JP4711980B2 - Liquid fuel production equipment from biomass - Google Patents

Description

  The present invention relates to an apparatus for producing liquid fuel by gasifying biomass. More specifically, biomass such as woody biomass such as unused trees, thinned wood, residual lumber, driftwood, pruned wood, building waste, sewage sludge, chicken manure, cow dung, waste biomass such as RDF, weeds, grass The present invention relates to an apparatus for producing liquid fuel from biomass for efficiently gasifying and liquefying herbaceous biomass such as sugarcane as a raw material.

  Liquid fuel target biomass generally refers to a living organism that can be used as an energy source, and is one of the renewable energies generated using solar energy. Biomass is the only renewable organic matter that can be converted to energy.

  Currently, more than 30% of the primary energy we use is oil, and more than 40% is liquid fuel for transportation. Therefore, it is very useful to produce liquid fuel from renewable biomass. Production of liquid fuel from biomass can be realized by a combination of several techniques and has been conventionally performed. Among them, biomass is gasified, CO and hydrogen are obtained, and liquid fuel is produced by a catalytic reaction, and this technique is attracting attention. Next, a conventional technique for producing a liquid fuel will be described.

Biomass comes in a wide variety of forms such as woody, waste and herbaceous. On the other hand, CO and hydrogen are required in the liquid fuel production process. Here, the process of producing liquid fuel from biomass via gasification may be simpler than other processes in that CO and hydrogen can be obtained regardless of the type of biomass.
When biomass is gasified, the gas yield and the amount of tar produced depend greatly on the gasifier type, gasifying agent, and reaction conditions.

  Gasifier types are broadly divided into fixed beds, fluidized beds, and spouted beds. The fixed floor has a simple structure, low equipment costs, and is suitable for small scale. Comparing the downdraft and the updraft, the downdraft produces less tar than the updraft. The fluidized bed is suitable for the medium scale, but in order to keep the bed in the gasification furnace fluidized, it is necessary to supply a process flow gas corresponding to at least three times the minimum fluidization speed, resulting in gasification. The gas contains nitrogen at a high concentration.

  In addition, the amount of tar produced is high. The spouted bed does not depend on the scale and has the advantage that the amount of tar generated is low, but it requires the power to pulverize the gasification raw material, and the process flow gas that floats the powder in the gasification furnace is necessary. Therefore, as with the fluidized bed, the gasification gas contains a high concentration of nitrogen.

  Typical gasifying agents include air, carbon dioxide, and water vapor. When air is used, there is an advantage that external heat is unnecessary, the gasification rate is high, and the gas yield is high, but nitrogen is mixed in the gasification gas. Also, when oxygen is used, there are similar advantages, but the cost of separating nitrogen from air is high.

  When carbon dioxide is used, nitrogen is not mixed in the gasification gas, and when the liquid fuel production process continues in the latter stage, there is an advantage that the gasification gas cooling process is unnecessary, but external heat is required, and the reaction rate Is slow. Furthermore, when the liquid fuel production process continues in the subsequent stage, the yield of liquid fuel is low because the hydrogen / CO ratio is low. In the case of using water vapor, a gas with a high hydrogen / CO ratio can be obtained with a low mixing of nitrogen as a process flow gas in the gasification gas. However, external heat is required, and the use of excess water vapor increases the water vapor fraction in the gasification gas, thus requiring a cooling step for removal as water.

  The gas purification process can be broadly divided into a wet method in which impurities are dissolved in a solvent, particularly water, and a dry method that does not use water. Generally, a wet method is used. However, the initial cost and the running cost of the entire process are increased from the viewpoint of the huge processing equipment and the cost of wastewater treatment.

  Regarding the dry method, a method of removing tar and particulate matter contained in the gasification gas at a pressure of atmospheric pressure and a temperature of 130 ° C. or less has been reported (for example, see Non-Patent Documents 1 and 2). This is a method of collecting dust using a cyclone or a method using an adsorbent such as sand or activated carbon. Since both the wet method and the dry method have a purification gas temperature of 130 ° C. or lower, a process for reheating is required when the subsequent process requires a reaction temperature higher than the purification gas temperature. It becomes.

  In addition, since conventional gas purification methods are performed near atmospheric pressure, it is necessary to input power to compress the gas when the subsequent process is operated under pressurized conditions such as liquid fuel production and membrane separation. Become. Accordingly, a compressor is required, resulting in an increase in the initial cost of the process. In addition, some have a heat exchanger that recovers the heat of the gasified gas and the purified gas, but the initial cost for installing the heat exchanger increases.

  In the process for producing liquid fuel from biomass via gasification, an apparatus for producing methanol after gasifying organic waste and purifying the gas has also been proposed. When liquid fuel is produced from CO and hydrogen, the equilibrium yield is preferably under pressurized conditions of about several megapascals. However, the pressure conditions of the conventional technology are not limited, and it is difficult to obtain high methanol under normal pressure conditions. In addition, some have a heat exchanger that recovers the heat of the gasified gas and the gas after purification, but the initial cost for installing the heat exchanger increases. Furthermore, the power to pressurize the purified gas results in an increase in energy input to the process. Therefore, the initial cost also increases due to the booster device installation.

  Next, a specific conventional example related to the present invention will be described. In technologies for burning and gasifying biomass, for example, a partial combustion gas having oxygen gas reacts with biomass, and after the biomass is partially burned, it is reacted with a gasification gas having water vapor to gasify the biomass. The technique to make is known (for example, refer patent document 1).

  In addition, a technique is also disclosed in which, when burning biomass, a combustion exothermic reaction of biomass and an endothermic reaction of biomass are separately performed in a combustion space and a gasification space (for example, patents). Reference 2).

