JP2011111511A - Regeneration treatment method of carbon compound, gasification apparatus and regeneration treatment system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regeneration treatment method of solid organic waste, wherein tar is not produced and yield of an aqueous gas is not reduced, even when heating temperature in a carbonization furnace is lowered to ≤900°C, a gasification apparatus, and a regeneration treatment system. <P>SOLUTION: The regeneration treatment method of a carbon compound uses the carbonization furnace 5 and a heating temperature of 700-900°C and comprises steps of: replacing air inside the furnace with superheated steam; and subsequently introducing a mixture comprising a raw material containing the carbon compound and a catalyst promoting a reaction represented by formula (A): CO<SB>2</SB>+C→2CO into the furnace together with the superheated steam. As the catalyst, iron oxide having an average particle size of 0.1-2.0 μm is introduced into the furnace in an amount corresponding to 1-20 wt.% in terms of dry matter based on the weight of the carbon compound. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

In the present invention, a raw material containing a carbon compound, for example, solid organic waste such as food residue, agricultural residue, woody biomass, activated sludge, waste plastic, etc., is further heated at a saturated steam temperature (638 ° C.) at normal pressure. playing the water gas mainly composed of hydrogen and carbon monoxide by pyrolysis with superheated water vapor in the heat radiating property the H ₂ O gas obtained by heating, further the water gas to the liquid fuel or electric energy The present invention relates to a regeneration treatment method, a gasification apparatus, and a regeneration treatment system for a carbon compound to be regenerated.

  Solid organic waste is thermally decomposed in superheated steam and regenerated to water gas mainly composed of hydrogen and carbon monoxide, and further regenerated to liquid fuel using the water gas as raw material, or engine generator There is a method of regenerating the fuel gas into electrical energy (for example, Patent Document 1). According to this, solid organic waste can be gasified and reformed at the same time as carbonization in a single furnace, and waste regeneration processing that can efficiently recycle carbide, useful gas, and liquid fuel even if the equipment scale is small. A method and a waste recycling system.

  According to the Example, the organic waste is put into superheated steam at a temperature of 1000 to 1100 ° C., and gasification is performed.

  However, at a high temperature of 1000 ° C. or higher, there is a problem that a special and expensive furnace material is required for the gasification furnace, and power consumption is increased.

JP 2008-260832 A

  In the organic waste regeneration treatment method for regenerating organic waste such as biomass as water gas in superheated steam, the heating temperature of the dry distillation furnace is a high temperature of 1000 ° C. or higher, so that an expensive special heat resistant furnace is used for the dry distillation furnace. Since the material is used and the economic load is large, the heating temperature is required to be lowered. However, lowering the heating temperature of the carbonization furnace to 900 ° C. or lower not only reduces tar water and reduces the water gas reaction, but also damages the carbonization furnace and reduces its function. It was difficult to lower the temperature.

  Therefore, the present invention provides a method for regenerating organic waste (raw material containing carbon compound) and a gasification apparatus in which tar is not generated and the production rate of water gas does not decrease even when the heating temperature of the carbonization furnace is lowered to 900 ° C. or lower. And a reproduction processing system.

The carbon compound regeneration treatment method of the present invention uses a carbonization furnace, the heating temperature is set to 700 ° C. to 900 ° C., the air in the furnace is replaced with superheated steam, the raw material containing the carbon compound, and the following (formula A) A mixture with a catalyst that accelerates the reaction is put into a furnace together with superheated steam.
CO ₂ + C → 2CO (Type A)

As the catalyst, iron oxide can be used. In this case, the average particle diameter of the iron oxide is preferably 0.1 μm or more and 2.0 μm or less. Further, the amount of the iron oxide added is preferably 1 wt% or more and 20 wt% or less in terms of dry matter with respect to the carbon compound to be added. The iron oxide is preferably magnetite having a composition of Fe _1-X O · Fe ₂ O ₃ (X <0.5).

