Summary of the invention
For above-mentioned technical problem, the invention provides the membrane concentration technique that Xylitol prepared by a kind of viscose fiber production pressed liquor.The Xylitol salinity obtained is low, and purity is high, and process operation efficiency is high, is adapted to scale operation.
For achieving the above object, the present invention adopts following technical scheme:
The membrane concentration technique that Xylitol prepared by pressed liquor produced by viscose fiber, it is characterized in that: concrete technology step is as follows:
A, membrane concentration
The pressed liquor that viscose fiber is produced is first through pre-filtering removing large granular impurity, and permeate is through concentrated 2-4 time of nanofiltration membrane circulation, and send after last concentrated solution thin up into ceramic membrane filter, gained concentrated solution is the concentrated solution of press lye; Concentrated 2-4 time of described nanofiltration membrane circulation, before each filtration, feed liquid all enters nanofiltration membrane after thin up.
B, extraction half fibre
By the concentrated solution acid neutralization of press lye, obtain half fine liquid.
C, enzymolysis
In half fine liquid, add prozyme, enzyme digestion reaction occurs and obtains enzymolysis solution;
D, fermentation
Enzymolysis solution at the effect bottom fermentation of candidiasis, 50-60 DEG C of bottom fermentation 0.5-2h;
E, purification
Fermented liquid is through ultrafiltration removal of impurities, and permeate, through nanofiltration membrane desalination, obtains the refined solution that concentrated solution is Xylitol, through ion-exchange, activated carbon treatment, condensing crystal, separation, obtains Xylitol.
Step A of the present invention, the molecular weight cut-off of nanofiltration membrane is 200-400, and the molecular weight cut-off of ceramic membrane is 800-1500.
The molecular weight cut-off of 200-400, makes alkali separate from permeate, progressively lowers alkali dense, promotes half fine concentration, retain a part of monose simultaneously; The molecular weight cut-off of ceramic membrane is 800-1500, can retain half fibre, improve the purity of product.
Step A of the present invention, before each nanofiltration membrane, the amount of thin up is 1 times of stock liquid volume, filters the concentrated solution volume obtained identical with stock liquid volume.While ensureing filtration efficiency, little to the damage of nanofiltration membrane.
Preferably, described permeate, containing alkali 200-300g/l, containing half fine 40-80 g/l, after nanofiltration membrane circulation is concentrated, obtains concentrated solution containing alkali 12-75g/l, containing half fine 40-80g/l.Under lowering the dense prerequisite of alkali, ensure the filtration efficiency of film.
Step A of the present invention, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.While ensureing filtration efficiency, little to the damage of ceramic membrane.
Preferably, containing alkali 2-4g/l in the concentrated solution of described ceramic membrane filter, containing half fine 40-80 g/l.Be down to minimum by dense for alkali, the salinity in half fine liquid is just low, and can not affect the activity of enzyme, the purity of the finished product Xylitol is high; The concentration of half fibre is high, ensure that the yield of the finished product Xylitol.
Pre-filtering of the present invention refers to, press lye is successively through rotary drum filtration, Plate Filtration and micro-filtrate membrane filtration removing large granular impurity.Pre-filtering makes press lye not containing the solid impurity of more than 5 microns, and protection film is not below damaged by solid impurity.
Step A of the present invention, the temperature of nanofiltration membrane is 40-60 DEG C, and the temperature of ceramic membrane filter is 60-80 DEG C, and filtration temperature is high, and liquid viscosity is lower, is conducive to filtration efficiency and improves.
Step A of the present invention, the mistake mould difference of nanofiltration membrane is 3-4bar, and the mistake mould difference of ceramic membrane is 5-6bar.For the feature that viscose glue press lye viscosity is higher, adopt higher pressure reduction to filter, can ensure that half fine concentration in alkali lye reaches processing requirement.
Step A of the present invention, the flow of feed liquid in nanofiltration membrane is 25-40m
3/ h, the flow in ceramic membrane is 200-250m
3/ h.The surface velocity that bonding props up film is higher, film is not easy contaminated.
