CN104399735A - Pretreatment method for straw biomass - Google Patents

Abstract

The invention provides a method for pretreatment of straw-like biomass. The straw-like biomass is pretreated through the steps of collecting and pulverizing raw materials, stacking and retting raw materials, soaking raw materials, mixing and adding bacteria, and sealing and degrading. The method can effectively convert and degrade the cellulose, hemicellulose and lignin rich in straw, the process is simple, easy to operate, low in operation cost, high in efficiency, does not pollute the environment, and provides convenience for processing straw-like biomass.

Description

A kind of pretreatment method of straw biomass

technical field

The invention belongs to the technical field of biomass utilization, and specifically relates to a pretreatment method of straw-like biomass, and more specifically realizes the three main components of cellulose, hemicellulose and Transformation and degradation of lignin.

Background technique

Due to the increasing shortage of traditional energy, the use of renewable energy including biomass is on the rise and is expected to play an important role in the future energy structure. Crop straw is the most abundant biomass resource on the earth. According to incomplete statistics, The world can produce nearly 2 billion tons of straw every year, and the annual output of crop straw in my country is about 600-700 million tons, ranking first in the world. Apart from being used for papermaking and feed, there are about 400 million tons of straw that can be used as energy materials. use.

There are two main technical obstacles in the utilization of straw-based biomass: one is that lignin is wrapped around the outside of cellulose and hemicellulose, thus forming a barrier to the degradation of cellulose and hemicellulose; the other is that The high crystalline structure of cellulose itself is not easy to degrade. Compared with the non-crystalline area, the crystalline area of cellulose occupies a dominant position, which can be as high as 70%. Therefore, pretreatment is a key way to utilize lignocellulosic biofuels and biological products.

Aiming at the problem of low fermentation efficiency in the straw biogas fermentation process, the Planning and Design Research Institute of the Ministry of Agriculture independently developed the straw integrated two-phase anaerobic digestion process technology, and improved the silage production process to a pretreatment technology suitable for straw anaerobic digestion , Since 2009, this process has been promoted and applied in Tianjin, Shandong, Shaanxi, Shanxi, Zhejiang, Hubei and other places for nearly 30 seats, and the operation effect is good.

However, judging from the application of this process, the scale of fermentation tanks in straw biogas projects is not large, and the volume is mostly between 500 and 1500m ³ . The amount of straw used in one harvest season covers a large area. Taking a biogas project with a fermenter size of 1000m ³ as an example, it can consume about 10t (about 15m ³ ) of silage straw per day. Calculated based on one year of operation, the volume of the supporting silage tank needs to be 5400m ³ , covering an area of about 1500m ² . Therefore, the traditional on-site silage method seriously restricts the large-scale development of this type of biogas project.

Chinese patent 200910194728.1 discloses a method for graded utilization of straw-like biomass. This method uses gas explosion technology to pretreat the straw-like biomass. The processing cost is high, which is not conducive to expanding application. In addition, Chinese patent CN103740767A discloses a pretreatment method for improving the efficiency of anaerobic digestion of straw-like biomass. The pretreatment method uses chemical agents for treatment, causing environmental pollution, waste of agents, and long processing time.

Contents of the invention

The purpose of the present invention is to address the deficiencies in the prior art and provide a method for pretreatment of straw-like biomass, which can effectively transform and degrade the cellulose, hemicellulose and lignin rich in straw, and provide a useful tool for processing Straw biomass provides convenience.

In order to achieve the above object, the specific technical solutions provided by the invention are as follows:

A method for pretreatment of stalk biomass, comprising the following steps:

1) After harvesting the whole stalks of the straw biomass, drying treatment is carried out to make the moisture content reach 15-25%;

2) crushing the stalk-like biomass obtained in step 1), with a crushing fineness≦3mm;

3) Put the straw-based biomass powder obtained in step 2) into a soaking tank, add biogas slurry to make the water content reach 40-50%, and carry out aerobic stack retting at 55-65° C. for 4 hours;

4) Add biogas slurry until the straw biomass powder is completely immersed in it, inoculate with EM bacteria and soak for 3 to 5 days;

5) Take out the biogas slurry, inoculate the mixture with probiotics and then seal it up, so that the soaked straw-like biomass powder is fermented and degraded for 8-10 days under the sealed condition, and then taken out for use.

The straw-based biomass is selected from one or more of the following materials: rice straw, wheat straw, bean straw, sorghum knots, corn cobs, corn stalks and cotton stalks.

