JP5032101B2 - Tar gasification catalyst for reforming and gasifying pyrolytic tar of carbonaceous raw material, tar gasification method, method for using tar gasification gas, and method for regenerating tar gasification catalyst - Google Patents

Description

  The present invention relates to a catalyst for reforming tar generated when pyrolyzing a carbonaceous raw material into a gas mainly composed of hydrogen, carbon monoxide and methane, a tar gasification method using the catalyst, and The present invention relates to a method for using a tar gasification gas generated by tar gasification and a regeneration method when a tar gasification catalyst is deteriorated.

  Due to the global warming problem in recent years, the use of biomass, which is one of carbonaceous raw materials, has attracted attention as an effective means of reducing carbon dioxide emissions, and research on high-efficiency energy conversion of biomass has been conducted in various places. In addition, from the viewpoint of securing energy resources in recent years, research on effective utilization of coal, which has been vigorously performed in the past, has been reviewed for practical use.

  For example, as described in Patent Document 1, a waste processing method and a pyrolysis gas recovery method and apparatus have been proposed. In order to gasify the tar in the pyrolysis gas, the apparatus needs to partially burn part of the pyrolysis gas generated in the pyrolysis furnace so as to have a high temperature of 1000 ° C. or higher. Therefore, there is a problem that the calorific value of the obtained gas is low and the gas energy recovery rate is also low. Furthermore, in order to increase the pyrolysis gas to 1000 ° C or higher, a heat-resistant structure of the reforming furnace and an oxygen generator required to increase gas calories due to oxygen enrichment during partial combustion are required. It becomes expensive.

Therefore, as a means for gasifying tar in a low temperature range of 500 to 800 ° C. without partial combustion, a catalyst has attracted attention and has been developed. For example, dolomite described in Non-Patent Document 1, or a catalyst in which cerium oxide is supported on the surface of silica as described in Patent Document 2, and rhodium is supported as a catalytically active metal (Rh / CeO). ₂ / SiO ₂₎ has been proposed. Patent Document 3 proposes a catalyst (Ru / CeO ₂ / Al ₂ O ₃ ) in which ruthenium and cerium oxide are supported on a carrier as a steam reforming catalyst for light naphtha. Further, Patent Document 4 proposes a catalyst in which rhodium is supported on alumina as a gasification catalyst for a light petroleum fraction. However, since rhodium, which is a noble metal, is expensive, the catalyst manufacturing cost itself becomes expensive when 5 mass% as shown in Patent Document 4 is supported. Further, rhodium and ruthenium exhibit catalytic activity specifically among noble metals, but there is a problem that tar gasification activity from a relatively low temperature is low as compared with transition metals such as nickel.

  On the other hand, although a nickel-based industrial catalyst for steam reforming is proposed in Non-Patent Document 2 as a catalyst for gasifying tar generated during coal dry distillation, it is necessary to sufficiently reduce it in a reducing atmosphere before the gasification reaction. In addition, when an oxidizing gas such as air or oxygen is introduced from the outside during the gasification reaction, there is a problem that sufficient activity cannot be obtained because the catalytically active nickel is oxidized.

JP-A-11-290810 JP 2003-246990 JP 56-81392 A JP 50-126005 A Ind.Eng.Chem.Res., Vol.36, p.3800 (1997) Energy & Fuels, Vol.13, p.702 (1999)

  The present invention relates to a tar gasification reaction in which tar generated during pyrolysis of a carbonaceous raw material is gasified by catalytic cracking with a catalyst, exhibits high activity at a relatively low reaction temperature, is relatively inexpensive, and is pre-reaction. It is an object of the present invention to provide a catalyst that does not require the reduction treatment and a tar gasification method using the catalyst.

  In addition, during the gasification reaction using this catalyst, oxygen or air is introduced into the oxidizing atmosphere together with the pyrolysis gas, thereby removing the precipitated carbon and adsorbed sulfur on the catalyst, and stable operation with little performance degradation. An object of the present invention is to provide a method for regenerating a tar gasification catalyst.

  Furthermore, the tar gasification gas obtained by tar gasification using this catalyst is used as a fuel for gas engines, gas turbines, and fuel cells, and a method for using tar gasification gas that uses power or generates electricity efficiently is provided. Objective.

The present inventors have found that the elements constituting the catalyst was examined intensively by focusing on the composition, the silica, on at least one carrier of alumina, oxides and cerium nickel as the catalyst active species, zirconium, titanium, When a carbonaceous raw material is pyrolyzed by supporting a catalyst containing one or more oxides of magnesium and further using a tar gasification catalyst prepared by supporting a small amount of a platinum group compound. Highly active from a relatively low temperature range for the tar gasification reaction by catalytically cracking the generated gaseous tar and reforming the tar into a gas mainly composed of hydrogen, carbon monoxide and methane Moreover, in addition to eliminating the need for reduction before the reaction, the deposited carbon and adsorbed sulfur on the catalyst can be reduced by contacting the mixed gas into which oxygen or air is introduced together with the pyrolysis gas during the reaction. A long period of time less can of performance degradation control has been found that it is possible to stable operation. Moreover, if this catalyst was utilized, it discovered that the gas mainly consisting of hydrogen, carbon monoxide, and methane obtained there could be utilized for a motive power or power generation equipment, and came to this invention.

  The characteristics are shown below.

(1) oxides of nickel, and cerium, comprising carrying zirconium, titanium, one or two or more oxides of magnesium, as well as platinum group compounds, silica, on at least one carrier of alumina Tarugasu The ratio of the total amount of metal components in the nickel oxide to the total catalyst is 1 to 40% by mass, and one or two of cerium, zirconium, titanium, and magnesium The ratio of the total amount of the oxides to the entire catalyst is 1 to 50% by mass, and the ratio of the total amount of the platinum group element components in the platinum group compound to the total catalyst is 0.01 to 1% by mass. A tar gasification catalyst for reforming and gasifying a pyrolytic tar of a carbonaceous raw material.

