阅读说明：本技术 一种分组液化进行混合原料发酵的方法 (Method for fermenting mixed raw materials by grouping liquefaction ) 是由 李勇 王林风 乔建援 薛宝 刘燕 樊国军 郑彬 于 2019-11-30 设计创作，主要内容包括：本发明公开了分组液化进行混合原料发酵的方法,其主要步骤为：将玉米粉加水拌浆、加液化酶预热、喷射液化、连消、闪蒸、冷却入糖化罐；将木薯粉与小麦淀粉浆按比例混合后拌浆、加液化酶预热、喷射液化、连消、闪蒸、冷却入糖化罐；然后将两者按比例混合并糖化发酵,最后蒸馏酒精。本发明有效的提高了混合原料的液化率,降低了液化时的能耗。相比于混合原料直接拌浆加液化酶液化,该方法有利于提高了原料的利用率,而且能够进一步节能降耗。(The invention discloses a method for performing mixed raw material fermentation by grouping liquefaction, which mainly comprises the following steps: adding water into corn flour, stirring, adding liquefying enzyme, preheating, spraying for liquefying, continuously sterilizing, flash evaporating, cooling, and feeding into a saccharification tank; mixing the cassava flour and the wheat starch slurry in proportion, then mixing the mixture with the slurry, adding liquefying enzyme for preheating, spraying for liquefying, continuously eliminating, flashing, cooling and then putting the mixture into a saccharification tank; then mixing the two according to a certain proportion, saccharifying and fermenting, and finally distilling alcohol. The invention effectively improves the liquefaction rate of the mixed raw materials and reduces the energy consumption during liquefaction. Compared with the method that the mixed raw materials are directly mixed with slurry and liquefied with the liquefied enzyme, the method is beneficial to improving the utilization rate of the raw materials and can further save energy and reduce consumption.)

1. A method for performing mixed raw material fermentation by group liquefaction is characterized by comprising the following steps:

1) two-stage crushing of the corn in a crushing workshop to obtain corn flour;

2) mixing the crushed corn flour in the step 1) into slurry to prepare corn slurry, pumping the corn slurry into a preheating tank, wherein the concentration of corn in the corn slurry is 250-350 g/L, and adding high-temperature resistant α -amylase;

3) preheating the corn steep liquor obtained in the step 2) in a preheating tank to 60 ℃, then enabling the corn steep liquor to enter a pre-liquefaction tank, pumping the corn steep liquor to a jet liquefier, introducing high-pressure steam, after jet liquefaction, entering a post-liquefaction tank, pumping the post-liquefaction tank to a continuous sterilizer, introducing steam, heating, and then entering a primary flash tower and a secondary flash tower to enable the liquefaction DE value to be 5-50%;

4) cooling by a flash tower, adding saccharifying enzyme, and feeding into a saccharifying tank;

5) the wheat is used as a raw material, the wheat is subjected to comprehensive processing, starch milk is used for alcohol production, and the pulp formed after water washing is called A/B pulp; crushing cassava in a crushing workshop;

6) the A/B slurry is prepared according to the following weight ratio of 1:1, fully mixing the slurry A/B and the cassava powder slurry, wherein the slurry A/B accounts for 60-80%, the cassava powder accounts for 20-40%, fully mixing the slurry A/B and the cassava powder slurry uniformly, preheating the mixture to 60 ℃, then entering a pre-liquefaction tank, pumping the pre-liquefaction tank to a jet liquefier, introducing high-pressure steam, entering a post-liquefaction tank after jet liquefaction, pumping the pre-liquefaction tank to a continuous sterilizer, introducing steam for heating, and then entering a primary flash tower and a secondary flash tower to enable the liquefied DE value to be 5-50%;

7) cooling by a flash tower, adding saccharifying enzyme, and feeding into a saccharifying tank;

8) mixing the corn mash added with the saccharifying enzyme with the wheat and cassava mash in a saccharifying tank, and pumping the mixture into a fermentation tank;

9) inoculating the yeast into a fermentation tank, stirring and circulating, and keeping the fermentation temperature of 34-36 ℃ until the fermentation is finished;

10) and extracting the ethanol in the fermentation liquor by adopting a distillation method.

