JP4899145B2 - A vertical reactor equipped with a solid retention part. - Google Patents

Description

  The present invention relates to a chemical reaction apparatus used for gasification for producing useful gas from biomass, plastic, coal, organic waste, and the like, and synthesis of liquid fuel using the produced gas.

  In recent years, effective use of organic waste such as biomass, plastic, coal, and garbage has been regarded as important from the viewpoint of reducing energy problems and environmental problems. However, since these organic substances generally have a low energy density and a low combustion temperature, the energy available by direct combustion is small. For this reason, an organic substance is reacted with a gasifying agent to generate a gas having a high energy density such as hydrogen or carbon monoxide and a high combustion temperature, thereby improving energy utilization efficiency. Further, since the produced gas can be used as a liquid fuel synthesis raw material such as methanol, the added value can be increased by gasification.

  At present, as one of gasification methods, a method of gasifying an organic substance with a gasifying agent at a high temperature (for example, see Patent Documents 1 to 4) has been tried, and some methods have already been put into practical use. However, these methods have disadvantages that heat dissipation increases as the temperature increases, and a lot of energy is consumed, and materials that can withstand high temperatures and the maintenance and operation of the apparatus become complicated. In addition, there are problems such as treatment of by-products such as solid residue and tar generated accompanying gasification, and a satisfactory method is not yet known.

  As another gasification method, an attempt has been made to gasify an organic substance at a low temperature using a catalyst. Specifically, using a catalyst having rhodium, ruthenium, palladium or platinum supported on the surface of a cerium oxide support, gasification is performed at a low temperature of 400 to 1000 ° C. (for example, see Patent Document 5), catalytic function There has been proposed a method in which a clay having a heat is used as a heat medium and gasified by fluid contact with a raw material (for example, see Patent Document 6). Gasification using these catalysts can reduce the amount of by-products such as solid residue and tar by shifting the reaction temperature to a lower temperature side. It is also advantageous in terms of management.

However, since various organic materials used as raw materials contain ash, sulfur, phosphorus, etc., there are problems such as catalyst poisoning and reduction of resistance (deactivation). Therefore, it is necessary to purify the gas by separating undesired sulfur and phosphorus from ash contained in various organic materials as raw materials.
In general, it is difficult to completely gasify the carbon contained in the organic substance, and the gas conversion rate (gasification rate) of the carbon content is usually 90 to 95% or less, and the rest is char. It must be separated and the gas must be purified. These solids (collectively referred to as solid residues) are collected by a cyclone or filter, or by a scrubber (water shower) or underwater bubbling. However, it is essential to discharge the solid residue regularly. A method that can be used stably over a long period of time is not yet known.

  Furthermore, synthesis of a liquid fuel such as methanol from a reaction product gas is usually performed in the presence of a catalyst. At that time, in order to improve the contact between the gas and the catalyst, a method of supporting on the surface of the carrier, a method of increasing the contact area by coating on the surface of the metal foil, etc. are adopted, and a method such as stirring is also used. However, no satisfactory method has been found yet.

JP-A-8-143873 JP 2001-240877 A JP 2001-240878 A JP 2002-38163 A JP 2002-346388 A JP 2003-41268 A

The present invention has been made in view of the above-described actual situation of the prior art. That is, an object of the present invention is to provide a vertical reaction apparatus that promotes a desired chemical reaction through efficient contact between a fluid and a solid by adopting a specific operation method for an apparatus having a simple shape. is there.
Another object of the present invention is to efficiently bring a product gas or a raw material gas resulting from gasification of an organic substance into contact with a catalyst, and at the same time, separate a catalyst and a by-product such as a solid residue or tar to produce a product gas composition. Another object of the present invention is to provide a good vertical reactor for gasification capable of reforming.
Another object of the present invention is to provide a good vertical reactor for synthesizing liquid fuel that promotes a synthesizing reaction in which a raw material gas and a catalyst are efficiently brought into contact to obtain a liquid fuel.

That is, the present invention is a vertical reaction apparatus used for the reaction of a chemical substance, comprising a plurality of tapered portions in a part of the apparatus, and a supply means for introducing fluid, catalyst and organic substance into the apparatus; And adjusting the flow of the fluid to cause the catalyst to stay in the taper portion, and the reaction means for bringing the staying catalyst into contact with the fluid and / or the organic substance in a floating state, the solid residue and the solid by-product It is a vertical reactor provided with a plurality of taper portions for catalyst retention, characterized in that it comprises means for retaining at the bottom of the apparatus and means for recovering the reaction product.
In the above vertical reactor, it is preferable to introduce a raw material gas and a catalyst from the lower part and use them for the synthesis of liquid fuel. The synthesis of the liquid fuel is preferably performed under heating conditions of 100 to 300 ° C. Further, the raw material gas is a gas containing carbon monoxide and hydrogen, and the liquid fuel to be produced is preferably methanol, dimethylethyl (DME) or the like.