  As a technique for compressing and purifying, for example, there is a technique that is applied to a pressure swing adsorption purifying apparatus, and purifies a part of the gas by purifying the remainder of the pressurized gas and the membrane separation and purifying apparatus and then introducing the gas pressurized by the compressor. It is known (see, for example, Patent Document 3).

  In the technology for producing methanol, the gas obtained by gasifying biomass is cooled to synthesize methanol, and heat is exchanged with water supplied from the outside by heat exchange means to generate high-temperature steam, which is purified. A technique for producing methanol fuel is known (see, for example, Patent Document 4).

  In addition, when biomass is gasified, water is electrolyzed with water electrolysis equipment using the power generated by the solar power generation facility or wind power generation facility, and the amount of hydrogen in the generated gas is reduced by 2 to the amount of carbon monoxide. A technique for producing methanol by supplying hydrogen gas so as to be twice or more is known (see, for example, Patent Document 5).

  Furthermore, the gas containing hydrogen and carbon monoxide obtained by biomass gasification is stored in a gas tank, pressurized to 0.5-5.0 MPa with a pressure pump, and then produced in a methanol synthesis unit filled with a catalyst. There is also known a technique of cooling methanol gas to obtain methanol (see, for example, Patent Document 6).

  As a technology configured to move a series of devices that gasify biomass, for example, a mobile vehicle equipped with components for the process of temporarily storing pulverized biomass, and a process associated with the production of purified gas that gasifies biomass What was comprised as a mobile vehicle carrying a component apparatus is known (for example, refer patent document 7).

  Further, as a technology for burning char, clay is used as a catalyst for gasification. However, a technology is disclosed in which char is burned to supplementally heat biomass to promote gasification, and carbon monoxide and A technique is also disclosed in which methanol is produced by performing a methanol synthesis reaction after components of a biomass gas containing hydrogen are adjusted by a shift reactor as necessary to remove carbon dioxide (see, for example, Patent Document 8).

JP 2002-235091 A JP 2002-88379 A JP-A-6-210120 JP 2001-240878 A JP 2002-193858 A Japanese Patent Laid-Open No. 2005-13239 JP-A-9-176664 JP 2003-41268 A Hasler, P., and Nussbaumer, T., Biomass & Bioenergy, 16, 385 (1999) Devi, L., Ptasinski, K. J., and Janssen, F. J. J. G., Biomass & Bioenergy, 24, 125 (2003)

Since the step of compressing the gasification gas and the purified gas leads to an increase in the initial cost of the process and the input energy, it is necessary to omit the compression process.
In order to obtain CO (carbon monoxide) and hydrogen in the gasification process, steam is usually used as a gasifying agent. However, the steam / water separation process, which causes an increase in the initial cost, is limited to the input of steam. There is a need.

  When liquid fuel is produced from CO and hydrogen, as described above, the equilibrium yield is preferably under a pressurized condition of about several megapascals. However, for example, in the case of the aforementioned patent document, the pressure condition is not limited, and a high methanol yield cannot be obtained under the normal pressure condition. As described above, in the conventional technique, there are conditions that can be applied to each technique, but it is not necessarily performed efficiently in the entire process of gasifying biomass to produce liquid fuel.

  In a liquid fuel production process, since a high synthesis gas (CO + hydrogen) partial pressure is desirable, a process is required in which a purified gas having a low or no nitrogen, oxygen, carbon dioxide, or water vapor concentration is obtained. Furthermore, the process must be a process for efficiently producing liquid fuel by gasifying biomass with as little waste as possible. The present invention has been made in order to overcome the above-mentioned problems against the background of such a situation.

  That is, the object of the present invention is necessary for gasification, which is a factor that increases the input energy without using a gas compression device and a heat exchanger, which are factors that increase the initial cost of the liquid fuel production process via gasification. A device for producing liquid fuel from biomass in which the concentration of nitrogen, oxygen, water vapor, carbon dioxide, etc. is reduced in the liquid fuel synthesis process, which reduces the amount of heat and reduces the gas compression power and liquid fuel yield There is.

  Another object of the present invention is to circulate unreacted materials again in the same apparatus and efficiently reuse them without waste in order to streamline a series of steps for gasifying biomass and producing liquid fuel. The object is to provide an apparatus for producing liquid fuel from biomass.

  Thus, as a result of extensive research on the background of such problems, the present inventor does not include the pressurization step of gasification gas and purified gas, and does not require compression power and related equipment and heat exchanger. And found a simple process that can achieve high liquid fuel yield while reducing the initial cost and input energy of the plant using only a minimum amount of nitrogen, and completed the present invention based on this knowledge. It is. Next, specific means will be described.

The apparatus for producing liquid fuel from biomass according to the first aspect of the present invention holds a fixed amount of one or more kinds of biomass selected from woody biomass, waste biomass, and herbaceous biomass, and heats them with a heating element, 1 to 5 MPa. A gasification part that gasifies in the pressure range of the gas, and at least one substance selected from particulate matter, tar, sulfur compounds, and nitrogen compounds from the biomass gas generated by the gasification part, and the biomass gas A gas purification unit for purifying the biomass, a liquid fuel production unit for liquefying the purified biomass purified gas by Fischer-Tropsch synthesis to produce a biomass liquid fuel stock solution that is a hydrocarbon, and the biomass liquid fuel stock solution as a biomass liquid fuel , A gas-liquid separation part that separates into water and light hydrocarbons, and biomass separated in the gas-liquid separation part A vacuum recovery unit for recovering the body fuel under reduced pressure, the gasification unit by burning unreacted materials are not gasified, and a combustion portion for supplying generated heat to the gasification section, made from the gasification The pressure until the liquefaction is kept constant, and there is no pressurizing device for pressurizing the biomass gas or the biomass refined gas.