  Further, the gasifier of the present invention is for generating a gas mainly composed of hydrogen and carbon monoxide from a raw material containing a carbon compound, and a catalyst mixing means for mixing a catalyst with the raw material, A dry distillation furnace having a supply port for supplying a raw material, an exhaust port for discharging the gas, and a solid matter recovery port for collecting the solid matter by blocking it from outside air, and supplying superheated steam to the dry distillation furnace It comprises a superheated steam supply means and a heating means for heating the dry distillation furnace.

  The regeneration processing system of the present invention includes the above-described gasifier of the present invention, and a liquid fuel synthesizer that synthesizes hydrogen and carbon monoxide generated by the gasifier to generate liquid fuel. It is characterized by doing.

  In this case, the regeneration processing system includes a generator connected to the liquid fuel synthesizing device, and a surplus gas supply device that supplies surplus gas generated in the liquid fuel synthesizing device as fuel for power generation of the generator. Is preferred. Further, an auxiliary fuel supply device for supplying the liquid fuel to the generator may be provided. As the generator, an engine generator, a micro gas turbine generator, or a fuel cell can be used.

According to the present invention, after using a carbonization furnace, the heating temperature is set to 700 ° C. to 900 ° C., the atmosphere in the furnace is replaced with superheated steam to form an oxygen-free atmosphere, and then a carbon compound such as solid organic waste is contained. A mixture of the starting material and the catalyst for promoting the reaction of the following (formula A) is charged into the furnace together with superheated steam. Thereby, water gas reaction of the following (formula 1) in which superheated steam reacts with carbon generated by thermal decomposition without generating tar,
C + H ₂ O → H ₂ + CO (1 set)
The shift reaction of (Formula 2) below, in which carbon monoxide generated by the water gas reaction of Formula 1 reacts with superheated steam,
CO + H ₂ O → H ₂ + CO ₂ (2 formulas)
And the reactor gas reaction of (Formula A) in which carbon dioxide produced by the shift reaction of (Formula 2) reacts with unreacted carbon,
CO ₂ + C → 2CO (Type A)
Can be circulated with each other to increase the production rate of water gas. Further, a raw material containing a carbon compound such as solid organic waste can be regenerated using an economical dry distillation furnace that does not require an expensive heat-resistant material and can reduce power consumption. In addition, the iron oxide powder that has been charged can be recovered and recycled.

  In addition, since the hydrogen component of the generated water gas increases in the circulation reaction of the present invention, the reactivity of the Fischer-Tropsch method for synthesizing liquid fuel or as a fuel for high-calorie diesel generators is improved. There is an effect.

  Further, the regeneration treatment system of the present invention performs solid-state organic waste pyrolysis and water gas synthesis reaction in one dry distillation furnace, and the produced gas is organically transferred to a heat exchange device, a liquid fuel synthesis device and an engine-type power generation device. Are suitable for a small-scale distributed solid organic waste recycling system.

It is a process flow figure of a method of the present invention.

An embodiment of the present invention will be described with reference to FIG. The carbon compound regeneration treatment method of the present invention uses a carbonization furnace, the heating temperature is set to 700 ° C. to 900 ° C., the air in the furnace is replaced with superheated steam, the raw material containing the carbon compound, and the following (formula A) A mixture with a catalyst that promotes the reaction is put into a furnace together with superheated steam.
CO ₂ + C → 2CO (Type A)

  In addition, a carbon compound means the compound containing carbon, for example, corresponds to an organic compound. Moreover, the raw material containing a carbon compound corresponds to solid organic wastes such as food residues, woody biomass, and waste plastics.

