CN101386872A - Method for preparing ethanol by raw materials containing cellulose - Google Patents
Method for preparing ethanol by raw materials containing cellulose Download PDFInfo
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- CN101386872A CN101386872A CNA200710121559XA CN200710121559A CN101386872A CN 101386872 A CN101386872 A CN 101386872A CN A200710121559X A CNA200710121559X A CN A200710121559XA CN 200710121559 A CN200710121559 A CN 200710121559A CN 101386872 A CN101386872 A CN 101386872A
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Abstract
The invention discloses a method for preparing alcohol by adopting a raw material containing cellulose, which comprises the steps of exploding the raw material containing the cellulose by steam, enzymolyzing an obtained steam explosion product, and fermenting an obtained enzymolysis product, wherein a method for exploding the raw material containing the cellulose by steam comprises the following steps: the raw material containing the cellulose is continuously conveyed into a thermal insulation pressure device, and partial raw material containing the cellulose is released to normal pressure in the thermal insulation pressure device every 5 to 12 seconds after the raw material containing the cellulose is maintained for 3 to 10 minutes in the thermal insulation pressure device. The method for preparing the alcohol by continuously exploding the raw material containing the cellulose by steam can ensure that the raw material containing the cellulose continuously and fully absorbs moisture under steady conditions, ensure that water vapor dashes out during the pressure release, and fully destroys a lignin sheath used to embed the cellulose and hemicellulose in the raw material containing the cellulose to increase the proportion of the cellulose, which can contact enzyme, in the raw material containing the cellulose, thereby improving the yield of the alcohol.
Description
Technical field
The invention relates to a kind of preparation alcoholic acid method, more specifically, is about adopting the feedstock production alcoholic acid method of cellulose.
Background technology
Prior art can be used the feedstock production ethanol of cellulose, and the raw material of described cellulose is generally the root of plant, stem and leaf, comprises stalk.Described stalk is remaining, stem and a leaf behind farm crop (being generally herbaceous plant) results seed or the fruit, be mainly stem and leaf, as comprise the cereal grass of maize straw, jowar stalk, rice straw, wheat straw stalk, comprise stalk and the cotton stalk of the oilseed plant of beanstalk.Mierocrystalline cellulose, hemicellulose and xylogen are combined closely by covalent linkage and/or non covalent bond in the stalk, and the three accounts for the 70-90 weight % of stalk dry-matter gross weight.The content of Mierocrystalline cellulose, hemicellulose and xylogen can the difference to some extent with the different piece of the farm crop of different sources or farm crop in the stalk.
Mierocrystalline cellulose can be degraded into glucose under the effect of cellulase, hemicellulose can be degraded into wood sugar under the effect of hemicellulase, glucose and wood sugar may be used to fermentative production of ethanol, can prepare ethanol by glucose fermentation such as yeast saccharomyces cerevisiae, pichia stipitis can prepare ethanol by xylose-fermenting.But xylogen is a kind of non-polysaccharide material that is polymerized by phenyl-propane, thereby water insoluble being difficult to degrades.Since xylogen by the derivative of aromatic hydrocarbon with-C-C-key ,-the O-key is crosslinked in length and breadth, side chain and hemicellulose are with covalent bonds, form fine and close network structure---xylogen sheath embedding Mierocrystalline cellulose and hemicellulose, thereby making cellulase and hemicellulase be difficult for contacting with hemicellulose with Mierocrystalline cellulose, the result causes stalk also to be difficult to degraded.
Existing feedstock production alcoholic acid method with cellulose generally adopts steam explosion and/or acid hydrolysis to carry out pre-treatment, to destroy the embedding of xylogen to Mierocrystalline cellulose and hemicellulose.Though acid hydrolysis can destroy xylogen, also can destroy Mierocrystalline cellulose, reduce the productive rate of glucose then, and also need after the acid hydrolysis to add in a large amount of alkali and could carry out enzymolysis and fermentation.Therefore more tendency is only finished preprocessing process by steam explosion, reaches the embedding effect of xylogen to Mierocrystalline cellulose and hemicellulose that destroy.
Document " to the introduction of straw biomass to alcohol conversion process " for example, Zhang Xuefeng, orchid is kindly helped secure the success of, wine brewing, the 29th the 4th phase of volume, 37-38 page or leaf, in July, 2002, disclose a kind of method of utilizing straw to produce alcohol, this method comprises to be removed maize straw after the stone deironing cleans, and cuts into 1.5 centimetres segment, water logging 40 minutes, feed 2.5 MPa steam, be incubated 8 minutes, pressure release, the steam explosion products of washing 1/10th, and this wooden enzyme produces cellulase in cultivating in described 1/10th steam explosion products, and the gained culture is mixed with other 9/10ths steam explosion products, is incubated 50 ℃ of hydrolysis 24 hours, obtain 6% liquid glucose after filtration, mineral membrane is condensed into the liquid glucose more than 20%, adds Xiu Hata yeast (0.8-1.2 hundred million/milliliter), ferments 24 hours, produce wine part 10%, distill 99.5% alcohol.
CN1117835C discloses a kind of method of dissolve with ethanol steam burst straw lignin prepare liquid fuel, and this method is a raw material with the steam puffed stalk, in autoclave, with the xylogen in the alcohol extraction steam puffed stalk; Obtain filtrate with vacuum filtration again, and steam puffed stalk is extracted slag carry out the synchronous saccharification solid state fermentation of ethanol through, alcohol extraction liquid and vacuum filtration gained filtrate are the liquid fuel of this method preparation.
The preparation method of described steam puffed stalk raw material comprises plant materials such as wheat straw, straw or the cornstalk steam-explosion jar of packing into of chopping, under 1.2-1.7 MPa pressure, keeps pressure 5-10 minute, and afterwards, instant decompression discharges.
The method of the xylogen in the described alcohol extraction steam puffed stalk is in autoclave, adds steam puffed stalk and ethanol, and steam puffed stalk and alcoholic acid volume ratio are 1:10-1:50, keeps 1-2 hour in the pressure range of 1.5-2.0 MPa.
Describedly steam puffed stalk is extracted slag carry out the synchronous saccharification solid state fermentation of ethanol through and be meant: in 33-35 ℃ of scope (fermentation), kept 14-16 hour, in 38-40 ℃ of scope (enzymolysis), keep 68 hours, and fermentation 2-3 days that hockets.
CN1193099C discloses a kind of use heat resistant type yeast and produced the alcoholic acid method from the lignin fiber cellulosic biomass, and this method may further comprise the steps:
It is the 15-30 millimeter that the lignin fiber cellulosic biomass is ground into granular size; The lignin fiber cellulosic biomass of pulverizing is carried out the vapor explosion pre-treatment, keep the pressure of 1-3 MPa and 190-230 ℃ temperature 1-10 minute time, cause explosive decompression afterwards according to the type of material therefor; Collect pretreated material and pass through filtering separation liquid and solid part, solid part is introduced in the fermentation storage; Adding concentration to the fermentation storage is that 15FPU/ restrains the cellulosic beta-glucosidase of cellulosic cellulase and 12.6 international unit/restrain; Give fermentation storage inoculation Marx Crewe Vickers yeast CECT the suspension of 10875 heat resistant type yeast cultures; Mixture was shaken under 42 ℃ 72 hours.
But in the feedstock production alcoholic acid method of existing employing cellulose, the steam explosion pre-treatment destroys inadequately the xylogen sheath of embedding Mierocrystalline cellulose and hemicellulose in the raw material of cellulose, thereby causes final alcohol yied low.In addition, the amount of the raw material of the cellulose that existing steam explosion method was handled in the unit time is less, thereby production efficiency is not high.
Summary of the invention
The objective of the invention is to overcome the low shortcoming of alcohol yied of the feedstock production alcoholic acid method preparation of existing employing cellulose, the feedstock production alcoholic acid method of the high employing cellulose of a kind of alcohol yied is provided.