2. The method for mixed raw material fermentation by group liquefaction according to claim 1, wherein the fineness of the pulverized corn flour is less than or equal to 20 mesh, the fineness of the tapioca flour is less than or equal to 40 mesh, and the fineness of the wheat flour is less than or equal to 80 mesh in step 1), and the agitation is used for making the corn steep liquor and the tapioca steep liquor more uniform.

3. The method for mixed raw material fermentation by grouping liquefaction according to claim 1, wherein the liquefaction temperature of the corn raw material in the step 3) is 95-105 ℃.

4. The method for performing mixed raw material fermentation by grouping liquefaction according to claim 1, wherein the liquefaction temperature of the wheat and cassava raw materials in the step 6) is 85-95 ℃.

5. The method for mixed raw material fermentation by grouping liquefaction according to claim 1, wherein the adding of the liquefying enzyme in the steps 3) and 6) is 10-20 units per gram of dry material.

6. The method for performing mixed raw material fermentation by grouping liquefaction according to claim 1, wherein an acidic protease or a nitrogen source is added in the step 8) according to the proportion of 0.03-0.15 per mill, and the acidic protease can effectively decompose protein in the material to be used as an organic nitrogen source required by fermentation; the inorganic nitrogen source can be selected from ammonium sulfate, ammonium bicarbonate or urea.

7. The method for mixed raw material fermentation by grouping liquefaction according to claim 1, wherein the expanding culture of dry yeast or the inoculation of yeast by multi-stage expanding culture can be used in step 9).

8. The method for mixed raw material fermentation by group liquefaction according to claim 1, wherein the fermentation is finished when the apparent sugar degree and residual reducing sugar in the fermented mash are not reduced and the alcohol content is not increased in the step 9).

Technical Field

The invention belongs to the technical field of biological fermentation, and particularly relates to a method for liquefying mixed raw materials consisting of wheat, corn and cassava.

Background

The method for producing alcohol includes a fermentation method using a plant-based substance as a raw material and a chemical synthesis method using a petroleum-based substance as a raw material. The production of alcohol by fermentation is the most basic industry in the current biological industry, and the production technology is continuously making new progress along with the development of the bioengineering technology. The fermentation production method takes wheat, corn, non-grain crops, cassava and other series substances as raw materials. With the continuous progress of production technology, the processing of grain crops by enterprises is more refined and the utilization rate is higher, and simultaneously, the country advocates that non-grain crops are encouraged to produce ethanol, so that mixed raw materials are adopted to produce ethanol from practical aspects, namely wheat, corn and cassava.

The liquefaction is to gelatinize starch at high temperature and break starch molecules into short chains under the action of liquefying enzyme to form a large amount of dextrin and a small amount of saccharides, so that the viscosity of the starch is reduced, the fluidity is good, and conditions are created for saccharification. The liquefaction technology is a key technology in fermentation production. The quality of starch liquefaction directly affects the difficulty of the subsequent working procedure and the production benefit.

At present, enzymatic spray liquefaction is adopted at home and abroad, high-temperature resistant amylase is added through pH adjustment, high-temperature spray liquefaction at 105 ℃ or 130 ℃ is carried out, the flash evaporation temperature is reduced to about 90 ℃, heat preservation liquefaction is carried out for 90 min, and the DE value is 15-18%. The consumption of liquefied steam is large, the grain size formed by different crushing processes of mixed raw materials is different, particularly, the starch structure of corn is tightly crystallized and is not easy to be affected by enzyme, the structure of the corn needs to be damaged by higher temperature, the wheat starch milk and the cassava flour are fragile, the grain size is below 40 meshes after crushing, and the loss of fermentable substances is easily caused by overhigh gelatinization and liquefaction temperature.