  (2) The tar gasification catalyst according to (1), wherein the platinum group element in the platinum group compound is at least one element selected from platinum, ruthenium, palladium, and rhodium.

( 3 ) A method for producing the catalyst according to (1) or (2) , wherein at least one of silica and alumina is supported on one or more of cerium, zirconium, titanium and magnesium compounds. after impregnation solution and dried and calcined, then after impregnated with a solution of a compound of nickel to those performed drying and firing, followed by drying and firing, platinum and further was followed by drying and baking A method for producing a catalyst for tar gasification, which comprises drying and calcination after impregnation with a group compound solution.

(4) (1) or a method for producing a catalyst according to (2), silica, on at least one carrier of alumina, a compound of nickel, and cerium, zirconium, titanium, of the magnesium compound Tar gasification characterized by impregnating a mixed solution of one or two or more compounds, drying and firing, and then impregnating the dried and fired platinum group compound solution, followed by drying and firing. For producing a catalyst for use.

( 5 ) To the catalyst described in (1) or (2) , air or oxygen is added to the pyrolysis gas containing tar generated when the carbonaceous raw material is pyrolyzed, or to the pyrolysis gas containing the tar. A tar gasification method for reforming and gasifying tar by bringing a mixed gas into contact therewith.

( 6 ) The tar gasification method according to ( 5 ), wherein the temperature at which the pyrolysis gas or mixed gas is brought into contact with the catalyst is 400 to 1000 ° C.

( 7 ) The tar gasification method according to ( 5 ) or ( 6 ), wherein an externally heated rotary kiln is used for the thermal decomposition of the carbonaceous raw material.

( 8 ) The solid carbide generated together with the pyrolysis gas when the carbonaceous raw material is pyrolyzed is partially oxidized into a combustible gas, and the combustible gas is burned to be used as a heat source for the externally heated rotary kiln. The tar gasification method according to any one of ( 5 ) to ( 7 ), wherein

( 9 ) A tar gasification gas comprising a tar reforming gas and a pyrolysis gas produced by the tar gasification method according to any one of ( 5 ) to ( 8 ) is used as a fuel for a gas engine, a gas turbine, or a fuel cell. A method for using tar gasification gas, characterized in that it is used as:

( 10 ) When the catalyst is deteriorated in performance by carbon deposition or sulfur poisoning by the tar gasification method according to any one of ( 5 ) to ( 8 ), the catalyst has at least one of water vapor and air. A method for regenerating a catalyst for tar gasification, which comprises contacting the catalyst.

  According to the present invention, the carbonaceous raw material is thermally decomposed tar at a relatively low temperature with high efficiency and gasified, has high catalytic activity, is inexpensive, does not require reduction, and is used for a long time. Can be produced, and the catalyst is brought into contact with a pyrolysis gas containing tar or a mixed gas obtained by adding pyrolysis gas and air or oxygen to the catalyst, and mainly contains hydrogen, carbon monoxide, and methane. It can be reformed to gas. Further, after the gas mainly composed of hydrogen, carbon monoxide, and methane is purified, it can be used for power or power generation equipment.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

Tarugasu of catalyst of the present invention, an oxide of nickel, cerium, zirconium, titanium, one or two or more oxides of magnesium, silica, supported on at least one carrier of alumina, further A tar gasification catalyst comprising supporting a platinum group compound , wherein a ratio of the total amount of metal components in the nickel oxide to the entire catalyst is 1 to 40% by mass, and the cerium, zirconium, The ratio of the total amount of one or more oxides of titanium and magnesium to the entire catalyst is 1 to 50% by mass, and the total amount of the platinum group element component in the platinum group compound is the entire catalyst The ratio to 0.01 is 0.01-1 mass% .

Under the reaction atmosphere, some or all of the platinum group compounds are in a metallic state, causing a spillover phenomenon. Even in an oxidizing atmosphere, the main active component elements are maintained in a reduced state from a relatively low temperature range, thereby providing a catalytic function. the acts of cocatalyst to sufficiently exhibited, therefore some or all of the oxides of nickel is to function as a main active ingredient a metallic state, cerium, zirconium, titanium, of magnesium One or more oxides have the function of occluding and releasing oxygen or the function of adsorbing oxygen species such as carbon dioxide on the surface of the oxide, thereby preventing hydrocarbons from depositing on the main active component elements. Therefore, it is considered that the catalyst surface can be kept clean and the catalyst performance can be stably maintained for a long period of time in order to exhibit the role of oxidizing and removing as carbon monoxide. Further, it is considered that at least one of the supports of silica and alumina has a high strength and a large surface area, and serves to provide a reaction field that allows the reaction to proceed efficiently.

  The carbonaceous raw material here is a raw material containing carbon that is pyrolyzed to produce tar, and refers to a wide range of materials that contain carbon as a constituent element such as coal and waste. Remaining wood, thinned wood, unused wood, wood leftover, construction waste, woody waste such as rice straw, or secondary products such as wood chips and pellets made from them, and reusable as recycled paper This refers to papermaking waste such as waste paper, containers and packaging, agricultural residues, food waste such as potatoes, and activated sludge.

  Further, tar generated when pyrolyzing a carbonaceous raw material is different in properties depending on the raw material to be pyrolyzed, but is an organic compound that is liquid at room temperature containing 5 or more carbons, and is a chain hydrocarbon, This refers to either cyclic hydrocarbons or a mixture of them, and in the case of coal pyrolysis, condensed polycyclic aromatics such as naphthalene, phenanthrene, pyrene, anthracene, etc. are the main components. If present, in addition to oxygen-containing compounds such as cellulose and lignin, hetero compounds containing hetero atoms such as nitrogen in the compound are also included. Pyrolysis tar exists in a gaseous state immediately after pyrolysis.

