JP4923649B2 - Plant biomass processing system using microwaves - Google Patents

Description

  The present invention relates to a processing system for processing plant biomass using microwaves.

  As part of global warming countermeasures, power generation technology using biomass as fuel is known. Biomass includes industrial biomass such as municipal waste, food residue, sewage sludge, animal biomass such as livestock manure, plant biomass such as cultivated plants, felled trees and agricultural crop residues. Plant-based biomass generates electricity using pulverized material or processed material (carbonized material, liquefied material, gasified material, etc.) as fuel.

  However, since solid biomass is bulky and requires a large amount of energy for collection and transportation, it is unsuitable when a large amount must be procured or when power generation is performed at a distance. In order to solve this, there are technologies for liquefaction and gasification of biomass (ethanolification, DME, hydrogenation), but currently all of them require large-scale equipment (such as culture equipment for ethanolization) High cost (DME, hydrogenation, etc.).

  In addition, various biomass contains various components, and some of them contain essential oil components with high added value. However, in the current method of using biomass, these components with high added value are consumed as fuel. Or have disappeared (volatilized, decomposed) during fuel processing and are not used at all.

  As a method for extracting essential oil from plant biomass, methods such as pressing, steam, hot water, organic solvents, lard, etc. have been conventionally carried out. However, extraction efficiency is low in pressing, and extraction time is long in steam distillation. In addition, the energy consumption is increased, and extraction with hot water or an organic solvent has a problem that the extraction time is long or complicated and the energy consumption is large. When a water bath or electric heater is used as the heating means, the reaction vessel must also be heated, and heating at a higher temperature setting including heating loss is required to overheat the reaction product to the expected temperature. Had to do. In the case of extraction from a solid, it is necessary to finely pulverize the extraction target or to perform an extraction reaction for a long time in order to increase extraction efficiency. Further, when the extract is weak against heat, the extract may be decomposed and deteriorated by heating for a long time.

  Therefore, in recent years, extraction methods using microwaves (Patent Document 1 and the like) and heating apparatuses using microwaves (Patent Documents 2 to 4) have been proposed. In Patent Document 1, a mixture of a pulverized raw material plant and an extraction solvent (water, polyhydric alcohol) is microwaved (1500 W, 2450 MHz) in an apparatus composed of a glass tube having an endless screw surrounded by a microwave generator. ) For 30 seconds to extract a plant extract from the raw plant.

Patent Document 2 discloses a liquid heating apparatus that uses a microwave to heat a fluid liquid such as curry or jam, or a liquid such as a chemical liquid. Patent Document 3 discloses a microwave continuous heating apparatus that does not need to intermittently irradiate microwave power when an object to be heated is carried into and out of a heating tank and can prevent leakage of microwave power. Furthermore, the microwave continuous heating apparatus for implement | achieving quality improvement of a heating object by the uniform irradiation of the microwave electric power to a to-be-heated object is disclosed.
JP 2004-089786 A JP-A-10-27685 JP 2003-100441 A JP 2003-106773 A

  In view of the above circumstances, the present inventors have heated, by microwave irradiation, a method, an apparatus (Japanese Patent Application No. 2005-258861) for extracting essential oil from plant biomass in a short time, energy saving and low cost, Proposed an apparatus (Japanese Patent Application No. 2006-56429) capable of preventing excessive heating by microwaves.

  However, the above extraction apparatus is excellent in that it can extract essential oil without irradiating and heating the plant biomass and the solvent with microwaves without decomposing and degrading the extract, but it is a batch type apparatus. Therefore, the processing capacity was limited.

  The present invention provides a plant biomass processing system using microwaves that can process a large amount of plant biomass and can carry out essential oil extraction operations continuously with energy saving, and can also effectively use essential oil extraction residues. The task is to do.

  In order to solve the above problems, the present invention takes the following means.

