A method for producing lactic acid from bagasse

Abstract

The invention discloses a method for producing lactic acid from bagasse. The method comprises the following steps: grinding and filtering bagasse: adding water to the bagasse, carrying out wet grinding on the bagasse by virtue of a disc mill and sieving the bagasse; carryin gout green liquor-ethanol coupling pretreatment: carrying out a pretreatment course in a pressure-proof reaction kettle, adding the ground bagasse to the reactor and adding a green liquor, wherein heating temperature is 140-145 DEG C and reaction duration is 2-4h; filtering after the pretreatment so as to obtain solid residues; carrying out synchronous saccharification and fermentation: adding cellulase and lactobacillus strain to the solid residues obtained from pretreatment in a mode of taking the solid residues as a fermentation substrate, and reacting at 45 DEG C at pH value of 4.8-5.0 for 72-96h so as to produce the lactic acid. The method for producing the lactic acid from bagasse disclosed by the invention is high in conversion rate of hydrolyzing cellulase into cellulose and semi-cellulose; and the utilization rate of bagasse resource component is high and production cost is low.

Description

technical field

[0001] The invention relates to the technical field of biochemistry and chemical engineering, in particular to a method for producing lactic acid from bagasse. Background technique

[0002] Bagasse is a by-product of the sugar industry. It is the fibrous residue left after extracting sugar juice by different methods. Its composition is mainly cellulose (43.6%), hemicellulose (21.5%) and lignin (26.4%). , contains a small amount of protein, less starch and soluble sugar. Compared with other fiber raw materials, bagasse has the characteristics of concentrated sources, large output, simple collection, convenient transportation, high total cellulose content, uniform properties, etc., and its physical and chemical composition are suitable for use as raw materials for biotransformation. Bagasse raw material is rich in cellulose, hemicellulose and lignin. When using cellulase to hydrolyze monosaccharides, the cellulase must be contacted and adsorbed on the cellulos...

Examples

Embodiment 1

[0023] The present embodiment provides a kind of method of producing lactic acid by bagasse, specifically:

[0024] The bagasse is pulverized by adding water to a disk mill, and sieved by an industrial vibrating sieve through a 20-mesh sieve. The pretreatment process is carried out in a pressure-resistant reactor, the mass percentage of bagasse is 10% (w / v), and the reaction is heated at 145° C. for 3 hours. Ethanol: water: 1:1 (V / V), green liquid (sodium carbonate is 75.2g / L, sodium hydroxide is 23.0g / L, iron ion is 1.14g / L, calcium ion is 0.39g / L, pH13. 3. Taken from a paper mill in Shandong) dosage: 1.5ml / (g substrate). Filtration is performed after pretreatment, and the filtrate is separated by acid precipitation to separate lignin, then concentrated to recover ethanol, and the residue is burned to recover heat energy and green liquor. The solid filter residue directly enters the synchronous saccharification and fermentation to produce lactic acid. Add 50 g of pretreate...

Embodiment 2

[0027] The present embodiment provides a kind of method of producing lactic acid by bagasse, specifically:

[0028] The bagasse is pulverized by adding water to a disk mill, and sieved by an industrial vibrating sieve through a 20-mesh sieve. The pretreatment process is carried out in a pressure-resistant reactor, the mass percentage of bagasse is 10% (w / v), and the reaction is heated at 140° C. for 2 hours. Ethanol: water: 1:1 (V / V), the amount of green solution: 0.5ml / (g substrate). Filtration is performed after pretreatment, and the filtrate is separated by acid precipitation to separate lignin, then concentrated to recover ethanol, and the residue is burned to recover heat energy and green liquor. The solid filter residue directly enters the synchronous saccharification and fermentation to produce lactic acid. Add 50 g of pretreated bagasse and 5 g of tea seed cake to 1 liter of fermentation system, and use 10% NaOH or 10% H 2 SO 4 The solution adjusted the pH of the s...

