Background technology
Although biorefinery has become study hotspot in recent years, but the real Biomass Economy epoch not yet arrive, the biorefinery technology being realized bioenergy and biobased products by wood fiber biomass is still faced with many bottleneck problems, and pre-treatment and the enzymolysis problem of wherein lignocellulose-sugared platform (pre-treatment, enzymolysis and sugar-fermenting) are particularly outstanding.Wyman CE thinks when analyzing biorefinery cellulosic ethanol, and the process cost of cellulosic ethanol accounts for 67% of total cost, and wherein the cost of raw materials pretreatment is the highest, and be secondly the production process of enzymic hydrolysis and enzyme, enzymolysis efficiency is on the low side.
In wood fiber biomass pre-treatment, method representative at present has: dilute sulfuric acid process, hot-water process, the quick-fried method of vapour and lime method etc., their in pre-treatment evaluation (economy, validity, treatment time, security and environmental friendliness and on subsequent technique impact) also exist problem all to some extent, especially Financial cost aspect is higher, be difficult to the requirement meeting biorefinery, and also have certain distance with desirable preconditioning technique.As New Pre treatment process likely, it is good and be convenient to the features such as recovery that Small molecule organic solvents slurrying has pre-treatment selectivity, causes and pay close attention to widely, such as ALCELL method and ACETOSOLV method etc. within the quite a while.But the shortcoming that they show especially when engineering is amplified, hinders its process of industrialization, as: volatile, the easy leakage of solvent, inflammable and explosive even poisonous etc.; High-voltage operation operates.For this problem, although Rezayati-Charani P is et al, Rodriguez A et al and domesticly oldly cellulosic has been carried out to the research of high boiling organic solvent slurrying for team that is strong and Cheng Xian Sue, but still there is the catalyzer such as pressurization, acid adding/alkali and the too high problem of boiling solvent cost.Visible, finding low-cost high boiling solvent is the breakthrough point building economical and efficient and environmental friendliness organic solvent preconditioning technique.
On the other hand, industry glycerol is as the byproduct (1/4 biofuel amount) of biofuel, output constantly rises along with the sharp increase day by day of Global biodiesel, occur that serious supply exceed demand, and these low grade purification of glycerin need advanced technology and high cost of investment to food and medicine level (-99.5%).Although Demirbas A is based on the consideration of renewable forest tree resource pulping and paper-making and energy aspect in the world, carries out glycerine, as organic solvent, the research that slurrying removes xylogen and liquefaction vaporization aspect has been carried out to timber; Yadhu NathGuragain team utilizes raw glycerine process wheat straw and Herba Eichhorniae, have also been obtained desirable treatment effect.Domestic aspect we utilize industry glycerol as boiling solvent treatment wheat straw, obtain best pretreatment condition (treatment temp 220 DEG C, treatment time 3h, liquid-solid ratio 20,70% aqueous glycerin solution) equally.Herein under reason condition, Mierocrystalline cellulose retention rate about 98%, hemicellulose decreasing ratio about 70%, delignification rate about 65%, robust fibre is through 48h enzymolysis, and enzymolysis efficiency reaches 90%.Prove that industry glycerol all can reach good treatment effect as boiling solvent treatment wood fibre raw material thus.
But the above-mentioned glycerine that utilizes is comparatively large as glycerine demand during boiling solvent treatment lignocellulosic material, and liquid-solid ratio reaches 20, this considerably increases the cost of process lignocellulosic material, thus seriously hinders its large-scale industrial production.Therefore we are on the basis of forefathers, the method that further exploratory development utilizes industry glycerol how can greatly reduce costs as boiling solvent, through experiment many times and summary, find to adopt glycerin/water to circulate pretreated method to process bagasse, both good treatment effect had been reached, greatly reduce again the consumption of glycerine, significantly reduce the cost of Treating straw lignocellulose raw material and saved a large amount of water, decrease environmental pollution, for the large-scale industrial production of lignocellulose raw material biorefinery is from now on laid a good foundation, produce larger Social benefit and economic benefit.