The apparatus for producing liquid fuel from biomass according to the present invention 2 is an apparatus for producing liquid fuel from biomass according to the present invention 1, wherein the gasification unit is configured to supply water vapor containing moisture contained in biomass to a molar ratio of carbon in the biomass. Is gasified in the range of 0 to 1, and the liquid fuel production apparatus does not have a heat exchanger that recovers heat of the biomass gas or the biomass refined gas.

The apparatus for producing liquid fuel from biomass of the present invention 3 is an apparatus for producing liquid fuel from the biomass of the present invention 1 or 2, wherein the gasification unit is configured to heat the biomass at a temperature of 600 to 1000 ° C. by the heating element. Heating , the gas purification unit removes at least one substance selected from particulate matter, tar, sulfur compounds and nitrogen compounds from the biomass gas at a temperature of 200 to 900 ° C., and the liquid fuel production part Liquefy the purified biomass purified gas at a temperature of 100 to 400 ° C. by a catalytic reaction, and the liquid fuel production apparatus does not have a mechanism for reheating the biomass gas or the biomass purified gas. Features. In the present invention 3, the heating temperature of the biomass is preferably 700 to 800 ° C.

The apparatus for producing liquid fuel from biomass according to the present invention 4 is an apparatus for producing liquid fuel from biomass according to the present invention 3, wherein the gas-liquid separator performs gas-liquid separation at a temperature from room temperature to 100 ° C. And

In a liquid fuel production process using a general catalytic reaction (not limited to Fischer-Tropsch synthesis), the catalytic reaction is a Cu—Zn-based catalyst, the addition of γ-alumina as a dehydration catalyst, or an Fe, Co, Ru-based catalyst. The reaction is carried out with one catalyst selected from catalysts. By changing the type of catalyst used, hydrocarbons such as methanol, dimethyl ether, gasoline, kerosene and light oil can be produced. For example, methanol is synthesized by the following reaction formula using a Cu—Zn-based catalyst.
CO + 2H ₂ → CH ₃ OH. . . . . (1)

Since dimethyl ether has a structure in which two molecules of methanol are dehydrated, the addition of γ-alumina as a dehydration catalyst can be obtained by the following general reaction formula.
3CO + 3H ₂ → CH ₃ OCH ₃ + CO ₂ . . . . . (2)
As a specific catalytic reaction, there is a reaction by a catalyst in which a Cu / Zn catalyst and γ-Al ₂ O ₃ are mixed. Liquid fuel can be extracted by DME synthesis.

In addition, the production of hydrocarbons such as gasoline, kerosene, and light oil is represented by the following reaction formula using Fe, Co, and Ru-based catalysts.
nCO + (2n + 1) H ₂ → C _n H _{2n + 2} + nH ₂ O. . . . . (3)

The apparatus for producing liquid fuel from biomass according to the fifth aspect of the present invention is the apparatus for producing liquid fuel from one biomass selected from the first to fourth aspects of the present invention, wherein the biomass is a woody biomass, and in the Fischer-Tropsch synthesis In addition, a catalytic reaction with an alumina-supported ruthenium catalyst is performed. Liquid fuel can be extracted by FT synthesis.

In the first to fifth aspects of the present invention , a mounting base may be provided at a lower portion of the liquid fuel production apparatus so that the liquid fuel production apparatus can be transported via the mounting base .

In the first to fifth aspects of the present invention , a moving carriage can be provided at a lower portion of the liquid fuel production apparatus so that the liquid fuel production apparatus can be moved via the movement carriage .

In the first to fifth aspects of the present invention, a tar decomposition catalyst may be provided at the bottom of the gasification unit. Biomass is processed in a semi-batch process in the gasification section. Semi-batch treatment means opening the gasification furnace, charging the raw material biomass, heating it, raising it to the specified pressure, and then allowing the minimum amount of nitrogen, carbon dioxide, or recycle gas to flow through to advance the gasification reaction Means that.

Further, the tar decomposition catalyst may be one catalyst selected from dolomite, CaO, Ni-based catalyst, and Rh-based catalyst . For example, dolomite is obtained by replacing a part of calcium with magnesium in seawater after corals and the like are deposited on the seabed to form limestone. Calcium and magnesium act on biomass to cause tar decomposition.

In 5 from the invention 1 has a plurality of the gasification unit, be sequentially run multiple gasification unit by connecting a plurality of the gasification unit to the selected gas refining section the required gasification unit it can.

In the present inventions 1 to 5, the gas purification unit has two gas purification units, and the flow path can be switched to the other gas purification unit before the adsorbent of one gas purification unit breaks through, and can be used alternately. structure can be made to have a such.

In the first to fifth aspects of the present invention, the liquid fuel production section can be configured so that the unreacted biomass gas that has not been liquefied can be liquefied again .

In the first to fifth aspects of the present invention , the gas-liquid separator can be configured to send unreacted biomass gas that could not be gas-liquid separated to the gasifier so that it can be gasified again .

In the first to fifth aspects of the present invention, the gas-liquid separation unit can be configured to send unreacted biomass gas that could not be gas-liquid separated to the liquid fuel production unit so that it can be liquefied again .

In 5 from the present invention 1, wherein if unreacted substances Ru char der, the combustion unit may be a device for combusting the char extracted from the gasification unit during the stop.

  The apparatus for producing liquid fuel from biomass according to the present invention does not use a gas compression device or a heat exchanger, reduces the amount of heat necessary for gasification, such as nitrogen, oxygen, water vapor, carbon dioxide, etc. in the liquid fuel synthesis process. Since the concentration was lowered, the structure was simple. In addition, since the unreacted material is reused by recirculating it in the same apparatus, a high yield of liquid fuel can be obtained. In addition, since a plurality of gasification furnaces are provided, a plurality of gasification furnaces can be used while being switched to operate continuously, resulting in an efficient apparatus.

