JP2010031187A - Manufacturing method of liquid fuel capable of being easily transferred and stored by gasifying plant-based biomass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method capable of changing plant-based biomass into liquid fuel capable of being easily transferred and stored, and enabling residual heat and a byproduct generated in the process to be effectively used. <P>SOLUTION: The plant-based biomass is partly oxidized by oxygen-containing gas and is gasified at 700 to 820°C. Dimethyl ether or methanol is synthesized by using the obtained gas of a low sulfur content, and a water content of the plant-based biomass is adjusted by using heat generated in the reaction. The gas is separated from the product after the synthetic reaction, and the whole or a part of the gas is incinerated to give gas containing isolated oxygen of not less than 0.2% to not more than 2.5%, which is supplied to a greenhouse for vegetable cultivation. The moisture obtained by cooling the gasified product and/or the moisture separated from the product by the synthetic reaction is used as a part of a raw material for methane fermentation treatment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a fuel that can be transported and stored as a liquid, such as ethanol or dimethyl ether, after gasifying plant biomass such as waste fungus bed used for cultivation of trees, bamboo, grass, waste wood, and moss. The present invention relates to a method for efficiently producing wastewater and effectively utilizing residual heat and by-products generated in the process.

  As one method for suppressing global warming due to an increase in the concentration of carbon dioxide in the atmosphere, it has become an important issue to expand the use of plant biomass as an energy source instead of fossil fuels. There are various types of plant biomass such as trees, bamboo, and grass. These are organic substances mainly composed of carbon and hydrogen, which are formed by photosynthesis of plants using carbon dioxide in the atmosphere. When they are burned and used as energy, they generate carbon dioxide, which was originally generated using carbon dioxide in the atmosphere and again used for plant photosynthesis, so it is defined as carbon neutral. ing. The challenges in effectively using this plant biomass as an energy source are distributed compared to fossil fuels, so how to reduce the energy and cost required to collect and transport it, and Therefore, it is an important issue how to efficiently convert to an energy form that is easy for humans to use.

The method of directly burning and using biomass such as wood as an energy source such as a large boiler or a part thereof is effective under conditions where the generated heat can be effectively used continuously, such as a factory. In many places, because a large amount of generated residual heat cannot be used effectively, seawater for cooling is often wasted and thrown away. Therefore, in order to demonstrate the features of biomass energy, there is considered a method of gasifying biomass once and burning it in order to make efficient use of power generation and generated residual heat in a regionally distributed type, that is, in a small and medium scale. (Patent Document 1 etc.). However, the demand for electricity and generated residual heat generally fluctuates depending on the time of day and night, day of the week, and season. On the other hand, there is a problem that it is not easy to store electricity and heat economically. There are big restrictions. In order to solve this problem, in order to make the produced energy easy to transport and store, it can be treated as a liquid by gas synthesis and methanolization (Patent Document 2, etc.), dimethyl etherification (Patent Document 3, etc.). There is a way to do so. However, in the conventional methods, a large-scale plant is required to carry out these synthesis reactions from gases such as carbon monoxide and hydrogen obtained from fossil fuels. Therefore, a method of gasifying plant biomass and using the generated gas to convert it into an energy source that can be easily transferred and stored by gas synthesis has not been put into practical use.
JP 2008-81636 A Japanese Patent Laid-Open No. 2005-13239 Japanese Patent Laid-Open No. 10-182531

  The present invention converts plant-based biomass such as wood, bamboo, grass, wood waste, waste fungus bed used for cultivation of moss into liquid fuel that is easy to transport and store, and in the process The present invention relates to a method for effectively using generated heat and by-products.

  The first specific means for solving the problems of the present invention is to partially oxidize plant biomass with a gas containing oxygen and gasify it at 700 to 820 ° C., and use the obtained low sulfur content gas. The synthesis of dimethyl ether or methanol is to adjust the water content of the plant biomass raw material using the heat generated during the reaction.

