CN105400830A - Method for producing ethyl alcohol through lignocellulose raw material - Google Patents

Abstract

The invention provides a method for producing ethyl alcohol through a lignocellulose raw material. The method includes the following steps of 1, pretreatment, wherein the lignocellulose raw material is subjected to dilute-acid pretreatment, and a pretreatment raw material is obtained; 2, premashing, wherein mashing is conducted on the pretreatment raw material obtained in step 1, and a premashing material is obtained; 3, material feeding is conducted in batches, and diastatic fermentation is conducted synchronously. According to the method for producing the ethyl alcohol, the concentration of the ethyl alcohol can be effectively raised, the ethyl alcohol yield and productive rate are high, production capacity is high, the production cost of the ethyl alcohol is lowered, and a good industrial application prospect is achieved.

Description

A kind of method utilizing producing ethanol by using lignocellulose materials

Technical field

The present invention relates to a kind of production method of ethanol, particularly a kind of method utilizing producing ethanol by using lignocellulose materials.

Background technology

Lignocellulose biomass is formed primarily of Mierocrystalline cellulose, hemicellulose and xylogen, because it has the advantages such as output is large, cost is low, renewable, take lignocellulose biomass as raw material, adopt microbial method production ethanol to receive the extensive concern of countries in the world.

The traditional technology of producing ethanol by using lignocellulose materials is utilized to mainly contain four kinds: substep saccharification and fermentation, synchronous glycosylation fermentation (SSF), synchronous glycosylation and altogether fermentation and consolidated bioprocessing [Li Jiang etc., the saccharification and fermentation process progress of lignocellulosic materials for fuel ethanol, chemical industry is in progress, and 2011 (30): 284-291].But during this four kinds of traditional method alcohol prepared by fermenting, the alcohol concn in the fermented liquid obtained is too low, causes alcohol yied low, and what is more important, can cause the high cost of distilation.

According to reports such as Huang, when alcohol concn is lower than 4%w/w, distillation cost is very high, and when concentration is more than or equal to 4%w/w, then distill cost and greatly reduce [Wei-DongHuangetal, Analysisofbiofuelsproductionfromsugarbasedonthreecriteri a:Thermodynamics, bioenergetics, andproductseparation, EnergyEnviron.Sci., 2011,4,784 – 792; See Fig. 5].But during aforementioned four kinds of traditional method alcohol prepared by fermenting, SSF method is as the most frequently used technique, and in obtained fermented liquid, alcohol concn is relatively high, but is also difficult to reach aforementioned threshold value, and distilation cost is high.

Notification number is the SSF method that patent discloses a kind of improvement of CN103074385B, alcohol concn is brought up to 3.45%w/w (i.e. 39.4g/L), the method improves the alcohol concn in fermented liquid to a certain extent, but the alcohol concn of the fermented liquid obtained is still remarkable in 4%w/w, distilation cost is still very high.

Therefore, for realizing utilizing producing ethanol by using lignocellulose materials efficiently, economically, being badly in need of improving existing method, to improve the alcohol concn in fermented liquid, reducing distilation cost, improving productive rate.

Summary of the invention

The object of the present invention is to provide a kind of method utilizing producing ethanol by using lignocellulose materials.

The invention provides a kind of method utilizing producing ethanol by using lignocellulose materials, it comprises the steps:

A, pre-treatment: dilute acid pretreatment is carried out to lignocellulosic material, obtains pretreating raw material;

B, premashing: saccharification is carried out to the pretreating raw material that step a obtains, obtains premashing material;

C, fed-batch simultaneous saccharification and fermentation:

After the premashing material obtained until step b is cooled to 35 DEG C, inoculation yeast, is 4.8-5.0,150rpm, 35 DEG C of condition bottom fermentations in pH value, adds feed supplement material in fermenting process; Last feed supplement, after 24 hours, stops fermentation;

Wherein, feed supplement material is prepared by following method:

Get the pretreating raw material that step a obtains, add cellulase, then add water, adjust pH to 4.8-5.0, then keep 24 hours under 150rpm, 50 DEG C of conditions, obtain feed supplement material; Wherein, the solids concn of pretreating raw material is 20% (g/ml), and the add-on of cellulase is 15FPU/g solid.

