JP2008006372A - Wood-based biomass pretreatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wood-based biomass pretreatment method which enables a reduction in energy needed to grind wood-based biomass when the wood-based biomass is pretreated with microorganism and biomass energy is produced by multi-fuel combustion or gasification or when pretreatment for saccharification of wood-based biomass is carried out by means of sulfuric acid hydrolysis or the like. <P>SOLUTION: This is a wood-based biomass pretreatment method which requires grinding processing using white-rot fungi having lignin-decomposing activity. In the pretreatment method, the white-rot fungi are Trametes hirsuta, and the Trametes hirsuta is preferably Trametes hirsuta whose cellulose-decomposing activity is restrained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for pre-treating woody biomass with microorganisms and reducing the pulverization energy of woody biomass during biomass energy production by co-firing or gasification or pretreatment for saccharification by sulfuric acid hydrolysis.

Using woody biomass material such as thinned wood, forest residue or building waste, thermal power generation by co-combustion with coal reduces the amount of coal used as fossil resources, and wood that is a renewable and carbon neutral resource Motivation to make effective use of biomass is increasing. In the same attempt, woody biomass resources are expected to be used in gasification power generation systems, gasification methanol production systems, and ethanol production systems.
However, as a problem in these techniques, a pretreatment technique of woody biomass, that is, how to efficiently pulverize is a big problem.
Specifically, in a pulverized coal-fired boiler, coal is made into fine particles by a pulverized coal machine and burned while being suspended in the air. At this time, the particle size of the pulverized coal is such that the passing rate of 200 mesh (75 μm) is 70 to 80% and the passing rate of 100 mesh (150 μm) is about 90%. For this reason, in order to co-fire biomass with a pulverized coal-fired boiler, it is also necessary to finely pulverize the biomass (Non-patent Document 1).
New Energy Industrial Technology Development Organization (NEDO) Biomass Energy High-efficiency Technology Development Research and Development of Coal / Wood Biomass Mixed Firing Technology Fiscal 2002 Performance Report 157-158, (2002)

  However, it is known that more than 10 times more power is required to obtain the same particle size as compared with the pulverization power required for coal used in a coal-fired boiler of a normal thermal power plant. For example, when using a roller mill as a pulverizer in coal, it is 10 to 20 kWh / t, whereas when wood biomass is pulverized with a pulverizer such as an impact mill, there are differences depending on the material, but usually 100 to 100 200 kWh / t. An object of the present invention is to reduce the pulverization power of woody biomass.

  As a result of intensive research to solve the above technical problems, lignin-degrading enzyme activity effective in decomposing the matrix structure based on phenylpropane structure contained in a large amount in woody biomass in advance before pulverization is obtained. It has been found that the pulverization power by a mill or the like can be reduced by pretreatment with microorganisms possessed, and the present invention has been completed.

  Furthermore, suppression of cellulolytic enzyme activity can also suppress a decrease in yield of biomass, and it has become easier to efficiently perform biomass pretreatment.

  That is, the present invention provides 1) a pretreatment method for woody biomass that requires pulverization using a white rot fungus having lignin resolution. In addition, the present invention provides 2) a method for pretreatment of woody biomass using agaricus mushroom. Furthermore, the present invention provides 3) a pretreatment method for woody biomass using agaricus mushroom that has suppressed cellulolytic enzyme activity.

  Woody biomass can be pretreated with microorganisms, and can be used in technologies for reducing the pulverization energy of woody biomass during biomass energy production by co-firing or gasification or saccharification pretreatment by sulfuric acid hydrolysis.

Hereinafter, the present invention will be described in detail.
First, as the woody biomass used in the present invention, it is possible to use all or a part of a tree, forest land remnants, thinned wood, construction waste, etc., and a lignocellulosic material containing about 1 to 30% lignin. Can be used. Any microorganism can be used in the present invention as long as it has lignin-degrading ability. Examples of lignin-degrading bacteria include Trachetes hirsuta, Flavia tremellosa, and Pleurotus ostereatus. ), Larvae (Lenzites betuluna), Phanerochae chrysosporium (Phanerochaete chrysosporium), which is said to be relatively excellent in lignin resolving ability, and Seripoliopis saberoporopis (Ceriporpis), a selective lignin-degrading bacterium. Etc. can be used.