Any catalyst may be used as long as it promotes the reaction of formula (A). For example, iron oxide can be used. As the iron oxide, any iron oxide such as hematite α-Fe ₂ O ₃ , goethite α-FeOOH, magnetite Fe ₃ O ₄ , maghemite γ-Fe ₂ O ₃ can be used. Preferably, since the inside of the carbonization furnace is a reducing gas atmosphere at a temperature of 700 ° C. or higher, any iron oxide is reduced to magnetite when it is introduced into the carbonization furnace. Therefore, the iron oxide initially introduced is preferably magnetite. The composition of magnetite is the composition Fe _1−X O · Fe ₂ O ₃ (X <0.5). Since oxidation proceeds excessively when X is 0.5 or more, the preferable range of X is 0.05 to 0.3. More preferably, the carbon-containing magnetite powder obtained by collecting the input iron oxide is recycled.

  As the iron oxide powder, it is better to use a powder composed of particles having an average particle size of 0.1 μm or more and 2.0 μm or less. If the particle size of the powder is 0.1 μm or less, uniform mixing with solid organic waste is difficult, and if the particle size is 2.0 μm or more, the chemical activity decreases, which is not preferable. Therefore, the preferable range of the average particle diameter of the iron oxide powder is 0.1 μm to 1.0 μm, more preferably 0.2 μm to 0.5 μm.

  Moreover, the addition amount of iron oxide powder is 1 wt% or more and 20 wt% or less. If it is 1 wt% or less, an effective effect cannot be obtained. 20 wt% or more is not preferable because it hinders improvement in the yield of product gas. A preferable range is 3 wt% to 15 wt%, and a more preferable range is 5 wt% to 10 wt%.

  Such a catalyst is mixed with a raw material containing a carbon compound, for example, solid organic waste. Specifically, first, a solid organic waste such as a food residue containing carbon compounds, woody biomass, and waste plastic is processed into powder by a pulverizer 1, and then a catalyst mixing means 2, for example, a commonly used mixer. Then, a predetermined amount of iron oxide powder prepared in advance may be added and mixed to prepare a mixture.

  Next, the temperature of the dry distillation furnace 5, for example, the rotary kiln type external heating electric furnace is adjusted to 700 ° C. to 900 ° C., and the air in the furnace core tube is replaced with superheated steam supplied by the boiler 4 (superheated steam supply means). Use an oxygen-free atmosphere. Further, the adjusted mixture is continuously fed into the core tube of the dry distillation furnace 5 together with the superheated steam supplied by the boiler 4 from the charging device 3 at the inlet (supply port) of the dry distillation furnace 5.

  Here, the dry distillation furnace 5 is a furnace for internally heating the raw material and superheated steam in an air-blocked state, and pyrolyzing the raw material to generate a gas mainly composed of hydrogen and carbon monoxide. It is formed in a horizontally long cylindrical shape that inclines downward from the mouth toward the outlet. In this case, the carbonization furnace 5 may be formed as a rotary furnace that is rotated by a rotary drive device such as a motor. The material of the carbonization furnace may be any material as long as it can withstand the temperature and pressure during the thermal decomposition.

  Further, the supply port of the dry distillation furnace 5 is provided with raw material supply means such as a piston operated by air pressure or hydraulic pressure, a conveyor, a rotating screw, etc., whereby the raw material is quantitatively continuously supplied into the dry distillation furnace 5. Just do it.

  Further, a gas pressure adjusting means (not shown) for adjusting the pressure of the gas generated in the gasification furnace, a pressure detecting means for detecting the pressure in the dry distillation furnace 5, and a pressure detected by the pressure detecting means. A pressure control means for controlling the gas pressure adjusting means and maintaining the pressure in the dry distillation furnace 5 in a certain range may be provided. For example, a pressure sensor may be provided near the supply port side or the discharge port of the gasification furnace to detect the pressure, and the pressure in the dry distillation furnace 5 may be adjusted to a positive pressure of 0 to 0.3 kPa with respect to the atmospheric pressure.

  Further, a solid matter recovery device 6 that recovers the solid matter such as discharged charcoal, ash, catalyst, etc. in a state where the inside of the dry distillation furnace 5 is blocked from the outside air by a liquid such as water is provided at the solid matter recovery port of the dry distillation furnace 5. Is provided. Thereby, the used catalyst can be recovered while maintaining the atmosphere in the dry distillation furnace 5.