Step A of the present invention, it is 26.8m that the list of nanofiltration membrane props up filtration area
2, it is 0.6m that the list of ceramic membrane props up filtration area
2, single film has larger filtration area under the prerequisite taking less space.
Step B of the present invention, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4-5.The advantage adding hydrochloric acid is that the molecules of salt amount formed is lower, and be conducive to the desalination in later stage, pH value is 4-5, adapts to the pH value requirement of enzymolysis.
Step C of the present invention, prozyme is zytase, cellulase and polygalacturonase, can improve sugared associative key susceptibility to enzymic hydrolysis after adding appropriate cellulase and pectin in zytase.
Preferably, the ratio of described zytase, cellulase and polygalacturonase is 3:2:1, and adopt the prozyme of this ratio to carry out degrading and can make the maximum production of xylo-oligosaccharide, the percent hydrolysis of hemicellulose is up to more than 95%.
Preferably, the enzymolysis time of described enzyme digestion reaction is 0.5-2h, and temperature is 50-60 DEG C, and the pH value of enzyme digestion reaction is 4-5, and under this condition, the activity of enzyme is the highest.
Preferably, the enzyme concentration of described enzyme digestion reaction is 0.5-1.5%, and now the catalytic effect of enzyme is best.
D step of the present invention, the amount adding candidiasis is 0.5-1%, improves the enzymolysis efficiency of enzyme.
Add wood sugar in the enzymolysis solution of D step of the present invention, add-on is 1-1.5%, can improve the transformation efficiency of wood sugar, make maximize conversion.
E step of the present invention, the aperture of described ultra-filtration membrane is 0.001-0.005 micron, the Xylitol liquid in separate fermentation liquid and enzyme.
Preferably, described enzymolysis solution is 60-80m by the flow of ultra-filtration membrane
3/ h, temperature is 30-40 DEG C, and crossing mould difference is 2-3bar.
D step of the present invention, the molecular weight cut-off of described nanofiltration membrane is 100-200.Owing to adopting hydrochloric acid neutralization, the salt of generation is sodium-chlor, and the molecular weight of sodium-chlor is smaller, and far below 100, xylitol molecules amount is greater than 100.Effectively can realize being separated of salt and Xylitol.
Preferably, described nanofiltration membrane desalination, crossing mould difference is 3-4bar, and temperature is 30-40 DEG C, and single filtration area is 26.8 m
2, adapt to the change of low catching molecular, guarantee salt is separated with Xylitol.
Preferably, the material liquid volume before described nanofiltration membrane concentrates is 10-15 times of concentrated solution volume, is conducive to reducing the salt content in Xylitol.
Beneficial effect of the present invention is:
1, the present invention adopts nanofiltration membrane and ceramic membrane combination filtering and concentrating half fibre, because the filtration efficiency of nanofiltration membrane is higher than ceramic membrane, first adopt repeatedly nanofiltration membrane that alkali concn is progressively dropped to certain degree, simultaneously concentrated half fibre, reduce the damage to film, then adopt ceramic membrane filter; The feed liquid that ceramic membrane is applicable to filter the dense height of later stage low alkali half fine is run, and is the powerful guarantee that low alkali is dense.Nanofiltration membrane and ceramic membrane cooperatively interact, and have complementary advantages, and make containing alkali 2-4g/l in final concentrated solution, containing half fine 40-80 g/l, achieve low alkali dense, height half is fine; And process operation efficiency is high, little to the damage of film, cost is low.
2, the amount of nanofiltration membrane thin up of the present invention is 1 times of stock liquid volume, filters the concentrated solution volume obtained identical with stock liquid volume at every turn; Ceramic membrane filter, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.This technique can realize nanofiltration membrane water 10m excessively per hour
3left and right, ceramic membrane is per hour crosses water 45m
3left and right, ensure that filtration efficiency; Meanwhile, little to the damage of film, the 2-3 that can reach its quality guarantee period work-ing life doubly, reduces cost to a great extent, is adapted to industrialization scale operation.