The pretreatment process of the raw material of the cellulose of prior art adopts the intermittent type steam explosion usually, this method comprises that elder generation is delivered to steam blasting device with a collection of cellulose containing raw material, feed the pressure of steam to steam explosion, and insulation for some time, moment pressure release is then finished steam explosion and is collected steam explosion products; Then second batch of fibrous raw material is delivered in the steam blasting device, feeds the pressure of steam once more to steam explosion, and insulation for some time, moment pressure release is then finished steam explosion and is collected steam explosion products; And, according to the method described above subsequently fibrous raw material is carried out the intermittent type steam explosion according to treatment capacity.The present inventor finds, and is all identical as pressure and temperature even guarantee the condition of each steam explosion when adopting such steam explosion method, still, can't guarantee that but the explosion degree of the steam explosion products that obtains behind each steam explosion is all identical.The reason of inferring may be, because the amount of every batch of raw material of inserting the cellulose in the steam blasting device is more, and the factors such as instability of the difference of the accumulation mode of every batch of raw material or steam explosion condition cause can't guarantee to make and fully absorb water vapor in the short several minutes of whole cellulose containing raw materials after feeding steam, therefore, still have the raw material of most of cellulose owing to can't fully absorb water vapor, and can not be popped by its inner water vapour fully, cause that the xylogen sheath of embedding Mierocrystalline cellulose and hemicellulose can't fully be destroyed in the raw material of cellulose, reduce the cellulose ratios that can contact with enzyme in the raw material of cellulose, thereby reduced ethanol yield.In addition, the method for intermittent type steam explosion consumed time in the pre-treatment of raw material is longer, and the treatment capacity of raw material is lower in the unit time, thereby is unfavorable for the raising of production efficiency.
The invention provides a kind of feedstock production alcoholic acid method that adopts cellulose, this method comprises the raw material of steam blasting cellulose-containing, the steam explosion products that enzymolysis obtains, the enzymolysis product that fermentation obtains, wherein, the method of the raw material of steam blasting cellulose-containing comprises that the raw material with cellulose is delivered in the heat preservation pressure device continuously, make the raw material of cellulose in this heat preservation pressure device, keep making the raw material of the part cellulose in the described heat preservation pressure device be discharged into normal pressure second every 5-7 after 3-7 minute.
Method of the present invention adopts the method for continuous steam explosion that fibrous raw material is carried out pre-treatment, can make the described raw material successive of the whole cellulose in the steam blasting device of inserting under stable steam explosion condition, in the heat preservation pressure device, fully absorb aqueous vapor, and make the aqueous vapor of the raw material inside of cellulose change into water vapor, water vapour is gone out by the raw material inside of cellulose when pressure release, the xylogen sheath of embedding Mierocrystalline cellulose and hemicellulose in the raw material of abundant destruction cellulose, increase the cellulose ratios that can contact with enzyme in the raw material of cellulose, thereby improved ethanol yield effectively.And, the method of the raw material of steam blasting cellulose-containing of the present invention is that successive makes the raw material of cellulose be incubated and keep pressure in the heat preservation pressure device, successive is finished the steam explosion of raw material then, therefore, the treatment capacity of the raw material of the cellulose that method of the present invention was handled in the unit time is more, helps the raising of production efficiency.In addition, under the preferable case, the water content of controlling the raw material of the cellulose that is used for steam explosion is 30-60 weight %, can further guarantee under the steam explosion condition, to make the aqueous vapor of the raw material inside of cellulose to change into water vapor, helping when pressure release water vapour is gone out by the raw material inside of cellulose, with the xylogen sheath of embedding Mierocrystalline cellulose and hemicellulose in the raw material of abundant destruction cellulose, thereby further improve ethanol yield.
For example, under all identical situation of other steam explosion condition, the employing water content of embodiment 1 is that the alcohol yied that the fibrous feedstock production of 40 weight % obtains reaches 23.9%, the ethanol yield of embodiment 2 is 23.0%, and the alcohol yied of Comparative Examples 1 only is 18.2%, and increase rate is up to 26.4-31.3%.And the continuous steam explosion method of embodiment 1 per hour can be handled the raw material 400-500 kilogram of cellulose, and the steam explosion method of Comparative Examples 1 per hour can only be handled the raw material 180-260 kilogram of cellulose.
Description of drawings
Fig. 1 is the electron scanning micrograph of natural corn stalk;
Fig. 2 is the electron scanning micrograph according to stalk behind the method steam explosion of Comparative Examples 1 of the present invention;
Fig. 3 is the electron scanning micrograph according to stalk behind the method steam explosion of Comparative Examples 2 of the present invention;
Fig. 4 is the electron scanning micrograph according to stalk behind the method steam explosion of the embodiment of the invention 1.
Embodiment
According to the present invention, the feedstock production alcoholic acid method of described employing cellulose comprises the raw material of steam blasting cellulose-containing, the steam explosion products that enzymolysis obtains, the enzymolysis product that fermentation obtains, wherein, the method of the raw material of steam blasting cellulose-containing comprises that the raw material with cellulose is delivered in the heat preservation pressure device continuously, make the raw material of cellulose in this heat preservation pressure device, keep after 3-10 minute, after being preferably 4-7 minute, every 5-12 second, be preferably 7-10 and make the raw material of the part cellulose in the described heat preservation pressure device be discharged into normal pressure second.
According to the present invention, the raw material of described cellulose is to be delivered to continuously in the heat preservation pressure device, and is continued to transmit in this device, and is incubated and keeps pressure in this heat preservation pressure device.The specification of the different heat preservation pressure devices that industrial scale adopted is also different, therefore, the transfer rate of the heat preservation pressure device of different size is also different, the present invention is not particularly limited the transfer limes speed of the raw material of described cellulose, the transfer limes speed of the raw material of described cellulose kept 3-10 minute in this heat preservation pressure device as long as guarantee the raw material of described cellulose, so that in the temperature of this device, the aqueous vapor that pressure forms down can fully enter in the raw material of cellulose, water vapour is gone out when the pressure release by the raw material inside of cellulose, with the xylogen sheath of embedding Mierocrystalline cellulose and hemicellulose in the raw material of abundant destruction cellulose.
Described heat preservation pressure device can be various heat preservation pressure devices, as long as can make the raw material of the cellulose of continuous conveying reach the condition of steam explosion in this device.The condition of described continuous steam explosion can adopt the steam explosion condition of prior art routine, and as the temperature of steam explosion, promptly the temperature of heat preservation pressure device can be 180-200 ℃, more preferably 185-195 ℃; The pressure of described steam explosion, promptly the pressure of heat preservation pressure device can be 1.4-2.0 MPa, more preferably 1.5-1.6 MPa.Under above-mentioned steam explosion condition, can both fully destroy the xylogen sheath of stalk embedding Mierocrystalline cellulose and hemicellulose, realize purpose of the present invention.
Described raw material with the part cellulose in the heat preservation pressure device is discharged into the method that non-pressurized method can adopt various routines, for example, can realize by the pressure valve that control is arranged on the heat preservation pressure device, described pressure valve is arranged on the exit of heat preservation pressure device, when the pressure in the heat preservation pressure device reaches the pressure of described steam explosion, valve opening, make the raw material of the part cellulose in the heat preservation pressure device be discharged into normal pressure and ejection in the moment of valve opening, the described opening time is about 2-3 second, closing presure valve then, recover the temperature and pressure in the heat preservation pressure device, subsequently, every 5-12 second, be preferably 7-10 second, pressure valve can be opened so that the raw material of the part cellulose in the heat preservation pressure device is discharged into normal pressure automatically, closes automatically then, to realize the continuous steam explosion of fibrous raw material.