Lignocellulosic material is a large kind of biomass, form primarily of xylogen, Mierocrystalline cellulose and hemicellulose, the lignocellulosic material that can be used for producing ethanol comprises the agricultural wastes such as stalk, trade waste is as the fibrous residue etc. in paper mill, and forestry waste and urban waste are as waste paper, wrapping paper etc.

FPU: filter paper enzyme activity unit of force (Filterpaperunit), is used to the conventional unit describing cellulase activity.

15FPU/g solid: enzyme addition, refers to that the enzyme activity amount that every g pretreating raw material dry weight (solid weight in dry weight and pretreating raw material) needs add is 15FPU.

During saccharification, according to the solids concn of 15% (g/ml), then required total enzyme activity amount is 15FPU/g solid × 15g=225FPU.The enzyme activity of cellulase is 140FPU/mL, then the addition of cellulase is 225/140=1.6mL.

Wherein, in step a, described pretreated method is:

1) get lignocellulosic material, add sulfuric acid and water by solids concn 10% (g/ml) and sulfuric acid final concentration 1% (g/ml), then keep 10-20min in 140-150 DEG C;

2) separation obtains solid residue;

3) clean;

Wherein, described lignocellulosic material is corn cob, maize straw, rice straw, wheat stalk, rape stalk, bagasse and/or reed.

Cleaning refers to: clean solid residue with water, identical with the pH value of water to the pH value of solid residue.

Wherein, in step a, described pretreated method is:

1) get lignocellulosic material, regulate solids concn to be 15% (g/ml);

2) pulverize under 5000rpm, regulate pH to 4.8-5.0;

Wherein, described lignocellulosic material is paper.

Wherein, in step b, the method for described premashing is:

Get the pretreating raw material of step a, add cellulase, then add water, adjust pH to 4.8-5.0, then under 150rpm, 50 DEG C of conditions, keep 16-24 hour, obtain premashing material; Wherein, the solids concn of pretreating raw material is 15% (g/ml), and the add-on of cellulase is 15FPU/g solid.

Further, described cellulase is CellicCTec2.

Wherein, described solids concn is by the adjustment that adds water.

Wherein, in step c, in the premashing material after inoculation yeast, yeast quantity is 1-2 × 10 ⁷individual/mL.

Wherein, in step c, the number of times of described feed supplement is 2-3 time; The addition of each feed supplement material is all identical with the pretreating raw material volume of step b.

Wherein, the 1st feed supplement time is 0-24 hour after fermentation; 2nd feed supplement time is after the 1st feed supplement 24 hours.

Method ethanol production provided by the invention, premashing is carried out to lignocellulose, concentrate the advantage of substep diastatic fermentation and simultaneous saccharification and fermentation, in the fermentation liquid obtained, alcohol concn is 4 ~ 4.6%w/w (i.e. 46.5 ~ 53.7g/l), be not less than the stagnation point of 4%w/w, ethanol distillation reclaims the cost consumed to be reduced greatly, and alcohol getting rate, productive rate and throughput that the present invention obtains are high, have good prospects for commercial application.

Obviously, according to foregoing of the present invention, according to ordinary technical knowledge and the customary means of this area, not departing under the present invention's above-mentioned basic fundamental thought prerequisite, the amendment of other various ways, replacement or change can also be made.

The embodiment of form by the following examples, is described in further detail foregoing of the present invention again.But this should be interpreted as that the scope of the above-mentioned theme of the present invention is only limitted to following example.All technology realized based on foregoing of the present invention all belong to scope of the present invention.

Accompanying drawing explanation

Fig. 1 technique diagram of the present invention

Embodiment

Be described further with embodiment below, but the present invention is not limited to these embodiments.

Embodiment 1 the present invention produces the method for ethanol

1, experiment material

Cellulase: the CellicCTec2 that Novi's letter is produced, it is 140FPU/mL that the method (Measurementofcellulaseactivites) of recommending according to American National National Renewable Energy Laboratory (NationalRenewableEnergyLaboratory) measures its filter paper enzyme activity;

Maize straw: be taken from farmland, Shuangliu County, Chengdu, the content that the method (Determinationofstructuralcarbohydratesandlignininbiomass) of recommending according to American National National Renewable Energy Laboratory (NationalRenewableEnergyLaboratory) measures its component and structure sugar is as follows:

Note: institute's array structure sugar, xylogen and ash oontent all calculate based on dry weight.

