阅读说明：本技术 一种糖蜜精制脱毒及发酵生产丙酮、丁醇的方法 (Method for refining, detoxifying and producing acetone and butanol by fermentation of molasses ) 是由 陈新德 王梦琨 熊莲 陈雪芳 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种糖蜜精制脱毒及发酵生产丙酮、丁醇的方法,糖蜜精制脱毒的方法包括：(1)脱灰分、胶质：将糖蜜稀释,稀释后加入酸液调节pH至溶液呈酸性,水浴加热溶液使糖蜜中的非还原糖水解转化为还原糖,之后加入絮凝剂,搅拌后静置,使胶质絮凝沉降,冷却后取上层澄清液,加入钙盐调节pH至中性,离心过滤硫酸钙沉淀,得到清液；(2)脱磷除氮：向清液中加入含镁无机化合物和含磷无机化合物并搅拌,同时用碱液调节pH至碱性,生成鸟粪石沉淀,过滤沉淀后得到澄清液；(3)脱色：向澄清液中加入大孔吸附树脂震荡脱色,之后过滤即可。本发明提供的丙酮、丁醇生产方法成本低廉、经济环保,通过对糖蜜精制脱毒从而提高发酵液的品质,提高丙酮、丁醇的产量。(The invention discloses a method for molasses refining detoxification and fermentation production of acetone and butanol, which comprises the following steps: (1) ash removal and colloid removal: diluting molasses, adding acid liquor to adjust the pH value of the diluted molasses until the solution is acidic, heating the solution in water bath to hydrolyze non-reducing sugar in the molasses into reducing sugar, adding a flocculating agent, stirring, standing to flocculate and settle colloid, cooling, taking supernatant, adding calcium salt to adjust the pH value to be neutral, and centrifugally filtering calcium sulfate precipitate to obtain clear liquid; (2) dephosphorization and denitrogenation: adding a magnesium-containing inorganic compound and a phosphorus-containing inorganic compound into the clear liquid, stirring, adjusting the pH to be alkaline by using an alkali liquor, generating struvite sediment, and filtering the sediment to obtain clear liquid; (3) and (3) decoloring: adding macroporous adsorption resin into the clarified liquid, shaking for decolorization, and filtering. The method for producing the acetone and the butanol has low cost, is economic and environment-friendly, improves the quality of fermentation liquor by refining and detoxifying the molasses, and improves the yield of the acetone and the butanol.)

1. A method for refining and detoxifying molasses is characterized by comprising the following steps:

(1) ash removal and colloid removal: diluting molasses, adding acid liquor to adjust the pH value of the diluted molasses until the solution is acidic, heating the solution in water bath to hydrolyze non-reducing sugar in the molasses into reducing sugar, adding a flocculating agent, stirring, standing to flocculate and settle colloid, cooling, taking supernatant, adding calcium salt to adjust the pH value to be neutral, and centrifugally filtering calcium sulfate precipitate to obtain clear liquid;

(2) dephosphorization and denitrogenation: adding a magnesium-containing inorganic compound and a phosphorus-containing inorganic compound into the clear liquid, stirring, adjusting the pH to be alkaline by using an alkali liquor, generating struvite sediment, and filtering the sediment to obtain clear liquid;

(3) and (3) decoloring: adding macroporous adsorption resin into the clarified liquid, shaking for decolorization, and filtering to obtain filtrate, i.e. refined and detoxified molasses solution.

2. The method for refining and detoxifying molasses according to claim 1, characterized in that in the step (1), the molasses is diluted to baume degree of 15-30 ° Be; the acid solution comprises sulfuric acid or phosphoric acid, and the pH value of the solution is adjusted to 1.5-3.5 by the acid solution; the water bath heating temperature is 60-95 ℃, and the heating time is 0.5-3 h.

3. The method for refining and detoxifying molasses according to claim 1 or 2, characterized in that in step (1), the flocculating agent is an inorganic flocculating agent, an organic flocculating agent or a mixture of the inorganic flocculating agent and the organic flocculating agent, the inorganic flocculating agent comprises polyaluminium chloride, polyferric sulfate or polyaluminium ferric chloride, and the organic flocculating agent comprises polyacrylamide; the addition amount of the inorganic flocculant is 50-300 ppm, and the addition amount of the organic flocculant is 5-20 ppm.