The second specific means is that in 0005, all or a part of the gas obtained by separating the product after the synthesis reaction is combusted to reduce the free oxygen to 0.2% or more and 2.5% or less. Is to supply to the greenhouse for plant cultivation.

  The third specific means is that in 0005, water obtained by cooling the gasified product and / or water separated from the product of the synthesis reaction is used as a part of the raw material for the methane fermentation treatment. It is to be.

    By the method of 0005 to 0007, various plant biomass can be converted into an energy source that can be handled as a liquid that can be easily transported and stored, and the gasifier can be used without restriction of time of day, day of the week, and season. You can drive efficiently. In addition, residual heat and by-products generated in the process can be used effectively.

Examples of the fuel that can be transported and stored in a liquid state to be produced by gas synthesis in the present invention include methanol (CH ₃ OH) and dimethyl ether (DME; CH ₃ OCH ₃ ). Methanol is liquid at room temperature and is harmful when entering the human body, but if it is noted, it can be used effectively as a liquid fuel. On the other hand, dimethyl ether can be liquefied at room temperature at about 6 atmospheres or more, and can be transferred and stored as a liquid like propane. Furthermore, dimethyl ether is a harmless gas, as has been shown so far as a nebulizer gas. In addition, compared with liquid fuel, calorific value is about 60% when compared with liquid fuel, but since it is difficult to generate harmful gases during combustion, methods of using it as various fuels are being investigated. This is one of the important fuels in the future. On the other hand, bioethanol, which has recently been attracting attention as an effective liquid fuel, is not easy to produce by gas synthesis, so it is mainly produced by fermenting biomass such as corn. There is a risk of entanglement. On the other hand, methanol and dimethyl ether can be produced by gas synthesis from carbon monoxide, hydrogen gas, or the like, as shown in equations (1) and (2), respectively.
CO + 2H ₂ = CH ₃ OH (1)
_{3CO + 3H 2 = CH 3 OCH} 3 + CO 2 (2)
The gas containing carbon monoxide and hydrogen used as raw materials for this synthesis reaction has been considered to be mainly made from fossil fuels such as coal and petroleum. However, in order to take advantage of the characteristics of carbon neutral, biomass is used. It is desirable to use what was made from resources. For that purpose, it is necessary to make it compact so that it can also be used as a regional distributed facility.

  FIG. 1 shows an example of a process for producing a gas used for gas synthesis of the present invention using plant biomass. Examples of plant biomass raw materials to be used in the present invention include unused systems such as trees, bamboo, and grass, waste systems such as wood waste, and waste fungi beds used for cultivation of moss. These usually contain 30-70% moisture. Before putting them into a gasification furnace, they are made into chips or briquettes, and the size is processed to a length of, for example, 70 mm or less, a width of 70 mm or less, and a thickness of 10 mm or less. Before or after the processing, the moisture content is adjusted by heating and drying. The moisture brought into the gasifier along with the biomass raw material acts to increase the hydrogen gas concentration while adjusting the temperature of the gasifier downward, so in the present invention, the gasifier temperature and the hydrogen gas of the resulting gas It becomes one of the means for adjusting the content of carbon monoxide, and is adjusted to a value in the range of 10 to 45% depending on the degree of heating and drying. As the heat source for the heating and drying for the adjustment, the residual heat in the system, in particular, the residual heat (water vapor or high-temperature gas) used for temperature adjustment of the exothermic gas synthesis reaction targeted by the present invention is used. be able to. The biomass material is heated and dried after the chips are processed and the briquettes are processed.