2, method ethanol production

(1) pre-treatment:

Get 222.8g maize straw (i.e. dry weight 200g), add the sulphuric acid soln that 400mL concentration is 5% (g/ml), add 1577.2mL water (calculation formula of water is: 2000-400-(222.8-200)) again, make solids concn be 10% (g/ml);

Under 150 DEG C of conditions, process 10min, obtain 523.8g solid residue through solid-liquid separation, namely obtain pretreated corn stalk raw material, for subsequent use.

In pretreated corn stalk raw material, moisture content is 78.7%, and dry weight is 523.8 × (1-78.7%)=111.6g.

In pretreated corn stalk raw material component and structure sugar content as follows:

Note: institute's array structure sugar, xylogen and ash oontent all calculate based on dry weight.

(2) premashing:

Get 70.4g (dry weight=70.4 × (1-78.7%)=15g) pretreated corn stalk raw material, add cellulase 1.6mL (calculation formula is: 15FPU/g solid × 15g/140FPU/mL=1.6), add water 38mL, uses 20%H ₂sO ₄after adjust ph to 4.8, then to add water to total liquid volume be 100mL, and after mixing, saccharification 16h under 50 DEG C of conditions, obtains premashing liquid.

(3) simultaneous saccharification and fermentation (SSF):

After premashing liquid is cooled to 35 DEG C, add 10mL yeast starter liquid, in yeast starter liquid, yeast quantity is 10 ⁸individual/mL, starts fermentation; Add feed supplement material during the fermentation;

Wherein, feed supplement material is prepared by following method: get 93.9g (dry weight=93.9 × (1-78.7%)=20g) step (1) pretreated corn stalk raw material, add cellulase 2.1mL (15FPU/g solid × 20g/140FPU/mL=2.1), add water 15mL, uses 20%H ₂sO ₄regulate after pH to 4.8, then to add water to total liquid volume be 100mL, with premashing 24h under 50 DEG C of conditions after mixing;

Feed supplement time: carry out feed supplement after feed supplement temperature to be prepared is down to 35 DEG C, altogether feed supplement 2 times.Feed supplement time first time is 24h after SSF starts; The second time feed supplement time is that first time feed supplement is after 24 hours.

Stop: 24h after second time feed supplement, terminate SSF.

3, experimental result

1) alcohol concn (E) in mash is measured

Be interior mark with Virahol, with gas chromatography determination, alcohol concn is 46.5g/l.

Be scaled massfraction representation, alcohol concn E ':

$E^{\′}=\frac{W_L}{W+W_L}\×E=\frac{100+100+100+10}{(15+20+20)+(100+100+100+10)}\×46.5=4.0\%w/w$

W: total raw material amount (g) added;

W _lfor the liquid portion total mass of reaction system, its density is regarded as 1g/mL.

2) alcohol yied (Y): be 90.3%;

Calculation formula is as follows:

$Y=\frac{E}{E_0}\×100\%=\frac{46.5}{51.5}\×100\%=90.3\%$

$E_0=\frac{W\×C_g\×0.511}{V}=\frac{(15+20+20)\×56.8\%\×0.511}{0.1+0.1+0.1+0.01}=51.5g/L$

Wherein,

Y: alcohol yied;

E: the alcohol concn (g/L) fermented in rear mash;

E ₀: theoretical producing and ethanol concentration (g/L);

W: total raw material amount (g) added;

C _g: the glucose content in raw material;

0.511: the theoretical amount of glucose producing and ethanol;

V: total liquid volume (L) of reaction system;

3) alcohol getting rate (Y '): be 77.4%;

Calculation formula is as follows:

$Y^{\′}=\frac{G\×w}{G_0\×w_0}\×Y=\frac{111.6\×56.8\%}{200\×37.0\%}\×90.3\%=77.4\%$

G: the glucose content in pretreated corn stalk raw material;

W: pretreated maize straw matter heavy (g);

G ₀: the glucose content in corn stalk raw material;

W ₀: the quality (g) of corn stalk raw material;

Y: alcohol yied.

4) ethanol production (P): be 0.53g/L/h;

Calculation formula is as follows:

$P=\frac{E}{T}=\frac{46.5}{16+24+24+24}=0.53g/L/h$

P: throughput (g/L/h);

The total fermentation time (h) of T:SSF.