4. The method for refining and detoxifying molasses of claim 1, wherein in the step (2), the inorganic compound containing magnesium comprises one or more of magnesium oxide, magnesium hydroxide, magnesium chloride, magnesium sulfate and magnesium carbonate, and the inorganic compound containing phosphorus comprises one or more of phosphoric acid, disodium hydrogen phosphate, dipotassium hydrogen phosphate and trisodium phosphate; the addition amount of the magnesium-containing inorganic compound satisfies N (NH)₄ ⁺):n(Mg²⁺) 1:1 to 1.4, wherein the phosphorus-containing inorganic compound is added in an amount satisfying N (NH)₄ ⁺):n(PO₄ ^3-) 1: 0.6-1, wherein N (NH)₄ ⁺) Representing the total NH in solution₄ ⁺The amount of substance(s) of (c).

5. The molasses refining and detoxifying method as claimed in claim 1, wherein the calcium salt is calcium oxide, the alkali liquor is sodium hydroxide solution, and the pH of the alkali liquor is adjusted to 8.0-10.0; in the step (3), the macroporous adsorption resin comprises one or a mixture of more of non-polar resin, medium-polar resin and polar resin, and the addition amount of the macroporous adsorption resin is 2-12% of the mass of the molasses; the shaking mode is shaking by a shaking table, and the shaking time is 15-90 min.

6. A method for producing acetone and butanol by fermentation after refining and detoxifying molasses, which is characterized by comprising the method for refining and detoxifying molasses as claimed in any one of claims 1-5, and further comprising the following steps:

(4) domesticating fermented thalli: preparing the refined and detoxified molasses solution into domestication culture media with different concentrations, sequentially inoculating clostridium acetobutylicum from a low molasses concentration culture medium to a high molasses concentration culture medium for gradual domestication culture according to the sequence of molasses concentration in the domestication culture media from low to high, and obtaining a domesticated acetobutanol fermentation strain after inoculating the clostridium acetobutylicum to the culture medium with the highest molasses concentration for culture;

(5) and (3) acetone butanol fermentation: inoculating the acclimated acetone-butanol fermentation strain into the sterilized refined detoxified molasses culture medium, adding a nitrogen source for constant-temperature culture, and fermenting to produce acetone and butanol.

7. The method for producing acetone and butanol by fermentation after refining and detoxifying molasses according to claim 6, wherein in the step (4), the domesticated culture solution is a mixture of a corn fermented glutinous rice culture solution and the refined and detoxified molasses solution.

8. The method for fermentation and catalytic production of acetone and butanol after refining and detoxification of molasses according to claim 6, wherein in the step (4), the concentration of molasses in the low-molasses-concentration acclimation culture medium is 5-10%, and the acclimation time of clostridium acetobutylicum in the low-molasses-concentration acclimation culture medium is 12-24 h; the concentration of molasses in the culture solution is 10-100% during step-by-step acclimation culture, the molasses is gradually increased step by step, and the step-by-step acclimation culture time is 12-48 h respectively; the culture temperature of the clostridium acetobutylicum during acclimation is 34-37 ℃.

9. The method for producing acetone and butanol by fermentation and catalysis after refining and detoxification of molasses according to claim 6, wherein the macroporous adsorbent resin used in step (3) is washed by a mixed solution of absolute ethyl alcohol and pure water, dried after washing, and cyclically and repeatedly used in step (3); the volume ratio of the absolute ethyl alcohol to the pure water in the mixed solution is 1-10: 1, and the volume ratio of the macroporous adsorption resin to the mixed solution is 1: 1-5 during washing; the drying temperature is 70-90 ℃, and the drying time is 30-90 min.

10. The method for producing acetone and butanol by fermentation and catalysis after refining and detoxification of molasses according to claim 6, wherein in the step (5), the nitrogen source is an organic nitrogen source comprising one or more of soybean meal, bran and yeast extract powder, and the addition amount of the nitrogen source is 1-2% of the mass of the fermentation liquid; the constant-temperature culture time is 48-120 h.

Technical Field

The invention relates to the technical field of acetone and butanol production, in particular to a method for refining, detoxifying and producing acetone and butanol by fermentation of molasses.

Background

Under the big background that petroleum resources are gradually exhausted and clean biofuel is increasingly developed in the present society, acetone butanol fermentation is used as a green environment-friendly biofuel preparation method, biomass can be used as a fermentation substrate to directly produce liquid fuel butanol, and therefore worldwide attention and research are gained. At present, the conventional butanol fermentation substrate is mainly starchy raw materials including agricultural products such as corn, potatoes and grains, but the raw materials are single in source and high in fermentation cost, and meanwhile, the agricultural products such as the corn, the potatoes and the grains are used as grains for main population and livestock in China, and excessive consumption does not meet the national grain safety development trend. Therefore, it is necessary to develop research work on non-food substrates in biological butanol fermentation, search for fermentation substrates with wide sources and low price, overcome the influence of fermentation inhibitors, improve the butanol yield, and reduce the production cost.