  Many of the lignin-degrading bacteria used for biological pretreatment, including the bacteria used in this technology, consume other components of biomass such as cellulose together with lignin when decomposing biomass. In order to reduce the yield, it is more preferable to use genetically modified technology and use white-rot fungi with suppressed cellulolytic enzyme activity, leading to effective energy saving and cellulolytic enzyme activity developed by the present inventors. It is also an option to use a suppressor strain (Japanese Patent Application No. 2005-297869 “Utilization of drug resistance gene”).

  In the present invention, the above biomass is inoculated with the above lignin-degrading white rot fungi previously grown under conditions suitable for each fungus or the lignin-degrading white rot fungus with suppressed cellulolytic enzyme activity, and cultured with the biomass for a certain period of time. Process by. It is effective to add the following medium at the same time as or before or after the inoculation of lignin-degrading bacteria.

  As the medium, any medium can be used as long as lignin-degrading white rot fungi or cellulolytic enzyme activity-suppressing host cells can grow. For example, as a carbon source, waste molasses, glucose, cellobiose, amorphous In addition to cellulose and the like, pulp, paper, cotton and the like can be used. As the nitrogen source, nitrogen compounds such as yeast extract, peptone, various amino acids, soybean meal, corn steep liquor, various inorganic nitrogen can be used. Furthermore, various salts, vitamins, minerals, and the like can be used as needed.

  The culture temperature and pH can be appropriately set within a range in which the lignin-degrading white rot fungi and the cellulose-degrading enzyme activity-suppressed lignin-degraded white rot fungi can grow. For example, the culture temperature is 20 to 60 ° C., preferably 25 to 37. ° C and the pH is 3-9, preferably 4-6. The ventilation is 0.001 to 1.0 vvm, preferably 0.05 to 0.2 vvm. Furthermore, the period of the bacterial treatment can be appropriately set, but 5 to 20 days is preferable in consideration of industrial use. After the fungus treatment, the biomass can be used directly or after drying for subsequent grinding treatment. The grinding energy could be reduced by the above operation.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the scope of the present invention is not limited to these specific examples.

[Example 1]
“Crushing of hardwood wood chips treated with white rot fungus Alagekawaratake NBRC4917”
The white rot fungus Alagekawaratake NBRC4917 was cultured on potato dextrose agar at 28 ° C. and stored at 4 ° C. Five sections of this plate punched out with a cork borer with a diameter of 5 mm were prepared in glucose peptone medium (glucose 3%, polypeptone 1%, KH ₂ PO ₄ 0.15%, MgSO ₄ 0.05%, pH 5 with phosphoric acid. In a 300 ml Erlenmeyer flask containing 100 ml each, and cultured with shaking at 28 ° C. and 100 rpm for 1 week. After the cultivation, the cells were filtered off, and the medium remaining in the cells was washed with sterilized water. The cells were pulverized for 45 seconds together with sterilized water using a Waring blender, and inoculated so that the dry weight of the cells was 5 mg on a hardwood eucalyptus / globula chip having an absolute dry weight of 1 kg. After inoculation, the mixture was stirred well so that the bacteria spread throughout. The culture was carried out by static culture for 2 weeks with aeration at 28 ° C. Saturated water vapor was aerated as needed so that the moisture content of the chip was 40 to 65%. The amount of ventilation when venting was 0.01 vvm per chip.
The chip dry weight before and after the treatment was measured, and the chip yield was calculated using the following formula.
(Absolute dry weight after treatment) / (absolute dry weight before treatment) × 100
The results are shown in Table 1.
20g dry weight of wood chips after fungus treatment was pulverized using a laboratory wheelie pulverizer (Yoshida Seisakusho, Tokyo, Japan) for the production of wood flour. At the same time, the power consumption was integrated with a watt meter (Hiokidenki model 3133). Measurement was performed using a meter (model 3141).
The results are shown in Table 5.
The obtained wood flour was also measured for particle size distribution using a sieving machine.
The results are shown in Table 2.