3, the present invention adds hydrochloric acid neutralization to the concentrated solution obtained, then adopts molecular weight cut-off to be the nanofiltration membrane desalination of 100-200.In hydrochloric acid and the salt generated be sodium-chlor, the molecular weight of sodium-chlor, far below 100, and xylitol molecules amount is much larger than 100, effectively can realize being separated of salt and Xylitol.Be conducive to the desalination in later stage, further increase the purity of Xylitol.
4, fermented liquid is first used Xylitol liquid in ultra-filtration and separation fermented liquid and enzyme by the present invention, ensure product purity, permeate enters nanofiltration membrane desalination again, thus have effectively achieved being separated of salt and Xylitol, the specific conductivity finally obtaining Xylitol is 8000-10000 μ s/cm, and ignition residue is 3-6%.Ignition residue is the direct indicator weighing inorganic salt, and the massfraction described in Xylitol shared by inorganic salt is only 3-6%; Specific conductivity is the electrolytical degree existed in reaction liquid, and the main electrolyte of Xylitol is exactly inorganic salts, so this index also can reflect the number of salinity in product.It is low that low conductivity and ignition residue describe the Xylitol salinity adopting the inventive method to obtain, high purity more than 85%.
Embodiment
Below in conjunction with embodiment, essentiality content of the present invention is described in further detail.
Embodiment 1
The membrane concentration technique that Xylitol prepared by pressed liquor produced by viscose fiber, and concrete technology step is as follows:
A, membrane concentration
The pressed liquor that viscose fiber is produced is first through pre-filtering removing large granular impurity, and permeate is through concentrated 2 times of nanofiltration membrane circulation, and send after last concentrated solution thin up into ceramic membrane filter, gained concentrated solution is the concentrated solution of press lye; Concentrated 2 times of described nanofiltration membrane circulation, before each filtration, feed liquid all enters nanofiltration membrane after thin up.
B, extraction half fibre
By the concentrated solution acid neutralization of press lye, obtain half fine liquid.
C, enzymolysis
In half fine liquid, add prozyme, enzyme digestion reaction occurs and obtains enzymolysis solution;
D, fermentation
Enzymolysis solution at the effect bottom fermentation of candidiasis, 55 DEG C of bottom fermentation 1h;
E, purification
Fermented liquid is through ultrafiltration removal of impurities, and permeate is through nanofiltration membrane desalination, and gained concentrated solution is the refined solution of Xylitol, through ion-exchange, activated carbon treatment, condensing crystal, separation, obtains Xylitol.
Embodiment 2
The membrane concentration technique that Xylitol prepared by pressed liquor produced by viscose fiber, and concrete technology step is as follows:
A, membrane concentration
The pressed liquor that viscose fiber is produced is first through pre-filtering removing large granular impurity, and permeate is through concentrated 3 times of nanofiltration membrane circulation, and send after last concentrated solution thin up into ceramic membrane filter, gained concentrated solution is the concentrated solution of press lye; Concentrated 3 times of described nanofiltration membrane circulation, before each filtration, feed liquid all enters nanofiltration membrane after thin up.
B, extraction half fibre
By the concentrated solution acid neutralization of press lye, obtain half fine liquid.
C, enzymolysis
In half fine liquid, add prozyme, enzyme digestion reaction occurs and obtains enzymolysis solution;
D, fermentation
Enzymolysis solution at the effect bottom fermentation of candidiasis, 50 DEG C of bottom fermentation 2h;
E, purification
Fermented liquid is through ultrafiltration removal of impurities, and permeate is through nanofiltration membrane desalination, and gained concentrated solution is the refined solution of Xylitol, through ion-exchange, activated carbon treatment, condensing crystal, separation, obtains Xylitol.
Embodiment 3
The membrane concentration technique that Xylitol prepared by pressed liquor produced by viscose fiber, and concrete technology step is as follows:
A, membrane concentration
The pressed liquor that viscose fiber is produced is first through pre-filtering removing large granular impurity, and permeate is through concentrated 4 times of nanofiltration membrane circulation, and send after last concentrated solution thin up into ceramic membrane filter, gained concentrated solution is the concentrated solution of press lye; Concentrated 4 times of described nanofiltration membrane circulation, before each filtration, feed liquid all enters nanofiltration membrane after thin up.