The cane molasses is a viscous dark reddish brown flowable liquid, is a byproduct of sugar production by industrial utilization of sugarcane, has the advantages of large yield, centralized production place, single and stable components, no need of sorting treatment, controllable quality and the like, and has higher utilization value in the industries of chemical industry, light industry, food, medicine and building materials. The molasses comprises the main components of sucrose, glucose and fructose, accounts for more than 45% of the total content, and can be used as a carbon source required by the growth and development of microorganisms. In addition, molasses also contains many nutrient elements such as amino acids, vitamins, mineral salts and the like required by microbial fermentation, and is a good fermentation substrate. Meanwhile, the molasses raw material also contains substances such as pigments, organic acids, sugar colloid, ash and the like, has toxicity to microorganisms, influences the growth of the microorganisms and inhibits the generation of fermentation products. Therefore, before acetone butanol fermentation is carried out by using molasses as a fermentation substrate, the molasses fermentation inhibitor needs to be removed in a targeted manner, namely, the molasses is refined and detoxified, so that the quality of a fermentation product and the fermentation efficiency are improved.

The main white granulated sugar production method in the sugar refinery in China is a sulfurous acid method, and a large amount of phosphoric acid and sulfur are used in the production process to generate calcium phosphate and calcium sulfite to adsorb impurities in cane juice so as to clarify the cane juice. Therefore, a large amount of sulfite ions and phosphate ions are often present in the molasses spent liquor. SO according to the report of related documents₃ ^2-Has strong inhibiting effect on acetone-butanol fermentation. In addition, the crude protein contained in the molasses mostly belongs to non-protein nitrogen, mainly comprises ammonia nitrogen, and has low biological value. Excess NH during butanol fermentation₄ ⁺The utilization of NADH (reduced coenzyme I) in the clostridium acetobutylicum cell body is inhibited, the total solvent yield is reduced, and therefore, the proper removal of the original ammonia nitrogen in the molasses is required.

Fermentation inhibitors such as pectin and ash in molasses need to be treated by a clarification process. The pigment in molasses is the main growth inhibitor in the acetone butanol fermentation process, and has obvious cytotoxicity on the growth of clostridium. The pigment is mainly derived from phenolic substances and some high molecular polymers, including high molecular dark substances generated by decomposing and polycondensing the phenolic substances in the caramelization reaction and carrying out Maillard reaction on reducing sugar and amino acid. At present, two common sugar decoloring methods are mainly adopted, the first method is to add active carbon with very high specific surface area into the acidified and hydrolyzed molasses and remove the active carbon through physical adsorption, but the generated active carbon has more waste and poor economy and environmental protection; the second method is to separate and extract the pigment by a membrane filtration method, which has high cost and low pigment removal efficiency.

Disclosure of Invention

The method is economic and environment-friendly, can effectively refine and detoxify the molasses, reduces the inhibiting effect of substances such as pigments, organic acids, sugar colloid, ash content and the like in the molasses on the fermentation reaction, improves the quality of fermentation liquor and the fermentation efficiency, and further improves the yield of products such as acetone, butanol and the like.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a method for refining and detoxifying molasses comprises the following steps:

(1) ash removal and colloid removal: diluting molasses, adding acid liquor to adjust the pH value of the diluted molasses until the solution is acidic, heating the solution in water bath to hydrolyze non-reducing sugar in the molasses into reducing sugar, adding a flocculating agent, stirring, standing to flocculate and settle colloid, cooling, taking supernatant, adding calcium salt to adjust the pH value to be neutral, and centrifugally filtering calcium sulfate precipitate to obtain clear liquid;

(2) dephosphorization and denitrogenation: adding a magnesium-containing inorganic compound and a phosphorus-containing inorganic compound into the clear liquid, stirring, adjusting the pH to be alkaline by using an alkali liquor, generating struvite sediment, and filtering the sediment to obtain clear liquid;

(3) and (3) decoloring: adding macroporous adsorption resin into the clarified liquid, shaking for decolorization, and filtering to obtain filtrate, i.e. refined and detoxified molasses solution.