Alcohol concn in the mash that present method obtains is 46.5g/l, i.e. 4.0%w/w, and alcohol yied is 90.3%, and alcohol getting rate is 77.4%, and ethanol production is 0.53g/L/h.

Embodiment 2 the present invention produces the method for ethanol

1, experiment material

Cellulase: with embodiment 1;

Printer paper: provided by Hitachi's shipbuilding, the content of component and structure sugar is as follows:

Note: institute's array structure sugar, xylogen and ash oontent all calculate based on dry weight.

2, method ethanol production

(1) pre-treatment:

Get 16.5g printer paper (dry weight: 16.5 × (1-9.1%)=15g), add 90mL water and 5mL20% (g/ml) sulphuric acid soln adjustment pH to 4.8-5.0, then under 5000rpm condition, pulverize 10min with pulverizer.If pH is higher than 5.0 after pulverizing, again use 20% (g/ml) sulphuric acid soln to regulate pH to 4.8-5.0, finally adding water to total liquid volume is 100mL, obtains pretreating raw material.

(2) premashing:

In pretreating raw material, add cellulase 1.6mL (15FPU/g solid × 15g/140FPU/mL=1.6), with saccharification 16h under 50 DEG C of conditions after mixing, obtain premashing liquid.

(3) simultaneous saccharification and fermentation (SSF):

After sample after premashing is cooled to 35 DEG C, add 10mL yeast starter liquid, in yeast starter liquid, yeast quantity is 2 × 10 ⁸individual/mL, starts SSF, adds feed supplement material in reaction process;

Wherein, feed supplement material is prepared by following method: get 22g printer paper (dry weight: 22 × (1-9.1%)=20g), add 85mL water and 5.5mL20% (g/ml) sulphuric acid soln adjustment pH to 4.8-5, then under 5000rpm condition, pulverize 10min with pulverizer.If pH is higher than 5.0 after pulverizing, 20% (g/ml) sulphuric acid soln is again used to regulate pH to 4.8-5.0;

Add cellulase 2.1mL (15FPU/g solid × 20g/140FPU/mL=2.1), the 5.4mL (100-85-5.5-(22-20)-2.1=5.4) that adds water again is 100mL to total liquid volume, with premashing 24h under 50 DEG C of conditions after mixing.

Feed supplement time: carry out feed supplement after feed supplement temperature of charge to be prepared is down to 35 DEG C, altogether feed supplement 2 times.Feed supplement time first time is 0h after SSF starts; The second time feed supplement time is that first time feed supplement is after 24 hours.

Stop: 24h after second time feed supplement, terminate SSF.

3, experimental result

1) alcohol concn (E) in mash is measured: be 53.7g/l.

Be scaled massfraction representation, alcohol concn E ':

$E^{\′}=\frac{W_L}{W+W_L}\×E=\frac{100+100+100+10}{(15+20+20)+(100+100+100+10)}\×53.7=4.6\%w/w$

W _lfor the liquid portion total mass of reaction system, its density is regarded as 1g/mL.

2) alcohol yied (Y): be 90.7%;

Calculation formula is as follows:

$Y=\frac{E}{E_0}\×100\%=\frac{53.7}{59.2}\×100\%=90.7\%$

$E_0=\frac{W\×C_g\×0.511}{V}=\frac{(15+20+20)\×\mathrm{65}\mathrm{.3}\%\×0.511}{0.1+0.1+0.1+0.01}=59.2g/L$

3) alcohol getting rate (Y ') equals alcohol yied: be 90.7%;

4) ethanol production (P): be 0.84g/L/h;

Calculation formula is as follows:

$P=\frac{E}{T}=\frac{53.7}{16+24+24}=0.84g/L/h$

Alcohol concn in the mash that present method obtains is 53.7g/l, i.e. 4.6%w/w, and alcohol yied is 90.7%, and alcohol getting rate is 90.7%, and ethanol production is 0.84g/L/h.

Beneficial effect of the present invention is illustrated below by way of test example.

The feed supplement of comparative example 1 lignocellulose is without the contrast experiment of premashing

1, experiment material: with embodiment 1.

2, method ethanol production

(1) pre-treatment: with embodiment 1.

