CN105732846B - It is a kind of for extracting the straw pretreatment method of hemicellulose - Google Patents
It is a kind of for extracting the straw pretreatment method of hemicellulose Download PDFInfo
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- CN105732846B CN105732846B CN201610172806.8A CN201610172806A CN105732846B CN 105732846 B CN105732846 B CN 105732846B CN 201610172806 A CN201610172806 A CN 201610172806A CN 105732846 B CN105732846 B CN 105732846B
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
- C08B37/14—Hemicellulose; Derivatives thereof
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Abstract
The invention discloses a kind of for extracting the straw pretreatment method of hemicellulose.This method are as follows: take stalk pretreatment fluid to impregnate wetting, gained mixture is sent into defibrination in fiberizer, makes the partial size of resulting material after defibrination be less than or equal to 1.0mm, and be separated by solid-liquid separation to resulting material, collects solid, extracts after washing for hemicellulose；The pretreatment fluid is the alkaline solution that concentration is 1~20g/L.The present invention first uses the lye infiltration soften stalk fibre of low concentration; it is re-introduced into fiberizer and defibrination is carried out to the stalk after infiltration; greatly improve the contact area of fiber and pretreatment fluid in stalk; it is more advantageous to the impurity such as the acetyl group sloughed in stalk fibre, pigment; the impurity content in subsequent hemicellulose extract is reduced while not losing hemicellulose in stalk; hemicellulose recovery rate is improved, and material processing power consumption is low in method.
Description
Technical field
The present invention relates to the extractions of active constituent in stalk, and in particular to a kind of stalk for extracting hemicellulose is located in advance
Reason method.
Background technique
Stalk is by-product caused by mankind's grain and Sugar Production process, belongs to human society and most collects neutralization most convenient
The main component of the renewable resource utilized, stalk is made of cellulose, hemicellulose and lignin, and cellulose is glucose
The polymer that (hexose) is formed with β-Isosorbide-5-Nitrae glycosidic bond, hemicellulose are a kind of renewable polysaccharide that content is only second to cellulose,
It is mainly the glycans of principal component with xylan (pentose, the polymer of xylose).Macromolecular state xylan and cellulose knot
Difference on structure makes it have unique physicochemical property and bioactivity, all has in fields such as food, medicine and chemical industry important
Development volue.
The principal structural component of cellulose, hemicellulose and lignin as plant cell wall in stalk, with cellulose
As " skeleton ", hemicellulose and the lignin macromolecular with tridimensional network wind mutually be filled in microfibre it
Between, and connect to form natural complex in the form of chemical bond, hemicellulose is extracted, these connection structures, mesh must be destroyed
The preceding method for mainly thering are sour water solution, steam blasting, enzyme hydrolysis and alkali carries to take.
Sour water solution and steam blasting are the important means for destroying stalk natural structure, but since hemicellulose sugar chain is easy to water
It solves and is difficult to obtain macromolecular state xylan, and cellulose is also affected and is difficult to use in slurrying after the processing of these methods
Papermaking.Enzyme hydrolysis method can achieve the purpose that destruction stalk structure by hydrolytic lignin, Publication No. CN103556517A's
Patent of invention disclose it is a kind of directly mixed with bagasse using laccase, degraded under certain condition using the specificity of enzymatic reaction
Lignin is without influencing hemicellulose and cellulose, to improve the effect of subsequent oxygen alkali pulping.But this method still has
The shielding action of cellulose and hemicellulose, enzymolysis efficiency be not high.
The method taken with alkali carries can effectively dissolved lignin and hemicellulose, but often exist in the epidermis of stalk more
Wax, this is also the obstacle for extracting solution contacting material, and the patent of invention of Publication No. CN103205473A discloses a kind of sugarcane
The preprocess method of slag is crossed after specifically dry, pulverize bagasse and takes 18~40 mesh sieve fractions, then with NaOH and H2O2Mixing
Aqueous solution processing.This method can effectively dissolve out hemicellulose and lignin, but bagasse is dry and crush, power consumption compared with
It is more, it industrially applies and uneconomical, cellulose can not be used as pulping and paper-making raw material.
