A method for simultaneous fermentation of cassava residues to produce ethanol and hydrogen

Abstract

The invention discloses a method for simultaneously producing ethanol and hydrogen by using cassava residue through fermentation. The method comprises the following steps of: preparing two kinds of thermo-anaerobes and yeast seed liquor; preparing a fermentation medium and sterilizing; performing thermophilic fermentation and collecting the hydrogen; and performing ethanol fermentation and the like. In the integrated fermentation process, after the thermophilic fermentation is performed for 72 to 108 hours, yeast is inoculated, fermentation is continued for 12 to 24 hours, fermented liquor has the alcohol content of more than 7.12g / L, the fermentation efficiency is over 75 percent and the fermentation is stopped. The cassava residue is a waste in the cassava starch industry, contains fine-particle starch and cellulose, has a larger specific surface area, is easily hydrolyzed and utilized by enzyme producing microbes without pretreatment, can be used for integrated fermentation of the ethanol and the hydrogen without additional enzyme, has the characteristic of negative cost, can be changed into treasure, and solves the problem of environmental pollution in the cassava starch industry.

Description

technical field

[0001] The invention relates to the field of microbial fermentation production, in particular to a method of using cassava residue, a waste of the cassava starch industry, as a raw material, using two thermophilic bacteria to co-cultivate hydrogen and hydrolyze the raw material, and then using yeast to rapidly ferment the method for producing alcohol. Background technique

[0002] The gradual depletion of fossil energy requires us to develop alternative, sustainable and clean new energy sources. In recent years, the production of hydrogen and fuel alcohol has also been increasing. Using various biomass and industrial and agricultural wastes as raw materials is considered to be an effective way to reduce the cost of new energy and replace traditional energy. However, at present, most energy alcohol is produced from cornstarch or sugar crops, which leads to food shortage and price rise, and the cost of raw materials is very high, which hinders the development o...

Examples

Embodiment 1

[0024] The method for producing ethanol and hydrogen by simultaneous fermentation of cassava residues, the specific process is as follows:

[0025] (1) Preparation of thermophilic anaerobic bacteria seed liquid: the Clostridium thermocellum After activation in 10mL vials and amplification in 100mL serum bottles, cultured for 18 hours OD 600 ~0.6 seed solution; the medium is MTC medium, and the main components of the medium are A, B, C, D, and E liquids, and the five components are 45:2:1:1:1 ( V / V ) mixed with a sterile syringe. Liquid A is 3 g / L cellulose. Solution B: 50 g / L tripotassium citrate, 31.25 g / L citric acid monohydrate, 25 g / L sodium sulfate, 25 g / L potassium dihydrogen phosphate, 62.5 g / L sodium bicarbonate; solution C: chlorine Ammonium chloride 75 g / L, urea 250 g / L, yeast extract 50 g / L; liquid D: magnesium chloride hexahydrate 50 g / L, ferrous chloride tetrahydrate 5 g / L, calcium chloride dihydrate 10 g / L g / L, cysteine ​​hydrochloride monohydrate 50 g...

Embodiment 2

[0032] The method for producing ethanol and hydrogen by simultaneous fermentation of cassava residues, the specific process is as follows:

[0033] (1) Preparation of thermophilic anaerobic bacteria seed solution: store at -20°C Thermoanaerobacterium aotearoense After activation in 10mL vials and amplification in 100mL serum bottles, cultured for 24 hours OD 600 ~0.8 seed solution; the medium is MTC medium, and the main components of the medium are A, B, C, D, and E liquids, and the five components are 45:2:1:1:1 ( V / V ) mixed with a sterile syringe. Liquid A is 5 g / L xylose. Solution B: 50 g / L tripotassium citrate, 31.25 g / L citric acid monohydrate, 25 g / L sodium sulfate, 25 g / L potassium dihydrogen phosphate, 62.5 g / L sodium bicarbonate; solution C: chlorine Ammonium chloride 75 g / L, urea 250 g / L, yeast extract 50 g / L; liquid D: magnesium chloride hexahydrate 50 g / L, ferrous chloride tetrahydrate 5 g / L, calcium chloride dihydrate 10 g / L g / L, cysteine ​​hydrochlor...