Summary of the invention
The invention provides a kind of method extracting Bagasse-cellulose.
Technical scheme of the present invention is as follows:
1, the optimization of bagasse normal pressure glycerine autocatalysis pretreatment condition: put into 60 DEG C of baking ovens after bagasse being pulverized 20 mesh sieve and dry to constant weight.Get 10g to load in three hole flasks, add 200g, the 70% industry glycerol aqueous solution stirs evenly, normal pressure intensification boiling in constant-temperature heating sleeve, the heating-up time is about about 40min, boiling temperature 200 DEG C-240 DEG C, cooking time 1h-5h.After boiling, cool, when being cooled to about 120 DEG C, slowly add 150g boiling water, rapid stirring fully dissolves about 10min, starts to use G
3sand core funnel suction filtration, and be 100 DEG C by temperature, 500g, 50% aqueous glycerin solution washing, suction filtration twice, it is 100 DEG C by temperature again, 400g distilled water wash, suction filtration twice, after washing, the filter cake obtained is glycerine crude fibre, american energy laboratory NREL method is adopted to measure its cellulosic component, Mierocrystalline cellulose retention rate is 94%, lignin removing rate is 60%, wet filter cake adds 0.05M by solids concn 2%, then pH4.8 citrate buffer solution adds after 50 μ L cellulases shake up, at 50 DEG C, 150rpm shakes enzymolysis 48h, sugar is surveyed in sampling, calculate enzymolysis efficiency.Fig. 1 is shown in the impact of boiling temperature on each component and enzymolysis efficiency, and Fig. 2 is shown in the impact of cooking time on each component and enzymolysis efficiency.Best pretreatment condition is judged, for further research and utilization glycerin/water circulation pretreating scheme lays the foundation by comparing process rear component, pre-treatment amount and enzymolysis efficiency.2, glycerin/water circulation pretreatment technology: comparison diagram 1 and Fig. 2 experiment draw: best pretreatment condition is 220 DEG C, 2h, 200g, 70% aqueous glycerin solution, use above-mentioned optimal treatment condition to carry out glycerin/water circulation pretreatment technology and probe into.Concrete operation step is as follows: raw material 10g loads in three hole flasks, add 50% washing of 280g recovery, suction filtration industry glycerol water as boiling solvent, at 220 DEG C of insulation 2h, cool, when being cooled to about 120 DEG C, slowly add 150g boiling water, rapid stirring fully dissolves about 10min, starts to use G
3sand core funnel suction filtration, and be 100 DEG C of 50% aqueous glycerin solution 500g washings of reclaiming, suction filtration twice by temperature, again with temperature be 100 DEG C, 400g distilled water wash, suction filtration twice, after washing, the filter cake obtained is glycerine crude fibre, american energy laboratory NREL method is adopted to measure its cellulosic component, wet filter cake adds 0.05M by solids concn 2%, then pH4.8 citrate buffer solution adds after 50 μ L cellulases shake up, at 50 DEG C, 150rpm shakes enzymolysis 48h, and sugar is surveyed in sampling, calculates enzymolysis efficiency.And repeatedly repeat above-mentioned experiment and replication, inspection reclaim 50% aqueous glycerin solution washing, suction filtration repeatedly boiling use after situation, cycle applications glycerine boiling number of times, on the impact of each component and enzymolysis efficiency, is shown in and accompanying drawing 3 is described.
3, existing steaming plant is improved, prolong is added in digestion process, reclaim in heating up process the moisture that evaporates and 400g water washing, moisture that suction filtration obtains, as precipitate lignin water, thus reduce the utilization of water, be industrialization and scale operation based theoretical further.