B, extraction half fibre
By the concentrated solution acid neutralization of press lye, obtain half fine liquid.
C, enzymolysis
In half fine liquid, add prozyme, enzyme digestion reaction occurs and obtains enzymolysis solution;
D, fermentation
Enzymolysis solution at the effect bottom fermentation of candidiasis, 60 DEG C of bottom fermentation 0.5h;
E, purification
Fermented liquid is through ultrafiltration removal of impurities, and permeate is through nanofiltration membrane desalination, and gained concentrated solution is the refined solution of Xylitol, through ion-exchange, activated carbon treatment, condensing crystal, separation, obtains Xylitol.
Embodiment 4
The present embodiment is substantially the same manner as Example 1, on this basis:
Described step A, the molecular weight cut-off of nanofiltration membrane is 200, and the molecular weight cut-off of ceramic membrane is 800.
The nanofiltration membrane circulation of described step A is concentrated, and the amount of thin up is 1 times of stock liquid volume, filters the concentrated solution volume obtained identical with stock liquid volume at every turn.
Embodiment 5
The present embodiment is substantially the same manner as Example 2, on this basis:
Described step A, the molecular weight cut-off of nanofiltration membrane is 400, and the molecular weight cut-off of ceramic membrane is 1500.
The nanofiltration membrane circulation of described step A is concentrated, and the amount of thin up is 1 times of stock liquid volume, filters the concentrated solution volume obtained identical with stock liquid volume at every turn.
Embodiment 6
The present embodiment is substantially the same manner as Example 3, on this basis:
Described step A, the molecular weight cut-off of nanofiltration membrane is 300, and the molecular weight cut-off of ceramic membrane is 1000.
The nanofiltration membrane circulation of described step A is concentrated, and the amount of thin up is 1 times of stock liquid volume, filters the concentrated solution volume obtained identical with stock liquid volume at every turn.
Embodiment 7
The present embodiment is substantially the same manner as Example 1, on this basis:
Described step A, the molecular weight cut-off of nanofiltration membrane is 250, and the molecular weight cut-off of ceramic membrane is 900.
The nanofiltration membrane circulation of described step A is concentrated, and the amount of thin up is 1 times of stock liquid volume, filters the concentrated solution volume obtained identical with stock liquid volume at every turn.
Embodiment 8
The present embodiment is substantially the same manner as Example 4, on this basis:
Described step A, permeate, containing alkali 300g/l, containing half fine 80g/l, after nanofiltration membrane circulation is concentrated, obtains concentrated solution containing alkali 75g/l, containing half fine 80g/l.
Embodiment 9
The present embodiment is substantially the same manner as Example 5, on this basis:
Described step A, permeate, containing alkali 260g/l, containing half fine 70g/l, after nanofiltration membrane circulation is concentrated, obtains concentrated solution containing alkali 32.5g/l, containing half fine 80g/l.
Embodiment 10
The present embodiment is substantially the same manner as Example 6, on this basis:
Described step A, permeate, containing alkali 200g/l, containing half fine 40g/l, after nanofiltration membrane circulation is concentrated, obtains concentrated solution containing alkali 12.5g/l, containing half fine 40g/l.
Embodiment 11
The present embodiment is substantially the same manner as Example 7, on this basis:
Described step A, permeate, containing alkali 220g/l, containing half fine 60g/l, after nanofiltration membrane circulation is concentrated, obtains concentrated solution containing alkali 55g/l, containing half fine 60g/l.
Embodiment 12
The present embodiment is substantially the same manner as Example 8, on this basis:
Described step A, ceramic membrane filter, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.
Described step A, containing alkali 2g/l in the concentrated solution of ceramic membrane filter, containing half fine 40g/l.
Described pre-filtering refers to, pressed liquor is successively through rotary drum filtration, Plate Filtration and micro-filtrate membrane filtration removing large granular impurity.
Embodiment 13
The present embodiment is substantially the same manner as Example 9, on this basis:
The ceramic membrane filter of described step A, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.