  In addition, the tar gasification reaction, in which tar is gasified by catalytic cracking, has a complicated reaction path and is not always clear. However, a steam reforming reaction or hydrogen that can occur with hydrogen or steam present in the pyrolysis gas is not always clear. Refers to chemical reaction and shift reaction.

In the reforming catalyst of the present invention, is a main active ingredient nickel is primarily oxides, hydroxides otherwise, nitrates, halides carbonate, including the sulfates, chlorides and mixtures thereof Also good. A part or all of this main active component is reduced to a metal state by a spillover phenomenon of a platinum group compound added in a small amount as a promoter component in a reducing atmosphere in a pyrolysis gas in a state heated to a constant temperature. Thus, it is considered that the catalytic function is exhibited from a relatively low temperature range without the reduction treatment before the reaction.

Further, the catalyst of the present invention, the ratio of the total amount of the metal component of the nickel to the entire catalyst Ru 1-40% by mass of oxides of nickel which is the main active ingredient.

Here, when the total amount of the metal component of the main active ingredient is less than 1 wt%, the catalytic activity is not a sufficient. In addition, when the total amount of the main active component metal components exceeds 40% by mass, the ratio of oxides such as cerium added as a co-catalyst and a carrier such as alumina that provides a reaction field is reduced. sufficiently exhibited by such have.

Furthermore, the catalyst of the present invention, cerium added as a co-catalyst, zirconium, titanium, the proportion of the total amount of one or two or more oxides to the total catalyst of magnesium Ru 1-50% by mass.

However, each oxide may partially include hydroxide, nitrate, carbonate, sulfate, chloride, or a mixture thereof. Here, when the total amount of the oxide is less than 1 mass%, the function of the oxidation removal of carbon components deposited on utilizing oxygen storage or release functions of the oxide catalyst is not a sufficient. Also, if the total amount of the oxide is more than 50 wt% is a main active ingredient for the supported amount of a compound of nickel is low, the catalytic activity is not sufficient.

In addition, the catalyst of the present invention, the content of platinum group elements in the platinum group compound added as co-catalyst, Ru 0.01% by mass relative to the total catalyst. When the content of the platinum group element is less than 0.01 wt% Here, hardly causes spillover phenomenon of platinum group elements without main active ingredient is sufficiently reduced to metallic state, the catalyst function is not such to exhibit. Further, if the content of platinum group elements exceeds 1 wt%, the effect is due to continue to saturate, the economic aspects at most 1 mass%.

  Further, in addition to the above elements, inevitable impurities that are mixed in the catalyst manufacturing process or the like may be included, but it is desirable that impurities are not mixed as much as possible.

  The carrier used in the catalyst of the present invention is selected from porous oxides of silica and alumina, and can be used as a molded body such as powder, sphere, tablet or ring.

Next, as a method for producing the catalyst of the present invention, at least one of silica and alumina supports is impregnated with a solution of one or more compounds of cerium, zirconium, titanium, and magnesium compounds, and then dried and calcined. was carried out, then, after impregnated with a solution of a compound of nickel in those was dried and calcined, after drying and calcination, a more platinum group compound solution impregnation, or by carrying out the drying and firing.

Or silica, on at least one carrier of alumina, after impregnation compound and cerium nickel, zirconium, titanium, a mixed solution of one or more compounds of the magnesium compound, followed by drying and firing, then It can be produced by impregnating the platinum group compound solution, followed by drying and baking.

  The impregnation method referred to here is a state in which a solution of a metal compound to be supported on the support surface in water or an organic solvent having a volume smaller than the pore volume of the support is dropped on the support surface and the support surface is uniformly wetted. In addition, after leaving the solution in an excess state, the wet wet method in which water or the organic solvent is evaporated, or after immersing the carrier in the solution of the metal compound to be supported, the solvent is evaporated with stirring. There is an evaporation to dryness method in which a metal compound is attached to the surface of a carrier.

  Here, the catalyst of the present invention may be in the form of a powder or a molded body. In the case of a molded body, a spherical or cylindrical shape, a ring shape, a wheel shape, a granular shape, etc. Any of the materials coated with a catalyst component may be used.

  Next, as a method for tar gasification using the catalyst of the present invention, the catalyst of the present invention is brought into contact with a pyrolysis gas containing tar produced in the pyrolysis step or a mixed gas obtained by adding air or oxygen to the pyrolysis gas. In other words, reforming to a gas mainly composed of hydrogen, carbon monoxide, and methane.

  The reaction temperature is preferably 400 to 1000 ° C. A reaction temperature of less than 400 ° C. is not preferable because the catalytic activity is not sufficient when the tar is reformed to a gas mainly composed of hydrogen, carbon monoxide, and methane. On the other hand, when the reaction temperature exceeds 1000 ° C., the reformer becomes expensive because, for example, a heat-resistant structure is required, which is economically disadvantageous. Furthermore, as a reaction format used here, various things, such as a fixed bed, a fluidized bed, and a spouted bed, can be used.

  Furthermore, it is preferable to use an externally heated rotary kiln when the carbonaceous raw material is pyrolyzed in the present invention. Compared with internal heating furnaces, externally heated rotary kilns do not burn combustible gas in the furnace, so the combustion gas does not mix with pyrolysis gas, and the pyrolysis gas has a high It can hold calories and is highly advantageous in terms of heat efficiency.

  In addition, solid carbide generated together with the pyrolysis gas when pyrolyzing the carbonaceous raw material is partially oxidized into a combustible gas, and this combustible gas is burned and used as a heat source for the external heat rotary kiln. Further, it is preferable because the thermal efficiency becomes higher.