As a further improvement of the scheme, in the step (1), the molasses is diluted to a baume degree of 15-30 DEG Be; the acid solution comprises sulfuric acid or phosphoric acid, and the pH value of the solution is adjusted to 1.5-3.5 by the acid solution; the water bath heating temperature is 60-95 ℃, and the heating time is 0.5-3 h.

As a further improvement of the above scheme, in the step (1), the flocculant is an inorganic flocculant, an organic flocculant or a mixture of the inorganic flocculant and the organic flocculant, the inorganic flocculant comprises polyaluminium chloride, polyferric sulfate or polyaluminium ferric chloride, and the organic flocculant comprises polyacrylamide; the addition amount of the inorganic flocculant is 50-300 ppm, and the addition amount of the organic flocculant is 5-20 ppm.

As a further improvement of the above scheme, in the step (2), the inorganic compound containing magnesium comprises one or more of magnesium oxide, magnesium hydroxide, magnesium chloride, magnesium sulfate and magnesium carbonate, and the inorganic compound containing phosphorus comprises one or more of phosphoric acid, disodium hydrogen phosphate, dipotassium hydrogen phosphate and trisodium phosphate; the addition amount of the magnesium-containing inorganic compound satisfies N (NH)₄ ⁺):n(Mg²⁺) 1:1 to 1.4, wherein the phosphorus-containing inorganic compound is added in an amount satisfying N (NH)₄ ⁺):n(PO₄ ^3-) 1: 0.6-1, wherein N (NH)₄ ⁺) Representing the total NH in solution₄ ⁺The amount of substance(s) of (c).

In the process of removing ammonia nitrogen by a struvite method, N (NH) is added under the alkaline condition according to the reaction mechanism₄ ⁺):n(Mg²⁺):n(PO₄ ^3-) The reaction is carried out at a ratio of 1:1:1 to generate struvite sediment. After a plurality of times of experimental verification, N (NH) is obtained₄ ⁺):n(Mg²⁺)＝1:1～1.4，n(NH₄ ⁺):n(PO₄ ^3-) The ammonia nitrogen removal effect can be better within the range of 1: 0.6-1. After fermentation experiments were performed, higher solvent yields were obtained.

As a further improvement of the scheme, the calcium salt is calcium oxide, the alkali liquor is sodium hydroxide solution, and the pH value of the solution is adjusted to 8.0-10.0 by the alkali liquor; in the step (3), the macroporous adsorption resin comprises one or a mixture of more of non-polar resin, medium-polar resin and polar resin, and the addition amount of the macroporous adsorption resin is 2-12% of the mass of the molasses; the shaking mode is shaking by a shaking table, and the shaking time is 15-90 min.

During the refining and detoxicating process of molasses, calcium salt is first added and magnesium salt is then added to prevent Mg²⁺With Ca²⁺Competitive PO₄ ^3-Formation of calcium phosphate precipitate, thereby disfavoring NH₄ ⁺And (4) removing. The struvite method is to remove ammonia nitrogen and PO in solution simultaneously₄ ^3-One of the most commonly used methods is by adding a quantity of magnesium,Phosphorus precipitant, PO under alkaline conditions₄ ^3-、NH₄ ⁺And Mg²⁺The reaction is carried out according to the mass ratio of 1:1:1 to generate insoluble magnesium ammonium phosphate, namely struvite sediment, and the insoluble magnesium ammonium phosphate can be removed by further filtration. The colloid, ash and other fermentation inhibitors in molasses are subjected to mutual aggregation of colloidal particles through the action of electric neutralization, adsorption, bridging and the like by macromolecular inorganic and organic flocculants such as polyaluminium chloride, polyferric sulfate, polyacrylamide and the like to form floccules which are then precipitated. Although part of pigment of molasses can be removed in the struvite precipitation and flocculation process in the process, the effect is limited, so that the decoloring is further performed through macroporous adsorption resin which has higher specific surface area, and especially the super-crosslinked macroporous adsorption resin has good adsorption performance on pigment molecular groups. Meanwhile, the decolorized resin can be repeatedly washed by the mixed solution of absolute ethyl alcohol and pure water for regeneration, can be repeatedly utilized for many times, does not need to additionally use acid, alkali and other organic solvents in the regeneration process, and is environment-friendly and environment-friendly.