That is, the present invention is as follows.
(1) a crusher for crushing plant biomass;
A microwave extractor connected to a crusher and extracting essential oil from plant biomass with a microwave heating solvent ,
A screw conveyor for conveying plant biomass is provided in the microwave extraction device, and a microwave irradiation unit is disposed on one end side of the screw conveyor to prevent overheating of the plant biomass by the microwave, and the screw A plant biomass processing system using microwaves, characterized in that the screw shaft of the conveyor is formed of a hollow material with low microwave absorption .
The (2) Microwave extraction device, solvent condenser and essential oils recovery devices are connected, the essential oil recovery apparatus, the return pipe for returning condensed solvent fraction to the extraction device is provided (1) Plant biomass processing system using the described microwave.
( 3 ) The plant biomass processing system using the microwave according to (1) or (2) , wherein a solvent is introduced into the microwave extraction device.
( 4 ) The plant biomass processing system using the microwave according to any one of (1) to ( 3 ), wherein the extraction solvent is water.
( 5 ) The plant biomass is a plant biomass processing system using a microwave according to any one of (1) to ( 4 ), wherein the plant biomass is a cultivation plant biomass or a waste plant biomass.
( 6 ) The plant biomass processing system using the microwave according to any one of (1) to ( 5 ), wherein the temperature in the microwave extraction apparatus is not lower than the boiling point of the solvent and not higher than 200 ° C.
( 7 ) The microwave extraction apparatus is connected to a microwave heating apparatus for carbonizing the plant biomass residue after extraction of the essential oil, and the microwave heating apparatus is provided with a conveying means for conveying the plant biomass residue (1) ) -Plant biomass processing system using the microwave according to any one of ( 6 ).
( 8 ) The plant biomass processing system using the microwave according to ( 7 ), wherein the temperature in the microwave heating apparatus is 300 to 1300 ° C.
( 9 ) Plant biomass treatment using the microwave according to any one of (1) to ( 8 ), wherein the essential oil extraction solvent solution used in the microwave extraction apparatus is introduced into an ethanol fermenter to produce ethanol. system.

  According to the first aspect of the present invention, the microwave irradiated portion is made to be a transportable type so as to prevent the plant biomass from being overheated by the microwave. It can be processed continuously with irradiation.

According to this invention which concerns on Claim 1 , since the middle part of the belt conveyor or screw conveyor along the conveyance direction of plant biomass was arrange | positioned in the microwave irradiation area | region in a microwave extractor, there was no local heating of plant biomass. The microwave can be irradiated uniformly, and the extract is not likely to be decomposed or deteriorated.

According to this invention which concerns on Claim 1 , after arrange | positioning a microwave irradiation part on the one end side of a belt conveyor or a screw conveyor, the pulverized plant biomass is directly irradiated with a microwave, and is heated, Since the inside of the apparatus is transported, the plant biomass is quickly heated, and there is no local heating, so that the microwave can be uniformly irradiated, and there is no possibility that the extract is decomposed or deteriorated.

According to the present invention of claim 1 , since the screw shaft is hollow and is formed of a material having a low microwave absorption property, the microwave can be guided into the extraction device via the screw shaft, A plant biomass can be efficiently irradiated with a microwave.

According to the second aspect of the present invention, since the essential oil recovery device has a function of returning the condensed solvent into the extraction device, it is possible to avoid overheating and maintain an appropriate solvent vapor, and to extract and recover the essential oil. It can be done more quickly.

According to the third aspect of the present invention, since the solvent is introduced into the microwave extraction apparatus, the extraction operation can be facilitated by supplementing the water deficient with the water contained in the plant biomass from the outside. And overheating due to lack of solvent.

According to the present invention of claim 4 , if water is used as the extraction solvent, a cheaper and safer processing system can be constructed.

According to this invention which concerns on Claim 5 , there exists an advantage which essential oil recovery amount increases by utilizing cultivation plant biomass or waste plant biomass.