4, with reference to the three large compound mensuration methods of U.S.'s renewable energy source laboratory (NREL):
Accurately take the bagasse 0.3g of drying to constant weight and put into 10mL test tube, add the sulfuric acid 3mL of 72%, 60min is reacted in 30 DEG C of water-baths, each 5-10min takes out concussion once---→ hydrolyzed solution of above-mentioned gained is transferred in 250mL triangular flask, and add 84mL distilled water, hydrolysis 60min is continued at 121 DEG C, take out after pressure kettle cooling---→ vacuum filtration of reactant filtering crucible is obtained filtrate and filter residue respectively, filtrate is divided into two portions, a part measures acid-soluble content of lignin by distilled water diluting certain multiple under 240nm, distilled water does blank group, glucose is measured with HPLC after another part calcium carbonate is diluted to neutrality, the concentration of pectinose and wood sugar, and calculate Mierocrystalline cellulose and hemicellulose level with this---→ with hot distilled water by after residue washing to neutrality, dry to constant weight at 105 DEG C, weigh m1, ashing at 600 DEG C afterwards, obtain ash content and crucible gross weight m
2, m
1-m
2be the content of sour insoluble xylogen.
Mierocrystalline cellulose %=glucose concn × 87 × 10
-3× 0.9/0.3 × 100%
Hemicellulose %=(arabinose concentrations+xylose concentration) × 87 × 10
-3× 0.88/0.3 × 100%
Content of lignin %=(acid-soluble content of lignin+sour insoluble content of lignin)/0.3 × 100%
Light absorption value × 87 × 10, acid-soluble xylogen %=240nm place
-3× extension rate/ε × 0.3 (ε is the specific absorptioies of biomass under specific length, is 25L/g cm for bagasse)
Reducing sugar typical curve: Y=1.3628X-0.0654 (X is concentration of reduced sugar, and Y is light absorption value)
Reducing sugar content=concentration of reduced sugar × 25mL × 10
-3(25mL is enzyme digestion reaction system)
Enzymatic hydrolyzation=reducing sugar content/zymolyte doses × 100%.
Attached caption
Fig. 1 boiling temperature is on the impact of each component and enzymolysis efficiency
Fig. 2 cooking time is on the impact of each component and enzymolysis efficiency
Fig. 3 cycle applications glycerine boiling number of times is on the impact of each component and enzymolysis efficiency
Wherein:
Fig. 1 is the changing conditions that 10g bagasse adds 200g, 70% aqueous glycerin solution pre-treatment amount, Mierocrystalline cellulose retention rate, xylogen retention rate and enzymolysis efficiency when different boiling temperature insulation 2h, as seen from the figure, be before 220 DEG C in temperature, cellulase hydrolysis efficiency along with the rising increase of temperature very fast, 53% is reached 220 DEG C time, xylogen retention rate also obviously declines, and 220 DEG C time, xylogen retention rate reaches 40%.But along with the rising of temperature, cellulase hydrolysis rate does not significantly raise and declines on the contrary, and xylogen does not also significantly remove, and fiber retention changes always and not quite slightly declines, and pre-treatment amount slightly reduces along with the rising of temperature.This may be due to boiling temperature excessive time cause reaction too violent, the Mierocrystalline cellulose in bagasse likely decomposes in high temperature, and xylogen occurs also likely to there occurs condensation reaction.So the optimal temperature of glycerine solution process bagasse is 220 DEG C.
Fig. 2 be 10g bagasse add pre-treatment amount, Mierocrystalline cellulose retention rate, xylogen retention rate and enzymolysis efficiency 200g, 70% aqueous glycerin solution are incubated different time during when boiling temperature is 220 DEG C changing conditions.As seen from the figure, pre-treatment amount and fiber retention slightly reduce along with the lengthening of cooking time, be before 2h at cooking time, cellulase hydrolysis efficiency obviously raises along with the lengthening of cooking time, 53% is reached when 2h, xylogen retention rate obviously reduces along with the lengthening of cooking time, reaches 40% when 2h.Along with the continuous lengthening of cooking time, pre-treatment amount and fiber retention slightly reduce, and cellulase hydrolysis efficiency is not increased significantly and reduces on the contrary, and xylogen retention rate does not also significantly reduce, so the glycerine solution boiling bagasse optimum time is at this temperature 2h.