Therefore, suitable stalk processing method is selected, stalk fibre tissue is sufficiently broken up into separation, increases substantially fiber
Surface area, and cellulosic structure is not destroyed, guarantee that the high extraction of subsequent hemicellulose, cellulose still can be used for slurrying and make
Paper, this will greatly improve the overall benefit of straw resource utilization.
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of for extracting the straw pretreatment method of hemicellulose.The party
Method carries out defibrination to the stalk after infiltration by introducing fiberizer, greatly improves the contact surface of fiber and pretreatment fluid in stalk
Product, is more advantageous to the acetyl group sloughed in hemicellulose, subsequent hemicellulose is reduced while not losing hemicellulose in stalk
Impurity content in plain extracting solution and the recovery rate for improving hemicellulose.
The straw pretreatment method of the present invention for being used to extract hemicellulose are as follows: take stalk to be impregnated with pretreatment fluid,
Gained mixture is sent into defibrination in fiberizer, so that the partial size of resulting material after defibrination is less than or equal to 1.0mm, and to resulting material
It is separated by solid-liquid separation, collects solid, extracted after washing for hemicellulose；The pretreatment fluid is that concentration is 1~20g/L's
Alkaline solution.
In the method for the invention, the stalk is stem, leaf or the fringe portion point except gramineae crop seed, reality.Specifically,
It can be the group selected from one or more of straw, straw, cornstalk, sorghum stalk, corncob, bagasse and sugarcane top
It closes.When stalk is when being selected as above-mentioned any two or more combinations, the proportion between them can be any proportion.The straw
Stalk is preferably pre-processed after break process again, and the break process, which can be, makes stalk in Filamentous or coarse-grained place
Reason such as carries out rubbing silk processing, is crushed to obtain the processing of the particle compared with coarse grain diameter by crusher, either by wire kneading machine
Carry out squeezing processing etc. by squeezer may be implemented broken conventional treatment mode in the prior art.Specifically, when stalk is
When the elongated stalks such as straw, cornstalk or sugarcane top, the segment that length is 1~5cm can be cut into cutting machine；When stalk is jade
It when the stalk of rice this kind of shape of core, can be flattened with squeezer, or being broken into granularity with crusher is the small of 2~10mm
Grain.
In the method for the invention, the dosage of pretreatment fluid is that stalk can be made to obtain sufficiently impregnating, it is preferable that institute
The ratio for stating stalk weight and pretreatment fluid dosage is 1g (over dry weight, similarly hereinafter): 7~15mL, more preferable stalk weight and pre- place
The ratio for managing liquid dosage is 1g:8~10mL.Stalk can also be impregnated with excessive pretreatment fluid.In order to improve defibrination
Machine working efficiency part pretreatment fluid can be discharged before material enters fiberizer, meet remaining pretreatment liquid measure can
Fiberizer service requirement.
It sufficiently impregnates, can be being soaked by increasing soaking time or improving stalk in order to guarantee that stalk can be pretreated liquid
Temperature when bubble realizes, such as stalk immersion >=4h time (preferably 4~12h of immersion) under normal temperature conditions, or makes straw
Stalk immersion >=0.5h time (preferably immersion 0.5~2h) under the conditions of 50~70 DEG C, or stalk boiled >=10min is (excellent
10~30min is boiled in choosing).In wetting, preferably stalk is placed in container, (makes the air in stalk tissue after vacuumizing
Also be pumped) suck pretreatment fluid again and carry out immersion under room temperature or heating condition, at this time pretreatment fluid under vacuum with
Organization internal, softening wetting swollen stalk can be immersed after stalk contact rapidly, while increasing the cunning of stalk in material transportation process
Dynamic property.