The drying process adopts natural air drying, and the drying process is ventilated and dehumidified.

The inoculum amount of the EM bacteria is 1‰-1% of the weight of straw-like biomass.

The inoculum amount of the probiotics is 0.5‰～1% of the weight of the straw biomass, which can be all lactic acid bacteria, or more than 50% of the lactic acid bacteria and Clostridium butyricum, Bifidobacterium, Lactobacillus acidophilus, actinomycetes, yeast one or more of them.

The present invention has the following beneficial effects:

1. Compared with the prior art, the present invention has simple process and is easy to operate.

2. The present invention has low operating cost, high efficiency and no environmental pollution.

3. The present invention adopts the method of "aerobic retting + biogas slurry soaking + microbial treatment" to fully degrade and transform the three components (lignin, cellulose and hemicellulose) of straw-like biomass, realizing Maximize the utilization of straw biomass.

Description of drawings

Fig. 1 is an operation flow chart of a pretreatment method for straw-like biomass

Detailed ways

Example 1

After harvesting the whole stalks of corn stalks, use natural air drying for drying treatment, ventilation and dehumidification during the drying process, so that the moisture content reaches 15-25%, and the dried straw biomass is crushed, and the crushing fineness is ≦ 3mm; the obtained straw Put the biomass powder into the soaking tank, add biogas slurry to make the water content reach 40-50%, carry out aerobic retting at 55-65°C for 4 hours, add biogas slurry until the straw-based biomass powder is completely immersed in it, and inoculate the straw Soak 1‰ of biomass-like EM bacteria for 5 days, extract the biogas slurry, inoculate lactic acid bacteria and mix them and seal them. The inoculum amount of lactic acid bacteria is 0.5‰ of the weight of straw-like biomass. After 10 days of fermentation and degradation under the same conditions, it was taken out for later use.

Example 2

After harvesting the whole stalks of corn stalks, use natural air drying for drying treatment, ventilation and dehumidification during the drying process, so that the moisture content reaches 15-25%, and the dried straw biomass is crushed, and the crushing fineness is ≦ 3mm; the obtained straw Put the biomass powder into the immersion tank, add the biogas slurry until the water content reaches 40-50%, carry out aerobic retting at 55-65°C for 4 hours, add the biogas slurry until the straw-like biomass powder is completely immersed in it, and inoculate the straw Soak EM bacteria with 1% of the weight of biomass-like biomass for 3 days, take out the biogas slurry, inoculate lactic acid bacteria and mix them, and seal them. After 8 days of fermentation and degradation under the same conditions, it was taken out for later use.

Claims (6)

1. a preprocess method for stalk biomass, is characterized in that, comprises the following steps:

1), after the whole stalk results of stalk biomass, carry out drying process, make moisture content reach 15 ~ 25%;

2) by step 1) stalk biomass that obtains pulverizes, the broken Xi Du≤3mm of Fen;

3) by step 2) the stalk biomass powder that obtains puts into fermentation vat, and add natural pond liquid and make water content reach 40 ~ 50%, at 55 ~ 65 DEG C, carry out aerobic stack retting 4 hours;

4) add natural pond liquid to be immersed completely to stalk biomass powder, inoculation EM bacterium is soaked 3 ~ 5 days;

5) natural pond liquid is extracted out, airtight after then inoculating probio mixing, make the stalk biomass powder after immersion take out for subsequent use after 8 ~ 10 days in the degraded of airtight condition bottom fermentation.

2. the preprocess method of a kind of stalk biomass according to claim 1, is characterized in that, described stalk biomass selects one or more in following material: straw, wheat straw, beanstalk, Chinese sorghum knot, corncob, cornstalk and Cotton Stalk.

3. the preprocess method of a kind of stalk biomass according to claim 1, is characterized in that, described dry run, adopts natural air drying, dry run ventilation drying.

4. the preprocess method of a kind of stalk biomass according to claim 1, is characterized in that, described EM bacterium inoculum concentration is 1 ‰ ~ 1% of stalk biomass weight.

5. the preprocess method of a kind of stalk biomass according to claim 1, is characterized in that, described probio inoculum concentration is 0.5 ‰ ~ 1 ‰ of stalk biomass weight.

6. the preprocess method of a kind of stalk biomass according to claim 1 or 5, it is characterized in that, described probio can be all lactic acid bacteria, and also can be more than 50% lactic acid bacteria mixes with clostridium butyricum, lactic acid bacteria, Bifidobacterium, lactobacillus acidophilus, actinomyces, saccharomycete wherein one or more.