The second aspect of the invention provides a method for producing acetone and butanol by fermentation after refining and detoxification of molasses, which comprises the following steps:

(1) ash removal and colloid removal: diluting molasses, adding acid liquor to adjust the pH value of the diluted molasses until the solution is acidic, heating the solution in water bath to hydrolyze non-reducing sugar in the molasses into reducing sugar, adding a flocculating agent, stirring, standing to flocculate and settle colloid, cooling, taking supernatant, adding calcium salt to adjust the pH value to be neutral, and centrifugally filtering calcium sulfate precipitate to obtain clear liquid;

(2) dephosphorization and denitrogenation: adding a magnesium-containing inorganic compound and a phosphorus-containing inorganic compound into the clear liquid, stirring, adjusting the pH to be alkaline by using an alkali liquor, generating struvite sediment, and filtering the sediment to obtain clear liquid;

(3) and (3) decoloring: adding macroporous adsorption resin into the clarified liquid, shaking for decolorization, and filtering to obtain filtrate, i.e. refined and detoxified molasses solution;

(4) domesticating fermented thalli: preparing the refined and detoxified molasses solution into domestication culture media with different concentrations, sequentially inoculating clostridium acetobutylicum from a low molasses concentration culture medium to a high molasses concentration culture medium for gradual domestication culture according to the sequence of molasses concentration in the domestication culture media from low to high, and obtaining a domesticated acetobutanol fermentation strain after inoculating the clostridium acetobutylicum to the culture medium with the highest molasses concentration for culture;

(5) and (3) acetone butanol fermentation: inoculating the acclimated acetone-butanol fermentation strain into the sterilized refined detoxified molasses culture medium, adding a nitrogen source for constant-temperature culture, and fermenting to produce acetone and butanol.

As a further improvement of the scheme, in the step (1), the molasses is diluted to a baume degree of 15-30 DEG Be; the acid solution comprises sulfuric acid or phosphoric acid, and the pH value of the solution is adjusted to 1.5-3.5 by the acid solution; the water bath heating temperature is 60-95 ℃, and the heating time is 0.5-3 h.

As a further improvement of the scheme, in the step (1), the flocculant is an inorganic flocculant, an organic flocculant or a mixture of the inorganic flocculant and the organic flocculant, the inorganic flocculant comprises polyaluminium chloride, polyferric sulfate or polyaluminium ferric chloride, the organic flocculant comprises polyacrylamide, the addition amount of the inorganic flocculant is 50-300 ppm, and the addition amount of the organic flocculant is 5-20 ppm.

As a further improvement of the above scheme, in the step (2), the inorganic compound containing magnesium comprises one or more of magnesium oxide, magnesium hydroxide, magnesium chloride, magnesium sulfate and magnesium carbonate, and the inorganic compound containing phosphorus comprises one or more of phosphoric acid, disodium hydrogen phosphate, dipotassium hydrogen phosphate and trisodium phosphate; the addition amount of the magnesium-containing inorganic compound satisfies N (NH)₄ ⁺):n(Mg²⁺) 1:1 to 1.4, wherein the phosphorus-containing inorganic compound is added in an amount satisfying N (NH)₄ ⁺):n(PO₄ ^3-)＝1:0.6～1。

As a further improvement of the scheme, the calcium salt is calcium oxide, the alkali liquor is sodium hydroxide solution, and the pH value of the solution is adjusted to 8.0-10.0 by the alkali liquor; in the step (3), the macroporous adsorption resin comprises one or a mixture of more of non-polar resin, medium-polar resin and polar resin, and the addition amount of the macroporous adsorption resin is 2-12% of the mass of the molasses; the shaking mode is shaking by a shaking table, and the shaking time is 15-90 min.

As a further improvement of the above scheme, in the step (4), the acclimation culture solution is a mixture of a corn fermented glutinous rice culture solution and a refined and detoxified molasses solution.

As a further improvement of the scheme, in the step (4), the concentration of molasses in the low-molasses-concentration domestication culture medium is 5-10%, and the domestication time of clostridium acetobutylicum in the low-molasses-concentration domestication culture medium is 12-24 h; the concentration of molasses in the culture solution is 10-100% during step-by-step acclimation culture, the molasses is gradually increased step by step, and the step-by-step acclimation culture time is 12-48 h respectively; the culture temperature of the clostridium acetobutylicum during acclimation is 34-37 ℃.

The invention uses refined molasses fermentation liquor to domesticate the strain. The molasses has very complex components, and still has certain chromatic value and other fermentation inhibitors after refining and detoxification. The method domesticates clostridium acetobutylicum, and sequentially inoculates the clostridium acetobutylicum from a low-molasses-concentration culture medium to a high-molasses-concentration culture medium for gradual domestication culture to obtain a strain with good molasses tolerance.