Described step A, containing alkali 4g/l in the concentrated solution of ceramic membrane filter, containing half fine 80 g/l.
Described pre-filtering refers to, pressed liquor is successively through rotary drum filtration, Plate Filtration and micro-filtrate membrane filtration removing large granular impurity.
Described step A, the temperature of nanofiltration membrane is 40 DEG C, and the temperature of ceramic membrane filter is 60 DEG C.
Embodiment 14
The present embodiment is substantially the same manner as Example 10, on this basis:
The ceramic membrane filter of described step A, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.
Described step A, containing alkali 3g/l in the concentrated solution of ceramic membrane filter, containing half fine 50g/l.
Described pre-filtering refers to, pressed liquor is successively through rotary drum filtration, Plate Filtration and micro-filtrate membrane filtration removing large granular impurity.
Described step A, the temperature of nanofiltration membrane is 60 DEG C, and the temperature of ceramic membrane filter is 80 DEG C.
Described step A, the mistake mould difference of nanofiltration membrane is 4bar, and the mistake mould difference of ceramic membrane is 6bar.
Embodiment 15
The present embodiment is substantially the same manner as Example 11, on this basis:
The ceramic membrane filter of described step A, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.
Described step A, containing alkali 2.5g/l in the concentrated solution of ceramic membrane filter, containing half fine 60g/l.
Described pre-filtering refers to, pressed liquor is successively through rotary drum filtration, Plate Filtration and micro-filtrate membrane filtration removing large granular impurity.
Described step A, the temperature of nanofiltration membrane is 45 DEG C, and the temperature of ceramic membrane filter is 65 DEG C.
Described step A, the mistake mould difference of nanofiltration membrane is 3bar, and the mistake mould difference of ceramic membrane is 5bar.
Described step A, the flow of feed liquid in nanofiltration membrane is 25m
3/ h, the flow in ceramic membrane is 200m
3/ h.
Embodiment 16
The present embodiment is substantially the same manner as Example 11, on this basis:
The ceramic membrane filter of described step A, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.
Described step A, containing alkali 3.5g/l in the concentrated solution of ceramic membrane filter, containing half fine 70g/l.
Described pre-filtering refers to, pressed liquor is successively through rotary drum filtration, Plate Filtration and micro-filtrate membrane filtration removing large granular impurity.
Described step A, the temperature of nanofiltration membrane is 55 DEG C, and the temperature of ceramic membrane filter is 75 DEG C.
Described step A, the mistake mould difference of nanofiltration membrane is 3.6bar, and the mistake mould difference of ceramic membrane is 5.6bar.
Described step A, the flow of feed liquid in nanofiltration membrane is 40m
3/ h, the flow in ceramic membrane is 250m
3/ h.
Described step A, it is 26.8m that the list of nanofiltration membrane props up filtration area
2, it is 0.6m that the list of ceramic membrane props up filtration area
2.
Embodiment 17
The present embodiment is substantially the same manner as Example 11, on this basis:
The ceramic membrane filter of described step A, feed liquid first enters ceramic membrane device through thin up, and add water to feed liquid gradation in working cycle, total amount of water is 5 times of material liquid volume, and gained concentrated solution volume is identical with stock liquid volume.
Described step A, containing alkali 3.8g/l in the concentrated solution of ceramic membrane filter, containing half fine 65g/l.
Described pre-filtering refers to, pressed liquor is successively through rotary drum filtration, Plate Filtration and micro-filtrate membrane filtration removing large granular impurity.
Described step A, the temperature of nanofiltration membrane is 55 DEG C, and the temperature of ceramic membrane filter is 72 DEG C.
Described step A, the mistake mould difference of nanofiltration membrane is 3.6bar, and the mistake mould difference of ceramic membrane is 5.2bar.
Described step A, the flow of feed liquid in nanofiltration membrane is 30m
3/ h, the flow in ceramic membrane is 220m
3/ h.
Described step A, it is 26.8m that the list of nanofiltration membrane props up filtration area
2, it is 0.6m that the list of ceramic membrane props up filtration area
2.
Embodiment 18
The present embodiment is substantially the same manner as Example 8, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.