In general, in order to gasify biomass materials such as wood, a fixed bed type, a circulating bed type, a jet type, or an internal heat and external heat rotary kiln type are used. Among them, the fixed bed type is particularly suitable for the present invention. Compared to the rotary kiln type, the fixed bed type has fewer moving parts. Compared to the circulating bed type and jet type, the raw material size is wider and it is easy to operate, and the concentration of carbon monoxide and hydrogen gas is wide. It is because it can adjust to. A fixed-bed gasifier supplies biomass raw material and oxidizing gas into a cylindrical tank and supplies biomass raw material (containing carbon, hydrogen and oxygen).
2C (in solid) + O ₂ = 2CO (3)
_{2CO + O 2 = 2CO 2 (} 4)
_{H 2 O + C = CO +} H 2 (5)
2H (in solids) = _H 2 (6)
_{2H 2 + O 2 = 2H 2} O (7)
C _m H _n (in solid) + O ₂
= C _p H _q (liquid or gas) + CO + H ₂ (8)
Gasification is performed by a reaction such as the above to generate a gas containing CO, H ₂ , CO ₂ , H ₂ O, CH _{4 and the} like, and at the same time, solid oxide ash is separated. In addition, when p in the formula (8) is 3 or more and q is 5 or more, a hydrocarbon that becomes tar (liquid at room temperature) is generated, which adversely affects stable operation. Therefore, it is a requirement for the gasifier to suppress tar generation as much as possible. Usually, as an oxidizing gas for gasification, air is preheated and blown in to partially burn. However, in that case, nitrogen contained in the air remains, and after cooling to remove moisture, for example, CO = 22 ± 2%, H ₂ = 20 ± 2%, CO ₂ = 8% CH ₄ = 1 to 4% and N ₂ = 46%.

  As described above, a gas containing nitrogen can also be used for the gas synthesis of the present invention. However, if the nitrogen gas content is high, the adverse effect is caused by dilution in the circulation use of unreacted gas after the gas synthesis reaction. The gas is preferably 20% or less, preferably 10% or less. For this purpose, an oxygen-based gas obtained by previously separating nitrogen gas from air is used. The oxygen-based gas may be one obtained by cryogenic separation from air, or one obtained by separating nitrogen from membrane separation or the like. As described above, the gas containing oxygen such as air or oxygen gas is used as the main oxidizing gas (heated by gasification), and the generation of tar described in 0011 is suppressed, and the ash is melted and fixed to stabilize the operation. In order to prevent adverse effects, the temperature in the furnace is adjusted to a range of 700 to 820 ° C., and in order to adjust the ratio of hydrogen gas / carbon monoxide in the produced gas to a predetermined value, the biomass raw material is dried. Adjust the amount of residual moisture, the amount of carbon dioxide, or the amount of water vapor depending on the conditions.

  As the carbon dioxide gas used for this, carbon dioxide produced outside may be used, and as described in 0015, a method such as membrane separation from the produced gas after cooling the produced gas to remove moisture The carbon dioxide gas removed by the step may be used. The amount of carbon dioxide is within the range of carbon dioxide / oxygen gas = 0.05 to 0.8 (volume ratio). Thus, for example, carbon monoxide = 36 ± 2%, hydrogen = 37 ± 2%, methane gas = 1 to 4%, carbon dioxide gas = 16 ± 2%, nitrogen = 8 ± 2% (cooled to remove moisture) Analyzed by condition).

  Of the obtained gas composition, hydrogen gas and carbon monoxide play an important role as reaction gases in the subsequent gas synthesis reaction, and therefore the ratio thereof must be adjusted according to the organic substance to be synthesized. The first method for increasing the ratio of hydrogen gas / carbon monoxide under the restriction of using oxygen gas as the main oxidant and adjusting the temperature in the gasification furnace is to supply water or water vapor as a sub-oxidant. Is to reduce the supply of carbon dioxide. This allows the hydrogen gas / carbon monoxide ratio to be adjusted up to an upper limit of 2.5.

  When the gas obtained by gasification is cooled, water is separated as a liquid. Since this liquid contains about 1% of organic matter, it is necessary to treat activated sludge or the like due to COD regulations when draining. The first of the countermeasures is a method of heating and steaming into the gasification furnace. As a result, the water vapor functions in the furnace in the same manner as the moisture contained in the biomass raw material to increase the adjustment of the temperature in the furnace and the amount of hydrogen gas generated. Moreover, the organic substance accompanying water is decomposed in the gasifier. However, it is necessary to enhance the drying of the raw material so as to reduce the amount of water brought in from the biomass raw material in response to the increase in the amount of water brought in by this. Moreover, the 2nd of the countermeasure is the method of processing the water containing organic substance as 1 part of the raw material of methane fermentation. If it is 10% or less of the total amount of the methane fermentation raw material, even if this liquid is used, the contained organic matter can be converted into methane gas and used without adversely affecting the methane fermentation.