The described amount that at every turn is discharged into non-pressurized fibrous raw material is not particularly limited, the specification difference of the different heat preservation pressure devices that industrial scale adopted, the processing power of each steam explosion is also different, therefore, can select the device of different size for use according to producing needs, thus the amount of the each cellulose containing raw material of handling of decision.According to the present invention, under the preferable case, the raw material that at every turn is discharged into non-pressurized cellulose is the 6-15 weight % of cellulose containing raw material in the heat preservation pressure device, more preferably 8-12 weight %.Generally, the raw material that at every turn is discharged into non-pressurized cellulose is the 120-180 gram, is preferably the 120-150 gram.Generally speaking, the raw material of described cellulose is at the uniform velocity to carry, and therefore, the transfer rate of the raw material of cellulose remains unchanged the amount of the raw material of the cellulose in this heat preservation pressure device substantially.
In addition, when adopting the raw material of prior art steam blasting cellulose-containing, the raw material that it has been generally acknowledged that described cellulose is maize straw for example, fully water logging, can obtain the effect of better steam explosion, because fully water logging can make the raw material of described cellulose for example contain a large amount of water in maize straw inside, when steam explosion, the raw material of the described cellulose for example water of maize straw inside can be gasificated into water vapor, for example go out maize straw inside by the raw material of described cellulose during pressure release, with the raw material that fully the destroys described cellulose from inside to outside xylogen sheath of maize straw embedding Mierocrystalline cellulose and hemicellulose for example, the present inventor is surprised to find that, the water content of controlling the raw material of the cellulose that is used for steam explosion is 30-60 weight %, can further guarantee under the steam explosion condition, to make the aqueous vapor of the raw material inside of cellulose to change into water vapor, helping when pressure release water vapour is gone out by the raw material inside of cellulose, with the xylogen sheath of embedding Mierocrystalline cellulose and hemicellulose in the raw material of abundant destruction cellulose, thereby further improve ethanol yield.Therefore, under the preferable case, the water content of the raw material of described cellulose is 30-60 weight %, more preferably 35-50 weight %.
According to the present invention, can obtain the raw material that water content is the cellulose of 30-60 weight % by variety of way.The raw material of the different batches cellulose that there are differences for water content can carry out different processing, such as for the high stalk of water content, can 45-90 ℃ of oven dry part moisture, and make it water content and be reduced to 30-60 weight %; For the low stalk of water content, can adopt control water logging time method, the water content that increases stalk is to 30-60 weight %; Just in time at stalk, can directly carry out steam explosion for water content to 30-60 weight %.The water content of the raw material of the preferred described cellulose that is used for steam explosion is 35-50 weight %.Unless specified otherwise, the water content of the raw material of cellulose of the present invention all is meant the initial weight W1 of cellulose containing raw material and dries poor to the dried meter weight W 2 of the cellulose containing raw material of constant weight under 70-100 ℃, with the weight percent of the initial weight W1 of cellulose containing raw material, i.e. water content (weight %)=(W1-W2)/W1 * 100%.
Under the preferable case, continuous processing for the raw material of realizing cellulose, can drench carrying out water in the continuous conveying process before the raw material of cellulose is in being delivered to the heat preservation pressure device continuously, the water consumption that water drenches makes the water content of the raw material of cellulose remain on 30-60 weight %, be preferably 35-50 weight %, and then be delivered to continuously and carry out steam explosion in the heat preservation pressure device.
Described enzymolysis step can be finished by this area method commonly used, such as adding microbes producing cellulase and/or enzyme in steam explosion products, is incubated under the growth temperature of microbes producing cellulase and/or the great-hearted temperature of enzyme and finishes.Described microbes producing cellulase be can eccrine fiber the microbes producing cellulase of plain enzyme.Described enzyme comprises cellulase.
Because microorganism growth can produce by product, therefore the preferred enzyme that directly adds, the consumption of described enzyme is The more the better, for cost consideration, preferably with the dry weight basis of the raw material of every gram cellulose, the consumption of described cellulase is the 8-20 enzyme activity unit, more preferably with the dry weight basis of the raw material of every gram cellulose, and the 10-15 enzyme activity unit.The enzyme activity of cellulase of the present invention is according to American National renewable energy source laboratory (National Renewable Energy Laboratory, NREL) standard method that provides---cellulase activity is measured NREL LAP-006 and is measured, the enzyme activity unit of described cellulase is under the condition determination of this standard method regulation, and transforming 1 gram Whatman No.1 filter paper in 1 minute is the micrograms of the required enzyme of glucose.The temperature of described enzymolysis can be any optimum temperature of cellulase, is generally 45-55 ℃, more preferably 48-52 ℃.The longer the better on the time theory of described enzymolysis, considers plant factor, and the time of preferred described enzymolysis is 25-48 hour, more preferably 30-40 hour.The pH value of described enzymolysis can be generally 3.0-7.0 for the suitableeest any action pH of cellulase, and more preferably the pH value is 4.5-5.5.Because the fluctuation of pH value is little in the enzymolysis process, therefore the pH value of described enzymolysis can be regulated before adding enzyme according to this area method commonly used, for example earlier steam explosion products and water or substratum (are enzyme-addedly generally mixed with water, adding microbes producing cellulase generally mixes with the substratum of this microorganism) mix, the consumption of water or substratum is not particularly limited, the solid content that generally makes the gained mixture is 50-75 weight %, pH value according to the gained mixture, the mixture pH regulator that to treat enzymolysis with sulphuric acid soln or sodium hydroxide more preferably is adjusted to the pH value and is 4.5-5.5 to 3.0-7.0.
Described cellulase is a prozyme, comprises C at least
1The plain enzyme of fiber type, the plain enzyme of Cx fiber type and three kinds of enzymes of cellobiase.
C
1Enzyme can make the crystalline Mierocrystalline cellulose change amorphous Mierocrystalline cellulose into.
C
xThe plain enzyme of fiber type is divided into C again
X1Plain enzyme of fiber type and C
X2Two kinds of the plain enzymes of fiber type.C
X1The plain enzyme of fiber type is the endo-type cellulase, can be from the plain intramolecular action of hydration amorphous cellulose in β-1, and the 4-glycosidic link generates cellodextrin and cellobiose.C
X2The plain enzyme of fiber type is a kind of circumscribed-type cellulase, can act on β-1 from the non-reducing end of hydration non-cellulose molecule, and the 4-glycosidic link cuts off β-1 one by one, and the 4-glycosidic link generates glucose.
Cellobiase then acts on cellobiose, makes the cellobiose enzymolysis generate glucose.
The enzyme that preferred described enzymolysis uses also comprises hemicellulase.Because hemicellulase is degraded into water-soluble wood sugar with hemicellulose, so the enzyme that enzymolysis uses comprises hemicellulase, one side is the exposed fibers element more fully, increase the contact probability of Mierocrystalline cellulose and cellulase, hemicellulose degraded product wood sugar can be generated ethanol by the pichia stipitis fermentation on the other hand, and two aspect effects can increase alcohol yied.With the dry weight basis of the raw material of every gram cellulose, the consumption of described hemicellulase is the 4.4-8.8 enzyme activity unit.
The enzyme activity unit of hemicellulase of the present invention (U) is under 50 ℃, pH=4.8 condition, and it is that 1 weight % xylan solution produces the required enzyme amount of 1 microgram reducing sugar (in wood sugar) that per minute decomposes concentration.