(2) premashing: with embodiment 1.

(3) simultaneous saccharification and fermentation (SSF):

After premashing liquid is cooled to 35 DEG C, add 10mL yeast starter liquid, in yeast starter liquid, yeast quantity is 10 ⁸individual/mL, starts SSF reaction; The feed supplement material of non-premashing is added in reaction process;

Wherein, the feed supplement material of non-premashing is prepared by following method:

Get 93.9g (dry weight=93.9 × (1-78.7%)=20g) pretreated maize straw, add cellulase 2.1mL (15FPU/g solid × 20g/140FPU/mL=2.1), add water 15mL, uses 20%H ₂sO ₄regulate after pH to 4.8, then to add water to total liquid volume be 100mL, for feed supplement after mixing.

Feed supplement time: carry out feed supplement after feed supplement temperature of charge to be prepared is down to 35 DEG C, altogether feed supplement 2 times.Feed supplement time first time is 24h after SSF starts; The second time feed supplement time is that first time feed supplement is after 24 hours.

Stop: 24h after second time feed supplement, terminate SSF.

3, experimental result

1) alcohol concn (E) in mash is measured: be 33.6g/l.

2) alcohol yied (Y): be 65.2%;

Calculation formula is as follows:

$Y=\frac{E}{E_0}\×100\%=\frac{33.6}{51.5}\×100\%=65.2\%$

$E_0=\frac{W\×C_g\×0.511}{V}=\frac{(15+20+20)\×56.8\%\×0.511}{0.1+0.1+0.1+0.01}=51.5g/L$

3) alcohol getting rate (Y '): be 55.9%;

Calculation formula is as follows:

$Y^{\′}=\frac{G\×w}{G_0\×w_0}\×Y=\frac{111.6\×56.8\%}{200\×37.0\%}\×65.2\%=55.9\%$

4) ethanol production (P): be 0.38g/L/h;

Calculation formula is as follows:

$P=\frac{E}{T}=\frac{33.6}{16+24+24+24}=0.38g/L/h$

In present method, feed supplement material is without premashing, and the alcohol concn in the mash obtained is 33.6g/l, and alcohol yied is 65.2%, and alcohol getting rate is 55.9%, and ethanol production is 0.38g/L/h.

The feed supplement of comparative example 2 lignocellulose is without the contrast experiment of premashing

1, experiment material: with embodiment 2.

2, method ethanol production

(1) pre-treatment: with embodiment 2.

(2) premashing: with embodiment 2.

(3) simultaneous saccharification and fermentation (SSF):

After premashing liquid is cooled to 35 DEG C, add 10mL yeast starter liquid, in yeast starter liquid, yeast quantity is 2 × 10 ⁸individual/mL, starts SSF reaction; The feed supplement material of non-premashing is added in reaction process;

Wherein, the feed supplement material of non-premashing is prepared by following method:

Get 22g printer paper (dry weight: 22 × (1-9.1%)=20g), add 85mL water and 5.5mL20% (g/ml) sulphuric acid soln adjustment pH to 4.8-5, then under 5000rpm condition, pulverize 10min with pulverizer.If pH is higher than 5.0 after pulverizing, 20% (g/ml) sulphuric acid soln is again used to regulate pH to 4.8-5.0;

Add cellulase 2.1mL (15FPU/g solid × 20g/140FPU/mL=2.1), then the 5.4mL that adds water (100-85-5.5-(22-20)-2.1=5.4) is 100mL to total liquid volume, for feed supplement after mixing.

Feed supplement time: carry out feed supplement after feed supplement temperature of charge to be prepared is down to 35 DEG C, altogether feed supplement 2 times.Feed supplement time first time is 0h after SSF starts; The second time feed supplement time is that first time feed supplement is after 24 hours.

Stop: 24h after second time feed supplement, terminate SSF.

3, experimental result

1) alcohol concn (E) in mash is measured: be 41.8g/l.