  Hereinafter, the apparatus for producing liquid fuel from biomass according to the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 1 shows a first embodiment of an apparatus for producing liquid fuel from biomass according to the present invention. The configuration of the apparatus for producing liquid fuel from biomass is as described in the above section. Biomass A is thrown into the gasification unit 2 for biomass gasification. The gasification unit 2 has a plurality of gasification furnaces. Hereinafter, the gasification unit 2 will be described by using the first gasification furnace 2a as a representative. The form of biomass A is more effective for gasification because the surface area becomes larger when it is made finer.

  Biomass A is charged into the gasification furnace 2a in such a manner that a certain amount is maintained. In this charging, a means such as a hopper may be used, but the type is not limited. The reason why the amount of biomass A is constant is that a stable gasification process is performed in consideration of the fact that the reaction conditions after gasification become substantially constant. It is also for batch processing described later. The apparatus of this embodiment is configured to enable batch processing. Batch processing, as described above, refers to putting a certain amount of biomass into a gasifier and conducting a gasification reaction by circulating a small amount of nitrogen, carbon dioxide, etc. Gasification of the plurality of gasification furnaces thus made is carried out selectively and sequentially in stages.

  This gasification unit 2 is a downdraft type fixed bed gasification furnace type, in which gasification raw material biomass A is filled in the gasification furnace 2a, and a small amount of nitrogen or carbon dioxide is circulated as a process flow gas. Yes. The upper part is a gasification furnace 2a for charging and gasifying the biomass A, and the lower part is a catalyst storage part 3a for a catalyst for decomposing tar. For a gasification furnace 2b, which will be described later, a catalyst housing 3b is provided. The biomass gas obtained by gasifying the biomass A is discharged from the gasification furnace 2a through the catalyst storage unit 3a.

Here, if the molar ratio of water vapor to carbon in the biomass ([H ₂ O] / [C]) including water contained in the biomass A is up to 1, a heat exchanger is unnecessary. For this reason, it is also possible to distribute a small amount of water vapor. This gasification step is maintained at the same pressure including the subsequent steps. This pressure is in the range of 1 to 5 MPa, and there is no pressurizing device for raising the pressure in the middle.

  The gasification of the biomass A proceeds by heating the gasification furnace 2a from the outside with an electric furnace. After the gasification step, it is connected to the next gas purification unit 4. As the gasification temperature is higher, the gas yield is higher. However, if the gasification temperature is 1000 ° C. or higher, an expensive material or a special structure of the gasification furnace is required. Further, when the gasification temperature is high, 700 to 800 ° C. is desirable because ash in the biomass may melt and clog the gasification furnace.

  The catalyst storage unit 3a at the bottom of the gasification furnace 2a can be filled with a catalyst such as dolomite, CaO, Ni-based catalyst, or Rh-based catalyst as a catalyst for decomposing tar. For example, dolomite contains calcium and magnesium as described above and is a substance suitable for tar decomposition. The tar content contained in the gasified biomass gas is decomposed on the dolomite in the catalyst storage unit 3a.

  In order to promote gasification, a combustion section 1 is provided adjacent to the gasification furnace 2a. Unreacted char, which has not been gasified in the gasification furnace 2a, is taken out from the combustion section 1 after the operation of the gasification furnace 2a is stopped, and is installed in the combustion section 1 as indicated by a dotted line B. Entered. Combustion heat due to combustion of unreacted char is supplied to the gasification furnace 2a as an auxiliary heating source to promote gasification.

  A plurality of gasification units 2 are provided. If the amount of gas generated in the first gasification furnace 2a in operation, for example, decreases, before the system begins to depressurize, for example, the second system of the second system. The operation for the gasification process can be continued by switching to the gasification furnace 2b. A switching unit C for this switching is provided, and switching control is appropriately performed according to the selection of the required gasifier. Therefore, a plurality of gasifiers can be selectively operated sequentially. With this configuration, a series of gasification processes can be performed continuously without stopping, and the processing efficiency is improved.

  The gas sent out from the gasification furnace 2a is sent into the gas purification unit 4 as biomass gas. The gas purification unit 4 is an apparatus that removes particulate matter, tar, sulfur compounds, and nitrogen compounds contained in the biomass gas generated in the gasification unit 2 and purifies the biomass gas. The gas purification unit 4 is filled with an adsorbent such as a dust removal filter, activated carbon for adsorbing tar, charcoal, and sand, and the gas purification temperature is controlled to 200 to 900 ° C.

  This gas purification unit 4 has two systems, and is configured such that the flow path can be switched before the internal adsorbent breaks through. For example, the flow path of the biomass gas from the gasification section 2 is connected to the first gas purification section 4a, but the flow path is switched to the second gas purification section 4b before the adsorbent breaks through. It is. The figure shows the configuration, and the flow path can be switched by the switching means 4c.

  With such a configuration, it is possible to take out the adsorbent immediately before the breakthrough of the first gas purification unit 4a stopped by the switching, and to fill and wait for a new adsorbent. If the adsorbent of the second gas purification unit 4b is just before breakthrough, the flow path is switched again to the first gas purification unit 4a. If this is repeated, the gas purification process can be continued without stopping.

  Next, the biomass refined gas purified by the gas purification unit 4 is sent to the liquid fuel production unit 5 in order to produce a liquefied liquid fuel. The liquid fuel production process is connected to the outlet side of the gas purification process and receives the purified biomass refined gas. In the liquid fuel production process, a catalyst for producing a desired liquid fuel is filled. If the liquid fuel is methanol, it is a Cu—Zn-based catalyst. Since dimethyl ether has a structure in which two molecules of methanol are dehydrated, it is necessary to add a γ-alumina catalyst as a dehydration catalyst. Further, if the liquid fuel is a hydrocarbon type such as gasoline, kerosene and light oil, an Fe, Co, Ru type catalyst is used.