The vigor of hemicellulase of the present invention refers to the unit of activity that every gram hemicellulase is had.It is that hydrolysis 1 weight % xylan produces reducing sugar (in wood sugar) under 4.8 the condition at 50 ℃, pH that the vigor of described hemicellulase utilizes hemicellulase, gained reducing sugar and excessive 3, color reaction takes place in 5-dinitrosalicylic acid (DNS), records the proportional mensuration of growing amount of the absorbance value and the reducing sugar (in wood sugar) of reaction solution 550 nanometers with spectrophotometer.Concrete measuring method is as follows:
Accurately take by weighing 1.000 gram xylans, dissolve, use deionized water constant volume to 100 milliliter then, obtain 1 weight % xylan solution with the 0.1 mol acetate-sodium acetate buffer of 0.5 milliliter of pH=4.8;
Take by weighing 30 gram Rochelle salts and put into 500 milliliters of Erlenmeyer flasks, after adding 16 gram NaOH, add 50 ml deionized water, dissolve, add 1 gram 3 with 5 ℃/minute speed heating in water bath to solid matters, 5-dinitrosalicylic acid, to dissolving, be cooled to room temperature, be settled to 100 milliliters with deionized water, can get 3,5-dinitrosalicylic acid (DNS) solution;
Wood sugar is dried to constant weight for 80 ℃, accurately take by weighing 1.000 grams and be dissolved in 1000 ml waters, it is anticorrosion to add 10 milligrams of sodiumazide, obtains the normal wood sugar soln of 1 mg/ml;
Accurately take by weighing 1.000 gram solid hemicellulases or pipette 1 milliliters of liquid hemicellulase stoste, 0.1 mol acetate-sodium acetate buffer dissolving with 0.5 milliliter of pH=4.8, use deionized water constant volume to 100 milliliter then, obtain diluting 100 times enzyme liquid to be measured;
Respectively will be in 2 milliliters of wood sugar gradient standardized solution (0.1 mg/ml of 60 minutes of 50 ℃ of heating in water bath, 0.2 mg/ml, 0.3 mg/ml, 0.4 mg/ml and 0.5 mg/ml, described wood sugar gradient standardized solution is mixed with the normal wood sugar soln of deionized water and 1 mg/ml) or deionized water (wood sugar blank), with 2 milliliters of DNS mixing boiling water baths 5 minutes, cooling, behind 15 milliliters of the deionized water constant volumes, absorbance value with spectrophotometer wood sugar gradient standardized solution behind difference assaying reaction under 550 nanometers, with the absorbance value is X-coordinate, and xylose concentration is an ordinate zou drawing standard curve.Can get regression equation y=bx+a by this typical curve, wherein, x is an absorbance value, and y is an xylose concentration, and a is the intercept of gained straight-line equation, and b is the slope of gained straight-line equation;
Get 0.1 mol acetate, one sodium acetate buffer solution (xylan blank) of 0.2 milliliter of enzyme liquid to be measured and 1.8 milliliters of described 1 weight % xylan solutions or pH=4.8, according to the step test light absorption value identical with above-mentioned wood sugar gradient standardized solution.And calculate the vigor of hemicellulase according to following formula:
X is the absorbance value of enzyme liquid to be measured in the formula, b is consistent to b in the regression equation of absorbance value and a with xylose concentration with a, n is the extension rate of enzyme, and 60 times that are expressed as enzymatic reaction were 60 minutes, and 5 are sampling multiple (having taken out 0.2 milliliter here from 1 milliliter of enzyme liquid to be measured tests).
Can determine the vigor of concrete hemicellulase according to aforesaid method, and then calculate the consumption of hemicellulase.
Can ferment pentoses and/or the microorganism of hexose may be used to fermenting process of the present invention because yeast saccharomyces cerevisiae is the microorganism of the zymohexose that ethanol-tolerant, by product are few, alcohol yied is high of widespread usage on the wine industry; Pichia stipitis for both can ferment pentoses also can zymohexose microorganism (referring to " pichia stipitis continuously ferment pentose and hexose generate alcohol ", Ji Gengsheng etc., Nanjing Forestry University's journal natural science edition, the 28th the 3rd phase of volume, the 9-13 page or leaf, 2004), therefore the employed yeast of preferred described fermentation is pichia stipitis and yeast saccharomyces cerevisiae.In every gram enzymolysis product, the employed zymic inoculum size of described fermentation is 10
3-10
8Colony-forming unit, more preferably 10
4-10
6Colony-forming unit.Employed yeast is fermented in the present invention can be for being purchased yeast solids preparation (such as dried yeast powder) or barms (such as the cereuisiae fermentum of ATCC numbering 2601).Described zymic colony-forming unit can be measured by means commonly known in the art, such as the methylene blue staining viable bacteria counting method.The concrete grammar of methylene blue staining viable bacteria counting method is as follows:
1 gram dried yeast powder is dissolved in 10 ml sterile waters, or 1 milliliter of actication of culture liquid is diluted to 10 milliliters with sterilized water, add 0.5 milliliter of 0.1 weight % methylene blue, be incubated 30 minutes down at 35 ℃.Under 10 times of opticmicroscopes,, can get the number of viable bacteria in 1 gram dry yeast or the 1 milliliter of actication of culture liquid, i.e. colony forming single-digit with the number (dead bacterium dyeing, viable bacteria is not dyeed) of viable bacteria in the solution after the blood counting chamber counting insulation.
Described yeast can adopt conventional method inoculation, for example adds the seed liquor of 5-15 volume % in enzymolysis product.Described seed liquor can be the aqueous solution or the culture medium solution of dry yeast, also can or be purchased the activated seed liquid of bacterial classification for dry yeast.The temperature of described fermentation can be any temperature that is suitable for yeast growth, is preferably 30-36 ℃, more preferably 32-35 ℃.The time of described fermentation can be for beginning from inoculation to occur to the decline phase of yeast growth the time of (being that fermentation time is that lag phase, logarithmic phase add stationary phase), and the time of preferred fermentation is 32-48 hour, more preferably 32-40 hour.Tunning ethanol can be with conventional method, according to requirement (requiring alcoholic acid purity to reach more than 99% such as the fuel alcohol) separation and refining of different Industrial products, such as distilling, concentrate, dewatering.
In addition, the pressure and temperature of steam explosion can be sterilized, for preventing that in enzymolysis process assorted bacterium (mainly being bacterium) pollutes the toxin of the enzyme activity that exerts an influence, and prevent that living contaminants influences the zymic growth during the fermentation, preferably added the bacteria antibiotic such as industrial penicillin before enzymolysis, described microbiotic does not have effect to yeast but the growth of the bacterium that can suppress to mix.With every milliliter of enzymolysis solution or fermented liquid is benchmark, and described antibiotic add-on is a 1-10 unit.Described enzymolysis solution comprises steam explosion products, enzyme and water, and described fermented liquid comprises the yeast of enzymolysis product and inoculation.
Because under the high-temperature and high-pressure conditions of steam explosion, the raw material of cellulose can produce the inhibition such as furfural, furans, described inhibition can reduce the vigor and the zymogenic activity of enzyme, therefore described method also is included in after the raw material of steam blasting cellulose-containing, before the steam explosion products that enzymolysis obtains, wash described steam explosion products.Described washing is that steam explosion products is mixed with water, stirs, and centrifugation steam explosion products then owing to above-mentioned inhibition easily is dissolved in the water, thereby can be removed inhibition by washing from steam explosion products.The temperature of described washing is high more, and is can the dissolved inhibition many more, considers energy consumption, and the temperature of preferred described washing is 60-90 ℃, more preferably 60-80 ℃.Because the water that washing is added is many more, the inhibition that then dissolves is also many more, but consider the energy consumption of centrifugation, preferably with the dry weight basis of the raw material of the described cellulose of every gram, the amount of water of described washing is the 2-10 gram, more preferably with the dry weight basis of the raw material of every gram cellulose, the amount of water of described washing is the 2-3 gram.