  In addition, in the present invention, it is preferable to use a tar gasification gas obtained by reforming a pyrolysis gas containing tar as a fuel for a gas engine, a gas turbine, or a fuel cell. Since the tar gasification gas has a high hydrogen concentration and is suitable as a raw material gas for a fuel cell, it can be used effectively. In particular, since tar gasification gas has a high sensible heat of several hundred degrees Celsius, the generated tar gasification gas is introduced into a gas engine or gas turbine immediately after that and used with high efficiency. Is possible.

  In addition, waste heat from gas engines, gas turbines, and fuel cells, and flammable gas generated as off-gas when purifying hydrogen from dry gasification gas, can be used as a heat source for the above external heating rotary kiln. Can be improved.

  Next, the details of the tar gasification method using the catalyst of the present invention will be described.

  Although FIG. 1 shows a schematic example of a tar gasifier, the present invention is not particularly limited to this. As shown in the figure, the tar gasification apparatus temporarily stores a receiving hopper 1 that receives a raw material as a raw material supply process, a conveyor 2 that conveys the raw material to the furnace, and a raw material that has reacted on the conveyor 2, and measures the cutout amount. A weighing hopper 3, an air blocking device 4, and a screw feeder 5 are provided.

  In addition, a pyrolysis furnace 6 of an externally heated rotary kiln is provided as a raw material pyrolysis means, and a catalyst dry gas for reforming and gasifying the tar in the pyrolysis gas by bringing the pyrolysis gas into contact with the catalyst at the subsequent stage. Catalyst reactor 7 which is a reaction field of the gasification step, fixed bed type partial combustion gasification furnace 9 as a means for combustible gasification of solid carbide generated by pyrolysis, and gas shut-off for shutting off this partial combustion gasification furnace 9 A rotary valve 8 is provided as a device.

  Further, downstream of the catalytic reactor 7 is a scrubber 10, a dust remover 11, a gas compressor 12, a gas holder 13, and a use facility 14 such as a gas engine for cooling, washing, dust removal, compression, storage and power generation. Prepare.

  In the raw material supply process, the supply amount of the raw material is batch measured with the weighing hopper 3, and the atmosphere in the pyrolysis furnace 6 is sucked into the furnace without releasing the gas in the pyrolysis furnace 6 into the atmosphere through the double atmosphere shut-off device 4. Without being supplied on the screw feeder 5. The space between the double shut-off devices can be shut off more effectively by purging with an inert gas such as steam or nitrogen. The pyrolysis furnace is continuously inserted into the pyrolysis furnace 6 by a screw feeder 5.

  In the pyrolysis process, the pyrolysis furnace 6 is an externally heated rotary kiln and is generated in a partial combustion gas furnace 9 that partially burns and solidifies the solid carbide obtained in the pyrolysis furnace 6 as a heat source for external heat. The burned gas (not shown) which introduces the combustible gas which was introduced and mixes with the air from the combustion air fan 15 in the external heat part 6a is combusted at a temperature of 500 to 900 ° C. The furnace shell 6b of the rotary kiln is a partition wall configured to be cut off from the external heat part 6a, and the combustion gas in the external heat part 6a and the pyrolysis gas inside the kiln are not mixed but indirectly heated. Moreover, the residence time of the raw material to process is adjusted between 20 minutes-3 hours. That is, by appropriately adjusting the residence time according to the moisture adhering to the raw material, the volatile component in the raw material can be substantially volatilized and gasified. If the residence time is less than 20 minutes, the raw material is not completely gasified, and if it is more than 3 hours, the furnace will be enlarged unnecessarily, which is not economical.

The raw material charged into the pyrolysis furnace 6 is heated to 400 to 900 ° C. by heat conduction from the furnace shell 6b and separated into pyrolysis gas and solid carbide. Pyrolysis gas is a gasification of the moisture and volatile matter in the raw material that has been dried and pyrolyzed, and consists of H ₂ , CO, CH ₄ main gas and tar vapor or water vapor that liquefies at room temperature. The decomposition furnace outlet temperature is 400 to 900 ° C. The solid carbide partially contains volatile components depending on the pyrolysis temperature, but most is a carbide composed of fixed carbon and ash, and the temperature of the pyrolysis furnace is 400 to 900 ° C.

  In the catalyst dry gasification step, the pyrolysis gas generated in the pyrolysis step enters the fixed bed catalyst reactor 7. The furnace shell 7a of the catalytic reactor 7 is filled with the catalyst according to the present invention, and the pyrolysis gas passes through the furnace shell 7a, and the tar content of the catalyst shell 7a is mainly hydrogen, carbon monoxide, and methane. It is converted into gas. Moreover, the furnace shell 7a of the catalytic reactor 7 is a steel partition wall that is cut off from the external heating part 7b, and the combustion exhaust gas at a temperature of 500 to 900 ° C. generated from the external heating part 6a of the external heating rotary kiln 6 is removed. Introduce and indirectly supplement the heat required for tar gasification.

  The solid carbide is not cooled and combustible gas is generated by partial combustion with air in the partial combustion gasification furnace 9 via the rotary valve 8. A part of the combustible gas is used as a heat source for indirect heating of the external heat rotary kiln 6 and the catalytic reactor 7, and the rest is recovered at the outlet of the catalytic reactor 7 by joining with the reformed gas.

  The recovered gas is cooled by the scrubber 10 in a gas cooling and cleaning process, and chlorine and sulfur in the gas are neutralized and removed by NaOH from the NaOH tank 16. The waste water of the scrubber 10 is circulated after the solid content is removed by the solid-liquid separator 17. The temperature of the scrubber outlet is sufficiently lowered to 40 ° C. or lower, suppresses the water vapor contained therein, and is temporarily stored in the gas holder 13 through the dust remover 11 and the gas compressor 12 as a high-calorie and clean recovery gas. The power and power generation are used by the use facility 14 such as an engine or a fuel cell. At this time, if the heat recovery of the gas engine is performed with steam or hot water, heat can be supplied to other facilities, and the amount of heat of the carbonaceous raw material can be most effectively used.