  Thus, each target product can be obtained by changing a catalyst. In this liquid fuel production part 5, a liquid fuel is produced in a pressure range of 1 to 5 MPa at a temperature of 100 to 400 ° C. by a catalytic reaction. The manufactured liquid fuel is fed into the gas-liquid separator 6 as a liquid fuel stock solution. The liquid fuel stock solution manufactured by the liquid fuel manufacturing unit 5 contains water, light hydrocarbons, and the like. For this reason, it is separated into liquid fuel refined liquid, water, light hydrocarbons, unreacted gas and the like by this gas-liquid separation unit 6. The separated water is condensed in this step and discharged out of the gas-liquid separation unit 6.

  Next, the liquid fuel purified liquid separated by the gas-liquid separation unit 6 is sent to the reduced pressure recovery unit 7. In this reduced pressure recovery section 7, the separated liquid fuel purified liquid is cooled and decompressed. The decompression recovery unit 7 is provided with a decompression valve 7 a and is connected to a delivery port of the gas-liquid separation unit 7. Water and liquid fuel have different saturation vapor pressure curves and can be taken out of the system as a liquid from a substance having a high boiling point in the cooling process. The liquid fuel purified liquid taken out through the pressure reducing valve 7a is a liquid fuel 7b as a regular product that can be used, and is collected in a tank or the like.

[Second Embodiment]
FIG. 2 is a diagram showing a second embodiment of the apparatus for producing liquid fuel from biomass according to the present embodiment. In the liquid fuel production process, an embodiment is considered in which processing cannot be performed by a single process. A flow path 5 a is provided for returning unreacted gas that has not been liquefied by the liquid fuel production unit 5 to the receiving port of the liquid fuel production unit 5. By providing this flow path 5a, the biomass-refined gas is caused to flow through the liquid fuel production section 5 many times, whereby the unreacted gas is liquefied in a reused form. Therefore, the biomass purified gas can be liquefied efficiently.

[Third Embodiment]
FIG. 3 is a diagram showing a third embodiment of the apparatus for producing liquid fuel from biomass according to the present embodiment. After the biomass liquid fuel stock solution was separated from the liquid fuel and water in the cooling process of the gas-liquid separator 6, the unreacted gas was returned to the upstream of the gasification process via the flow path 6a. Thereby, the unreacted gas is gasified again, the liquefaction process is performed again, and the gas-liquid separation process is performed again. Thus, the present embodiment has a structure that can be efficiently converted into CO and hydrogen.

[Fourth Embodiment]
FIG. 4 is a diagram showing a fourth embodiment of the apparatus for producing liquid fuel from biomass according to the present embodiment. After the biomass liquid fuel stock solution was separated from the liquid fuel and water in the cooling process of the gas-liquid separator 6, the unreacted gas was returned to the upstream of the liquid fuel production process via the flow path 6b. Thereby, the unreacted gas is liquefied again, and the gas-liquid separation process is performed again.

  The second to fourth embodiments are examples in which biomass is effectively used without waste and the yield of liquid fuel is increased by recycling unreacted substances in the same apparatus and reusing them. Next, other embodiments applicable to any embodiment will be described. That is, an installation base 8 is provided in the lower part of the liquid fuel production apparatus from biomass, and the liquid fuel production apparatus can be transported through the installation base 8, and the liquid fuel production apparatus from biomass is moved to the lower part. In this example, a carriage 9 is provided, and the liquid fuel production apparatus can be moved through the movable carriage 9.

For example, the mounting base 8 at the lower part of the apparatus can be lifted with a crane or the like to transport the liquid fuel production apparatus to a predetermined position. Further, the liquid fuel production apparatus can be moved to a predetermined position by pulling the movable carriage 9 at the lower part of the apparatus manually or by power. Although the figure showing the embodiment is a figure in which a movable carriage 9 is provided, it may be a mounting base 8.
While various embodiments have been described above, it goes without saying that the present invention is not limited to these embodiments.

As woody biomass, 10.2 g of rice pine (Douglas fir, Pseudotsuga menziesii) was used. Table 1 shows the analysis results. As the tar decomposition catalyst, 29.2 g of dolomite (manufactured by Yoshizawa Lime Industry Co., Ltd.) was used. As the tar adsorbent, 15.0 g of commercially available activated carbon (2-4 mm) was used. As a catalyst for DME synthesis, 16.0 g of an activated carbon (2-4 mm) obtained by physically mixing a Cu / Zn-based catalyst manufactured by Engelhard and γ-Al ₂ O ₃ was used. DME is an abbreviation for Di-Methyl Ether. It is attracting attention as clean energy that does not generate sulfur oxides or soot during combustion. Example 1 is an example of a liquid production technique using DME.

  As Example 1, FIG. 5 shows a block diagram of an experimental apparatus for pressurized gasification-DME synthesis. The configuration of this apparatus mainly includes a pressurized steam gasification unit, a tar cracking unit using dolomite, a gas cleaning unit using activated carbon, and a DME synthesis unit.

  Generation in this example was performed as follows. First, the three-way valve 21 flows gas in the X direction. In the pressurized steam gasification unit 11, the biomass raw material 13 that has been supplied to the reactor in advance, that is, Yonematsu, is heated in an electric furnace 14 in a nitrogen stream whose flow rate is adjusted by the mass flow controller 30, and pyrolyzed. Was converted to char. Thereafter, steam was introduced to perform char steam gasification of char.