In the method for the invention, the fiberizer is paper industry commonly middle concentration or high concentration disc type papermaking
Fiberizer controls the granularity or length of solid matter in discharging by adjusting fiberizer.In the application, to guarantee that material has
Good water filtering performance, while increasing the contact area of material and lye as far as possible again, the extraction efficiency of subsequent technique is improved, it is excellent
Choosing is 0.1~1.0mm of partial size of resulting material after making defibrination, more preferably 0.1~0.5mm.
In the method for the invention, the pretreatment fluid specifically can be the metal ion K that concentration is 1~20g/L2 +、Na+Or Ca2+Alkaline solution, more specifically, can be concentration be the NaOH aqueous solution of 1~20g/L, KOH aqueous solution,
Na2CO3Aqueous solution or Ca (OH)2Aqueous solution etc..The concentration of the pretreatment fluid is more preferably 2~10g/L, further
Preferably 2~5g/L, more preferably 5g/L.It is soaked by the immersion of pretreatment fluid, generates stalk during storage micro-
The impurity such as biological metabolite, partial pigment dissolve in pretreatment fluid, reduce the purifying cost of subsequent alkaline liquid extract；On the other hand
Impregnating the stalk after wetting with pretreatment fluid has good sliding capability, can reduce the power during material conveying and defibrination
Consumption.
In the method for the invention, realize that the mode of separation of solid and liquid is same as the prior art, the application is preferably using centrifugation
Or the mode of filters pressing.
In the method for the invention, the solid after washing generallys use existing conventional alkalinity extraction to extract hemicellulose
Element.It has been found that will be when resulting raw material uses alkalinity extraction again after above-mentioned pretreatment, impurity is few in gained extracting solution,
The recovery rate of hemicellulose is high.
Compared with prior art, the present invention first uses the lye infiltration soften stalk fibre of low concentration, is re-introduced into fiberizer
Defibrination is carried out to the stalk after infiltration, the contact area of fiber and pretreatment fluid in stalk is greatly improved, is more advantageous to and sloughs straw
The impurity such as acetyl group, pigment in stalk fiber reduce subsequent hemicellulose while not losing hemicellulose in stalk and extract
Impurity content in liquid improves hemicellulose recovery rate, and material processing power consumption is low in method.
Specific embodiment
The present invention is described in further detail combined with specific embodiments below, content to better understand the invention, but
The present invention is not limited to following embodiments.
The weight of stalk is the weight of over dry material in following embodiment.
Embodiment 1
Bagasse 100kg is added in extractor, after extractor vacuumizes, is sucked in the ratio that solid-to-liquid ratio is 1g:10mL pre-
Treatment fluid (concentration be 5g/L sodium hydrate aqueous solution) 1000L impregnates 10h under normal temperature condition.It is discharged later free in bagasse
Lye 330L, the solution of discharge are in dark-brown, and surplus material is sent into high concentration disc type paper-making paste mill in extractor, by object
Material wears into the filament that diameter is 0.1~0.5mm, and defibrination resulting material is centrifuged, the free lye in levigate fiber is discharged, and collects
Liquid 550L is obtained, and bagasse adds water 300L, and the centrifugation discharge 295L of water containing neutralizing treatment again is stirred after washing, three not good liquors are merged
Body obtains 1175L, wherein xylan is not detected；Collect solid, as treated sugarcane fiber, gained sugarcane fiber is soft thin
It is close.
Comparative example 1
Bagasse 100kg (raw material with embodiment 1 is with a collection of raw material) is added in extractor, after extractor vacuumizes,
Pretreatment fluid (concentration is 5g/L sodium hydrate aqueous solution) 1000L is sucked in ratio that solid-to-liquid ratio is 1g:10mL, under normal temperature condition
Impregnate 10h.Free lye 850L in centrifugation discharge bagasse, the solution of discharge is in dark-brown, and bagasse adds water 300L to be stirred
The centrifugation discharge 300L of water containing neutralizing treatment after washing merges lye twice and obtains 1150L, wherein xylan is not detected；Solid is collected, i.e.,
For treated sugarcane fiber.Gained sugarcane fiber thickness is uneven, and more bulk, texture is harder.