  In the case where it is more advantageous for the later gas synthesis to remove the carbon dioxide gas from the gas that has been removed from the gas from the gasification furnace by cooling, a membrane separation method or the like may be used. Carbon dioxide is removed. The carbon dioxide gas thus separated can be effectively used in the gasification step as described in 0013.

  Gases containing carbon monoxide, hydrogen, and a small amount of methane gas produced from plant biomass raw materials by the method shown in 0011 to 0016 are synthesized by the process shown in FIG. Converted to possible fuel. The gas is first pressurized to a predetermined pressure and then introduced into a reaction vessel in which a catalyst for advancing a target reaction is present. The feature of the present invention is that the gas used for synthesis is produced by gasification of plant biomass, so that the sulfur content is low, and the gas synthesis reaction can be efficiently advanced without adversely affecting the catalyst.

Various catalysts can be used as the catalyst for the gas synthesis reaction depending on the organic substance to be produced. In the present invention, the catalyst is not limited. For example, when methanol is synthesized according to the reaction formula (1), copper oxide is used. -Zinc oxide, zinc oxide-chromium oxide, copper oxide-zinc oxide / chromium oxide, copper oxide-zinc oxide / alumina catalysts can be used. On the other hand, when synthesizing dimethyl ether,
CO + 2H ₂ = CH ₃ OH (1)
2CH ₃ OH = CH ₃ OCH ₃ + H ₂ O (9)
CO + H ₂ O = CO ₂ + H ₂ (10)
A series of reactions occur, and (1), (9), (10) are combined as a whole
_{3CO + 3H 2 = CH 3 OCH} 3 + CO 2 (2)
The reaction represented by The catalyst for the reaction of the formula (1) has been described above, but in order to cause the reaction represented by the formula (9), an acid-base catalyst, alpha alumina, silica-alumina, zeolite, zeolite metal oxide; Alkali and alkaline earth oxides can be used. Further, in order to cause the reaction of (10), a catalyst for the reaction of the formula (1) can also be used. These reactions can be carried out separately by arranging the respective catalysts in separate reaction tanks, but by arranging these catalysts together in the same reaction tank, the reaction of the formula (2) can be advanced. Is possible. The degree of progress of each reaction is determined by the degree of contact between the reaction gas and the catalyst and the reaction rate in the contact state. As a method for installing the catalyst, there are a fixed bed type which is simple in terms of equipment, a slurry bed using a medium oil having a high degree of contact between the reaction gas and the catalyst, and the like.

  In order to advance the target gas synthesis reaction represented by the formulas (1) and (2) to the right, the lower the pressure and the lower the temperature, the better. However, in terms of speed, the higher the pressure and the higher the temperature, the more advantageous. The temperature and pressure are selected according to this balance, but the pressure is selected within the range of 10 to 70 atm and the temperature within the range of 250 to 350 ° C. Since the reaction represented by the formula (1) is exothermic, a pipe is inserted into the synthesis reaction tank and indirectly cooled with water or air to take out the heat, so that the temperature of the reaction tank is set to 230 to, for example, Adjust to the range of 280 ° C. The first method of using the extracted heat is to use it for heating, drying, etc. of the plant biomass before charging it into the gasification furnace. Moreover, the 2nd of the utilization method is using it for the temperature control, especially heating, when the greenhouse for plant cultivation is installed in proximity. In summer, heat can also be used for cooling by introducing an absorption cooling device.