According to the sixth aspect of the present invention, extraction can be performed without decomposing and degrading the essential oil by keeping the inside of the extraction device at a temperature of 100 to 200 ° C.

According to the seventh aspect of the present invention, since the microwave extraction apparatus is connected to the microwave extraction apparatus for carbonizing the essential oil extracted residual plant biomass, the extracted plant biomass residue (conventional steam distillation method and In contrast, the carbonization treatment (which can be almost dried) can minimize heating, save energy, and use volatile gas or carbide as fuel.

According to the eighth aspect of the present invention, since the gasification reaction proceeds by maintaining the inside of the extraction apparatus at a temperature of 300 to 1300 ° C., the heat conversion efficiency of the raw material can be increased.

According to this invention which concerns on Claim 9 , ethanol can be produced from the saccharide | sugar melt | dissolved in solvent water by introduce | transducing the essential oil extraction solvent used in the microwave extraction apparatus into an ethanol fermenter.

  Hereinafter, a preferred embodiment of a plant biomass processing system using a microwave according to the present invention will be described and described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a plant biomass processing system using microwaves according to Embodiment 1 of the present invention. The present processing system includes a pulverizing apparatus 10 that pulverizes plant biomass 1 and a microwave extraction apparatus 12 that is connected to the pulverizing apparatus 10 and extracts essential oil from the plant biomass 1 by microwave heating. Inside, a conveying means for conveying the plant biomass is provided to prevent the plant biomass from being overheated by the microwave. Conveying means for conveying the plant biomass, scan clew conveyor or the like are preferable, to place the scan clew conveyors along the transport direction of the plant biomass to microwave irradiation region of the microwave extraction device 12, the microwave irradiation unit Microwave irradiation .

  According to the treatment system illustrated in FIG. 1, first, plant biomass 1 such as leaves, fruits, branches, and the like is pulverized. As long as the pulverizer is an apparatus that finely pulverizes plant biomass, a biaxial cutter, a mill cutter, or the like can be used alone or in combination.

Next, the pulverized plant biomass is supplied onto a screw conveyor installed in the microwave extraction device 12. Since plant biomass itself retains moisture (see Table 1 below), it is possible to extract essential oil using the built-in water of this plant biomass, but solvent 6 is introduced into the microwave extraction device. Therefore, if necessary, it can be extracted by adding a solvent. In order to prevent local heating by microwaves, the extraction solvent 6 is preferably put to a height that does not contact the screw.

  Table 1 below is data showing the water content of various plant biomass, and the plant biomass contains about 30 to 60% by mass of water, although it varies depending on the type and part. Therefore, the moisture on the surface of the solvent and the plant biomass is heated by microwave irradiation, and the essential oil component in the plant biomass is efficiently extracted by the heating solvent by being heated from the inside by the moisture contained in the plant biomass. .

At the time of essential oil extraction, the microwave is irradiated from the microwave irradiation unit 11 into the extraction device 12 and at the same time the plant conveyor is transported by moving the screw conveyor at a constant speed, so that the microwave is uniformly irradiated to the plant biomass 1. The The temperature in the extraction device 12 during extraction is usually not lower than the boiling point of the solvent and not higher than 200 ° C., but is preferably maintained at 35 ° C. to 160 ° C., more preferably 75 ° C. to 120 ° C. By maintaining the reaction temperature within this range, it is possible to prevent the extracted essential oil component from being decomposed and increase the extraction efficiency. The extraction time is about 30 seconds to 1 hour, preferably about 1 minute to 30 minutes.