Embodiment 3

[0030] The present embodiment provides a kind of method of producing lactic acid by bagasse, specifically:

[0031] The bagasse is pulverized by adding water to a disk mill, and sieved by an industrial vibrating sieve through a 20-mesh sieve. The pretreatment process is carried out in a pressure-resistant reactor, the mass percentage of bagasse is 10% (w / v), and the reaction is heated at 140° C. for 4 hours. Ethanol: water ratio: 1:1 (V / V), green solution dosage: 1.0ml / (g substrate). Filtration is performed after pretreatment, and the filtrate is separated by acid precipitation to separate lignin, then concentrated to recover ethanol, and the residue is burned to recover heat energy and green liquor. The solid filter residue directly enters the synchronous saccharification and fermentation to produce lactic acid. Add 50 g of pretreated bagasse and 5 g of tea seed cake to 1 liter of fermentation system, and use 10% NaOH or 10% H 2 SO 4 The solution adjusted the pH of the sy...

technical field

[0001] The invention relates to the technical field of biochemistry and chemical engineering, in particular to a method for producing lactic acid from bagasse. Background technique

[0002] Bagasse is a by-product of the sugar industry. It is the fibrous residue left after extracting sugar juice by different methods. Its composition is mainly cellulose (43.6%), hemicellulose (21.5%) and lignin (26.4%). , contains a small amount of protein, less starch and soluble sugar. Compared with other fiber raw materials, bagasse has the characteristics of concentrated sources, large output, simple collection, convenient transportation, high total cellulose content, uniform properties, etc., and its physical and chemical composition are suitable for use as raw materials for biotransformation. Bagasse raw material is rich in cellulose, hemicellulose and lignin. When using cellulase to hydrolyze monosaccharides, the cellulase must be contacted and adsorbed on the cellulos...

Examples

Embodiment 1

[0023] The present embodiment provides a kind of method of producing lactic acid by bagasse, specifically:

[0024] The bagasse is pulverized by adding water to a disk mill, and sieved by an industrial vibrating sieve through a 20-mesh sieve. The pretreatment process is carried out in a pressure-resistant reactor, the mass percentage of bagasse is 10% (w / v), and the reaction is heated at 145° C. for 3 hours. Ethanol: water: 1:1 (V / V), green liquid (sodium carbonate is 75.2g / L, sodium hydroxide is 23.0g / L, iron ion is 1.14g / L, calcium ion is 0.39g / L, pH13. 3. Taken from a paper mill in Shandong) dosage: 1.5ml / (g substrate). Filtration is performed after pretreatment, and the filtrate is separated by acid precipitation to separate lignin, then concentrated to recover ethanol, and the residue is burned to recover heat energy and green liquor. The solid filter residue directly enters the synchronous saccharification and fermentation to produce lactic acid. Add 50 g of pretreate...

Embodiment 2

[0027] The present embodiment provides a kind of method of producing lactic acid by bagasse, specifically:

[0028] The bagasse is pulverized by adding water to a disk mill, and sieved by an industrial vibrating sieve through a 20-mesh sieve. The pretreatment process is carried out in a pressure-resistant reactor, the mass percentage of bagasse is 10% (w / v), and the reaction is heated at 140° C. for 2 hours. Ethanol: water: 1:1 (V / V), the amount of green solution: 0.5ml / (g substrate). Filtration is performed after pretreatment, and the filtrate is separated by acid precipitation to separate lignin, then concentrated to recover ethanol, and the residue is burned to recover heat energy and green liquor. The solid filter residue directly enters the synchronous saccharification and fermentation to produce lactic acid. Add 50 g of pretreated bagasse and 5 g of tea seed cake to 1 liter of fermentation system, and use 10% NaOH or 10% H 2 SO 4 The solution adjusted the pH of the s...

Embodiment 3

[0030] The present embodiment provides a kind of method of producing lactic acid by bagasse, specifically:

[0031] The bagasse is pulverized by adding water to a disk mill, and sieved by an industrial vibrating sieve through a 20-mesh sieve. The pretreatment process is carried out in a pressure-resistant reactor, the mass percentage of bagasse is 10% (w / v), and the reaction is heated at 140° C. for 4 hours. Ethanol: water ratio: 1:1 (V / V), green solution dosage: 1.0ml / (g substrate). Filtration is performed after pretreatment, and the filtrate is separated by acid precipitation to separate lignin, then concentrated to recover ethanol, and the residue is burned to recover heat energy and green liquor. The solid filter residue directly enters the synchronous saccharification and fermentation to produce lactic acid. Add 50 g of pretreated bagasse and 5 g of tea seed cake to 1 liter of fermentation system, and use 10% NaOH or 10% H 2 SO 4 The solution adjusted the pH of the sy...

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