As a further improvement of the scheme, the macroporous adsorption resin used in the step (3) is washed by a mixed solution of absolute ethyl alcohol and pure water, dried after washing, and circularly and repeatedly used in the step (3); the volume ratio of the absolute ethyl alcohol to the pure water in the mixed solution is 1-10: 1, and the volume ratio of the macroporous adsorption resin to the mixed solution is 1: 1-5 during washing; the drying temperature is 70-90 ℃, and the drying time is 30-90 min.

As a further improvement of the scheme, in the step (5), the nitrogen source is an organic nitrogen source and comprises one or a mixture of more of soybean meal, bran and yeast extract powder, and the addition amount of the nitrogen source is 1-2% of the mass of the fermentation liquor; the constant-temperature culture time is 48-120 h.

Compared with the prior art, the invention has the beneficial effects that:

1. excessive ammonia nitrogen in molasses is removed by using a struvite method, the inhibition of ammonia nitrogen on fermentation reaction is reduced, and the fermentation yield of acetone and butanol is improved;

2. the molasses is refined, detoxified and decolored by using macroporous adsorption resin, so that the quality of a fermentation product and the fermentation efficiency are improved;

3. the used macroporous adsorption resin can be recycled, regenerated and reused, is economic and environment-friendly, and reduces the cost of the decoloring process;

4. cheap and easily available industrial sugar production waste molasses is used as a substrate for acetone butanol fermentation, so that the production cost of the biofuel is reduced, and the resource utilization of the industrial waste is realized.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

Hereinafter, unless otherwise specified, the reagents or the materials such as strains are conventional in the art.

Example 1:

a method for producing acetone and butanol by fermentation after refining and detoxification of molasses comprises the following steps:

(1) ash removal and colloid removal: diluting the cane molasses stock solution to Baume degree of 15 Be, adding phosphoric acid to adjust the pH value to 1.5, and heating in a water bath at 95 ℃ for 0.5 h; then standing and cooling to 50 ℃, adding 20ppm of polyacrylamide flocculant for flocculation and sedimentation, cooling to room temperature, taking supernatant liquor, adding calcium oxide into the supernatant liquor to adjust the pH value to 7.0, generating calcium sulfate precipitate, and centrifugally filtering the calcium sulfate precipitate to obtain clear liquid;

(2) dephosphorization and denitrogenation: the clear solution is pressed according to N (NH)₄ ⁺):n(Mg²⁺)＝1:1，n(NH₄ ⁺):n(PO₄ ^3-) Magnesium chloride and potassium dihydrogen phosphate were added in an amount ratio of 1:0.6, the solution was magnetically stirred while adjusting the pH to 8.0 with sodium hydroxide solution, and struvite precipitate (MAP, chemical formula MgNH) was formed₄PO₄·6H₂O), filtering and precipitating to obtain a clarified liquid;

(3) and (3) decoloring: adding 2 parts of polar resin into 100 parts of the clarified liquid obtained in the step (2) for shaking decolorization, shaking for 30min, and filtering to obtain filtrate, namely refined and detoxified molasses solution;

(4) resin regeneration: putting the polar resin used in the step (3) into a mixed solution of anhydrous ethanol and water with the same volume (the volume ratio of the anhydrous ethanol to the water in the mixed solution is 10:1), repeatedly washing for three times, drying for 1h at 90 ℃, and using the dried polar resin for repeating the decoloring operation of the step (3) for twice;

(5) domestication of fermentation thalli: mixing the molasses solution obtained after two decolorizations with the corn fermented glutinous rice culture solution to prepare acclimation culture media (1# to 5# culture media) with different molasses concentrations shown in Table 1; during domestication, sterilizing a No. 1 culture medium by using high-pressure steam at 115 ℃ for 40min, inoculating clostridium acetobutylicum strains with an inoculation amount of 5%, domesticating and culturing at 37 ℃ for 12h, then transferring the clostridium acetobutylicum strains with the inoculation amount of 5% to a No. 2 culture medium by using a needle tube, sequentially transferring the clostridium acetobutylicum strains into a next-stage culture medium from low molasses concentration to high molasses concentration after culturing at constant temperature for 24h, and finally obtaining domesticated strains in the No. 5 culture medium;