[Example 2]
Grinding treatment of hardwood wood chips treated with a transformant with suppressed cellulolytic enzyme activity Cellulose-degrading enzyme activity-suppressed lignin-degrading bacterium according to “Utilization of drug resistance gene” (Japanese Patent Application No. 2005-297869) The produced carboxin resistant cellulolytic enzyme activity suppression strain was used.
The cellulolytic enzyme activity-suppressed strain was cultured at 28 ° C. on a potato dextrose agar medium, and stored at 4 ° C. Five sections of this plate punched out with a cork borer with a diameter of 5 mm were prepared in glucose peptone medium (glucose 3%, polypeptone 1%, KH ₂ PO ₄ 0.15%, MgSO ₄ 0.05%, pH 5 with phosphoric acid. In a 300 ml Erlenmeyer flask containing 100 ml each, and cultured with shaking at 28 ° C. and 100 rpm for 1 week. After the cultivation, the cells were filtered off, and the medium remaining in the cells was washed with sterilized water. The microbial cells were pulverized with sterilized water for 45 seconds using a Waring blender, and inoculated so that the dry weight of the microbial cells was 5 mg on a hardwood eucalyptus / globula chip with an absolute dry weight of 1 kg. After inoculation, the mixture was stirred well so that the bacteria spread throughout. The culture was carried out by static culture for 2 weeks with aeration at 28 ° C. Saturated water vapor was aerated as needed so that the moisture content of the chip was 40 to 65%. The amount of ventilation when venting was 0.01 vvm per chip.
The chip dry weight before and after the treatment was measured, and the chip yield was calculated using the following formula.
(Absolute dry weight after treatment) / (absolute dry weight before treatment) × 100
The results are shown in Table 1.
20g dry weight of wood chips after fungus treatment was pulverized using a laboratory wheelie pulverizer (Yoshida Seisakusho, Tokyo, Japan) for the production of wood flour. At the same time, the power consumption was integrated with a watt meter (Hiokidenki model 3133). Measurement was performed using a meter (model 3141).
The results are shown in Table 5.
The obtained wood flour was also measured for particle size distribution using a sieving machine.
The results are shown in Table 2.

Example 3
Grinding of softwood wood chips treated with white rot fungus Ceriporiopsis subvermisspora CZ-3 strain (ATCC 96608) After culturing white rot fungus Ceriporiopsis subvermisspora CZ-3 strain on potato dextrose agar medium at 28 ° C. did. Five sections of this plate punched out with a cork borer with a diameter of 5 mm were prepared in glucose peptone medium (glucose 3%, polypeptone 1%, KH ₂ PO ₄ 0.15%, MgSO ₄ 0.05%, pH 5 with phosphoric acid. In a 300 ml Erlenmeyer flask containing 100 ml each, and cultured with shaking at 28 ° C. and 100 rpm for 1 week. After the cultivation, the cells were filtered off, and the medium remaining in the cells was washed with sterilized water. The microbial cells were pulverized for 45 seconds together with sterilized water with a Waring blender, and inoculated so that the dry weight of the microbial cells was 5 mg on a 1-kg conifer larch chip. After inoculation, the mixture was stirred well so that the bacteria spread throughout. The culture was carried out by static culture for 2 weeks with aeration at 28 ° C. Saturated water vapor was aerated as needed so that the moisture content of the chip was 40 to 65%. The amount of ventilation when venting was 0.01 vvm per chip.
The chip dry weight before and after the treatment was measured, and the chip yield was calculated using the following formula.
(Absolute dry weight after treatment) / (absolute dry weight before treatment) × 100
The results are shown in Table 3.
20g dry weight of wood chips after fungus treatment was pulverized using a laboratory wheelie pulverizer (Yoshida Seisakusho, Tokyo, Japan) for the production of wood flour. Measurement was performed using a meter (model 3141).
The results are shown in Table 6.
The obtained wood flour was also measured for particle size distribution using a sieving machine.
The results are shown in Table 4.

