoring substances that meet food safety standards can be added as needed to improve the flavor.

[0025] Example 2:

[0026] Based on Example 1, this example describes the production of medical alcohol. Similar steps to those in Example 1 are used to obtain a crude alcohol product with an ethanol volume fraction of approximately 96%. Then, the crude alcohol product undergoes further processing: it is passed through a molecular sieve adsorption dehydration device for deep dehydration, yielding anhydrous ethanol with an ethanol volume fraction greater than 99.5%. A portion of the anhydrous ethanol is blended with sterile purified water to produce medical alcohol with an ethanol volume fraction of 75% or 95%. This is then subjected to impurity removal, sterilization, and testing to ensure compliance with medical standards. This product is used for skin disinfection, medical device disinfection, etc.

[0027] Example 3:

[0028] Based on Example 1, this example describes the production of edible alcohol or baijiu base liquor. Similar steps to those in Example 1 are used to obtain a crude alcohol product with an ethanol volume fraction of approximately 96%. The crude alcohol product undergoes further distillation and purification to remove first- and last-stage impurities, yielding high-purity edible-grade base alcohol. This base alcohol is then blended with purified water that has undergone activated carbon treatment and high-purity filtration to adjust the ethanol concentration to the desired alcohol content. Depending on the flavor requirements of the target product, short-term aging or the addition of trace amounts of food-safe natural flavoring substances can be used for flavor modification, resulting in pure-tasting edible alcohol or high-quality baijiu base liquor.

[0029] Example 4: Based on Example 1, this company produces industrial ethanol using a similar procedure to Example 1, obtaining a crude alcohol product with an ethanol volume fraction of approximately 96%. This product can be used directly or after simple dehydration as biofuel ethanol, or as a raw material for industrial solvents and cleaning agents.

[0030] The basic principles and main features of the present invention have been described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope of the present invention. All such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for extracting alcohol from a byproduct of garlic oil production, characterized in that, Includes the following steps: Step 1, Pre-treatment step: Garlic mince, a byproduct generated during garlic processing, is pre-treated to obtain garlic mince with uniform particle size. Then, the garlic mince is mixed with water to form a slurry, and the slurry is cooked at high temperature, at a temperature of about 90-120℃, for about 30-90 minutes, in order to achieve starch gelatinization and sterilization. Step two, fermentation (about 10-15 days): After cooling the pretreated slurry to 25-35℃, add alcoholic active dry yeast or brewer's yeast and carry out anaerobic fermentation in a closed fermentation tank. The fermentation cycle is 48-96 hours, during which the pH value is controlled at 4.0-5.5 to convert the carbohydrates in the garlic cloves into ethanol. Step 3, distillation step: the fermented mash is separated into solid and liquid components. The liquid portion is introduced into a distillation column for distillation, and the ethanol fraction is collected to obtain crude alcohol product. Step four, refining step: According to the purity requirements of the target product, the crude alcohol product is further distilled and dehydrated to increase the ethanol concentration.

2. The method for extracting alcohol from a byproduct of garlic oil production according to claim 1, characterized in that, In the first pretreatment step, amylase and / or saccharifying enzyme can be added to the slurry before or after cooking for enzymatic hydrolysis. The enzymatic hydrolysis temperature is 50-65℃ and the time is 1-3 hours, so as to fully degrade the macromolecular starch in the garlic cloves into fermentable sugars, thereby improving the ethanol yield in the subsequent fermentation steps.

3. The method for extracting alcohol from a byproduct of garlic oil production according to claim 1, characterized in that, In step two, the fermenter is equipped with a stirring device that performs intermittent or continuous stirring at a rate of 20-50 revolutions per minute to ensure the uniformity of the fermentation system and promote mass transfer efficiency. At the same time, the activity of yeast can be maintained by supplementing nitrogen sources or phosphate nutrients during the fermentation process.

4. The method for extracting alcohol from a byproduct of garlic oil production according to claim 1, characterized in that, In step three, ethanol is initially separated by atmospheric distillation to obtain a primary distillate with an ethanol volume fraction of 40%-60%. This primary distillate is then pumped into a distillation column for pressurized distillation to finally obtain a crude alcohol product with an ethanol volume fraction of not less than 95%.

5. The method for extracting alcohol from a byproduct of garlic oil production according to claim 1, characterized in that, In step four, when used to produce medical alcohol or anhydrous ethanol, a dehydration and purification unit operation is also included. Specifically, the ethanol after distillation is deeply dehydrated using molecular sieve adsorption or pervaporation membrane method to reduce its water content to less than 0.5%, thereby obtaining anhydrous ethanol with an ethanol volume fraction greater than 99.5%.