  In addition, when the sulfur content in the recovered gas is small due to the properties of the raw materials, the gas engine or gas is maintained without using the scrubber 10 or directly through a dry desulfurization device while maintaining high-temperature gas sensible heat. It can also be used efficiently by introducing it into a turbine.

  Further, the tar gasification catalyst built in the catalyst reactor 7 was obtained by carbon deposited on the catalyst surface during the conversion from tar to a gas mainly composed of hydrogen, carbon monoxide, and methane, or obtained in the thermal decomposition step. The sulfur contained in the pyrolysis gas is adsorbed by the catalyst, so that the performance of the catalyst deteriorates, and the reforming performance from tar to gas mainly composed of hydrogen, carbon monoxide, and methane is lowered. Therefore, as a method of regenerating the deteriorated catalyst, first, the raw material supply is stopped, nitrogen is introduced from the external heating rotary kiln 6, the pyrolysis gas inside the external heating rotary kiln, the catalytic reactor 7, the scrubber 10, and the dust remover 11. The internal reformed gas is discharged outside the apparatus. Thereafter, nitrogen is stopped, and steam is introduced from the externally heated rotary kiln 6 to remove carbon on the catalyst surface by the reaction of steam and carbon, or sulfur adsorbed on the catalyst by the reaction of steam and sulfur in the form of hydrogen sulfide. By removing the catalyst, the catalyst can be regenerated. In addition, by replacing some or all of the water vapor with air, carbon on the catalyst surface is removed by the combustion reaction of oxygen and carbon in the air, or sulfur adsorbed on the catalyst is removed by the reaction of oxygen and sulfur. Thus, it is possible to regenerate the catalyst.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
Example 1
Ce (NO ₃ ) ₃ · 6H ₂ O and Ni (NO ₃ ) ₂ · 6H ₂ O, which are precursors of cerium oxide and nickel, to alumina powder (surface area 20m ² / g) pre-fired at 1273K for 3 hours After impregnating with the mixed aqueous solution, drying was performed at 383 K for 12 hours and then baking was performed at 773 K for 3 hours to obtain a powder carrying nickel oxide and cerium oxide on an alumina carrier. Further, a platinum acetylacetonate solution was supported on this powder by an incipient wetness method so that the mass ratio of platinum was 0.1%, then dried at 383 K for 12 hours, and then calcined at 773 K for 3 hours to prepare a catalyst. did. In this way, finally, nickel oxide, cerium oxide, and platinum are supported on the alumina support, and the nickel mass ratio (metal conversion) to the entire catalyst including the support is 10%, the cerium oxide mass ratio is 30%, A powdery catalyst having a platinum mass ratio of 0.1% was obtained.

  Using this catalyst, tar was subjected to catalytic dry gasification using cedar powder as a raw material using a fixed bed reactor.

Cedar flour was continuously fed from the top of the fixed bed reactor using N2 as the carrier gas. The reaction temperature was controlled by a thermocouple attached to the reactor outer wall. The flow rate of the product gas was measured with a soap film flow meter, and the gas measurement analysis was performed using a gas chromatograph. The gas chromatograph used was Shimadzu GC-14B, and H ₂ was analyzed using TCD (Molecular Sieve 13X), and other products were analyzed using FID (Gas Chropack 54), and the records were recorded by an integrator (Shimadzu Chromatopack CR-5A). I went there. A Dewar bottle with ice was installed downstream of the reactor to trap steam and tar.

The test conditions were as follows: catalyst amount 1 g, cedar powder supply rate 60 mg / min (C 2191 μmol / min, H 3543 μmol / min, O 1475 μmol / min), carrier gas N ₂ 60 cc / min, H ₂ O / C = 0.5 ( H ₂ O 1110 μmol / min), normal pressure, reaction temperature 823 K, reaction time 15 minutes.

The performance of the catalyst is the carbon conversion rate (C-conv.%), H ₂ production rate, the ratio of C in coke to the total amount of C of the supplied biomass (coke%), and the total amount of C of the supplied biomass. Judgment was based on the ratio of tar in tar (tar%), and these were calculated from the concentration of each component in the outlet gas by the following formula.

C-conv.% = (CO + CO ₂ + CH ₄ production rate) / (C supply amount of supplied biomass) x 100
coke% = (C amount in coke) / (Total C amount of supplied biomass) × 100
char% = (C amount in char) / (Total amount of supplied biomass) x 100
tar% = (100-(C-conv.%)-(char%)-(coke%))
Note that coke is carbon deposited on the catalyst surface, and char is fixed carbon that is generated by pyrolysis of biomass and remains without being gasified.

  When the reforming test was conducted for 15 minutes at a reaction temperature of 823K, the results shown in Table 1 were obtained, and high performance was exhibited with low tar% and high C-conv.%. Was confirmed.