TABLE 1 acclimatization Medium preparation

	1#	2#	3#	4#	5#
						Refined molasses	2mL	4mL	8mL	14mL	20mL
Corn fermented glutinous rice	18mL	16mL	12mL	6mL	0mL

(6) And (3) acetone butanol fermentation: the obtained domesticated strain is inoculated into a sterilized refined detoxified molasses culture medium by the inoculation amount of 5 percent, 2 percent of bran in mass fraction is added as a nitrogen source, then the culture is carried out for 96 hours at constant temperature, meanwhile, a control group is designed (the control group is that the non-domesticated clostridium acetobutylicum strain is inoculated into molasses stock solution with the same Baume degree for the culture under the same condition), the sampling is carried out at regular time, and a gas chromatograph is used for detecting and analyzing the fermentation product, and the result is shown in Table 2.

TABLE 2 fermentation yields in control and experimental groups

The results in table 2 show that the yields of acetone, ethanol and n-butanol in the product obtained by the method of the present embodiment are significantly higher than those of the control group, which indicates that the method of the present embodiment can improve the quality of the fermentation liquid and the fermentation efficiency after refining and detoxifying molasses, thereby improving the yields of products such as acetone and butanol.

Example 2:

a method for producing acetone and butanol by fermentation after refining and detoxification of molasses comprises the following steps:

(1) ash removal and colloid removal: diluting the cane molasses stock solution to a Baume degree of 30 Be, adding phosphoric acid to adjust the pH value to 3.5, and heating in a water bath at 60 ℃ for 3 h; then standing and cooling to 30 ℃, adding 50ppm of polyaluminium chloride flocculant for flocculation and sedimentation, cooling to room temperature, taking supernatant liquor, adding calcium oxide into the supernatant liquor to adjust the pH value to 7.0, generating calcium sulfate precipitate, and centrifugally filtering the calcium sulfate precipitate to obtain clear liquid;

(2) dephosphorization and denitrogenation: the clear solution is pressed according to N (NH)₄ ⁺):n(Mg²⁺)＝1:1.2，n(NH₄ ⁺):n(PO₄ ^3-) Magnesium chloride and sodium dihydrogen phosphate were added in an amount ratio of 1:0.8, the solution was magnetically stirred while adjusting the pH to 10.0 with sodium hydroxide solution, and struvite precipitate (MAP, chemical formula MgNH) was formed₄PO₄·6H₂O), filtering and precipitating to obtain a clarified liquid;

(3) and (3) decoloring: taking 100 parts of the clarified liquid obtained in the step (2), adding 6 parts of medium-polarity resin, shaking for decolorization, shaking for 90min, and filtering to obtain filtrate, namely refined and detoxified molasses solution;

(4) resin regeneration: putting the medium-polarity resin used in the step (3) into a mixed solution of 5 times of volume of anhydrous ethanol and water (the volume ratio of the anhydrous ethanol to the water in the mixed solution is 5:1), repeatedly washing for three times, drying for 1.5h at 70 ℃, and using the dried medium-polarity resin for repeating the decoloring operation of the step (3) for three times;

(5) domestication of fermentation thalli: mixing the molasses solution obtained after three decolorizations with the corn fermented glutinous rice culture solution to prepare acclimation culture media (1# to 5# culture media) with different molasses concentrations shown in Table 3; during domestication, sterilizing a No. 1 culture medium by using high-pressure steam at 115 ℃ for 40min, inoculating clostridium acetobutylicum strains with an inoculation amount of 5%, domesticating and culturing at 34 ℃ for 24h, then transferring the clostridium acetobutylicum strains with the inoculation amount of 5% to a No. 2 culture medium by using a needle tube, sequentially transferring the clostridium acetobutylicum strains into a next-stage culture medium from low molasses concentration to high molasses concentration after culturing at constant temperature for 48h, and finally obtaining domesticated strains in the No. 5 culture medium;

TABLE 3 acclimatization Medium preparation

	1#	2#	3#	4#	5#
						Refined molasses	1mL	3mL	7mL	13mL	20mL
Corn fermented glutinous rice	19mL	17mL	13mL	7mL	0mL

(6) And (3) acetone butanol fermentation: the obtained domesticated strain is inoculated into a sterilized refined detoxified molasses culture medium in an inoculation amount of 5%, 1% of soybean meal in mass fraction is added as a nitrogen source, then constant-temperature culture is carried out for 48 hours, meanwhile, a control group is designed (the control group is that non-domesticated clostridium acetobutylicum strains are inoculated into molasses stock solution with the same baume degree for same-condition culture), sampling is carried out at regular time, and a fermentation product is detected and analyzed by using a gas chromatograph, and the results are shown in table 4.