  The mixture containing the product after passing through the reaction tank containing the catalyst is separated and recovered by the operation such as changing the temperature and pressure. If the separated unreacted gas is as high as 20% or more of the supplied gas, for example, carbon dioxide gas is removed if necessary, and then used after circulation. On the other hand, when the ratio of the unreacted gas is as low as, for example, less than 20% of the supplied gas, it is possible to burn the gas as a gas using the boiler and use the heat.

  When the object of synthesis is methanol, the mixture after the reaction is separated from the gas as a liquid mixture of methanol and water by lowering the temperature, and then the liquid is reheated to 64 ° C. or more, and the methanol is distilled. Separate from water. Since the obtained methanol is a liquid at normal temperature and normal pressure, it can be transported and stored as a liquid. The first method for using the gas separated from the product is to circulate it in the reaction vessel.

The second method of use is to circulate the remaining part to be purged when air is not used, or even when one part is used for circulation, and burn it by adding air to exhaust the exhaust gas to the outside air. is there. Since the gas after the reaction has a low calorific value, the waste gas after combustion has a low content of nitrogen oxides (NO _X ), and the sulfur content (SO _X ) is originally contained in the plant biomass raw material instead of fossil fuel. Is low, so sulfur oxides are also low. Therefore, there is an advantage that the exhaust gas treatment can be simplified.

The third method of utilization is to use this combustion exhaust gas for carbon dioxide enrichment in greenhouse cultivation. In order to use it for carbon dioxide enrichment in a greenhouse, it is necessary that the nitrogen oxide and sulfur oxide concentrations in the gas be low (for example, 50 ppm or less). In order to satisfy this, what has a low calorific value, such as the reaction residual gas of the present invention, may be burned (oxidized) at a free oxygen gas content of 0.2% to 2.5%. If the free oxygen gas is less than 0.2%, CO remains, whereas if it exceeds 2.5%, NO _X tends to increase, such being undesirable. By supplying this gas before sunrise, particularly in the morning, so that the CO ₂ concentration in the greenhouse is 1000 to 1400 ppm, growth promotion and yield increase (about 20%) can be obtained. The carbon dioxide concentration in the greenhouse space is continuously measured by the infrared absorption method, and the gas supply amount is automatically adjusted to the optimum state.

  When the synthesis target is dimethyl ether, hydrogen gas / carbon monoxide = 0.8 to 1.2 (volume ratio) and nitrogen gas = 20% or less obtained by gasifying plant biomass Use. These are necessary conditions for increasing the gas reaction efficiency in the synthesis. After cooling the gas to remove moisture and further removing carbon dioxide, the gas was pressurized within a range of 7 to 50 atm, and the temperature was adjusted to a range of 200 to 270 ° C. and dimethyl ether in the presence of a catalyst. Is synthesized. The mixture after the reaction contains methanol, water, carbon dioxide, unreacted carbon monoxide, hydrogen gas and the like in addition to dimethyl ether. In order to separate this, carbon dioxide is separated by membrane separation or the like (which can be used for the gasification step as described in 0013), and then cooled and mixed with a mixture of dimethyl ether, water and ethanol, The reaction gas is separated into the main gas phase, and the unreacted gas is recycled. The mixture of methyl ether, water, and ethanol can be supplied in a liquid state as a mixture depending on the conditions of the user, or it can be divided into dimethyl ether and ethanol after the temperature and pressure are adjusted and separated. Is possible. In any case, those mainly composed of dimethyl ether can be easily liquefied if pressurized to 6 atm or more at room temperature, and can be transported and stored as a liquid. When it is desired to make the apparatus compact, the product gas is cooled, and dimethyl ether is recovered as a main liquid and is divided into a gaseous form and the gaseous form is heated as described in 0022 and 0023. As a carbon dioxide gas source with low nitrogen oxides and sulfur oxides, and the liquid component in that state is transported to a place with a purification and separation device to be intensively processed. It is also possible to take.