Embodiment 2
Weigh by 1 the method for embodiment treated sugarcane fiber 50kg with by 1 the method for comparative example, treated
Sugarcane fiber uses alkalinity extraction hemicellulose 50kg respectively.
Extraction conditions are as follows: solid-to-liquid ratio 1g:5mL, the lye of extraction are the NaOH aqueous solution of concentration 8% (w/v), when extraction
Between 12h, temperature is room temperature.
Then NaOH concentration is carried out to resulting hemicellulose extract, color compares, and with being equivalent to 3 times of extracting liqs
95% long-pending (v/v) ethyl alcohol alcohol precipitation, 75% ethanol washing hemicellulose, finally to dry hemicellulose powder color, purity
And recovery rate compares, the results are shown in Table 1.
Table 1:
As shown in Table 1, carry out that treated that bagasse uses conventional alkalinity extraction and purification again using the method for the invention
When hemicellulose, the impurity in bagasse fibre is largely removed, and extracting solution color is shallow compared with comparative example 1, bagasse after levigate processing
Specific surface area increases, and the purity of hemicellulose recovery rate and gained hemicellulose is higher compared with comparative example 1.
Embodiment 3
Cornstalk is cut into the segment that length is 1~3cm, 100kg is weighed and is put into extraction tank, be 1g by solid-to-liquid ratio:
Pretreatment fluid (concentration is 5g/L sodium hydrate aqueous solution) 1000L is added in the ratio of 10mL, impregnates 1h after being warming up to 60 DEG C.Later
The free lye 330L in material is discharged, solution is in dark-brown, then surplus material in extractor is sent to high concentration disc type and is made
In paper fiberizer, material is worn into the filament that diameter is 0.1~0.5mm, defibrination resulting material is centrifuged, is discharged in levigate fiber
Free lye, collection obtain liquid 560L, bagasse adds water 300L, be stirred washing after again centrifugation discharge water containing neutralizing treatment
298L merges liquid three times and obtains 1188L, wherein xylan is not detected；Collect solid, as treated cornstalk fibers, institute
It is fine and closely woven to obtain cornstalk fibers softness.
Embodiment 4
The particle that corncob is broken into 5~20mm with crusher, weighs 100kg and is put into extraction tank, and is 1g by solid-to-liquid ratio:
Pretreatment fluid (concentration is 5g/L potassium hydroxide aqueous solution) 1000L is added in the ratio of 10mL, impregnates 1h after being warming up to 60 DEG C.Later
The free lye 320L in material is discharged, solution is in dark-brown, then surplus material in extractor is sent to high concentration disc type and is made
In paper fiberizer, material is worn into the fine particle that diameter is 0.1~0.5mm, defibrination resulting material is centrifuged, is discharged levigate
Free lye in fiber, collection obtain liquid 520L, and bagasse adds water 300L, are stirred after washing centrifugation discharge again containing alkali
Washing water 290L merges liquid three times and obtains 1120L, wherein xylan is not detected；Solid is collected, as treated, and corncob is fine
Dimension.
Embodiment 5
The particle that corncob is broken into 5~20mm with crusher, weighs 100kg and is put into extraction tank, and is 1g by solid-to-liquid ratio:
Pretreatment fluid (concentration is 1g/L sodium hydrate aqueous solution) 1500L is added in the ratio of 15mL, impregnates 20min after boiling.Heel row
Free lye 500L in material out, solution is in dark-brown, then surplus material in extractor is sent to middle concentration disc type papermaking
In fiberizer, material is worn into the fine particle that granularity is 0.5~1.0mm, defibrination resulting material is centrifuged, levigate fiber is discharged
In free lye, collection obtains liquid 830L, and bagasse adds water 300L, is stirred after washing centrifugation discharge again containing neutralizing treatment
Water 310L merges liquid three times and obtains 1640L, wherein xylan is not detected；Collect solid, corn cob fiber that as treated.