  The inside of the dry distillation furnace 5 is heated by heating means such as an electric heater. The temperature at which the heater is heated is 700 ° C. or higher and 900 ° C. or lower. If it is 700 ° C. or lower, the production rate of water gas is lowered, which is not preferable. Moreover, when the temperature is 900 ° C. or higher, there is no problem with the reactivity of the water gas, but a furnace material that can withstand high temperatures is required. A preferred temperature range is 750 ° C to 850 ° C. In this case, a temperature detection means for detecting the temperature in the carbonization furnace and a temperature control means for controlling the heating means based on the temperature detected by the temperature detection means and adjusting the temperature in the carbonization furnace may be provided.

The mixture of the solid organic waste and the catalyst charged into the carbonization furnace 5 is thermally decomposed into flammable gas and carbon without generating tar. This carbon comes into contact with superheated steam to cause the following water gas reaction (formula 1) to produce hydrogen and carbon monoxide.
C + H ₂ O → H ₂ + CO (1 set)

Next, carbon monoxide generated in (formula 1) comes into contact with water vapor to cause a shift reaction of the following formula (formula 2) to generate hydrogen and carbon dioxide.
CO + H ₂ O → H ₂ + CO ₂ (2 formulas)

  However, since the reaction of (formula 1) decreases at a temperature of 900 ° C. or lower and reduces the production rate of water gas, the conventional method requires a heating temperature of 1000 ° C. or higher.

However, according to the method of the present invention, the following reactor gas reaction (also referred to as Boudouard reaction) catalyzed by magnetite occurs even at a heating temperature of 900 ° C. or lower. The generated carbon dioxide reacts with the unreacted carbon to produce carbon monoxide, thereby causing a reaction mutual circulation that promotes the shift reaction of (Formula 2) while gasifying the unreacted carbon, and is aqueous. The production rate of gas can be improved.
CO ₂ + C → 2CO (Type A)

  The produced water gas is transferred from the outlet of the carbonization furnace to the gas purification device 7 via the transfer line A, and after removing dust here, it is transferred to the heat exchange device 8 via the transfer line B. Moreover, the solid substance which has a carbide | carbonized_material and a magnetite as a main component is collect | recovered with the collection | recovery apparatus 6 from the solid substance collection | recovery port of a carbonization furnace, and it utilizes effectively for a black pigment, agricultural land soil improvement material, fuel charcoal, etc. Of course, it can also be reused as a catalyst.

  The purified gas having a sensible heat of about 800 ° C. transferred to the heat exchange device 8 is cooled to 200 ° C. by a heat exchanger and then transferred to the gas storage tank 11 by a transfer line C and stocked.

  Further, the high-temperature gas generated at this time is transferred to the superheated steam regenerator 9, regenerated to superheated steam, and recycled to the dry distillation furnace 5 through the superheated steam supply line 10.

The refined gas in the gas storage tank 11 is transferred to the liquid fuel synthesizing apparatus 12 through the transfer line D, and oil of C _n H _{2n + 2} composition is synthesized at C _{6 to} C ₂₅ using a Fischer-Tropsch synthesis catalyst. The produced oil separates oil and water, the oil is stocked in a storage tank (not shown), and the water is regenerated to warm water by the heat exchanger 8.

  The surplus gas generated in the liquid fuel synthesis reaction is transferred to a generator 13 such as an engine-type generator through a transfer line F, mixed with purified gas from the line E, and the diesel engine is operated to generate power.

  Alternatively, the refined gas in the gas storage tank 11 may be used as gas fuel to be transferred to the engine-type power generator 13 through the transfer line E, and the diesel engine may be operated to generate power.

  In addition, the gas refiner | purifier 7, the heat exchange apparatus 8, the liquid fuel synthesizer 12, and the generator 13 can respectively use the conventional apparatus and method. In addition to the engine generator, the generator 13 may be a micro gas turbine generator, a fuel cell, or the like.

[Example]
Next, an embodiment of the present invention will be described in detail with reference to FIG.