  The pyrolysis gas was analyzed by gas chromatograph GC after passing through the back pressure valve 22. The gas after DME synthesis was analyzed by gas chromatograph GC after passing through the back pressure valve 26.

  After the thermal decomposition has settled, the water is heated and fed through the feed pump 15, and is brought into contact with the char to be converted into pressurized steam gas. This is because the gas rich in CO and hydrogen can be stably obtained by the steam gasification of char. This steam gasified gas body was passed through dolomite 17 to decompose tar, that is, tar cracking, to promote gas conversion.

Next, in a continuous process, the gas body is transferred to a gas cleaning unit to purify the gas. The gas was kept warm via the ribbon heater 18 and cleaned with activated carbon 20. A gas chromatograph GC was used to analyze the gas whose pressure was reduced in the direction determined by the three-way valve 21 and reduced to normal pressure by the back pressure valve 22, and the composition of CO and H ₂ was increased. I confirmed.

Thereafter, the three-way valve 21 is switched to the Y side, and a gas having a high composition of CO and H ₂ is sent to the liquefaction process while maintaining a predetermined pressure by the back pressure valve 26, and the Cu / Zn catalyst is used as the DME synthesis catalyst 23. After passing through the catalyst mixture of γ-Al ₂ O ₃ , DME is synthesized, passed through the back pressure valve 26, the composition of DME is analyzed by gas chromatograph GC, and after passing through the integrating flow meter 27, the gas collection bag 28 Collected.

  This series of generation processing conditions is: pyrolysis of wood, steam gasification temperature of char is 850 ° C, cracking temperature of tar cracking part is 730 ° C, gas cleaning temperature by activated carbon is 300 ° C, and temperature of DME synthesis is 250 ° C there were. The pressure was 3 MPa in all steps. At the beginning of the experiment, the switching direction of the three-way valve 21 was set to the X side, and gas measurement obtained by char gasification of char was performed by a gas chromatograph GC. Next, by introducing water with a water pump, a gas cleaning unit filled with dolomite 17 and activated carbon 20 in a nitrogen stream of 20 cc / min (STP) at a pressure of 3 MPa in a pressurized steam gasification-high temperature gas cleaning unit. Was heated to 750 ° C. and 300 ° C., respectively, and after confirming that the composition of CO and hydrogen was high in the gas chromatograph GC, the X side of the three-way valve 21 was closed and the Y side was opened, and the experiment was started.

  Using a gas chromatograph equipped with TCD (thermal conductivity detector, 3000A Micro GC: Agilent, Molecular Sieve-5A, Porapak U), the gas composition after gas cleaning (measurement of gas passing through the back pressure valve 22) and DME The composition of the gas after synthesis (measurement of the gas that passed through the back pressure valve 26) was analyzed. The results were as shown in FIGS.

FIG. 6 shows changes over time in the temperatures of the gasification furnace and the dolomite layer, flow rates measured with a wet gas meter, and changes over time in the concentrations of H ₂ , CO, CH ₄ , and CO ₂ . Further, FIG. 7 shows the time course of the concentration of _{C 2 H 4, C 2 H} 6, DME was low compositional. In detail, in FIG. 6, between 0～100Min, is first heated dolomite _(a mixture of MgCO 3, CaCO _3), is CO ₂ released was detected at high concentrations by decarboxylation reaction proceeds . This is when heating the wood and dolomite simultaneously, the CO ₂ from the pyrolysis of wood, since CO ₂ from decarboxylation reaction by dolomite heating indistinguishable.

  Thereafter, the pressurized steam gasification part of the wood is heated, and after reaching a desired temperature, that is, 850 ° C., after the generation of hydrocarbons by thermal decomposition has settled, steam is introduced at a rate of 0.1 g / min. Then, high-pressure steam gasification was started (at 150 min).

  Here, at the same time as the thermal decomposition was started, the DME synthesis part introduced 300 cc / min of 60% hydrogen and 40% nitrogen gas into the catalyst layer at 300 ° C. under normal pressure (at 0 min) and reduced the hydrogen for 1.5 hours. Went. Then, it cooled to room temperature in nitrogen stream, and pressurized to 3 MPa. When 170 minutes passed, the three-way valve 21 was turned to the Y side, and a gas body (gas having a high composition of CO and hydrogen) by pressurized steam gasification was introduced into the DME synthesis section, and DME synthesis was started. Thereafter, each composition showed a constant value.

  In FIG. 7, DME started to be detected after 210 minutes. DME detection continued until 360 min. From this result, it was confirmed that DME can be continuously synthesized from woody biomass for 150 min using an experimental apparatus without a compression step and a reheating step.

In addition, it was verified how much the carbon in the input biomass was distributed to the product on a carbon basis. As a result, as a carbon conversion rate (carbon standard in input wood), CO, CO ₂ , CH ₄ , C ₂ : 62%, DME: 3%, Char: 19%, activated carbon adhering tar: 1%, unknown: 15%.
In this result, 3% can be converted into DME based on the carbon input.

  As woody biomass, 20.0 g of rice pine (Douglas fir, manufactured by Pseudotsuga menziesii) was used. As the tar decomposition catalyst, 29.9 g of dolomite (manufactured by Yoshizawa Lime Industry Co., Ltd.) was used. As the tar adsorbent, 15.0 g of commercially available activated carbon (2-4 mm) was used. As a catalyst for carbon hydrogen synthesis, 2.0 g of an alumina-supported ruthenium catalyst (Ru content: 5 wt%, manufactured by Wako Pure Chemical Industries, Ltd.) was used.