Embodiment 6
Cornstalk is cut into the segment that length is 1~2cm, 100kg is weighed and is put into extraction tank, after extractor vacuumizes,
Pretreatment fluid (concentration is 5g/L calcium hydroxide aqueous solution) 800L is sucked in the ratio that solid-to-liquid ratio is 1g:8mL, is soaked under normal temperature condition
Steep 6h.Surplus material in extractor is sent into high concentration disc type paper-making paste mill later, by material wear into diameter be 0.5~
Defibrination resulting material is centrifuged by the filament of 1.0mm, and the free lye in levigate fiber is discharged, and collection obtains liquid 650L, bagasse
Add water 300L, be stirred after washing the centrifugation discharge 290L of water containing neutralizing treatment again, merges liquid three times and obtain 940L, wherein not examining
Xylan out；Collect solid, as treated cornstalk fibers, gained cornstalk fibers softness is fine and closely woven.
Embodiment 7
It is weighed respectively by embodiment 3,4,5 and 6 the methods treated sugarcane fiber each 50kg alkalinity extraction half fiber
Dimension element.
Extraction conditions are as follows: solid-to-liquid ratio 1g:5mL, the lye of extraction are the NaOH aqueous solution of concentration 8% (w/v), when extraction
Between 12h, temperature is room temperature.
Then NaOH concentration is carried out to resulting hemicellulose extract, color compares, and with being equivalent to 3 times of extracting liqs
95% long-pending (v/v) ethyl alcohol alcohol precipitation, 75% ethanol washing hemicellulose, finally to dry hemicellulose powder color, purity
And recovery rate compares, the results are shown in Table 2.
Table 2:
Claims (7)
1. a kind of for extracting the straw pretreatment method of hemicellulose, it is characterised in that: stalk pretreatment fluid is taken to impregnate profit
Wet, gained mixture is sent into defibrination in fiberizer, so that the partial size of resulting material after defibrination is less than or equal to 1.0mm, and to gained
Material is separated by solid-liquid separation, and solid is collected, and is extracted after washing for hemicellulose；The pretreatment fluid be concentration be 1~
The alkaline solution of 20g/L.
2. according to claim 1 for extracting the straw pretreatment method of hemicellulose, it is characterised in that: the stalk
The ratio of weight and pretreatment fluid dosage is 1g:7~15mL.
3. according to claim 1 for extracting the straw pretreatment method of hemicellulose, it is characterised in that: the stalk
The ratio of weight and pretreatment fluid dosage is 1g:8~10mL.
4. according to claim 1 for extracting the straw pretreatment method of hemicellulose, it is characterised in that: after making defibrination
The partial size of resulting material is 0.1~1.0mm.
5. according to any one of claims 1 to 4 for extracting the straw pretreatment method of hemicellulose, feature exists
In: the pretreatment fluid is the metal ion K that concentration is 1~20g/L+、Na+Or Ca2+Alkaline solution.
6. according to any one of claims 1 to 4 for extracting the straw pretreatment method of hemicellulose, feature exists
In: the concentration of the pretreatment fluid is 2~10g/L.
7. according to any one of claims 1 to 4 for extracting the straw pretreatment method of hemicellulose, feature exists
In: the concentration of the pretreatment fluid is 2~5g/L.
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| CN101987473A (en) * | 2010-04-15 | 2011-03-23 | 洛阳理工学院 | Method for making package materials from straws |
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| CN104805151A (en) * | 2014-01-24 | 2015-07-29 | 华东理工大学 | Lignocellulosic feedstock pretreatment method without prepreg |
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