Therefore, the method of mixing and fermenting the raw materials with different particle sizes and different material characteristics after grouping liquefaction can reduce the steam consumption in the liquefaction process and avoid sugar loss in the high-temperature liquefaction process, thereby achieving the purposes of saving energy, reducing consumption and improving the utilization rate of the raw materials.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a method for fermenting mixed raw materials by grouping liquefaction.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for mixed raw material fermentation by group liquefaction comprises the following steps:

1) two-stage crushing of the corn in a crushing workshop to obtain corn flour;

2) mixing the crushed corn flour in the step 1) into slurry to prepare corn slurry, pumping the corn slurry into a preheating tank, wherein the concentration of corn in the corn slurry is 250-350 g/L, and adding high-temperature resistant α -amylase;

3) preheating the corn steep liquor obtained in the step 2) in a preheating tank to 60 ℃, then enabling the corn steep liquor to enter a pre-liquefaction tank, pumping the corn steep liquor to a jet liquefier, introducing high-pressure steam, after jet liquefaction, entering a post-liquefaction tank, pumping the post-liquefaction tank to a continuous sterilizer, introducing steam, heating, and then entering a primary flash tower and a secondary flash tower to enable the liquefaction DE value to be 5-50%;

4) cooling by a flash tower, adding saccharifying enzyme, and feeding into a saccharifying tank;

5) the wheat is used as a raw material, the wheat is subjected to comprehensive processing, starch milk is used for alcohol production, and the pulp formed after water washing is called A/B pulp; crushing cassava in a crushing workshop;

6) the A/B slurry is prepared according to the following weight ratio of 1:1, fully mixing the slurry A/B and the cassava powder slurry, wherein the slurry A/B accounts for 60-80%, the cassava powder accounts for 20-40%, fully mixing the slurry A/B and the cassava powder slurry uniformly, preheating the mixture to 60 ℃, then entering a pre-liquefaction tank, pumping the pre-liquefaction tank to a jet liquefier, introducing high-pressure steam, entering a post-liquefaction tank after jet liquefaction, pumping the pre-liquefaction tank to a continuous sterilizer, introducing steam for heating, and then entering a primary flash tower and a secondary flash tower to enable the liquefied DE value to be 5-50%;

7) cooling by a flash tower, adding saccharifying enzyme, and feeding into a saccharifying tank;

8) mixing the corn mash added with the saccharifying enzyme with the wheat and cassava mash in a saccharifying tank, and pumping the mixture into a fermentation tank;

9) inoculating the yeast into a fermentation tank, stirring and circulating, and keeping the fermentation temperature of 34-36 ℃ until the fermentation is finished;

10) and extracting the ethanol in the fermentation liquor by adopting a distillation method.

In the step 1), the fineness of the ground corn flour is less than or equal to 20 meshes, the fineness of the cassava flour is less than or equal to 40 meshes, and the fineness of the wheat flour is less than or equal to 80 meshes, and the corn pulp and the cassava pulp are stirred to be more uniform.

The liquefaction temperature of the corn raw material in the step 3) is 95-105 ℃.

In the step 6), the liquefaction temperature of the wheat and cassava raw materials is 85-95 ℃.

In the steps 3) and 6), the adding of the liquefying enzyme is 10-20 units per gram of dry materials.

Adding acidic protease or nitrogen source according to the proportion of 0.03-0.15 per mill in the step 8). The acidic protease can effectively decompose protein in the material to be used as an organic nitrogen source required by fermentation; the inorganic nitrogen source can be selected from ammonium sulfate, ammonium bicarbonate or urea.

In the step 9), expanding culture dry yeast or yeast inoculation through multistage expanding culture can be adopted.

And 9) in the step 9), when the apparent sugar degree and the residual reducing sugar in the fermented mash are not reduced any more, the alcohol content is not increased any more, and the fermentation is finished.