  A special method taken to make the gas synthesis tank containing the catalyst compact or increase the gas reaction efficiency is to generate and activate static electricity in the synthesis gas. In oil-related equipment, measures are generally taken not to generate static electricity. This is because there is a fear of ignition when a spark is generated by static electricity and the oil or gas generated therefrom coexists with air. On the other hand, since no oxygen gas is present in the gas synthesis reaction tank of the present invention, there is no fear of combustion due to ignition. On the contrary, it is possible to activate the gas by the effect of static electricity and promote the reaction of the formulas (1) and (2) in the presence of the catalyst. This makes it possible to reduce the gas reaction efficiency even if the gas synthesis tank containing the catalyst is made compact compared to the case where this is not used, or to increase the gas synthesis reaction efficiency if the gas synthesis tank containing the catalyst is the same. It becomes possible. In order to apply static electricity to the synthesis gas, for example, there is a method of rubbing the pressurized reaction vessel from the outside. In this case, in order to prevent the risk of ignition, it is desirable that the metal part of the container that gives the friction is insulated from the other metal parts of the apparatus.

  The present invention is a method for converting plant-based biomass such as trees, bamboo, and grass into liquid fuel that can be easily transferred and stored, and has high availability and high efficiency regardless of the surrounding conditions of the installation location of the equipment. Can perform operations. In addition, if the supply status of plant-based biomass, which is a raw material, changes by making the device compact, the entire apparatus of the present invention is moved to another location, including the collection and transportation of plant-based biomass raw materials. An optimal form can be adopted.

  Methanol was synthesized using a gas obtained by gasification using oxygen gas containing about 3% of nitrogen produced by separating nitrogen from air as a gas containing oxygen using plant biomass as a raw material. The gasification furnace is a 1 MW scale fixed-bed type from Pudas Energia, Finland, and the plant-based biomass feedstock is a mixture of 80% wood chips and 20% bamboo chips. The raw material chip contained 40 to 50% of moisture, but this was dried by using heated air of 120 to 140 ° C. utilizing the residual heat extracted from the methanol synthesis tank, so that the moisture content was 20 -25%. The chip was supplied to the gasifier at about 400 kg / h. As a gas supplied to the gasifier, a mixed gas in which oxygen gas / carbon dioxide gas = 10 is obtained by adding 1 part of carbon dioxide gas separated from the product gas described later to oxygen gas containing about 3% of nitrogen, Combined with preheated to 150 ° C, water separated by cooling the product gas described later, and water separated from the product after methanol synthesis into water vapor with preheat in the system Using. The gas temperature in the gasification furnace was continuously measured, and the amount of steam blown was adjusted so that the value was in the range of 740 to 760 ° C. The gas obtained by gasification was cooled to 80 ° C. or less when it was discharged from the gasification furnace. This separated the moisture from the gas. This moisture contained about 1% organic acid. This moisture treatment method is as described above. The components of the gas after moisture removal are carbon monoxide = 26 ± 2%, hydrogen = 50 ± 2%, methane gas = 1-3%, carbon dioxide = 16 ± 2%, nitrogen = 6 ± 2%, sulfur content <20 ppm. In addition, about 1.5 to 2.0% of the ash content remaining by gasification was obtained from the supplied biomass raw material weight, but this was used as a soil conditioner. About 90% of carbon dioxide was separated from this gas by membrane separation, and a part of the separated carbon dioxide was circulated and used for gasification as described above. The synthesis gas was pressurized to 20 atmospheres, and a copper oxide-zinc oxide catalyst was introduced into a fixed bed type 8.5 m high reaction layer to perform a methanol synthesis reaction. The reaction rate after one pass of gas was about 75%. The gas mixture after the reaction was cooled to about 50 ° C. and separated into a liquid containing ethanol and water and a gas. The liquid portion was heated again to about 80 ° C., the methanol portion was distilled, and the remaining water was steamed with residual heat in the system as described above, and was blown into the gasification furnace. The produced methanol was transported by tank car and used as energy for private power generation. Note that about 80% of the separated gas was mixed with the synthesis gas and recycled. The remaining 20% was purged and used as a heat source for the boiler, and was discharged with 1.2% free oxygen.