The present invention is also a vertical gasification apparatus used for gasification of an organic substance by introducing an organic substance and a gasifying agent, wherein at least one solid retention taper portion is provided in a part of the apparatus. The means for introducing the organic substance, the gasifying agent and the catalyst from the lower part of the apparatus and the amount of the introduced gas are adjusted so that the catalyst is retained in the retention taper portion, and the useful gas and gasifying agent of the main product are retained. And means for bringing the catalyst into contact with the solid in a floating state, means for retaining organic substances and by-product solid residues at the bottom of the apparatus, and means for recovering the generated useful gas components from the top of the apparatus. It is a vertical gasifier for organic substances.
In the gasifier, it is preferable to use, as the organic substance, organic waste that reacts with the gasifying agent in the heated state and gasifies. Moreover, it is preferable to perform the gasification on the heating conditions of 650-1500 degreeC.

  The present invention is a vertical reactor having a simple shape capable of efficiently performing a chemical reaction of an organic substance. In the gasification apparatus for an organic substance, the flow of a gasifying agent is used. It is a device that separates or retains solids such as catalysts and solid residues as by-products by adjusting the gas flow rate and the shape of the taper for retention of the vertical reactor using the gas flow of the raw material, The staying catalyst can efficiently contact with the gas and promote the gas composition reforming reaction or the liquid fuel synthesis reaction. Therefore, no special mechanism for separation or reaction promotion is required, and it is inexpensive and simple. It is a device that can produce gas and liquid fuel useful for efficiency.

INDUSTRIAL APPLICABILITY The present invention is used for reaction of chemical substances, and a fluid and a solid are obtained by a vertical reaction apparatus (hereinafter also referred to as “retention tapered vertical reaction apparatus”) provided with at least one taper portion in a part thereof. To promote a desired chemical reaction by efficiently contacting
One or more organic substances selected from waste such as biomass, plastic, coal, and garbage are gasified in the presence of solids such as a gasifying agent and a catalyst to convert them into useful gas, or the same gas is present in the catalyst. When converting to a useful liquid fuel by synthesizing below, the solid residue that has poisoning action and deactivates the catalyst is retained in the lower part of the reactor and the catalyst is retained in the taper part. Separation, gas is brought into contact with the catalyst efficiently, gas composition reforming reaction or liquid fuel synthesis reaction is promoted, separation of solid residue and catalyst and retention in the taper portion of the catalyst is caused by gasifying agent flow rate or raw material It is a device that performs by adjusting the gas flow rate and the shape of the staying taper.
By using this device, solids are retained in the taper by the flow of fluid, and specific reactions proceed efficiently while avoiding unnecessary or harmful reactions by reacting the retained solids with fluid or solids and solids. Can be made. For example, the organic substance and by-product residue solids are introduced by adjusting the amount of gas by introducing the organic substance, gasifying agent and catalyst as raw materials into the tapered vertical reactor for residence heated to the gasification temperature. Residue is retained at the bottom of the reactor and catalyst is retained at the retention taper to avoid deactivation due to poisoning of the catalyst by organic substances and by-products, while avoiding deactivation due to poisoning of the catalyst by organic substances and by-products. The useful gas component can be efficiently generated, and the generated useful gas component can be recovered from the upper part of the reaction apparatus.

FIG. 1 shows an example of a vertical reaction apparatus provided with a tapered portion in the present invention. (A) is a vertical reaction apparatus provided with one taper part, and (b) is a vertical reaction apparatus provided with two taper parts. In FIG. 2, the schematic block diagram of the vertical reactor which provided the taper part in this invention is shown.
In the vertical reactor with a taper for residence of the present invention, the lower part is a straight pipe having a substantially constant cross-sectional area, and has one or more staying taper parts in the substantially central part, and the upper part is a straight pipe having a substantially constant cross-sectional area. It consists of a tube. Each staying taper portion has a structure that gently spreads from the lower part to the upper part. In an organic material gasifier, a gasifying agent is flowed from the bottom to the top of the reactor. In the liquid fuel synthesizing apparatus, the raw material gas is allowed to flow from the lower part to the upper part of the reactor. As the cross-sectional area gradually increases in the staying taper portion, the flow velocity gradually decreases.