Compared with the prior art, the invention has the beneficial effects that: the invention can reduce the steam consumption in the liquefaction process, achieve the purposes of saving energy, reducing consumption and reducing production cost, and simultaneously, compared with the traditional liquefaction (original process) of mixed raw materials, the invention has better liquefaction effect, lower residual total sugar after fermentation is finished, and the alcohol content is improved by 0.5-3 percent after fermentation is finished, namely, fermentable substances are decomposed more and the loss is less.

Detailed Description

The present invention will be described in further detail with reference to the following examples, which are provided only for illustrating the present invention and are not intended to limit the scope of the present invention.

A method for mixed raw material fermentation by group liquefaction comprises the following steps:

1) two-stage crushing of the corn in a crushing workshop to obtain corn flour;

2) mixing the crushed corn flour in the step 1) into slurry to prepare corn slurry, pumping the corn slurry into a preheating tank, wherein the concentration of corn in the corn slurry is 250-350 g/L, and adding high-temperature resistant α -amylase;

3) preheating the corn steep liquor obtained in the step 2) in a preheating tank to 60 ℃, then enabling the corn steep liquor to enter a pre-liquefaction tank, pumping the corn steep liquor to a jet liquefier, introducing high-pressure steam, after jet liquefaction, entering a post-liquefaction tank, pumping the post-liquefaction tank to a continuous sterilizer, introducing steam, heating, and then entering a primary flash tower and a secondary flash tower to enable the liquefaction DE value to be 5-50%;

4) cooling by a flash tower, adding saccharifying enzyme, and feeding into a saccharifying tank;

5) the wheat is used as a raw material, the wheat is subjected to comprehensive processing, starch milk is used for alcohol production, and the pulp formed after water washing is called A/B pulp; crushing cassava in a crushing workshop;

6) the A/B slurry is prepared according to the following weight ratio of 1:1, fully mixing the slurry A/B and the cassava powder slurry, wherein the slurry A/B accounts for 60-80%, the cassava powder accounts for 20-40%, fully mixing the slurry A/B and the cassava powder slurry uniformly, preheating the mixture to 60 ℃, then entering a pre-liquefaction tank, pumping the pre-liquefaction tank to a jet liquefier, introducing high-pressure steam, entering a post-liquefaction tank after jet liquefaction, pumping the pre-liquefaction tank to a continuous sterilizer, introducing steam for heating, and then entering a primary flash tower and a secondary flash tower to enable the liquefied DE value to be 5-50%;

7) cooling by a flash tower, adding saccharifying enzyme, and feeding into a saccharifying tank;

8) mixing the corn mash added with the saccharifying enzyme with the wheat and cassava mash in a saccharifying tank, and pumping the mixture into a fermentation tank;

9) inoculating the yeast into a fermentation tank, stirring and circulating, and keeping the fermentation temperature of 34-36 ℃ until the fermentation is finished;

10) and extracting the ethanol in the fermentation liquor by adopting a distillation method.

In the step 1), the fineness of the ground corn flour is less than or equal to 20 meshes, the fineness of the cassava flour is less than or equal to 40 meshes, and the fineness of the wheat flour is less than or equal to 80 meshes, and the corn pulp and the cassava pulp are stirred to be more uniform.

The liquefaction temperature of the corn raw material in the step 3) is 95-105 ℃.

In the step 6), the liquefaction temperature of the wheat and cassava raw materials is 85-95 ℃.

In the steps 3) and 6), the adding of the liquefying enzyme is 10-20 units per gram of dry materials.

Adding acidic protease or nitrogen source according to the proportion of 0.03-0.15 per mill in the step 8). The acidic protease can effectively decompose protein in the material to be used as an organic nitrogen source required by fermentation; the inorganic nitrogen source can be selected from ammonium sulfate, ammonium bicarbonate or urea.

In the step 9), expanding culture dry yeast or yeast inoculation through multistage expanding culture can be adopted.

And 9) in the step 9), when the apparent sugar degree and the residual reducing sugar in the fermented mash are not reduced any more, the alcohol content is not increased any more, and the fermentation is finished.