Embodiment 19
The present embodiment is substantially the same manner as Example 9, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 5.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
Embodiment 20
The present embodiment is substantially the same manner as Example 10, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.5.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 0.5h, and temperature is 60 DEG C, and the pH value of enzyme digestion reaction is 4.5.
Embodiment 21
The present embodiment is substantially the same manner as Example 11, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.6.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 2h, and temperature is 50 DEG C, and the pH value of enzyme digestion reaction is 4.6.
The enzyme concentration of described enzyme digestion reaction is 0.5%.
Embodiment 22
The present embodiment is substantially the same manner as Example 16, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value 4.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 1h, and temperature is 52 DEG C, and the pH value of enzyme digestion reaction is 4.
The enzyme concentration of described enzyme digestion reaction is 1.5%.
Described D step, the amount adding candidiasis is 1%.
Embodiment 23
The present embodiment is substantially the same manner as Example 17, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 5.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 1.5h, and temperature is 55 DEG C, and the pH value of enzyme digestion reaction is 5.
The enzyme concentration of described enzyme digestion reaction is 1%.
Described D step, the amount adding candidiasis is 0.8%.
Add wood sugar in the enzymolysis solution of described D step, add-on is 1.2%.
Embodiment 24
The present embodiment is substantially the same manner as Example 17, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.2.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 0.6h, and temperature is 52 DEG C, and the pH value of enzyme digestion reaction is 4.2.
The enzyme concentration of described enzyme digestion reaction is 0.6%.
Described D step, the amount adding candidiasis is 0.5%.
Add wood sugar in the enzymolysis solution of described D step, add-on is 1%.
Described E step, the aperture of described ultra-filtration membrane is 0.001 micron.
Described D step, the molecular weight cut-off of nanofiltration membrane is 100.
The mistake mould difference of described nanofiltration membrane is 3bar, and temperature is 30 DEG C, and single filtration area is 26.8 m
2.
Embodiment 25
The present embodiment is substantially the same manner as Example 17, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.5.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 1.5h, and temperature is 58 DEG C, and the pH value of enzyme digestion reaction is 4.5.
The enzyme concentration of described enzyme digestion reaction is 0.8%.
Described D step, the amount adding candidiasis is 0.6%.
Add wood sugar in the enzymolysis solution of described D step, add-on is 1.5%.
Described E step, the aperture of described ultra-filtration membrane is 0.005 micron.
Enzymolysis solution is 60m by the flow of ultra-filtration membrane
3/ h, temperature is 30 DEG C, and crossing mould difference is 2bar.
Described D step, the molecular weight cut-off of nanofiltration membrane is 120.
The mistake mould difference of described nanofiltration membrane is 4bar, and temperature is 40 DEG C, and single filtration area is 26.8 m
2.
Described D step, the material liquid volume before nanofiltration membrane concentrates is 10 times of concentrated solution volume.
Embodiment 26
The present embodiment is substantially the same manner as Example 17, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 0.7h, and temperature is 52 DEG C, and the pH value of enzyme digestion reaction is 4.
The enzyme concentration of described enzyme digestion reaction is 0.8%.
Described D step, the amount adding candidiasis is 0.7%.
Add wood sugar in the enzymolysis solution of described D step, add-on is 1.3%.
Described E step, the aperture of described ultra-filtration membrane is 0.002 micron.
Enzymolysis solution is 80m by the flow of ultra-filtration membrane
3/ h, temperature is 40 DEG C, and crossing mould difference is 3bar.
Described D step, the molecular weight cut-off of nanofiltration membrane is 150.
The mistake mould difference of described nanofiltration membrane is 3.5bar, and temperature is 32 DEG C, and single filtration area is 26.8 m
2.
Described D step, the material liquid volume before nanofiltration membrane concentrates is 15 times of concentrated solution volume.
The activated carbon decolorizing of described D step refers to: adjusted to ph is 4, adds gac, at 50 DEG C, adsorb 1h.
The specific conductivity obtaining Xylitol is 8500 μ s/cm, and ignition residue is 4%.