Example 4
Grinding of softwood wood chips treated with a transformant that has suppressed cellulolytic enzyme activity Cellulose-degrading enzyme activity-suppressed lignin-degrading bacteria from “A drug-resistant gene” (Japanese Patent Application No. 2005-297869) The produced carboxin resistant cellulolytic enzyme activity suppression strain was used.
The cellulolytic enzyme activity-suppressed strain was cultured at 28 ° C. on a potato dextrose agar medium, and stored at 4 ° C. Five sections of this plate punched out with a cork borer with a diameter of 5 mm were prepared in glucose peptone medium (glucose 3%, polypeptone 1%, KH ₂ PO ₄ 0.15%, MgSO ₄ 0.05%, pH 5 with phosphoric acid. In a 300 ml Erlenmeyer flask containing 100 ml each, and cultured with shaking at 28 ° C. and 100 rpm for 1 week. After the cultivation, the cells were filtered off, and the medium remaining in the cells was washed with sterilized water. The microbial cells were pulverized for 45 seconds together with sterilized water with a Waring blender, and inoculated so that the dry weight of the microbial cells was 5 mg on a 1-kg conifer larch chip. After inoculation, the mixture was stirred well so that the bacteria spread throughout. The culture was carried out by static culture for 2 weeks with aeration at 28 ° C. Saturated water vapor was aerated as needed so that the moisture content of the chip was 40 to 65%. The amount of ventilation when venting was 0.01 vvm per chip.
The chip dry weight before and after the treatment was measured, and the chip yield was calculated using the following formula.
(Absolute dry weight after treatment) / (absolute dry weight before treatment) × 100
The results are shown in Table 3.
20g dry weight of wood chips after fungus treatment was pulverized using a laboratory wheelie pulverizer (Yoshida Seisakusho, Tokyo, Japan) for the production of wood flour. Measurement was performed using a meter (model 3141).
The results are shown in Table 6.
The obtained wood flour was also measured for particle size distribution using a sieving machine.
The results are shown in Table 4.

[Comparative Example 1]
Grinding treatment of eucalyptus and globulas chips not treated with fungus Eucalyptus and globulas chips not treated with fungi were subjected to aeration treatment so as to be 0.01 vvm for 2 weeks, and crushed using a wheelie mill as in Example 1. And the amount of power and the particle size distribution were measured. The results are shown in Table 5 and Table 2.
As described above, it is possible to reduce by about 20% in order to obtain biomass of a size required for biomass co-fired thermal power generation. Moreover, the yield fall of biomass could also be suppressed by using a cellulolytic enzyme activity suppression strain.

[Comparative Example 2]
Grinding treatment of larch chips not treated with bacteria Only lather treatment was performed so that larch chips not treated with bacteria were 0.01 vvm for 2 weeks, and crushing was performed using a Wiley type grinder in the same manner as in Example 3. The amount of power and the particle size distribution were measured. The results are shown in Table 6 and Table 4.

  As described above, pulverization energy could be reduced not only for hardwoods but also for conifers.

Woody biomass can be pretreated with microorganisms, and can be used in technologies for reducing the pulverization energy of woody biomass during biomass energy production by co-firing or gasification or saccharification pretreatment by sulfuric acid hydrolysis.

Claims (3)

  A pretreatment method for woody biomass that requires grinding using white rot fungi having lignin resolution.   The biomass pretreatment method according to claim 1, wherein the white rot fungus is Alagekawaratake. The biomass pretreatment method according to claim 2, wherein the mushroom mushroom is a mushroom mushroom strain with suppressed cellulolytic enzyme activity.