Owing to may contain sandstone impurity and iron contamination in the raw material of cellulose such as the maize straw, can cause damage to steam explosion equipment, therefore the present invention prepares the alcoholic acid method, can comprise the existing stone deironing routine operation that removes, such as removing the stone deironing with the raw material of " wind send " cellulose and the method for attraction.Sandstone can not be delivered in the steam explosion equipment by wind because quality is big, iron contamination since the attraction of magnet can not enter in the steam explosion equipment with raw material yet, thereby can finish except that the stone deironing.In addition, because the raw material of cellulose itself is entangled with and the occluding device pipeline easily, therefore the size of the raw material of preferred described cellulose is 0.2-1 centimetre of a 0.5-3 cm x 0.2-1 cm x, and more preferably the size of the raw material of described cellulose is 0.5-1 centimetre of a 1-2 cm x 0.4-0.6 cm x.
The present invention will be described in more detail below in conjunction with embodiment.
Embodiment 1
Present embodiment explanation the present invention feedstock production alcoholic acid method of cellulose.
(1) continuous steam explosion
Test maize straw raw material as shown in Figure 1, the water content that records maize straw according to above-mentioned method is 20 weight %, raw material is cut into the segment of 0.5 centimetre of 1.5 cm x, 0.2 cm x, with this water content is that the maize straw section of 20 weight % is sent into from feeder continuously, and carried out the water pouring before in being delivered to the heat preservation pressure device, it is 40 weight % that the water pouring makes the water content of this maize straw section.The maize straw that with 2000 these water content of gram is 40 weight % then continuously is delivered in the heat preservation pressure device, the pressure of described heat preservation pressure device is 1.6 MPas, temperature is 195 ℃, described maize straw transmits in this heat preservation pressure device continuously, the linear velocity that transmits makes that this maize straw can be at 195 ℃, 1.6 kept under the MPa 5 minutes, afterwards, every 10 seconds, the valve opening that makes this heat preservation pressure device once, after 2 seconds, valve closes makes the part maize straw be discharged into the normal pressure ejection, finish steam explosion, and repeat said process and carry out continuous steam explosion.The raw material that at every turn is discharged into non-pressurized cellulose is 11 weight % of cellulose containing raw material in the heat preservation pressure device, about 165 grams.Collect steam explosion products at last, and the water of gained steam explosion products and 70 ℃ mixed 30 minutes according to weight ratio 1:3, use LW400 type horizontal screw centrifuge (Zhangjiagang Huada Centrifugal Manufacturing Co., Ltd.) under 900 rev/mins of rotating speeds, to carry out solid-liquid separation then, obtain 3000 gram solid steam explosion products (water content is 60 weight %) altogether.
The mensuration of Mierocrystalline cellulose gross weight and hemicellulose gross weight in the gained solid steam explosion products:
Get the steam explosion products of 5 grams after the described washing and dry under 45 ℃ to constant weight 2.0 grams, 300.0 milligrams of this dried steam explosion products of weighing are positioned in heavy 80 100 milliliters of dry Erlenmeyer flasks that restrain.Adding 3.00 ml concns in described Erlenmeyer flask is the sulphuric acid soln of 72 weight %, stirs 1 minute.Then Erlenmeyer flask was heated 60 minutes in 30 ℃ of water-baths, every 5 minutes with stirring once to guarantee even hydrolysis.Water-bath makes the vitriolic concentration dilution to 4 weight % with deionized water after finishing.Filter steam explosion products acid hydrolysis liquid after the described dilution with B, obtain 84 milliliters of filtrates altogether.20 milliliters of filtrates are transferred in the triangular flask of 50 milliliters of dryings.Use 2.5 gram lime carbonate to regulate this pH value of filtrate to 5.5, left standstill 5 hours, collect supernatant liquid.0.2 the supernatant liquid that the micron membrane filtration is collected, the filtrate of gained supernatant liquid is analyzed with Biorad Aminex HPX-87P high performance liquid chromatography (HPLC).HPLC condition: sample size 20 microlitres; Moving phase is 0.2 micron membrane filtration, and the HPLC ultrapure water of the sonic oscillation degassing; Flow velocity is 0.6 ml/min; Column temperature 80-85 ℃; Detector temperature 80-85 ℃; Detector is a refractive index detector; Be 35 minutes working time.With D-(+) glucose of 0.1-4.0 mg/ml concentration range and 0.1-4.0 mg/ml concentration range D-(+) wood sugar as standard model.HPLC analyzes and to obtain that glucose concn is 2.22 mg/ml in the steam explosion products acid hydrolysis liquid, the steam explosion products acid hydrolysis that calculating can get after the described washing of 1 gram can obtain the glucose that weight is 0.186 gram, because being the sulphuric acid soln of 72 weight %, concentration the Mierocrystalline cellulose of the product of steam explosion all can be hydrolyzed into glucose, therefore the weight of gained glucose is 1.11 times of cellulosic weight in the steam explosion products, cellulose 0.168 gram in the steam explosion products after the i.e. described washing of 1 gram then is total to cellulose 504 grams in the 3000 gram steam explosion products.HPLC analyzes and to obtain that xylose concentration is 0.54 mg/ml in the steam explosion products acid hydrolysis liquid, the steam explosion products acid hydrolysis that calculating can get after the described washing of 1 gram can obtain the wood sugar that weight is 0.055 gram, because being the sulphuric acid soln of 72 weight %, concentration hemicellulose in the product of steam explosion all can be hydrolyzed into wood sugar, therefore the weight of gained wood sugar is 1.14 times of weight of hemicellulose in the steam explosion products, promptly contain hemicellulose 0.048 gram in the 1 gram steam explosion products, then contain hemicellulose 144 grams altogether in the 3000 gram steam explosion products.
(2) enzymolysis
With remaining washing steam explosion products behind step (1) sampling and testing, mix with 1000 gram water, regulate pH value to 5.0, after being heated to 50 ℃, with the dry weight basis of every gram stalk, add the cellulase (jade of the He family Bioisystech Co., Ltd) of 20 enzyme activity units, and be incubated 40 hours down at 50 ℃.Enzymolysis product is filtered with B, 20 milliliters of filtrates are transferred in 50 milliliters of triangular flasks of exsiccant, left standstill 5 hours, collect supernatant liquid.0.2 the supernatant liquid that the micron membrane filtration is collected, according to the described high performance liquid phase condition of step (1), the glucose of measuring and calculating in the enzymolysis product 524.8 restrains totally.The glucose weight that described enzymolysis obtains promptly totally 472.8 is restrained by the cellulosic weight of enzymolysis in the steam explosion products divided by 1.11, calculates cellulose conversion rate and monose productive rate according to following formula, and calculation result sees Table 1.
Cellulose conversion rate=100% * by the cellulosic weight of enzymolysis/cellulosic gross weight
Glucose weight/stalk dry weight that monose productive rate=100% * enzymolysis obtains
(3) fermentation
Make the temperature of enzymolysis product reduce to 35 ℃, in every gram enzymolysis product, inoculation is 10
5The yeast saccharomyces cerevisiae of colony-forming unit (the super highly active dry yeast in Angel, Hubei Angel Yeast stock company), gained mixture under 35 ℃ in fermentor tank stir culture 40 hours.At 100 ℃ of distillation gained tunnings, the gained distillation fraction can get ethanol 286.8 grams at 78.3 ℃ of following second distillations, calculates alcohol yied according to following formula, and calculation result sees Table 1.
Alcohol yied=100% * ethanol weight/stalk dry weight
Embodiment 2
Present embodiment explanation the present invention feedstock production alcoholic acid method of cellulose.
Method according to embodiment 1 prepares ethanol, different is, send into from feeder continuously in the maize straw section that with water content is 20 weight %, and carried out the water pouring before in being delivered to the heat preservation pressure device, it is 75 weight % that the water pouring makes the water content of this maize straw section.Be that the maize straw of 75 weight % is delivered to and carries out continuous steam explosion in the heat preservation pressure device continuously with 2000 these water content of gram according to the condition of embodiment 1 and method then, obtain 3000 gram solid steam explosion products (water content is 83.43 weight %) altogether after collecting steam explosion products and washing.
Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 3000 gram steam explosion products cellulose 210 grams altogether, hemicellulose 60 grams.
Method according to embodiment 1 is carried out enzymolysis and fermentation to above-mentioned steam explosion products, and according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 216.8 restrains totally.The glucose weight that described enzymolysis obtains promptly totally 195.3 is restrained by the cellulosic weight of enzymolysis in the steam explosion products divided by 1.11.Second distillation can get ethanol 114.9 grams.And calculate cellulose conversion rate, monose productive rate and alcohol yied according to the method for embodiment 1 and formula, calculation result sees Table 1.
Embodiment 3
Present embodiment explanation the present invention feedstock production alcoholic acid method of cellulose.
Method according to embodiment 1 prepares ethanol, different is, be not carry out water after the maize straw section of 20 weight % is sent into continuously to drench directly to be delivered to and carry out continuous steam explosion in the heat preservation pressure device from feeder with 2000 gram water content, the condition of steam explosion is collected steam explosion products and is also obtained 3556 gram solid steam explosion products (water content is 55 weight %) altogether after the washing with embodiment 1.
Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 3553 gram steam explosion products cellulose 672 grams altogether, hemicellulose 196.8 grams.
Method according to embodiment 1 is carried out enzymolysis and fermentation to above-mentioned steam explosion products, and according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 690.0 restrains totally.The glucose weight that described enzymolysis obtains promptly totally 621.6 is restrained by the cellulosic weight of enzymolysis in the steam explosion products divided by 1.11.Second distillation can get ethanol 362.3 grams.And calculate cellulose conversion rate, monose productive rate and alcohol yied according to the method for embodiment 1 and formula, calculation result sees Table 1.
Comparative Examples 1
This Comparative Examples explanation prior art adopts the feedstock production alcoholic acid method of cellulose.
Method according to embodiment 1 prepares ethanol, different is according to document " to the introduction of straw biomass to alcohol conversion process " (Zhang Xuefeng, orchid is kindly helped secure the success of, wine brewing, the 29th the 4th phase of volume, the 37-38 page or leaf, in July, 2002) disclosed method, stalk was soaked in water earlier before steam explosion 40 minutes, the water content that records the maize straw raw material after the immersion reaches 83 weight %, the maize straw of getting 2000 these water content of gram then and be 83 weight % (every batch 1000 gram) in two batches carries out the intermittent type steam explosion, the method of described intermittent type steam explosion is for keeping 5 minutes pressure release then with the described maize straw of 1000 grams earlier with the pressure of 1.6 MPas under 195 ℃; And then the described maize straw of remaining 1000 grams carried out steam explosion under same condition, obtain 1133 gram steam explosion products altogether after collecting steam explosion products and washing.Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 1133 gram steam explosion products cellulose 142.8 grams altogether, hemicellulose 51 grams.
Carry out enzymolysis and fermentation according to the method for embodiment 1 then, and according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 117.3 restrains totally.The glucose weight that described enzymolysis obtains promptly totally 105.7 is restrained by the cellulosic weight of enzymolysis in the steam explosion products divided by 1.11; Second distillation obtains ethanol 62 grams.And calculate cellulose conversion rate, monose productive rate and alcohol yied according to the method for embodiment 1 and formula, calculation result sees Table 1.
Comparative Examples 2
This Comparative Examples explanation prior art adopts the feedstock production alcoholic acid method of cellulose.
Method according to embodiment 1 prepares ethanol, different is, with 2000 gram water content is that 20 weight % maize straws were directly kept under the pressure with 1.8 MPas under 190 ℃ 4 minutes, pressure release then, finish steam explosion, collect steam explosion products and also obtain 4000 gram steam explosion products (water content is 60 weight %) altogether after the washing.Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 4000 gram steam explosion products cellulose 680 grams altogether, hemicellulose 224 grams.
Carry out enzymolysis and fermentation according to the method for embodiment 1 then, and according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 579.7 restrains totally.The glucose weight that described enzymolysis obtains promptly totally 522.2 is restrained by the cellulosic weight of enzymolysis in the steam explosion products divided by 1.11; Second distillation obtains ethanol 302.4 grams.And calculate cellulose conversion rate, monose productive rate and alcohol yied according to the method for embodiment 1 and formula, calculation result sees Table 1.
The electron microscopic observation result:
Amplify 1000 times of steam explosion products of observing Comparative Examples 1, Comparative Examples 2 and embodiment 1 with the JSM-35CF scanning electron microscope, the result is respectively as Fig. 2, Fig. 3 and shown in Figure 4.As can be seen from Figure 2, because stalk inside does not have moisture can be gasificated into water vapor, so steam explosion can not fully destroy stalk from inside to outside; As can be seen from Figure 3, the effect of Comparative Examples 1 maize straw steam explosion and bad, Mierocrystalline cellulose still is pencil, and cellulose surface is residual that the xylogen sheath arranged; And the steam explosion effect of embodiment 1 as shown in Figure 4 is fine, can see the free Mierocrystalline cellulose.
Embodiment 4
Present embodiment explanation the present invention feedstock production alcoholic acid method of cellulose.
(1) continuous steam explosion
Method according to embodiment 1 is carried out continuous steam explosion to maize straw, different is, water drenches that to make the water content that enters the maize straw before the heat preservation pressure device be 65 weight %, and the maize straw that is 65 weight % with this this water content of 1000 gram continuously is delivered to and carries out continuous steam explosion in the heat preservation pressure device.The raw material that at every turn is discharged into non-pressurized cellulose is 8.5 weight % of cellulose containing raw material in the heat preservation pressure device, about 127.5 grams.Condition is identical with embodiment 1, collect steam explosion products, and mixed 30 minutes according to weight ratio 1:3 with 60 ℃ water, use LW400 type horizontal screw centrifuge (Zhangjiagang Huada Centrifugal Manufacturing Co., Ltd.) under 900 rev/mins of rotating speeds, to carry out solid-liquid separation then, obtain 1300 gram solid steam explosion products (water content is 73.1 weight %) altogether.
Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 1300 gram steam explosion products cellulose 150.5 grams altogether, hemicellulose 45.5 grams.
(2) enzymolysis
With remaining steam explosion products behind step (1) sampling and testing, mixes with 400 gram water, regulate pH value to 6.0, be heated to 55 ℃ after, with the dry weight basis of every gram stalk, add the cellulase of 15 enzyme activity units, and descend to be incubated 30 hours at 55 ℃.Enzymolysis product is filtered with B, 20 milliliters of filtrates are transferred in the triangular flask of 50 milliliters of dryings, left standstill 5 hours, collect supernatant liquid.0.2 the supernatant liquid that the micron membrane filtration is collected, according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 154.8 restrains totally.The glucose weight that described enzymolysis obtains promptly totally 139.5 is restrained by the cellulosic weight of enzymolysis in the steam explosion products divided by 1.11, calculates cellulose conversion rate and monose productive rate according to following formula, and calculation result sees Table 1.
Cellulose conversion rate=100% * by the cellulosic weight of enzymolysis/cellulosic gross weight
Glucose weight/stalk dry weight that monose productive rate=100% * enzymolysis obtains
(3) fermentation
Make the temperature of enzymolysis product reduce to 32 ℃, in every gram enzymolysis product, inoculation is 10
6The yeast saccharomyces cerevisiae of colony-forming unit (the super highly active dry yeast in Angel, Hubei Angel Yeast stock company), gained mixture under 32 ℃ in fermentor tank stir culture 35 hours.At 100 ℃ of distillation gained tunnings, the gained distillation fraction can get ethanol 80.5 grams at 78.3 ℃ of following second distillations, calculates alcohol yied according to following formula, and calculation result sees Table 1.