The plant-based biomass raw material is about 80% of wood chips and about 20% of the waste fungi bed used for shiitake cultivation in briquettes. The gasification method and the gas composition obtained are almost the same as described in 0027. This gas was reacted in two stages of the reaction tanks described in 0027 to synthesize methanol, and the gas reaction rate after one-time passage of gas was 85%. The temperature of the methanol synthesis tank was adjusted by passing water through the pipe, and the air was indirectly heated using the obtained hot water, which was used for heating and drying the biomass material supplied to gasification. Purification of methanol from the resulting reaction is the same as described in 0027. The gas separated from the reaction mixture is burned in a boiler so that the free oxygen gas is about 0.9% to obtain hot water, and this hot water is supplied to the adjacent greenhouse for greenhouse cultivation from November to March. And used for heating. Further, the waste gas (CO ₂ ; about 35%, NO _x ; 35 ppm) was supplied to the leafy vegetable cultivation greenhouse from dawn until 14:00, and the indoor carbon dioxide concentration was adjusted to about 1100 ppm. This increased the yield by about 20%.

Wood biomass made from thinned wood into chips (about 12t / day; moisture content 30)
~ 50%) Partially combusted with preheated air in a fixed bed gasification furnace (Pudus, Finland), gasified in the furnace at a temperature of 720-750 ° C, once up to 70 ° C After cooling and coagulating and separating water, CO = 22 ± 3%, H ₂ = 20 ± 3%, CH ₃ = 1 to 3%, CO ₂ = 8 to 10%, and the remaining N ₂ gas were obtained. . This gas is supplied to a slurry bed (catalyst fine powder + medium oil) type dimethyl ether synthesizer and passed through two tanks having a reaction temperature of 250 to 270 ° C., a pressure of about 40 atm, a diameter of 2 m, and a height of 5 m. About 90% of the feed gas CO, H ₂ was converted to demethyl ether. Air was supplied into the demethyl ether synthesis tank through a pipe to remove generated heat, and the temperature was adjusted to be within the above range. This heated air was used to preheat and dry the chips supplied to the gasifier. Thereby, the moisture content of the chip | tip supplied to a gasification furnace was able to be adjusted in the range of 15-25%. Demethyl ether (purity 96%) separated as a liquid out of the produced mixture that came out of the reaction vessel was put in a pressurized container under a pressure of 7 atm and transported to a customer by a truck. What was separated as gas was burned in a boiler to produce hot water, and waste gas (free oxygen 1.0-1.6%) was diffused.