  The components of gas and synthetic oil were analyzed by gas chromatography, the waste composition was measured by atomic absorption, and the structural analysis was measured by X-ray diffraction. The shape of the particles was observed with a transmission electron microscope. For solid organic waste (raw material containing a carbon compound), palm oil squeezed potatoes having the main composition shown in Table 1 below were used.

  The iron oxide powder used as a catalyst is composed of goethite (yellow iron oxide) powder with an average particle size of 0.12 μm and magnetite (black iron oxide) powder with an average particle size of 0.15 μm produced by a wet synthesis method using an iron salt aqueous solution and alkali. Prepared and used.

As the dry distillation furnace, a rotary kiln type external heating type electric furnace 5 with a capacity of 30 KW was used. The electric furnace 5 is made of a stainless steel pipe having a core tube diameter of 200 mmφ and a length of 2 m, and is inclined from the inlet side toward the outlet side. The inlet side is equipped with a raw material charging device 3 and a superheated steam charging pipe supplied from the boiler 4, and the outlet side is a solid emission recovery device 6 such as carbide and magnetite, and the product gas is a gas purification step. 7 is provided with a transfer line A.
[Example 1]

  In FIG. 1 which shows the process flow of this invention, the to-be-processed object (raw material containing a carbon compound) of Table 1 was grind | pulverized with the grinder 1, and it was set as the powder with an average particle diameter of 4.5 mm. Next, in the catalyst mixing means 2, 10 wt% of the prepared magnetite powder (catalyst) having an average particle diameter of 0.35 μm was added to the object to be processed in terms of dry matter and mixed to obtain a raw material powder (mixture). . Next, while rotating the rotary kiln type external heating electric furnace of the carbonization furnace 5 at a rotation speed of 1.5 rpm, the heating temperature is adjusted to 800 ° C., and the air in the furnace core tube is replaced with superheated steam supplied by the boiler 4. And an oxygen-free atmosphere. And the adjusted to-be-processed mixture with the superheated steam supplied with the boiler 4 from the charging device 3 of the dry distillation furnace 5 was continuously injected into the core tube of the dry distillation furnace 5 at a rate of 5 kg for 1 hour.

The produced gas is transferred to the gas purification device 7 through the transfer line A, and after removing dust and the like, it is transferred to the heat exchange device 8 through the transfer line B, and the purified gas having a sensible heat of about 800 ° C. is transferred to the heat exchange device 8. After cooling to 200 ° C., the product was transferred to the gas storage tank 11 through the transfer line C and stocked. Further, the black mud discharged from the carbonization furnace 5 was recovered by the recovery device 6.
[Examples 2 to 4 and Comparative Examples 1 and 2]

  It implemented similarly to Example 1 except having changed the kind and addition amount of iron oxide powder, and the heating temperature of the electric furnace. These conditions are shown in Table 2.

  For each of Examples 1 to 4 and Comparative Examples 1 and 2, the composition was analyzed by extracting the purified gas from the gas purifier 7 after 60 minutes and 120 minutes from the time when the object to be processed was put into the electric furnace. . The results are shown in Table 3 below.

From Table 3, all of the examples had gas compositions with a high hydrogen content in which the ratio H ₂ / CO of hydrogen to carbon monoxide was 2 or more. As is well known, this has the characteristic of accelerating the reaction rate of the Fischer-Tropsch reaction, and is suitable for regenerating to liquid fuel and electric energy because it is a gas with high calories as a gas fuel. It was a gas. Further, it was confirmed that the carbon-containing magnetite powder used for recycling had the same effect as the prepared magnetite powder.

  On the other hand, any of the comparative examples clearly showed that the object could not be achieved outside the scope of the claims of the present invention.

  The black powder obtained by drying the muddy black matter recovered by the recovery device 6 for each example at 80 ° C. was subjected to X-ray analysis and electron microscope observation. As a result of X-ray analysis, all powders were a mixture of magnetite and carbon. Moreover, as a result of observing with an electron microscope, all the magnetite particles stopped the original particle shape.