That is, U1> U2, where U1 is the flow velocity at the lower portion of the staying taper portion, and U2 is the flow velocity at the upper portion. In general, one of the parameters representing the motion of a solid in a gas is the termination velocity, which is determined by the viscosity and density of the gas and the size and density of the solid. When a catalyst having a size such that the terminal end velocity (UC) of the catalyst satisfies U1>UC> U2, the catalyst can be retained in the retention taper portion. In addition, since the size of the solid residue is determined by the raw material and gasification conditions, if the flow rate of the gasifying agent and the shape of the taper for retention are determined so that the terminal velocity (UR) of the solid residue is UR> U1, the solid residue The residue can be retained in the lower part of the vertical reactor to separate the solid residue and the catalyst.
When the solid is spherical, the terminal velocity is 2 (ρ _p −ρ) gd _p ² / 9η.
Here, ρ is the gas density, η is the gas viscosity, ρ _p is the solid density, d _p is the radius of the solid, and g is the gravitational acceleration.

  By gradually increasing the cross-sectional area of the taper from the bottom to the top and smoothing the inner surface of the taper, even if catalyst or the like adheres to the wall, it slides down to the bottom of the reactor along the wall and accumulates on the wall And a structure that can continuously contribute to the reaction.

When providing a plurality of staying taper portions, a taper portion having a wide cross-sectional area is placed at the top, and each staying taper portion is connected by a straight pipe. When there are a plurality of gas composition reforming reactions or liquid fuel synthesis reactions, by selecting the size of each reaction catalyst, each catalyst can be retained in each retention taper portion, and the reaction can be promoted sequentially.
The catalyst stays in each taper, but when solids are present in the fluid, the catalyst moves irregularly due to the influence of vortices (such as Karman vortices) generated in the fluid. Is promoted. There is no need for a special mechanism for stirring.

  Since the organic substance and catalyst used as raw materials are heavier than the gasifying agent and the product gas, when the gas does not flow, the organic substance and the catalyst are precipitated at the bottom of the vertical reactor by gravity. When the gas flows from the lower part of the reactor to the upper part, the organic substance and the catalyst are subjected to upward force by the gas flow. This force depends on the gas flow rate, the viscosity and density of the gas, and the size and density of the solid (organic material, catalyst, solid residue). When the gas flow rate reaches a certain value (end velocity), gravity and upward force balance, and the solid stays at almost the same height. Since the gas flow rate (U) is determined by the gas volume (Q) and the cross-sectional area of the reactor (S) (U = Q / S), adjusting the cross-sectional area of the reactor (S) causes the solid to stay at a specific site. be able to. When a solid stays in the vicinity of a site due to a gas flow, vortices (Kalman vortex etc.) are generated in the gas flow. Due to the influence of this vortex, the solid moves irregularly, and the gas and the solid come into efficient contact.

  In the present invention, an organic substance, a gasifying agent, and a catalyst are introduced into a gasification furnace and converted into synthesis gas, and an organic substance is gasified and a raw material gas and a catalyst are introduced into the liquid fuel synthesis furnace and converted into liquid fuel. In the synthesis of fuel, it is desirable to use a vertical reactor having a staying taper portion in the substantially central portion. As the organic material raw material used for these, any organic material can be used. For example, biomass such as wood and vegetation, thermoplastic plastic such as polyethylene, polypropylene, PET, polyacrylic and polystyrene, One or more selected from wastes such as coal or raw garbage discarded from households, factories and the like.

  A gasifying agent is supplied to the organic material gasifier from the lower part of the reactor, and the product gas and the unreacted gasifier are recovered from the upper part. By appropriately adjusting the size of the catalyst, the shape of the tapered portion, and the gas flow rate, the solid residue can be retained mainly in the lower part of the reactor, and the catalyst can be retained in the tapered portion. Since the solid residue stays in the lower part of the reactor, the solid residue and the catalyst can be easily separated. In addition, since the catalyst staying in the taper portion due to the gas flow moves irregularly in the taper portion, the product gas efficiently contacts the catalyst in the taper portion, and the gas composition reforming reaction can be promoted.