  A solvent condensing device 15 and an essential oil collecting device 16 are connected to the microwave extracting device 12, and the essential oil collecting device is provided with a return pipe 18 for returning the condensed solvent content to the extracting device. As the microwave irradiation time elapses, the essential oil components and the solvent evaporate and go out of the extraction device 12 through the evaporation tube 17, and then the solvent and the essential oil condensed by the solvent condensing device 15 are recovered by the essential oil recovery device 16. . Since the essential oil recovery device is provided with the return pipe 18, when the amount of the essential oil and the solvent recovered by the essential oil recovery device becomes substantially the same height as the top of the return pipe 17, the essential oil recovery device 16 When the solvent returns into the extraction device 12 and the recovery unit water level and the outlet position height of the return pipe become the same, the atmospheric pressure becomes equal, so the water flow stops. This operation is repeated once or several times. Microwave irradiation is stopped at the stage where the transfer of plant biomass is completed, and the extracted essential oil component is recovered by opening and closing operations such as a cock provided in the essential oil recovery device 16. The temperature of the refrigerant in the solvent vapor condensing device 15 is usually −20 to 10 ° C., and preferably in the range of −10 to 5 ° C. when the solvent is water.

  As plant biomass, cultivation plant biomass and waste plant biomass are mainly used. These plant biomass can also be used 1 type or in mixture of 2 or more types. Cultivation plant biomass includes tree biomass such as eucalyptus, poplar, willow, palm palm, pine, cedar, camphor, camellia, eel, enoki, and rattan, and herbaceous biomass such as sugar cane, miscantas, rapeseed, switchgrass, sorghum, and corn. Examples include trees, grass leaves, fruits, branches, and roots. As the tree species, the myrtaceae, camphoraceae, citrus, and the like are preferable. Ocotea pretiosa (= O.cymbarum), Cinnamomum comphora, Cinnamomum zeylanicum, Pelargonium graveolens, other subspecies, Citrus aurantium amara, Citrus aurantifollicum , Styrax tonkinensis, Styrax benzoin.

  Waste plant biomass includes forest biomass such as timber, thinned wood, felled trees, pruned branches, sawdust, bark, chips, edgewood, driftwood, bamboo, firewood, wooden building waste; fir shells, rice straw, wheat straw Agricultural biomass such as palm shells of bagasse and oil palm (raw material of palm oil); food biomass such as food residues from food factories and restaurants.

  Among these plant biomass, from the viewpoint that the essential oil content is high, the cultivated plant biomass and the food-based biomass are suitable, and the cultivated plant biomass is suitable for the stability of the components. Further, among the cultivated plant biomass, fruits and leaves are preferable, and conifers are generally preferable to hardwoods.

  Examples of the extraction solvent include water, ethers, alcohols such as methanol and ethanol, ethyl acetate, pyridine, tetrahydrofuran, chloroform, and acetone. Among them, water is a cheap solvent, is easily available, and is a preferable solvent from the viewpoint of safety such as flammability at the time of spark. The ratio of the extraction solvent to the plant biomass is not particularly limited, but is preferably set to plant biomass: solvent = 1: 0.1 to 1: 5 (mass / mass). When the amount of the extraction solvent is less than the above ratio, the extraction efficiency of the essential oil is lowered. On the other hand, when the amount is large, the energy required for heating increases, which is not preferable.

  The output, frequency, and irradiation method of the microwave irradiated from the microwave generator are not particularly limited, and may be electrically controlled so that the reaction temperature can be maintained within a predetermined range. If the output is too low, the amount of solvent vapor generated will be small, and if the output is too high, biomass will ignite, bumping of the solvent and rapid evaporation will occur. Therefore, the electric control should be in the range of 10 W to 20 kW. preferable. The frequency of the microwave is preferably 0.5 to 10 GHz. If the frequency is less than 0.5 GHz, the solvent molecules can follow the direction of the electric field and the heating efficiency is poor. If the frequency exceeds 10 GHz, materials other than biomass are heated, which is not efficient. Microwave irradiation may be either continuous irradiation or intermittent irradiation, but it is preferable to perform continuous irradiation while being electrically controlled. As the microwave oscillator, a microwave oscillator such as a magnetron, a microwave oscillator using a solid element, or the like can be used as appropriate.