  As Example 2, a block diagram of an experimental apparatus used for pressurized steam gasification-hydrocarbon synthesis is shown in FIG. The configuration of the experimental apparatus mainly includes a pressurized steam gasification unit, a tar cracking unit using dolomite, a gas cleaning unit using activated carbon, and an FT synthesis unit.

The technology of the FT synthesis unit is an abbreviation for Fischer-Tropsch synthesis, and a reaction is performed by a reaction formula nCO + (2n + 1) H ₂ → C _n H _{2n + 2} + nH ₂ O on a catalyst with a synthesis gas that is a mixed gas of carbon monoxide and hydrogen. It is a technology to make it liquefied. It is attracting attention because it can be simply manufactured using biomass or the like as a raw material. Example 2 is an example of a liquid production technique by carbon hydrogen synthesis. The generation of this example was performed as follows.

  Similarly to Example 1, in the pressurized steam gasification unit 11, rice pine, which is a biomass raw material, was previously charged. Then, using the mass flow controller 30, the rice pine was pyrolyzed by the electric furnace 14 while circulating nitrogen, and char was made. After the generation of hydrocarbons due to thermal decomposition has settled, water is heated and fed through the feed pump 15, and is brought into contact with the char to be gasified into steam. This steam gasified gas body passed through dolomite 17 to perform tar cracking.

Next, in a continuous process, this gas body was transferred to a gas cleaning section, kept warm via a ribbon heater 18, and cleaned with activated carbon 20. The cleaned gas body was liquefied using an alumina-supported ruthenium (Ru / Al ₂ O ₃ ) catalyst as the FT synthesis catalyst 29. The three-way valve 21 is a two-way switching valve. Next, gas-liquid separation is performed, and a liquid for fuel is taken out. The liquid was collected in the liquid collection tube 25, and the gas part was collected in the gas collection bag 28 through the back pressure valve 26 and the integrated flow meter 27.

  At the beginning of the experiment, the switching direction of the three-way valve 21 was set to the X side, and the gas was measured by pyrolysis. In the pressurized steam gasification-high-temperature gas cleaning section, an experiment was conducted by heating the gas cleaning section filled with dolomite and activated carbon to 750 ° C and 300 ° C in a nitrogen stream of 200 cc / min (STP) at 3 MPa. Started. Thereafter, the gasification part was heated to reach a desired temperature of 800 ° C., and chard. After the generation of hydrocarbons due to thermal decomposition settled, pressurized steam gasification was started by introducing steam at a rate of 0.1 g / min.

  Simultaneously with the start of thermal decomposition, the FT synthesis unit introduced a gas of 130 cc / min of 20% hydrogen and 80% nitrogen into the catalyst layer at 300 ° C. and normal pressure (at 0 min) and carried out hydrogen reduction for 1.5 hours. . Then, it cooled to 180 degreeC in nitrogen stream, and pressurized to 3 MPa. At 220 min, the X side of the three-way valve 21 was set to the Y side, and gas from pressurized steam gasification was introduced into the hydrocarbon synthesis section, and an FT synthesis experiment was started at 230 ° C. (at 220 min).

  Using a gas chromatograph equipped with TCD (thermal conductivity detector, 3000A Micro GC: Agilent, Molecular Sieve-5A, Porapak U) and FID (hydrogen flame detector, GC353B: GL Sciences, DB-1, Squalane), The gas was analyzed before and after FT synthesis.

  The product definition and separation procedure is as follows. The gas passed through a wet gas meter 27 (W-NK-0.5: Shinagawa) and was collected in a gas collection bag 28. Since the thermal decomposition of the raw material biomass 13 was started (at 120 minutes), the collected gas was used as the product gas. The substance adsorbed on the activated carbon 20 was tar. The activated carbon 20 after the experiment was washed with anisole at room temperature for 30 minutes to obtain a tar anisole solution. Hydrocarbon compounds were collected as follows. After the experiment, the catalyst and the liquid in the liquid collection tube 25 were washed with dichloromethane. After filtration, the filtrate was allowed to stand and separated into an aqueous phase and an oil phase to obtain a hydrocarbon compound in dichloromethane.

The gas collected in the gas collection bag 28 was analyzed by a gas chromatograph GC equipped with TCD and FID. The carbon number of tar in the anisole solution was measured using the NPgram method. The hydrocarbon as a product was quantified as follows using an internal standard method. Naphthalene was added to the dichloromethane solution as a standard substance. The solution was analyzed by gas chromatograph GC equipped with FID.
The carbon number of the hydrocarbon having n carbon atoms was calculated as follows.
N (Cn) = A (Cn) / A (C ₁₀ H ₈ ) × N (C ₁₀ H ₈ )
Here, N (Cn): carbon number of CnH ₂ n + 2 in the dichloromethane solution. N (C ₁₀ H ₈ ): carbon number in C ₁₀ H ₈ in dichloromethane solution. A (Cn): Area of CnH ₂ n + 2. A (C ₁₀ H ₈ ): An area of C ₁₀ H ₈ .

  In addition, the code | symbols 12, 16, and 19 shown by FIG. 5 of Example 1 and FIG. 8 of Example 2 have all shown the thermocouple. Reference numeral 24 denotes a purge line in the liquid fuel production process. Although not specifically shown in these examples, it is possible to burn unreacted substances that are not gasified in the gasification section, and to supply the generated heat to the pressurized steam gasification section without waste. It is configured to do.

FIG. 9 shows the change with time of the gas after the high-temperature gas cleaning. FIG. 10 shows the change with time of the generated gas. During the experiment, there were no problems such as clogging due to tar trouble, high-pressure gasification, and subsequent high-temperature gas cleaning and FT synthesis could be continuously performed for 180 min (at 220 to 400 min). In FIG. 9, high concentration of CO ₂ (□ mark) was detected for 60 to 120 min by heating of dolomite as the tar decomposition catalyst. Subsequently, by thermal decomposition of the wood, while the _150~220min, CO _2, CO (.smallcircle), clear generation of _{H 2} (● mark) and CH ₄ (△ mark) was observed at 200 min, _{H 2 : 17.2mol%, CH 4: 24.1mol} %, CO: 7.9mol%, CO 2: 17.1mol% of the gas was obtained.