2) alcohol yied (Y): be 70.6%;

Calculation formula is as follows:

$Y=\frac{E}{E_0}\×100\%=\frac{41.8}{59.2}\×100\%=70.6\%$

$E_0=\frac{W\×C_g\×0.511}{V}=\frac{(15+20+20)\×65.3\%\×0.511}{0.1+0.1+0.1+0.01}=59.2g/L$

3) alcohol getting rate (Y ') equals alcohol yied: be 70.6%;

4) ethanol production (P): be 0.65g/L/h;

Calculation formula is as follows:

$P=\frac{E}{T}=\frac{41.8}{16+24+24}=0.65g/L/h$

Without premashing before feed supplement, the alcohol concn in the mash that present method obtains is 41.8g/l, and alcohol yied is 70.6%, and ethanol production is 0.65g/L/h.

In present method, feed supplement material is without premashing, and the alcohol concn in the mash obtained is 41.8g/l, and alcohol yied is 70.6%, and alcohol getting rate is 70.6%, and ethanol production is 0.65g/L/h.

By the ethanol evaluation index whether premashing obtains of feed supplement in the inventive method, be listed as follows:

Table 1 correlation data

Note: the two phase difference=(the inventive method numerical value-feed supplement is without the method numerical value of premashing)/feed supplement is without the method numerical value of premashing

From table 1, with feed supplement without premashing method compared with, in the fermentation liquid that the inventive method obtains, alcohol concn, productive rate, yield and throughput significantly improve, and can greatly reduce alcohol production cost, achieve significant technique effect.

To sum up, method ethanol production provided by the invention, improves the alcohol concn in fermented liquid, and reduce the energy consumption that ethanol distillation reclaims, improve alcohol yied, yield and throughput, alcohol production cost is low simultaneously, has good prospects for commercial application.

Claims (9)

1. utilize a method for producing ethanol by using lignocellulose materials, it is characterized in that, it comprises the steps:

A, pre-treatment: dilute acid pretreatment is carried out to lignocellulosic material, obtains pretreating raw material;

B, premashing: saccharification is carried out to the pretreating raw material that step a obtains, obtains premashing material;

C, fed-batch simultaneous saccharification and fermentation:

After the premashing material obtained until step b is cooled to 35 DEG C, inoculation yeast, is 4.8-5.0,150rpm, 35 DEG C of condition bottom fermentations in pH value, adds feed supplement material in fermenting process; Last feed supplement, after 24 hours, stops fermentation;

Wherein, feed supplement material is prepared by following method:

Get the pretreating raw material that step a obtains, add cellulase, then add water, adjust pH to 4.8-5.0, then keep 24 hours under 150rpm, 50 DEG C of conditions, obtain feed supplement material; Wherein, the solids concn of pretreating raw material is 20% (g/ml), and the add-on of cellulase is 15FPU/g solid.

2. method according to claim 1, is characterized in that, in step a, described pretreated method is:

1) get lignocellulosic material, add sulfuric acid and water by solids concn 10% (g/ml) and sulfuric acid final concentration 1% (g/ml), then keep 10-20min in 140-150 DEG C;

2) separation obtains solid residue;

3) clean;

Wherein, described lignocellulosic material is corn cob, maize straw, rice straw, wheat stalk, rape stalk, bagasse and/or reed.

3. method according to claim 1, is characterized in that, in step a: described pretreated method is:

1) get lignocellulosic material, regulate solids concn to be 15% (g/ml);

2) pulverize under 5000rpm, regulate pH to 4.8-5.0;

Wherein, described lignocellulosic material is paper.

4. method according to claim 1, is characterized in that, in step b, the method for described premashing is:

Get the pretreating raw material of step a, add cellulase, then add water, adjust pH to 4.8-5.0, then under 150rpm, 50 DEG C of conditions, keep 16-24 hour, obtain premashing material; Wherein, the solids concn of pretreating raw material is 15% (g/ml), and the add-on of cellulase is 15FPU/g solid.

5. the method according to claim 1 or 4, is characterized in that, described cellulase is CellicCTec2.

6. the method according to claim 1-4 any one, is characterized in that, described solids concn is by the adjustment that adds water.

7. method according to claim 1, is characterized in that, in step c, in the premashing material after inoculation yeast, yeast quantity is 1-2 × 10 ⁷individual/mL.

8. method according to claim 1, is characterized in that, in step c, the number of times of described feed supplement is 2-3 time; The addition of each feed supplement material is all identical with the pretreating raw material volume of step b.

9. method according to claim 8, is characterized in that, the 1st feed supplement time is 0-24 hour after fermentation; 2nd feed supplement time is after the 1st feed supplement 24 hours.