The pyrolysis gas components in this test were H ₂ -190 μmol / min, CO-599 μmol / min, and CH ₄ -195 μmol / min, while the tar gasification gas component after reforming was H _2- 1646 μmol / min, CO-635 μmol / min, and CH ₄ -206 μmol / min. The hydrogen concentration was high, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to main components.
(Example 2)
A catalyst was prepared in the same manner as in Example 1 except that the nickel mass ratio was 1%, and the catalytic activity was evaluated. As a result, the results shown in Table 1 were obtained, the tar% was low, and C-conv. % Has been confirmed to exhibit relatively high performance. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 3)
A catalyst was prepared in the same manner as in Example 1 except that the nickel mass ratio was 40%, and the catalytic activity was evaluated. As a result, the results shown in Table 1 were obtained, the tar% was low, and C-conv. It was confirmed that high performance was exhibited with high%. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
( Reference Example 4)
A catalyst was prepared in the same manner as in Example 1 except that cobalt was used instead of nickel, cobalt nitrate was used as a precursor, and the cobalt mass ratio was 10%. The results shown in the figure were obtained, and it was confirmed that the tar% was low and the C-conv.% Was high, exhibiting relatively high activity performance. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
( Reference Example 5)
A catalyst was prepared in the same manner as in Example 1 except that iron was used instead of nickel, iron nitrate was used as a precursor, and the iron mass ratio was 10%. The results shown in the figure were obtained, and it was confirmed that the tar% was low and the C-conv.% Was high, exhibiting relatively high activity performance. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 6)
A catalyst was prepared in the same manner as in Example 1 except that zirconium oxide was used instead of cerium oxide, zirconium nitrate oxide was used as its precursor, and the nickel mass ratio was 10% and the zirconium oxide mass ratio was 30%. When the catalytic activity was evaluated, the results shown in Table 1 were obtained, and it was confirmed that the tar% was low and the C-conv.% Was high, exhibiting highly active performance. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 7)
A catalyst was prepared in the same manner as in Example 1 except that titanium oxide was used instead of cerium oxide, titanium sulfate was used as a precursor, and the nickel mass ratio was 10% and the titanium oxide mass ratio was 30%. When the catalytic activity was evaluated, the results shown in Table 1 were obtained, and it was confirmed that high performance was exhibited with low tar% and high C-conv.%. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 8)
A catalyst was prepared in the same manner as in Example 1 except that magnesium oxide was used instead of cerium oxide, magnesium nitrate was used as a precursor, and the nickel mass ratio was 10% and the magnesium oxide mass ratio was 30%. When the catalytic activity was evaluated, the results shown in Table 1 were obtained, and it was confirmed that high performance was exhibited with low tar% and high C-conv.%. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
Example 9
A catalyst was prepared by the same method as in Example 1 except that the mass ratio of cerium oxide was 1%, and the catalytic activity was evaluated. As a result, the results shown in Table 1 were obtained. It was confirmed that conv.% is high and exhibits high activity. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 10)
Except that the mass ratio of cerium oxide was 50%, a catalyst was prepared in the same manner as in Example 1, and the catalytic activity was evaluated. As a result, the results shown in Table 1 were obtained, tar% was low, C- It was confirmed that conv.% is high and exhibits high activity. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 11)
A catalyst was prepared in the same manner as in Example 1 except that pre-calcined silica powder (surface area 30 m ² / g) was used instead of alumina, and the catalytic activity was evaluated. The results shown in Table 1 were obtained. As a result, it was confirmed that the tar% is low and the C-conv.% Is high. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 12)
The catalyst was prepared in the same manner as in Example 1 except that the mass ratio of platinum to be finally supported was 0.01%, and the catalytic activity was evaluated. The results shown in Table 1 were obtained, and tar% was It was confirmed that high performance was exhibited with low and high C-conv.%. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 13)
The catalyst was prepared in the same manner as in Example 1 except that the mass ratio of platinum to be finally supported was 1%, and the catalytic activity was evaluated. The results shown in Table 1 were obtained, and tar% was It was confirmed that high performance was exhibited with low and high C-conv.%. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 14)
As in Example 1, pre-calcined alumina powder was impregnated with cerium nitrate aqueous solution, dried at 383K for 12 hours, then calcined at 773K for 3 hours, then impregnated with nickel nitrate aqueous solution, and at 383K for 12 hours drying, by performing firing over the next 3 hours at 773K Te, 10% nickel weight ratio of cerium oxide mass ratio was obtained 30% of the powder. Further, a platinum acetylacetonate solution was supported on this powder by an incipient wetness method so that the mass ratio of platinum was 0.1%, then dried at 383 K for 12 hours, and then calcined at 773 K for 3 hours to prepare a catalyst. did. In this way, finally, nickel oxide, cerium oxide, and platinum are supported on the alumina support, and the nickel mass ratio (metal conversion) to the entire catalyst including the support is 10%, the cerium oxide mass ratio is 30%, A catalyst having a platinum mass ratio of 0.1% was obtained. The evaluation method of the catalyst was evaluated in the same manner as in Example 1. As a result, the results as shown in Table 1 were obtained, and the high tar performance was low and the C-conv.% Was high. confirmed. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 15)
Evaluation was conducted in the same manner as in Example 1 except that the catalyst prepared in the same manner as in Example 1 was used and the reaction temperature was set to 973 K. As a result, the results shown in Table 1 were obtained. It was confirmed that conv.% is high and exhibits high activity. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 16)
Evaluation was conducted in the same manner as in Example 1 except that the catalyst prepared in the same manner as in Example 1 was used and the reaction temperature was set to 1073 K. As a result, the results shown in Table 1 were obtained. It was confirmed that conv.% is high and exhibits high activity. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 17)
The catalyst was prepared in the same manner as in Example 1 except that rhodium nitrate was used in place of platinum acetylacetonate so that rhodium was 1% by mass, and the catalyst activity was evaluated. As a result, it was confirmed that the tar% is low and the C-conv.% Is high, exhibiting highly active performance. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 18)
Evaluation was conducted in the same manner as in Example 1 except that the catalyst prepared in the same manner as in Example 17 was used and the reaction temperature was set to 973 K. As a result, the results shown in Table 1 were obtained. It was confirmed that conv.% is high and exhibits high activity. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 19)
A catalyst was prepared in the same manner as in Example 1 except that palladium acetylacetonate was used in place of platinum acetylacetonate and palladium was supported at 1% by mass, and the catalytic activity was evaluated. The results shown in the figure were obtained, and it was confirmed that the tar% was low and the C-conv.% Was high, exhibiting highly active performance. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 20)
Evaluation was conducted in the same manner as in Example 1 except that the catalyst prepared in the same manner as in Example 19 was used and the reaction temperature was set to 973 K. As a result, the results shown in Table 1 were obtained. It was confirmed that conv.% is high and exhibits high activity. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 21)
A catalyst was prepared in the same manner as in Example 1 except that ruthenium was supported at 1% by mass using ruthenium acetylacetonate instead of platinum acetylacetonate. The results shown in the figure were obtained, and it was confirmed that the tar% was low and the C-conv.% Was high, exhibiting highly active performance. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 22)
Evaluation was conducted in the same manner as in Example 1 except that the catalyst prepared in the same manner as in Example 21 was used and the reaction temperature was set to 973 K. As a result, the results shown in Table 1 were obtained. It was confirmed that conv.% is high and exhibits high activity. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 23)
Using the catalyst prepared in the same manner as in Example 1, N ₂ 60ml / min as a carrier _{gas, H 2 O / C = 0.5} (H 2 O 1110μmol / min), O 2 /C=0.5(O 2 1110μmol / min ) Was evaluated in the same manner as in Example 1. As a result, the results shown in Table 1 were obtained, and it was confirmed that the tar% was low and the C-conv.% Was high, exhibiting highly active performance. It was done. In this case, it was confirmed that the reaction proceeded while maintaining the initial activity even when the reaction time was continued up to about 8 hours. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 24)
After continuing the reaction for 8 hours under the conditions of Example 1, the charging of the raw materials was stopped, and carrier gas N ₂ 60 cc / min for carrier gas, H ₂ O / C = 0.5 (H ₂ O 1110 μmol / min) ), The catalyst layer temperature was maintained at 1073 K for 2 hours, and carbon and sulfur deposited on the catalyst were removed, and then the starting of the raw material was newly started under the same conditions as in Example 1. Table 1 shows Thus, it was confirmed that the activity was almost the same as that before the regeneration. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Example 25)
As in Example 24, the reaction was allowed to proceed for 8 hours under the conditions of Example 1, and then the charging of the raw material was stopped. Under the conditions of carrier gas N ₂ 60 cc / min and air 60 cc / min. After removing the carbon and sulfur deposited on the catalyst while maintaining the catalyst layer temperature at 1073 K for 2 hours, the starting of the raw material was newly started under the same conditions as in Example 1. As shown in Table 1, It was confirmed that the activity was almost the same. The tar gasification gas component in this test also has a high hydrogen concentration, and it was confirmed that hydrogen, carbon monoxide, and methane were converted to the main gas.
(Comparative Example 1)
Aluminium (surface area 20m ² / g) pre-fired at 1273K for 3 hours was impregnated with Ce (NO ₃ ) ₃ · 6H ₂ O aqueous solution, which is a precursor of cerium oxide, dried at 383K for 12 hours, and then 773K Baked for 3 hours, then impregnated with Ni (NO ₃ ) ₂ · 6H ₂ O aqueous solution which is a precursor of nickel, dried at 383K for 12 hours, and then baked at 773K for 3 hours In the catalyst preparation method, finally, nickel oxide and cerium oxide are supported on an alumina support, and a catalyst having a nickel mass ratio (metal conversion) of 4% and a cerium oxide mass ratio of 30% with respect to the entire catalyst including the support is prepared. Obtained.