TABLE 4 fermentation yields in control and experimental groups

The results in table 4 show that the yields of acetone, ethanol and n-butanol in the product obtained by the method of the present embodiment are significantly higher than those of the control group, which indicates that the quality of the fermentation liquid and the fermentation efficiency can be improved after the molasses is refined and detoxified by the method of the present embodiment, thereby improving the yields of products such as acetone, butanol and the like.

Example 3:

a method for producing acetone and butanol by fermentation after refining and detoxification of molasses comprises the following steps:

(1) ash removal and colloid removal: diluting the cane molasses stock solution to a Baume degree of 25 Be, adding sulfuric acid to adjust the pH value to 2.5, and heating in a water bath at 80 ℃ for 2 h; then standing and cooling to 25 ℃, adding 300ppm of polymeric ferric sulfate flocculant for flocculation and sedimentation, cooling to room temperature, taking supernatant liquor, adding calcium oxide into the supernatant liquor to adjust the pH value to 7.0, generating calcium sulfate precipitate, and centrifugally filtering the calcium sulfate precipitate to obtain clear liquid;

(2) dephosphorization and denitrogenation: the clear solution is pressed according to N (NH)₄ ⁺):n(Mg²⁺)＝1:1.4，n(NH₄ ⁺):n(PO₄ ^3-) Magnesium sulfate and phosphoric acid were added in an amount ratio of 1:1, the solution was magnetically stirred while adjusting the pH to 9.0 with sodium hydroxide solution, and struvite precipitate (MAP, chemical formula MgNH) was generated₄PO₄·6H₂O), filtering and precipitating to obtain a clarified liquid;

(3) and (3) decoloring: taking 100 parts of the clarified liquid obtained in the step (2), adding 12 parts of nonpolar resin, shaking for decolorization, shaking for 90min, and filtering to obtain filtrate, namely refined and detoxified molasses solution;

(4) resin regeneration: placing the nonpolar resin used in the step (3) into a mixed solution of 3 times of volume of anhydrous ethanol and water (the volume ratio of the anhydrous ethanol to the water in the mixed solution is 1:1), repeatedly washing for three times, drying for 30min at 80 ℃, and using the dried nonpolar resin for repeating the decoloring operation in the step (3) for two times;

(5) domestication of fermentation thalli: mixing the molasses solution obtained after two decolorizations with the corn fermented glutinous rice culture solution to prepare acclimation culture media (1# to 5# culture media) with different molasses concentrations shown in Table 5; during domestication, sterilizing a No. 1 culture medium by using high-pressure steam at 115 ℃ for 40min, inoculating clostridium acetobutylicum strains with an inoculation amount of 5%, domesticating and culturing at 35 ℃ for 24h, then transferring the clostridium acetobutylicum strains with the inoculation amount of 5% to a No. 2 culture medium by using a needle tube, sequentially transferring the clostridium acetobutylicum strains into a next-stage culture medium from low molasses concentration to high molasses concentration after culturing at constant temperature for 24h, and finally obtaining domesticated strains in the No. 5 culture medium;

TABLE 5 acclimatization Medium preparation

	1#	2#	3#	4#	5#
						Refined molasses	1.5mL	4.5mL	8.5mL	14.5mL	20mL
Corn fermented glutinous rice	18.5mL	15.5mL	11.5mL	5.5mL	0mL

(6) And (3) acetone butanol fermentation: the obtained domesticated strain is inoculated into a sterilized refined detoxified molasses culture medium in an inoculation amount of 5%, yeast extract powder with the mass fraction of 1.5% is added as a nitrogen source, then the mixture is cultured at constant temperature for 120h, meanwhile, a control group is designed (the control group is that the non-domesticated clostridium acetobutylicum strain is inoculated into molasses stock solution with the same Baume degree for the same condition culture), sampling is carried out at regular time, and a gas chromatograph is used for detecting and analyzing fermentation products, and the results are shown in Table 6.

TABLE 6 fermentation yields in control and experimental groups

The results in table 6 show that the yields of acetone, ethanol and n-butanol in the product obtained by the method of the present embodiment are significantly higher than those of the control group, which indicates that the method of the present embodiment can improve the quality of the fermentation liquid and the fermentation efficiency after refining and detoxifying molasses, thereby improving the yields of products such as acetone and butanol.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.