  Dimethyl ether was produced using plant biomass as a raw material and gas obtained in a gasifier. The gasifier and plant biomass feedstock are the same as described in 0027. The raw material chip contained 40 to 50% of moisture, but this was dried using air at 120 to 140 ° C. utilizing residual heat in the system to make the moisture content 10 to 25%. The chip was supplied to the gasifier at about 400 kg / h. The gas supplied to the gasification furnace is oxygen gas containing about 3% of nitrogen obtained by separating nitrogen gas from air by membrane separation. Carbon dioxide gas separated from the product gas, which will be described later, is added to this oxygen gas, and a mixed gas in which oxygen gas / carbon dioxide gas = 3 is preheated to about 180 ° C. using preheat in the system, and is supplied to the gasifier. Supplied. Further, water that was separated by cooling the product gas, which will be described later, was steamed with residual heat in the system and was blown into the gasification furnace. The gas temperature in the gasifier was continuously measured, and the amount of steam blown was adjusted so that the value was in the range of 730 to 760 ° C. The gas obtained by gasification was indirectly cooled with water outside the gasification furnace to 80 ° C. or less. This separated the moisture from the gas. This moisture contained about 1% organic acid. This moisture treatment method is as described above. The components of the gas after moisture removal were carbon monoxide = 36 ± 2%, hydrogen = 37 ± 2%, methane gas = 1 to 4%, carbon dioxide gas = 16 ± 2%, nitrogen = 8 ± 2%. . About 90% of the carbon dioxide gas was separated by membrane separation and circulated and used in the gasification furnace as described above. In addition, about 1.5 to 2.0% of the ash content remaining by gasification was obtained from the supplied biomass raw material weight, but this was used as a soil conditioner. The gas for synthesis is pressurized to about 32 atm, and a powder mixture of a copper oxide-zinc oxide / chromium oxide catalyst and a catalyst containing alpha alumina, silica-alumina, zeolite is mixed with a medium oil composed of fatty acids. The synthesis reaction into dimethyl ether was carried out through the slurry layer dispersed in. Indirect cooling with water was performed at a temperature of 180 to 220 ° C. and a pressure of about 32 atm. The height of the reaction tank (one) was 9.2 m, and the reaction rate after one pass was about 75%. The mixture after the synthesis reaction is first cooled to 150 ° C., the catalyst medium oil is liquefied and returned to the reaction tank, and then cooled to −30 ° C. to dimethyl ether, about 2% water and about 8%. The liquid containing methanol was separated into solid and gas. As for the liquid-solid content, the temperature was raised to room temperature, dimethyl ether was distilled and separated, and it was liquefied by pressurizing to 6.5 atm. . Ethanol containing water was distilled at 70 ° C. to separate ethanol, and water was steamed with residual heat in the system as described above and was blown into the gasifier. About 80% of the separated gas was recycled for the synthesis reaction. The remaining 20% was burned in a boiler and used for heat, and then the waste gas was released into the atmosphere.

  Dimethyl ether was produced using plant biomass as a raw material and gas obtained in a gasifier. The process from gasification to synthesis of dimethyl ether is almost the same as 0030. The mixed gas after the synthesis reaction is first cooled to 150 ° C., the catalyst medium oil is liquefied, returned to the reaction tank, cooled to −30 ° C., converted to dimethyl ether, about 2% water and about 8%. Separated into liquid-solid and gas containing 1% methanol. Separation into liquid-solid and gas containing about 2% water and about 8% methanol in dimethyl ether. Those containing liquid dimethyl ether, water, and methanol were made liquid at room temperature and 7 atm, packed in a tank, transported, and used as fuel for diesel-type private power generation devices. Gas is used as fuel for boilers, and exhaust gas is adjusted to 0.8 to 1.4% free oxygen gas, so that both nitrogen oxides and sulfur oxides are 30 ppm or less. The greenhouse was supplied so that the carbon dioxide concentration was about 1200 ppm from sunrise to sunset. The cultivation amount of leafy vegetables increased by about 25%.

  In Example 4, after pressurizing the synthesis gas obtained by separating water and carbon dioxide gas from the gas emitted from the gasification furnace, a rotating brush is placed outside the 2.3 m long steel container up to the portion where the catalyst exists. To generate static electricity. As a result, the reaction rate of the synthesis gas could be increased by about 7%.

An example of the manufacturing process of the gas used for the gas synthesis of this invention is shown. An example of the gas synthesis process of the present invention is shown.

Claims (3)

  Plant biomass is partially oxidized with oxygen-containing gas and gasified at 700-820 ° C., and the resulting low-sulfur gas is used to synthesize dimethyl ether or methanol, using the heat generated during the reaction. A method for producing a liquid fuel that is easy to transport and store by gasifying plant biomass, wherein the plant biomass material is heated and dried to adjust the water content.   In Claim 1, the gas obtained by purifying and separating the product after the synthesis reaction is burnt all or a part of the gas, and the free oxygen is 0.2% or more and 2.5% or less. A method for producing liquid fuel that is easy to transport and store by gasifying plant biomass, characterized in that it is supplied to a greenhouse for plant cultivation. The moisture obtained by cooling the gasified product according to claim 1 and / or the moisture separated from the product of the synthesis reaction is used as a part of the raw material for the methane fermentation treatment. A method for producing liquid fuel that is easy to transport and store by gasifying plant biomass.

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