When a reforming test was conducted for 15 minutes at a reaction temperature of 823 K, the results shown in Table 1 were obtained. C-conv.% Was low, tar% was high, and the activity was low. Moreover, it was confirmed that the hydrogen concentration of the tar gasification gas component in this test was relatively low. Furthermore, since the coke% is very high, when the regeneration treatment is performed after the reaction, it is necessary to perform an oxidation treatment at a high temperature or for a long period of time. Performance is expected to be even lower.
(Comparative Example 2)
According to Example 1 of Patent Document 3, a powder in which a mixed aqueous solution composed of ruthenium chloride and cerium nitrate was supported on alumina (surface area 20 m ² / g) by evaporation to dryness was obtained. This was dried at 383K for 12 hours and then calcined at 823K for 2 hours to prepare a catalyst. In this way, finally, ruthenium and cerium oxide are supported on the alumina support, and the supported amount of ruthenium in the catalyst with respect to the whole catalyst including the support is 1% by mass, and cerium is 1 atomic ratio to ruthenium. A catalyst was obtained.

When a reforming test was conducted for 15 minutes at a reaction temperature of 823 K, the results shown in Table 1 were obtained. C-conv.% Was low, tar% was high, and the activity was low. Moreover, it was confirmed that the hydrogen concentration of the tar gasification gas component in this test was relatively low. Furthermore, since the coke% is very high, when the regeneration treatment is performed after the reaction, it is necessary to perform an oxidation treatment at a high temperature or for a long period of time. Performance is expected to be even lower.
(Comparative Example 3)
Following Example 1 of Patent Document 4, rhodium chloride was supported on alumina (surface area 20 m ² / g) pre-calcined at 1273 K for 3 hours by evaporation to dryness, then dried at 383 K for 12 hours, and subsequently 823 K. The catalyst was prepared by calcination for 2 hours. In this manner, rhodium was finally supported on the alumina support, and a catalyst having a supported amount of rhodium of 5% by mass with respect to the entire catalyst including the support was obtained.