Alcohol yied=100% * ethanol weight/stalk dry weight
Embodiment 5
Present embodiment explanation the present invention feedstock production alcoholic acid method of cellulose.
(1) continuous steam explosion
Method according to embodiment 1 is carried out continuous steam explosion to maize straw, different is, earlier be after the maize straw of 20 weight % is cut into the segment of 0.5 centimetre of 2.5 cm x, 0.5 cm x with water content, with vertical steeping cell (the auspicious mechanical company limited in river in Shangdong Province, Shandong) and weight is after 1/3rd water of described maize straw raw material weight mixes, and can get the maize straw of water content 50 weight %.The maize straw that is 50 weight % with this 1000 gram water content continuously is delivered in the heat preservation pressure device then, the pressure of described heat preservation pressure device is 1.5 MPas, temperature is 185 ℃, described maize straw transmits in this heat preservation pressure device continuously, the linear velocity that transmits makes that this maize straw can be at 185 ℃, 1.5 kept under the MPa 7 minutes, afterwards, every 8 seconds, the valve opening that makes this heat preservation pressure device once, after 2 seconds, valve closes makes the part maize straw be discharged into the normal pressure ejection, finish steam explosion, and repeat said process and carry out continuous steam explosion.The raw material that at every turn is discharged into non-pressurized cellulose is 9.2 weight % of cellulose containing raw material in the heat preservation pressure device, about 138 grams.Collect steam explosion products at last, after with described continuous steam explosion, collect not totally 1250 gram steam explosion products (water content is 60 weight %) through washing.
Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 1250 gram steam explosion products cellulose 215 grams altogether, hemicellulose 62.5 grams.
(2) enzymolysis
With remaining steam explosion products behind step (1) sampling and testing, mixes with 400 gram water, regulate pH value to 6.0, be heated to 55 ℃ after, with the dry weight basis of every gram stalk, add the cellulase of 15 enzyme activity units, and descend to be incubated 30 hours at 55 ℃.Enzymolysis product is filtered with B, 20 milliliters of filtrates are transferred in the triangular flask of 50 milliliters of dryings, left standstill 5 hours, collect supernatant liquid.0.2 the supernatant liquid that the micron membrane filtration is collected, according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 212.4 restrains totally.The glucose weight that described enzymolysis obtains promptly totally 191.4 is restrained by the cellulosic weight of enzymolysis in the steam explosion products divided by 1.11, calculates cellulose conversion rate and monose productive rate according to following formula, and calculation result sees Table 1.
Cellulose conversion rate=100% * by the cellulosic weight of enzymolysis/cellulosic gross weight
Glucose weight/stalk dry weight that monose productive rate=100% * enzymolysis obtains
(3) fermentation
Make the temperature of enzymolysis product reduce to 32 ℃, in every gram enzymolysis product, inoculation is 10
6The yeast saccharomyces cerevisiae of colony-forming unit (the super highly active dry yeast in Angel, Hubei Angel Yeast stock company), gained mixture under 32 ℃ in fermentor tank stir culture 35 hours.At 100 ℃ of distillation gained tunnings, the gained distillation fraction can get ethanol 112.6 grams at 78.3 ℃ of following second distillations, calculates alcohol yied according to following formula, and calculation result sees Table 1.
Alcohol yied=100% * ethanol weight/stalk dry weight
Embodiment 6
Present embodiment explanation the present invention feedstock production alcoholic acid method of cellulose.
(1) continuous steam explosion
Getting 1000 gram water content is the maize straw of 35 weight %, be cut into the segment of 0.7 centimetre of 1.2 cm x, 0.4 cm x, the maize straw that is 35 weight % with this 1000 gram water content continuously is delivered in the heat preservation pressure device then, the pressure of described heat preservation pressure device is 1.7 MPas, temperature is 200 ℃, described maize straw transmits in this heat preservation pressure device continuously, the linear velocity that transmits makes that this maize straw can be at 200 ℃, 1.7 kept under the MPa 4 minutes, afterwards, every 8 seconds, the valve opening that makes this heat preservation pressure device once, after 2 seconds, valve closes makes the part maize straw be discharged into the normal pressure ejection, finish steam explosion, and repeat said process and carry out continuous steam explosion.The raw material that at every turn is discharged into non-pressurized cellulose is 10 weight % of cellulose containing raw material in the heat preservation pressure device, about 150 grams.Collect steam explosion products at last, the water of gained steam explosion products and 75 ℃ was mixed 50 minutes according to weight ratio 1:2.5, use impeller pump LW400 type horizontal screw centrifuge (Zhangjiagang Huada Centrifugal Manufacturing Co., Ltd.) under 900 rev/mins of rotating speeds, to carry out solid-liquid separation then, obtain 2600 gram steam explosion products (water content is 75 weight %) altogether.
Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 2600 gram steam explosion products cellulose 286 grams altogether, hemicellulose 84.5 grams.
(2) enzymolysis
With remaining washing steam explosion products behind step (1) sampling and testing, mix with 1000 gram water, regulate pH value to 4.0, after being heated to 45 ℃, dry weight basis with every gram stalk, add the cellulase of 18 enzyme activity units and the hemicellulase of 8.0 enzyme activity units (Beijing chemical reagents corporation), and be incubated 35 hours down at 45 ℃.Enzymolysis product is filtered with B, 20 milliliters of filtrates are transferred in the triangular flask of 50 milliliters of dryings, left standstill 5 hours, collect supernatant liquid.0.2 the supernatant liquid that the micron membrane filtration is collected, according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 291.7 restrains totally, and wood sugar is totally 68.4 grams.The glucose weight that described enzymolysis obtains is divided by 1.11, be totally 262.8 to be restrained by the cellulosic weight of enzymolysis in the steam explosion products, the wood sugar weight that described enzymolysis obtains is divided by 1.14, be totally 60 to be restrained by the weight of the hemicellulose of enzymolysis in the steam explosion products, calculate cellulose conversion rate, hemicellulose transformation efficiency and monose productive rate according to following formula, calculation result sees Table 1.
Cellulose conversion rate=100% * by the cellulosic weight of enzymolysis/cellulosic gross weight
Hemicellulose transformation efficiency=100% * by the gross weight of the weight/hemicellulose of the hemicellulose of enzymolysis
Monose productive rate=100% * (the wood sugar weight that glucose weight+enzymolysis that enzymolysis obtains obtains)/stalk dry weight
(3) fermentation
Make the temperature of enzymolysis product reduce to 33 ℃, in every gram enzymolysis product, inoculation is 10
5The yeast saccharomyces cerevisiae of colony-forming unit (ATCC numbering 2601) and 10
3The pichia stipitis of colony-forming unit (ATCC numbering 58376), under 33 ℃ in fermentor tank stir culture 39 hours.At 100 ℃ of distillation gained tunnings, the gained distillation fraction can get ethanol 187.3 grams at 78.3 ℃ of following second distillations, calculates alcohol yied according to following formula, and calculation result sees Table 1.
Alcohol yied=100% * ethanol weight/stalk dry weight
Embodiment 7
Present embodiment explanation the present invention feedstock production alcoholic acid method of cellulose.
(1) continuous steam explosion
Getting 1000 gram water content is the maize straw of 55 weight %, be cut into the segment of 0.8 centimetre of 2.0 cm x, 0.6 cm x, the maize straw that is 55 weight % with this 1000 gram water content continuously is delivered in the heat preservation pressure device then, the pressure of described heat preservation pressure device is 1.55 MPas, temperature is 190 ℃, described maize straw transmits in this heat preservation pressure device continuously, the linear velocity that transmits makes that this maize straw can be at 190 ℃, 1.55 kept under the MPa 6 minutes, afterwards, every 7 seconds, the valve opening that makes this heat preservation pressure device once, after 2 seconds, valve closes makes the part maize straw be discharged into the normal pressure ejection, finish steam explosion, and repeat said process and carry out continuous steam explosion.The raw material that at every turn is discharged into non-pressurized cellulose is 8 weight % of cellulose containing raw material in the heat preservation pressure device, about 120 grams.Collect steam explosion products at last, the water of gained steam explosion products and 65 ℃ was mixed 40 minutes according to weight ratio 1:2, use impeller pump LW400 type horizontal screw centrifuge (Zhangjiagang Huada Centrifugal Manufacturing Co., Ltd.) under 900 rev/mins of rotating speeds, to carry out solid-liquid separation then, obtain 1500 gram steam explosion products (water content is 70 weight %) altogether.