  In the liquid fuel synthesizing apparatus, the raw material gas is supplied from the lower part of the reactor, the unreacted gas is recovered from the upper part, and the synthesized liquid fuel is recovered from the lower part. The catalyst can be retained in the tapered portion by adjusting the size of the catalyst, the shape of the tapered portion, and the gas flow rate. Since the catalyst flows irregularly at the taper portion by the gas flow, the raw material gas can be efficiently brought into contact with the catalyst and the liquid fuel synthesis reaction can be promoted.

Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 2 is a schematic configuration diagram of an example of an organic material gasifier having a tapered vertical reactor for residence. The reactor is heated by an electric furnace to a temperature necessary for gasification. When the organic substance pulverized to about 1 mm, the water vapor of the gasifying agent, and the catalyst are fed into the vertical reaction tube shown in FIG. 2, the catalyst stays in the tapered portion due to the gas flow. Organic substances react at the bottom of the reaction tube to produce synthesis gas and solid residues. When the flow rate of the gasifying agent and the cross-sectional area of the lower part of the reaction tube are adjusted and the flow velocity at the lower part of the reaction tube is slower than the terminal velocity (UR) of the solid residue, the solid residue is deposited at the lower part of the reaction tube. The synthesis gas and the unreacted gasifying agent rise inside the reaction tube, and the synthesis gas and the gasifying agent further react with each other by the catalyst at the taper portion to reform the gas composition. FIG. 3 shows an example organic material gasification system using the vertical gasification reaction apparatus of the present invention.

  Gasification of a cedar (wood part) or a mixture of cedar (wood part) and a catalyst was performed using a gasification apparatus comprising a vertical reaction tube with a taper for residence or a vertical reaction tube without a taper for residence. Table 1 shows the properties (elemental analysis) of the cedar (xylem) used, and Table 2 shows the properties (catalyst components and content) of the catalyst used.

Determination of gasifying agent amount (water vapor amount) by model experiment A model experiment was conducted by flowing nitrogen gas into a tapered vertical reaction tube for retention of transparent plastic at room temperature and putting a catalyst or solid residue. When the amount of nitrogen gas was about 12 L / min, the catalyst stayed in the staying taper part, and the solid residue stayed in the lower part of the reaction tube. When the temperature and viscosity are corrected, this nitrogen gas amount corresponds to a water vapor amount of about 1.4 g / min at 650 ° C.
When the amount of nitrogen was about 32 L / min, a solid residue stayed in the staying taper portion. When the temperature and viscosity are corrected, this nitrogen gas amount corresponds to a water vapor amount of about 3.9 g / min at 650 ° C.

Gasification of cedar or a mixture of cedar and catalyst The reaction temperature for gasification was 650 ° C. The proper catalyst-free gasification temperature of cedar is known to be 900 to 1000 ° C., and 650 ° C. was a gasification temperature at which the effect of the catalyst appears remarkably. The water vapor amount of the gasifying agent was set to 1.4 g / min or 3.9 g / min. Gasification was performed using a vertical reaction tube with a taper for residence (stepped) or a vertical reaction tube without a taper for retention (straight) under the condition of combining the amount of water vapor and the reaction tube (conditions 1 to 4). For comparison, gasification was performed using a reaction tube without catalyst and without a taper for retention (condition 0). Table 3 shows each of these experimental conditions.

A predetermined amount of water vapor as a gasifying agent was passed through the reaction tube. A raw material cedar or a mixture of cedar and catalyst was weighed in a raw material feeder and then attached to the upper part of the reaction tube. The raw material was supplied through a raw material introduction tube connected from the top to the bottom inside the reaction tube. The time for the raw material to pass through the introduction tube was about 0.1 second, and was supplied to the lower portion of the reaction tube with almost no reaction. The cedar used for one gasification was about 11 g, and the catalyst was 20% by weight of the cedar. About 0.7 g per minute was fed to react.
The total amount of the resulting product gas was recovered from the upper part of the reaction tube, and six types of H ₂ , CO, CO ₂ , CH ₄ , C ₂ and C ₃ were analyzed using a gas chromatograph. Moreover, after gasification was complete | finished and the reaction tube cooled to normal temperature, the solid residue decomposed | disassembled the reaction tube and collect | recovered.

A liquid fuel composed mainly of methanol was synthesized from the resulting product gas.
In general, methanol synthesis is represented by the following chemical formula, and hydrogen and carbon monoxide are useful gases that can be used for methanol synthesis.