When a reforming test was conducted for 15 minutes at a reaction temperature of 823 K, the results shown in Table 1 were obtained. C-conv.% Was low, tar% was high, and the activity was low. Moreover, it was confirmed that the hydrogen concentration of the tar gasification gas component in this test was relatively low. Furthermore, since the coke% is very high, when the regeneration treatment is performed after the reaction, it is necessary to perform an oxidation treatment at a high temperature or for a long period of time. Performance is expected to be even lower.
(Comparative Example 4)
Aluminium (surface area 20m ² / g) pre-fired at 1273K for 3 hours was impregnated with Ce (NO ₃ ) ₃ · 6H ₂ O aqueous solution, which is a precursor of cerium oxide, dried at 383K for 12 hours, and then 773K Thus, a powder having a cerium oxide mass ratio of 30% was obtained. Further, a rhodium nitrate aqueous solution was supported on this powder by an incipient wetness method so that the mass ratio of rhodium was 1%, dried at 383 K for 12 hours, and then calcined at 773 K for 3 hours to prepare a catalyst. In this way, finally, cerium oxide and rhodium were supported on the alumina support, and a catalyst having a cerium oxide mass ratio of 30% and a rhodium mass ratio of 1% with respect to the entire catalyst including the support was obtained.

When a reforming test was conducted for 15 minutes at a reaction temperature of 823 K, the results shown in Table 1 were obtained. C-conv.% Was low and coke% and tar% were high, resulting in low activity. Moreover, it was confirmed that the hydrogen concentration of the tar gasification gas component in this test was relatively low.
(Comparative Example 5)
A modification test was conducted in the same manner as in Example 1 except that a catalyst for naphtha primary reforming (model number SC11NK, Ni 20% by mass, alumina support) manufactured by Zude Chemie Catalysts was used as a catalyst. The results shown in Table 1 were obtained. was gotten. C-conv.% Was low, tar% was high, and the activity was low. Moreover, it was confirmed that the hydrogen concentration of the tar gasification gas component in this test was relatively low. Furthermore, since the coke% is very high, when the regeneration treatment is performed after the reaction, it is necessary to perform an oxidation treatment at a high temperature or for a long period of time. Performance is expected to be even lower.

It is an outline example of the tar gasification device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Receiving hopper 2 Conveyor 3 Weighing hopper 4 Air shut-off device 5 Screw feeder 6 Rotary kiln (pyrolysis furnace)
6a External heating part of rotary kiln 6b Furnace shell of rotary kiln 7 Catalytic reactor 7a Furnace shell of catalytic reactor 7b External heating part of catalytic reactor 8 Rotary valve (gas shut-off device)
DESCRIPTION OF SYMBOLS 9 Partial combustion gasifier 10 Scrubber 11 Dust remover 12 Gas compressor 13 Gas holder 14 Utilization facilities, such as a gas engine 15 Combustion air fan 16 NaOH tank 17 Solid-liquid separator

Claims (10)

Oxides of nickel, and cerium, zirconium, titanium, one or two or more oxides of magnesium, as well as platinum group compounds, silica, formed by carrying on at least one carrier of alumina, carbonaceous material A gasification catalyst for reforming and gasifying the pyrolysis tar of
The ratio of the total amount of metal components in the nickel oxide to the entire catalyst is 1 to 40% by mass,
The ratio of the total amount of one or more oxides of cerium, zirconium, titanium, and magnesium to the entire catalyst is 1 to 50% by mass,
The percentage of the total catalyst of the total amount of the platinum group element component in the platinum group compound, catalyst characteristics and to filter Rugasu the <br/> be 0.01 mass%.   2. The catalyst for tar gasification according to claim 1, wherein the platinum group element in the platinum group compound is at least one element selected from platinum, ruthenium, palladium, and rhodium. The method for producing a catalyst according to claim 1 or 2 , wherein at least one of silica and alumina supports is impregnated with one or more solutions of cerium, zirconium, titanium, and magnesium compounds. followed by drying and firing, then, after impregnation the solvent solution of the compound of nickel to those performed drying and firing, followed by drying and firing, Thereafter, impregnated with a platinum group compound solution having been subjected to the drying and baking Then, drying and baking are performed, The manufacturing method of the catalyst for tar gasification characterized by the above-mentioned. A method of manufacturing a catalyst according to claim 1 or 2, silica, on at least one carrier of alumina, a compound of nickel, and cerium, zirconium, titanium, one or two or more of the magnesium compound A method for producing a tar gasification catalyst comprising impregnating a mixed solution of the above compound, drying and calcining, then impregnating the dried and calcined material with a platinum group compound solution, followed by drying and calcining . The catalyst according to claim 1 or 2 is brought into contact with a pyrolysis gas containing tar generated when pyrolyzing a carbonaceous raw material, or a mixed gas obtained by adding air or oxygen to the pyrolysis gas containing the tar. Tar gasification method that reforms and gasifies tar. The tar gasification method according to claim 5 , wherein a temperature at which the pyrolysis gas or mixed gas is brought into contact with the catalyst is 400 to 1000 ° C. The tar gasification method according to claim 5 or 6 , wherein an external heating type rotary kiln is used for thermal decomposition of the carbonaceous raw material. The solid carbide generated together with the pyrolysis gas when the carbonaceous raw material is pyrolyzed is partially oxidized into a combustible gas, and the combustible gas is burned to be used as a heat source for the external heat type rotary kiln. The tar gasification method according to any one of claims 5 to 7 . A tar gasification gas comprising a tar reforming gas and a pyrolysis gas produced by the tar gasification method according to any one of claims 5 to 8 is used as a fuel for a gas engine, a gas turbine, or a fuel cell. A method of using a tar gasification gas characterized by the above. The tar gasification method according to any one of claims 5 to 8 , wherein when the performance of the catalyst is deteriorated due to carbon deposition or sulfur poisoning, the catalyst is brought into contact with at least one of water vapor and air. A method for regenerating a catalyst for tar gasification characterized by the above.

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