  Plant biomass after extraction of essential oil is in a dry state. This may be introduced into a microwave heating device 22 that is connected to a microwave extraction device and carbonizes the plant biomass residue 2 after extraction of essential oil, and may be further heat-treated using microwaves. In the microwave heating apparatus, conveying means for conveying the plant biomass residue is provided. As the conveying means for conveying the plant biomass residue, a screw conveyor or the like is preferable, and a midway part of the screw conveyor along the conveying direction of the plant biomass is arranged in the microwave irradiation area in the microwave heating device 22, and the microwave irradiation unit 21 irradiates microwaves. The microwave irradiation conditions are the same as in the extraction device 12. At the time of heat treatment, the microwave irradiation unit 21 irradiates the microwave into the heating device 22 and simultaneously drives the plant biomass by driving the screw at a constant speed, so that the microwave is uniformly irradiated to the plant biomass residue. . As the heating device for carbonization, an external heating type continuous horizontal screw type carbonization furnace can be used, and microwaves can be used as the heating means.

The temperature in the heating device 22 at the time of heating the plant biomass residue is not particularly limited because the temperature suitable for carbonization varies depending on the type of plant biomass and the like, but the gasification reaction of the raw material proceeds and the carbide 5 having a high fuel ratio is generated. It is preferable that it is hold | maintained at 300 to 1300 degreeC from the point which can improve the heat conversion efficiency of the raw material obtained, More preferably, it is 700 to 1300 degreeC. The heating time is about 10 minutes to 10 hours, preferably about 1 to 4 hours. During the heat treatment, volatile gas 4 such as CH ₄ , CO, H _2, etc. is generated. By collecting these volatile gases, they can be used as fuel or raw material gas.

  On the other hand, the solvent 3 used in the plant biomass extractor 12 normally contains about 5 to 30% by mass of monosaccharides such as hexoses and pentoses eluted from plant biomass, starch and the like. A solvent solution containing the components can be introduced into an ethanol fermentation tank, and yeast and fungi can be added and fermented to produce ethanol. The above-mentioned solvent liquid also contains plant biomass built-in water and adhering water.

  Bacteria that can be added to ethanol fermenters include yeasts belonging to the genus Saccharomyces such as Saccharomyces cerevisiae and Saccharomyces kluyveri, alcohol-fermenting bacteria belonging to the genus Zymomonas such as Zymomonas mobilis, and amylos such as Mucor javanicus. And yeasts commonly used in The fermentation time is not particularly limited, but is about 10 to 100 hours, preferably about 20 to 60 hours.

In the present embodiment, the biomass pulverization apparatus 10 is connected to the upper part of the biomass extraction apparatus 12 so that the pulverized plant biomass can be continuously supplied onto the screw conveyor 19 . Therefore, according to the present embodiment, after pulverization, components that easily volatilize can be introduced into the extraction apparatus without loss, and in the case of biomass that has a large amount of moisture such as leaves and is easily clogged in the supply unit, There is an advantage that can be supplied to.

Moreover, in this embodiment , it has the structure which has arrange | positioned the microwave irradiation part to the one end side of the belt conveyor which is a conveyance means. Therefore, according to the present embodiment, there is an advantage that the microwave can be irradiated to the inner part of the extraction device 12 by utilizing the straightness of the microwave.

Moreover, in this embodiment, it has the structure which has arrange | positioned the microwave irradiation part to the one end side of the screw conveyor which is a conveyance means.

  In the present embodiment, it is preferable that the screw shaft 19 is hollow and formed of a material having a low microwave absorbability, and the screw shaft is used as a microwave conduit. By transmitting microwaves through the screw shaft, it is possible to efficiently irradiate the plant biomass by transmitting the microwaves to the inner part of the extraction device 12.