2H ₂ + CO → CH ₃ OH
As can be seen from the above equation, the desired gas composition is [H ₂ ] / [CO] = 2. Table 4 shows the results after the gasification reaction (H ₂ concentration, CO concentration, [H ₂ ] / [CO] and solid residue amount).

[H ₂ ] / [CO] in Experiment 0 is 0.53, and in Experiment 1
[H ₂ ] / [CO] is 0.81, indicating that the catalyst has a gas composition improving effect. In addition, [H ₂ ] / [CO] in Experiment 2 was 1.12, indicating that the gas composition reforming effect of the catalyst was promoted by the catalyst remaining in the tapered portion.
Since the solid residue production rate in Experiment 1 is 14.1% and the solid residue production rate in Experiment 2 is 12.9%, it can be seen that the catalyst does not react with the solid residue and the solid residue and the catalyst are separated. In addition, [H ₂ ] / [CO] in Experiment 3 is 1.54, the solid residue production rate is 11.9%, and [H ₂ ] / [CO] in Experiment 4 is 1.45, which is a solid residue. The production rate is 11.2%, which is almost the same. The structure of the reaction tube has little influence on gasification, and it was experimentally confirmed that gasification reactions such as gas composition and solid residue production rate depend on whether or not the catalyst stays in the tapered portion.

Part of the use of organic materials such as biomass, plastics, coal, and garbage such as wastes as raw materials for energy and chemical synthesis by gasification and synthesis of liquid fuels using gas as raw materials It is clear that it will become more and more important in the future as oil resources become tighter, and its use in industry will also expand. By reducing the temperature of the reaction by the catalyst, it is possible to use inexpensive materials for the apparatus and simplify the structure and operation of the apparatus. Therefore, the application is expected to expand in the future.
However, a by-product such as a solid product generated by gasification has a poisoning action and deactivates the catalyst. Therefore, the by-product must be separated from the catalyst. In addition, the product gas or the raw material gas and the catalyst must be efficiently contacted.
The present invention provides an apparatus for realizing separation of by-products and catalyst and efficient contact between product gas and raw material gas and catalyst by a simple method in the above-described current state, and is used in the industry. Is expected to expand.

An example of the vertical reactor which provided the taper part in this invention is shown. (A) is a vertical reaction apparatus provided with one taper part, and (b) is a vertical reaction apparatus provided with two taper parts. It is a schematic block diagram of an example of the vertical reactor with a taper for a residence used for the Example of this invention. 1 is an example organic material gasification system using the vertical gasification reaction apparatus of the present invention. (A) is an overall view of the gasification system, and (b) is a vertical reaction tube provided with one tapered portion.

Claims (7)

A vertical reaction apparatus used for reaction of a chemical substance, comprising a plurality of tapered portions in a part of the apparatus, a supply means for introducing fluid, catalyst and organic substance into the apparatus, and a flow of the fluid the residence by adjusting, causes retained the catalyst tapered portion, and the reaction means for contacting the catalyst and the fluid and / or organic material that its staying in suspension, the solid residue produced from organic material in the bottom portion of the device And a means for recovering the reaction product, a vertical reaction apparatus provided with a plurality of taper portions for catalyst retention.   The vertical reactor according to claim 1, wherein the raw material gas and the catalyst are introduced from the lower part of the apparatus and used for the synthesis of the liquid fuel.   The vertical reactor according to claim 2, wherein the synthesis of the liquid fuel is performed under heating conditions of 100 to 300 ° C.   The vertical reactor according to claim 2 or 3, wherein the source gas is a gas containing carbon monoxide and hydrogen, and the liquid fuel is methanol.   A vertical gasification apparatus used for gasification of an organic substance by introducing an organic substance and a gasifying agent, wherein at least one solid retention taper portion is provided in a part of the apparatus, from the lower part of the apparatus By adjusting the means for introducing the organic substance, the gasifying agent and the catalyst, and the amount of gas to be introduced, the catalyst is retained in the retention taper portion, and the useful gas of the main product, the gasifying agent and the catalyst are solidified. An organic substance comprising: means for contacting in a floating state; means for retaining a solid residue produced by organic substances and by-products at the bottom of the apparatus; and means for recovering generated useful gas components from the upper part of the apparatus. Vertical gasifier.   6. The organic substance gasification apparatus according to claim 5, wherein the organic substance is an organic waste gasified by reacting with a gasifying agent in a heated state.   The gasification apparatus for organic substances according to claim 5 or 6, wherein the gasification is performed under a heating condition of 650 to 1500 ° C.

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