Thereafter, H ₂ and CO ₂ increased and CO and CH ₄ decreased due to steam gasification. 9 and 10, the composition of CO, H ₂ , CCO ₂ , and CH ₄ before FT synthesis (FIG. 9) after 250 minutes and those after synthesis (FIG. 10) were compared. The CO before FT synthesis was 6.9 to 12.3 mol%, and 0.7 to 2.4 mol% after FT synthesis. Therefore, the CO conversion rate in the FT synthesis step was approximately 87 to 97 mol% C-basis. Upon passing through the FT synthesis step, H ₂ decreased from about 33 to 1 mol%, CO ₂ increased from approximately 12 to 18 mol%, and CH ₄ increased from approximately 5 to 20 mol%. Further, the product gas contained hydrocarbons having 2 to 4 carbon atoms (x). These results indicate that CO was converted from C ₁ to C ₄ hydrocarbons.

  FIG. 11 shows a GC-FID chart of a dichloromethane solution to which naphthalene is added as a standard substance. The vertical axis represents voltage. A clear peak attributed to hydrocarbons having 8 to 29 carbon atoms could be obtained. This result shows that we have succeeded in producing hydrocarbons from woody biomass using the simple BTL process that we have proposed, without the equipment for pressurization and no reheating process.

Table 2 shows the distribution to each product on a carbon basis. From C ₈ to hydrocarbons _{C 29} were obtained by 0.03C-mol% yield. On the other hand, since the loss was -0.24 C-mol%, the input carbon was almost recovered. _{CH 4, CO, CO 2,} C 2 H 2, C 2 H 6, C 3 distribution to gases such as _{H 8} and _{n-C 4 H 10} was 64.54% in total. Approximately 58% conversion to CH ₄ and CO ₂ . This is presumed to be one of the causes of low hydrocarbon yield. Therefore, it is desirable to recycle part of the product gas to the gasification step.

  The distribution to char was 35.46%. Although char as a carbon source remained in the reactor, a sufficient amount of product gas could not be obtained after 400 min in order to keep the pressure in the reactor at 3 MPa. Therefore, in further examination, a plurality of high-pressure gasification steps are provided, and switching between them makes it possible to expect a longer operation time. It is also possible to use char as a heat source.

  In this example, high temperature gas cleaning was used. On the activated carbon after the reaction, 0.21% of the input carbon amount was adsorbed as tar. This indicates that the activated carbon has a tar removing ability in high-temperature gas cleaning. Gas cleaning without water is likely to reduce wastewater treatment costs as a result.

  The present invention relates to an apparatus for producing liquid fuel from biomass, that is, a highly efficient plant for producing liquid fuel from renewable biomass with high efficiency, but as long as the principle can be utilized, other fields such as It is applicable to the field of low-quality coal use, and the field of use is wide-ranging.

It is a block diagram of the liquid fuel manufacturing apparatus from biomass concerning a 1st embodiment. It is a block diagram of the liquid fuel manufacturing apparatus from biomass concerning a 2nd embodiment. It is a block diagram of the liquid fuel manufacturing apparatus from biomass concerning a 3rd embodiment. It is a block diagram of the liquid fuel manufacturing apparatus from biomass concerning a 4th embodiment. 1 is a block diagram of an apparatus for producing DME from biomass according to Embodiment 1. FIG. 2 is a time-dependent change in gas composition after passing through a catalyst layer according to Example 1. FIG. 2 is a time-dependent change in gas composition after passing through a catalyst layer according to Example 1. FIG. It is a block diagram of the hydrocarbon fuel manufacturing apparatus from the biomass which concerns on Example 2. FIG. 6 is a time-dependent change in the gas composition before the catalyst layer according to Example 2. FIG. 6 is a time-dependent change in the gas composition after the catalyst layer according to Example 2. FIG. It is a GC-FID chart figure of the dichloromethane solution which added naphthalene as a standard substance.

Explanation of symbols

1. Combustion furnace
2. Gasification department
3a, 3b. Catalyst compartment
4). Gas purification section
5. Liquid fuel production department
5a. Flow path
6). Gas-liquid separation unit
6a, 6b. Flow path
7). Vacuum recovery unit
7a. Pressure reducing valve
7b. Liquid fuel
8). Mounting base
9. Moving trolley

Claims (1)

A gasification part that holds a certain amount of woody biomass and heats it with a heating element, and gasifies in a pressure range of 1 to 5 MPa,
A gas purification unit for removing at least one substance selected from particulate matter, tar, sulfur compounds and nitrogen compounds from the biomass gas generated by the gasification unit, and purifying the biomass gas;
A liquid fuel production unit for producing a biomass liquid fuel stock solution that is a hydrocarbon by liquefying the purified biomass refined gas by Fischer-Tropsch synthesis using an alumina-supported ruthenium catalyst ;
A gas-liquid separator that separates the biomass liquid fuel stock solution into biomass liquid fuel, water, and light hydrocarbons;
A reduced pressure recovery unit that recovers the biomass liquid fuel separated by the gas-liquid separation unit by reducing the pressure;
Combusting unreacted material that is not gasified in the gasification unit, and supplying the generated heat to the gasification unit,
An apparatus for producing liquid fuel from biomass, characterized by not having a pressurizing device for keeping the pressure from gasification to liquefaction constant and pressurizing the biomass gas or the biomass refined gas.

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