Embodiment 27
The present embodiment is substantially the same manner as Example 17, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 5.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 2h, and temperature is 56 DEG C, and the pH value of enzyme digestion reaction is 5.
The enzyme concentration of described enzyme digestion reaction is 1.2%.
Described D step, the amount adding candidiasis is 0.8%.
Add wood sugar in the enzymolysis solution of described D step, add-on is 1.4%.
Described E step, the aperture of described ultra-filtration membrane is 0.003 micron.
Enzymolysis solution is 70m by the flow of ultra-filtration membrane
3/ h, temperature is 34 DEG C, and crossing mould difference is 2.5bar.
Described D step, the molecular weight cut-off of nanofiltration membrane is 180.
The mistake mould difference of described nanofiltration membrane is 3.6bar, and temperature is 35 DEG C, and single filtration area is 26.8 m
2.
Described D step, the material liquid volume before nanofiltration membrane concentrates is 12 times of concentrated solution volume.
The activated carbon decolorizing of described D step refers to: adjusted to ph is 5, adds gac, at 60 DEG C, adsorb 0.5h.
The specific conductivity obtaining Xylitol is 9000 μ s/cm, and ignition residue is 5%.
Embodiment 28
The present embodiment is substantially the same manner as Example 8, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.3.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 0.9h, and temperature is 53 DEG C, and the pH value of enzyme digestion reaction is 4.3.
The enzyme concentration of described enzyme digestion reaction is 1.1%.
Described D step, the amount adding candidiasis is 0.9%.
Add wood sugar in the enzymolysis solution of described D step, add-on is 1.1%.
Described E step, the aperture of described ultra-filtration membrane is 0.002 micron.
Enzymolysis solution is 65m by the flow of ultra-filtration membrane
3/ h, temperature is 32 DEG C, and crossing mould difference is 2.3bar.
Described D step, the molecular weight cut-off of nanofiltration membrane is 105.
The mistake mould difference of described nanofiltration membrane is 3.6bar, and temperature is 36 DEG C, and single filtration area is 26.8 m
2.
Described D step, the material liquid volume before nanofiltration membrane concentrates is 13 times of concentrated solution volume.
The activated carbon decolorizing of described D step refers to: adjusted to ph is 4.5, adds gac, at 52 DEG C, adsorb 0.6h.
The ion-exchange of described D step refers to: concentrated solution first by positive post, then falls charged impurity by cloudy post exchange adsorption.
The specific conductivity obtaining Xylitol is 10000 μ s/cm, and ignition residue is 6%.
Embodiment 29
The present embodiment is substantially the same manner as Example 9, on this basis:
Described step B, concentrated solution acid neutralization, refers to and adds hydrochloric acid neutralization, make pH value be 4.5.
Described step C, prozyme is zytase, cellulase and polygalacturonase, and ratio is 3:2:1.
The enzymolysis time of described enzyme digestion reaction is 1.5h, and temperature is 56 DEG C, and the pH value of enzyme digestion reaction is 4.5.
The enzyme concentration of described enzyme digestion reaction is 0.8%.
Described D step, the amount adding candidiasis is 0.5-1%.
Add wood sugar in the enzymolysis solution of described D step, add-on is 1.5%.
Described E step, the aperture of described ultra-filtration membrane is 0.005 micron.
Enzymolysis solution is 75m by the flow of ultra-filtration membrane
3/ h, temperature is 36 DEG C, and crossing mould difference is 2.6bar.
Described D step, the molecular weight cut-off of nanofiltration membrane is 120.
The mistake mould difference of described nanofiltration membrane is 3bar, and temperature is 32 DEG C, and single filtration area is 26.8 m
2.
Described D step, the material liquid volume before nanofiltration membrane concentrates is 12 times of concentrated solution volume.
The activated carbon decolorizing of described D step refers to: adjusted to ph is 4.5, adds gac, at 53 DEG C, adsorb 0.6h.
The ion-exchange of described D step refers to: concentrated solution first by positive post, then falls charged impurity by cloudy post exchange adsorption.
The specific conductivity obtaining Xylitol is 8000 μ s/cm, and ignition residue is 3%.