Embodiment 3

[0040] The method for producing ethanol and hydrogen by simultaneous fermentation of cassava residues, the specific process is as follows:

[0041] (1) Preparation of thermophilic anaerobic bacteria seed solution: store at -196°C Clostridium thermocellum with Thermoanaerobacterium aotearoense After 10mL cillin bottle activation and 100mL serum bottle amplification, the yellow substance was obtained after culturing for 48 hours. Clostridium thermocellum seed liquid and OD 600 ~1.1 Thermoanaerobacterium aotearoense Seed solution; the culture medium adopts MTC medium, and the main components of the medium are A, B, C, D, and E liquids, and the five components are formulated according to 45:2:1:1:1 ( V / V ) mixed with a sterile syringe. bacteria Clostridium thermocellum with Thermoanaerobacterium aotearoense The liquid A in the solution was 3 g / L of cellulose or 5 g / L of xylose. Solution B: 50 g / L tripotassium citrate, 31.25 g / L citric acid monohydrate, 25 g / L sodi...

technical field

[0001] The invention relates to the field of microbial fermentation production, in particular to a method of using cassava residue, a waste of the cassava starch industry, as a raw material, using two thermophilic bacteria to co-cultivate hydrogen and hydrolyze the raw material, and then using yeast to rapidly ferment the method for producing alcohol. Background technique

[0002] The gradual depletion of fossil energy requires us to develop alternative, sustainable and clean new energy sources. In recent years, the production of hydrogen and fuel alcohol has also been increasing. Using various biomass and industrial and agricultural wastes as raw materials is considered to be an effective way to reduce the cost of new energy and replace traditional energy. However, at present, most energy alcohol is produced from cornstarch or sugar crops, which leads to food shortage and price rise, and the cost of raw materials is very high, which hinders the development o...

Examples

Embodiment 1

[0024] The method for producing ethanol and hydrogen by simultaneous fermentation of cassava residues, the specific process is as follows:

[0025] (1) Preparation of thermophilic anaerobic bacteria seed liquid: the Clostridium thermocellum After activation in 10mL vials and amplification in 100mL serum bottles, cultured for 18 hours OD 600 ~0.6 seed solution; the medium is MTC medium, and the main components of the medium are A, B, C, D, and E liquids, and the five components are 45:2:1:1:1 ( V / V ) mixed with a sterile syringe. Liquid A is 3 g / L cellulose. Solution B: 50 g / L tripotassium citrate, 31.25 g / L citric acid monohydrate, 25 g / L sodium sulfate, 25 g / L potassium dihydrogen phosphate, 62.5 g / L sodium bicarbonate; solution C: chlorine Ammonium chloride 75 g / L, urea 250 g / L, yeast extract 50 g / L; liquid D: magnesium chloride hexahydrate 50 g / L, ferrous chloride tetrahydrate 5 g / L, calcium chloride dihydrate 10 g / L g / L, cysteine ​​hydrochloride monohydrate 50 g...

Embodiment 2

[0032] The method for producing ethanol and hydrogen by simultaneous fermentation of cassava residues, the specific process is as follows:

[0033] (1) Preparation of thermophilic anaerobic bacteria seed solution: store at -20°C Thermoanaerobacterium aotearoense After activation in 10mL vials and amplification in 100mL serum bottles, cultured for 24 hours OD 600 ~0.8 seed solution; the medium is MTC medium, and the main components of the medium are A, B, C, D, and E liquids, and the five components are 45:2:1:1:1 ( V / V ) mixed with a sterile syringe. Liquid A is 5 g / L xylose. Solution B: 50 g / L tripotassium citrate, 31.25 g / L citric acid monohydrate, 25 g / L sodium sulfate, 25 g / L potassium dihydrogen phosphate, 62.5 g / L sodium bicarbonate; solution C: chlorine Ammonium chloride 75 g / L, urea 250 g / L, yeast extract 50 g / L; liquid D: magnesium chloride hexahydrate 50 g / L, ferrous chloride tetrahydrate 5 g / L, calcium chloride dihydrate 10 g / L g / L, cysteine ​​hydrochlor...

Embodiment 3

[0040] The method for producing ethanol and hydrogen by simultaneous fermentation of cassava residues, the specific process is as follows:

[0041] (1) Preparation of thermophilic anaerobic bacteria seed solution: store at -196°C Clostridium thermocellum with Thermoanaerobacterium aotearoense After 10mL cillin bottle activation and 100mL serum bottle amplification, the yellow substance was obtained after culturing for 48 hours. Clostridium thermocellum seed liquid and OD 600 ~1.1 Thermoanaerobacterium aotearoense Seed solution; the culture medium adopts MTC medium, and the main components of the medium are A, B, C, D, and E liquids, and the five components are formulated according to 45:2:1:1:1 ( V / V ) mixed with a sterile syringe. bacteria Clostridium thermocellum with Thermoanaerobacterium aotearoense The liquid A in the solution was 3 g / L of cellulose or 5 g / L of xylose. Solution B: 50 g / L tripotassium citrate, 31.25 g / L citric acid monohydrate, 25 g / L sodi...