Analyze the method for the steam explosion products of sulphuric acid hydrolysis according to the described HPLC of embodiment 1, record in the 1500 gram steam explosion products cellulose 195.8 grams altogether, hemicellulose 57.6 grams.
(2) enzymolysis
With remaining washing steam explosion products behind step (1) sampling and testing, mix with 800 gram water, regulate pH value to 3.5, after being heated to 50 ℃, dry weight basis with every gram stalk, add the cellulase of 10 enzyme activity units and the hemicellulase of 4.5 enzyme activity units (Beijing chemical reagents corporation), and be incubated 48 hours down at 50 ℃.Enzymolysis product is filtered with B, 20 milliliters of filtrates are transferred in the triangular flask of 50 milliliters of dryings, left standstill 5 hours, collect supernatant liquid.0.2 the supernatant liquid that the micron membrane filtration is collected, according to the described high performance liquid phase condition of embodiment 1 step (1), the glucose of measuring and calculating in the enzymolysis product 198.2 restrains totally, and wood sugar is totally 46 grams.The glucose weight that described enzymolysis obtains is divided by 1.11, be totally 178.6 to be restrained by the cellulosic weight of enzymolysis in the steam explosion products, the wood sugar weight that described enzymolysis obtains is divided by 1.14, be totally 40.3 to be restrained by the weight of the hemicellulose of enzymolysis in the steam explosion products, calculate cellulose conversion rate, hemicellulose transformation efficiency and monose productive rate according to following formula, calculation result sees Table 1.
Cellulose conversion rate=100% * by the cellulosic weight of enzymolysis/cellulosic gross weight
Hemicellulose transformation efficiency=100% * by the gross weight of the weight/hemicellulose of the hemicellulose of enzymolysis
Monose productive rate=100% * (the wood sugar weight that glucose weight+enzymolysis that enzymolysis obtains obtains)/stalk dry weight
(3) fermentation
Make the temperature of enzymolysis product reduce to 34 ℃, in every gram enzymolysis product, inoculation is 10
4The yeast saccharomyces cerevisiae of colony-forming unit and 10
4The pichia stipitis of colony-forming unit, under 34 ℃ in fermentor tank stir culture 37 hours.At 100 ℃ of distillation gained tunnings, the gained distillation fraction can get ethanol 127 grams at 78.3 ℃ of following second distillations, calculates alcohol yied according to following formula, and calculation result sees Table 1.
Alcohol yied=100% * ethanol weight/stalk dry weight
Table 1
| Embodiment or Comparative Examples | Embodiment 1 | Comparative Examples 1 | Comparative Examples 2 | Embodiment 2 | Embodiment 3 | Embodiment 4 | Embodiment 5 | Embodiment 6 | Embodiment 7 |
| Cellulose conversion rate (%) | 93.8 | 74.0 | 76.8 | 93.0 | 92.5 | 92.7 | 89.0 | 91.9 | 91.2 |
| Hemicellulose transformation efficiency (%) | - | - | - | - | - | - | - | 71.0 | 70.0 |
| Monose productive rate (%) | 43.7 | 34.3 | 35.9 | 43.4 | 43.1 | 44.2 | 42.5 | 55.4 | 54.3 |
| Alcohol yied (%) | 23.9 | 18.2 | 19.0 | 23.0 | 22.6 | 23.0 | 22.5 | 28.8 | 28.2 |
As can be seen from Table 1, employing is prepared in the alcoholic acid method by the steam explosion products that the method for the fibrous raw material of steam explosion of the present invention obtains, and cellulose conversion rate, monose productive rate and alcohol yied all are significantly improved than the method for Comparative Examples 1 and Comparative Examples 2.
Claims (12)
1, a kind of feedstock production alcoholic acid method that adopts cellulose, this method comprises the raw material of steam blasting cellulose-containing, the steam explosion products that enzymolysis obtains, the enzymolysis product that fermentation obtains, it is characterized in that, the method of the raw material of steam blasting cellulose-containing comprises that the raw material with cellulose is delivered in the heat preservation pressure device continuously, make the raw material of cellulose in this heat preservation pressure device, keep making the raw material of the part cellulose in the described heat preservation pressure device be discharged into normal pressure second every 5-12 after 3-10 minute.
2, method according to claim 1, wherein, the raw material of cellulose kept 4-7 minute in this heat preservation pressure device, made the raw material of the part cellulose in the described heat preservation pressure device be discharged into normal pressure second every 7-10.
3, method according to claim 1, wherein, the raw material that at every turn is discharged into non-pressurized cellulose is the 6-15 weight % of the raw material of cellulose in the heat preservation pressure device.
4, according to any described method among the claim 1-3, wherein, the raw material that at every turn is discharged into non-pressurized cellulose is the 120-180 gram.
5, method according to claim 1, wherein, the temperature of described heat preservation pressure device is 180-200 ℃, pressure is the 1.4-2.0 MPa.
6, method according to claim 1, wherein, the water content of the raw material of described cellulose is 30-60 weight %.
7, method according to claim 6, wherein, the water content of the raw material of described cellulose is 35-50 weight %.
8, according to any described method in the claim 1,2,3,6 or 7, wherein, the size of the raw material of described cellulose is 0.2-1 centimetre of a 0.5-3 cm x 0.2-1 cm x.
9, according to any described method in the claim 1,2,3,6 or 7, wherein, the raw material of described cellulose is a stalk.
10, method according to claim 1, wherein, the enzyme that described enzymolysis uses comprises cellulase, with the dry weight basis of the raw material of every gram cellulose, the consumption of described cellulase is the 8-20 enzyme activity unit; The temperature of described enzymolysis is 45-55 ℃, and the time of described enzymolysis is 25-48 hour, and the pH value of described enzymolysis is 3.0-7.0.
11, method according to claim 10, wherein, the enzyme that described enzymolysis uses also comprises hemicellulase, with the dry weight basis of the raw material of every gram cellulose, the consumption of described hemicellulase is the 4.4-8.8 enzyme activity unit.
12, method according to claim 1, wherein, the employed yeast of described fermentation is pichia stipitis and yeast saccharomyces cerevisiae; In every gram enzymolysis product, the employed zymic inoculum size of described fermentation is 10
3-10
8Colony-forming unit, the temperature of described fermentation are 30-36 ℃, and the time of fermentation is 32-48 hour.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102643867A (en) * | 2012-04-23 | 2012-08-22 | 天津大学 | Device and method for producing cellulosic ethanol |
| CN114410712A (en) * | 2022-02-10 | 2022-04-29 | 农业部沼气科学研究所 | Special steam explosion method for improving concentration of corn straw enzymatic hydrolysis sugar |
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| CN1204316C (en) * | 2003-07-02 | 2005-06-01 | 云南工业用大麻实业有限公司 | Manufacturing method of newsprinting paper |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102643867A (en) * | 2012-04-23 | 2012-08-22 | 天津大学 | Device and method for producing cellulosic ethanol |
| CN114410712A (en) * | 2022-02-10 | 2022-04-29 | 农业部沼气科学研究所 | Special steam explosion method for improving concentration of corn straw enzymatic hydrolysis sugar |
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