  Since the screw shaft 19 is made of a material having low microwave absorption, the microwaves are repeatedly planted on the screw while repeatedly entering the screw shaft, reflecting inside the shaft, and emitting outside the shaft. It is transmitted to biomass. The material of the screw shaft is not particularly limited, and tetrafluoroethylene (TFE) resin, polyphenylene sulfide (PPS) resin, polyphenylene sulfone (PPSU) resin, polyarylate (polyarylate) can be used as long as the material transmits microwaves. PAR) resin, polysulfone (PSF) resin, polyethersulfone (PES) resin, polyetherimide (PEI) resin, polyamideimide (PAI) resin, polyetheretherketone (PEEK) resin, liquid crystal polyester (LCP) resin, A heat-resistant resin such as a liquid crystal polymer (LCP) resin, a polyacetal (POM) resin, a polyamide (PA) resin, a polybutylene terephthalate (PBT) resin, a polycarbonate (PC) resin, or a modified polyphenylene ether resin can be used.

  Although the microwave irradiated from the microwave irradiation part 11 arrange | positioned at the one end part of a conveyance means is irradiated to the plant biomass near the irradiation part 11, it is hard to reach plant biomass as it goes to the exit of the extraction apparatus 12. FIG. As illustrated in the present embodiment, by transmitting the microwave through the screw shaft, the microwave can reach the plant biomass away from the irradiation unit 11 and the extraction efficiency of the essential oil is improved.

  With the plant biomass processing system using the microwave of the present invention, it is possible to extract various essential oils from plant biomass and use them in various industrial fields such as pharmaceuticals, cosmetics, foods, fragrances, and dyes. Become. Moreover, the plant biomass after extraction can be utilized as a fuel. Furthermore, ethanol can also be produced from the extraction solvent.

It is a block diagram which shows the outline of the processing system which concerns on Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plant biomass 2 Dry biomass residue 3 Solvent 4 Volatile gas 5 Carbide 6 Solvent 10 Grinding device 11 Microwave irradiation part 12 Microwave extraction device 13 Endless belt 14a, 14b Conveyance device 15 Solvent condensing device 16 Essential oil collection device 17 Evaporating tube 18 Return pipe 19 Screw shaft 21 Microwave irradiation unit 22 Microwave heating device 31 Ethanol fermentation tank

Claims (9)

A crusher for crushing plant biomass;
A microwave extractor connected to a crusher and extracting essential oil from plant biomass with a microwave heating solvent ,
A screw conveyor for conveying plant biomass is provided in the microwave extraction device, and a microwave irradiation unit is disposed on one end side of the screw conveyor to prevent overheating of the plant biomass by the microwave, and the screw A plant biomass processing system using microwaves, characterized in that the screw shaft of the conveyor is formed of a hollow material with low microwave absorption . The microwave extraction device, solvent condenser and essential oils recovery devices are connected, the essential oil recovery system, a microwave according to claim 1, return pipe for returning condensed solvent fraction to the extraction device is provided Plant biomass processing system using The plant biomass processing system using a microwave according to claim 1 or 2 , wherein a solvent is introduced into the microwave extraction device. The plant biomass processing system using a microwave according to any one of claims 1 to 3 , wherein the extraction solvent is water. The plant biomass processing system using a microwave according to any one of claims 1 to 4 , wherein the plant biomass is a cultivation plant biomass or a waste plant biomass. The plant biomass processing system using a microwave according to any one of claims 1 to 5 , wherein the temperature in the microwave extraction apparatus is not lower than the boiling point of the solvent and not higher than 200 ° C. The microwave extraction device, is connected to a microwave heating apparatus for carbonizing the plant biomass residue after the essential oil extraction, in the microwave heating in the apparatus, according to claim 1 to 6 provided with a conveying means for conveying the plant biomass residues The plant biomass processing system using the microwave in any one. The plant biomass processing system using a microwave according to claim 7 , wherein the temperature in the microwave heating device is 300 to 1300 ° C. The plant biomass processing system using the microwave according to any one of claims 1 to 8 , wherein the essential oil extraction solvent solution used in the microwave extraction apparatus is introduced into an ethanol fermentation tank to produce ethanol.