Synthesizing map 1,2 is known, bagasse normal pressure glycerine best pretreatment condition is 10g bagasse, 200g, 70% aqueous glycerin solution, boiling temperature are 220 DEG C, soaking time is 2h.And under this conditions of cooking, Bagasse-cellulose retention rate is 94%, and delignification rate reaches 60%; Normal pressure glycerine autocatalysis pre-treatment bagasse is when cellulase 100 μ L/g dry bottom thing, and 48h cellulase hydrolysis efficiency is about 53%.
Fig. 3 is the changing conditions that 10g bagasse adds pre-treatment amount, Mierocrystalline cellulose retention rate, xylogen retention rate and cellulase hydrolysis efficiency 500g glycerin/water circulation cooking liquor is incubated 2h during when boiling temperature is 220 DEG C, as seen from the figure, be before 7 times at boiling number of times, cellulase hydrolysis efficiency declines slightly, can more than 47.48% be reached, xylogen retention rate is below 45.87%, but it is rapid in cellulase hydrolysis decrease in efficiency after multiple use 7 times to collect glycerine, and xylogen retention rate increases.Therefore, glycerin/water circulation pre-treatment reaches 7 times for optimum cycle number of times.
Embodiment
Example 1: take 10g and cross 20 mesh sieve and put into three hole flasks through 60 DEG C of oven for drying to the bagasse of constant weight, add 200g, 70% aqueous glycerin solution, put into heating jacket and be heated to 220 DEG C, and be incubated 2 hours, the left mouth of three hole flasks puts into temperature probe to control detected temperatures, centre is put into mechanical stirring rod and reaction mixture is fully mixed, and right mouth adds that prolong is to collect water of condensation and to prevent intensification too high.After boiling, cool, when being cooled to about 120 DEG C, slowly add 150g boiling water, rapid stirring fully dissolves about 10min, starts to use G
3sand core funnel suction filtration, and be 100 DEG C by temperature, 500g, 50% aqueous glycerin solution washing, suction filtration twice, it is 100 DEG C by temperature again, 400g distilled water wash, suction filtration twice, after washing, the filter cake obtained is glycerine crude fibre, employing american energy laboratory NREL method measures its cellulosic component and is: Mierocrystalline cellulose retention rate is 94%, xylogen retention rate reaches 40%, get 0.5g filter cake glycerine crude fibre simultaneously and add 25mL, 0.05M, then pH4.8 citrate buffer solution adds after 50 μ L cellulases shake up, at 50 DEG C, 150rpm shakes enzymolysis 48h, sugar is surveyed in sampling, enzymolysis efficiency is 54%.
Example 2: take 10g and cross 20 mesh sieve and put into three hole flasks through 60 DEG C of oven for drying to the bagasse of constant weight, the left mouth of three hole flasks puts into temperature probe to control detected temperatures, centre is put into mechanical stirring rod and reaction mixture is fully mixed, and right mouth adds that prolong is to collect water of condensation and to prevent intensification too high.Set best boiling temperature time 220 DEG C, 2h.Add the reusable 50% glycerine washing of 280g for 7th time, suction filtration liquid carries out boiling, all the other conditional parameters are with example 1, the filter cake obtained is glycerine crude fibre, employing american energy laboratory NREL method measures its cellulosic component and is: Mierocrystalline cellulose retention rate is 94%, xylogen retention rate reaches 45%, getting dry weight is that the filter cake that 0.5g is wet adds 25mL, 0.05M, then pH4.8 citrate buffer solution adds after 50 μ L cellulases shake up, at 50 DEG C, 150rpm shakes enzymolysis 48h, and sugar is surveyed in sampling, and calculating enzymolysis efficiency is 46%.
Example 3: improve existing steaming plant, in digestion process, add prolong, reclaim in heating up process the moisture that evaporates and 400g water washing, moisture that suction filtration obtains, as precipitate lignin water, general 80%-90% water can be reclaimed according to calculating, reach the object of water saving.