  Using the refined gas stocked in the gas storage tank 11, a Fischer-Tropsch synthesis experiment was performed by a conventional method. The results of analyzing the gas composition of the stock tank are shown in Table 4 below.

The resulting synthetic oil was a mixed oil with about 50% by volume of water. After a while, both solutions separated into water and oil. As a result of analyzing the components of the oil from which water was separated, it was an oil having a C ₁₁ -C ₂₁ C _n H _{2n + 2} composition. The separated water was recovered and regenerated to warm water by the heat exchanger 8.

  In addition, surplus gas generated during the synthesis reaction was transferred to an engine-type power generation device by a transfer line F, mixed with purified gas sent from the transfer line E, and used as fuel for a diesel engine.

  The refined gas stocked in the gas storage tank was transferred to the engine-type power generator by the transfer line E and used as fuel for the diesel engine, and the generator was driven to generate electricity.

  The carbon compound regeneration treatment method, gasification apparatus, and regeneration treatment system of the present invention is a method for converting various industrial wastes and agricultural wastes of currently increasing carbon compounds into water gas by lowering the operating temperature of the dry distillation furnace. Can be reprocessed into liquid fuel and electric energy, thus reducing capital investment and further reducing running costs, contributing to the recycling of organic waste and the preservation of the social environment in industry.

DESCRIPTION OF SYMBOLS 1 Crusher 2 Catalyst mixing means 3 Input device 4 Boiler 5 Dry distillation furnace 6 Solid matter recovery device 7 Gas purification device 8 Heat exchange device 9 Superheated steam generator
10 Superheated steam supply line
11 Gas storage tank
12 Liquid fuel synthesizer
13 Engine generator
A ~ F Gas transfer line

Claims (10)

Using a carbonization furnace, heating temperature is set to 700 ° C. to 900 ° C., air in the furnace is replaced with superheated steam, and then a mixture of a raw material containing a carbon compound and a catalyst that promotes the following reaction (formula A) is superheated. A carbon compound regeneration treatment method, wherein the carbon compound is put into a furnace together with steam.
CO ₂ + C → 2CO (Type A)   The method for regenerating a carbon compound according to claim 1, wherein the catalyst is iron oxide.   3. The carbon compound regeneration treatment method according to claim 2, wherein an average particle diameter of the iron oxide is 0.1 μm or more and 2.0 μm or less. The method for regenerating a carbon compound according to claim 2 or 3, wherein the amount of iron oxide added is 1 wt% or more and 20 wt% or less in terms of dry matter with respect to the carbon compound to be added. 5. The carbon compound regeneration treatment method according to claim 2, wherein the iron oxide is magnetite having a composition of Fe _1-X O · Fe ₂ O ₃ (X <0.5). A gasifier for generating a gas mainly composed of hydrogen and carbon monoxide from a raw material containing a carbon compound,
A catalyst mixing means for mixing a catalyst with the raw material;
A dry distillation furnace having a supply port for supplying the raw material, a discharge port for discharging the gas, and a solid material recovery port for recovering the solid material from outside air; and
Superheated steam supply means for supplying superheated steam to the dry distillation furnace;
Heating means for heating the carbonization furnace;
The gasifier characterized by comprising. A gasifier according to claim 6;
A liquid fuel synthesizing device that synthesizes hydrogen and carbon monoxide produced in the gasifier to produce a liquid fuel;
A reproduction processing system comprising: A generator connected to the liquid fuel synthesizer;
The regeneration processing system according to claim 7, further comprising: a surplus gas supply device that supplies surplus gas generated in the liquid fuel synthesizing device as fuel for power generation of the generator.   The regeneration processing system according to claim 8, wherein the generator is any one of an engine generator, a micro gas turbine generator, and a fuel cell.   The regeneration processing system according to claim 9, further comprising an auxiliary fuel supply device that supplies the liquid fuel to the generator.

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