DE2657856A1 - REACTOR SYSTEM FOR A FLUIDATE BED - Google Patents

Description

PATENT LAWYERS

Dipl.-Ing. P. WIRTH Dr. V. SCHMIED-KOWARZIK Dlpl.-Ing. G. DANNENBERG - Dr. P. WEINHOLD ■ Dr. D. GUDEL

281134 6 FRANKFURT AM MAIN

TELEPHONE (0611}

237014 GR. ESCHENHEIMER STP.ASSE

December 20 " ¹ 19? 6
Gu / Schu

COMMOm'ffiALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANIZATION Limestone Avenue
Campbell / AUSTRALIA

Reactor system for a fluidized bed

827/0930

The invention relates to tubular reactors in furnaces with a fluidized bed. It is particularly applicable to a self-contained reactor system for carbonaceous Materials in which at least a portion of the coke (char) or the gas or tar produced in the reactor comes from the fluidate Too "combustion in bed fed v / ir-K urn to maintain desr.temperature.

Systems in which chemical reactors and / or tubes with a fluid or particulate material are completely or partially immersed in a fluidized bed in order to control the temperature of a reaction or to draw off the poor or cold from the bed are known. For example, D »Kunii and 0. Levenspiel describe a chemical reactor from CF in their book" Fluidization Engineering ", page 24. Adams et al, mentioned in "Industrial Engineering Chemistry", Volume 46, page 2458 (1954). U3-r5 2,674,61-2 and 3,562,115 also describe reactor systems controlled by a fluidized bed (the first-named PS a tubular reactor system, the second-named PS a retort for carbonization immersed in a controlling fluidate bed), the same subject describes Australian patent application no. 51 833/73 (this document describes a kiln or kiln which is supported by an I fluidized bed, which is also, for example, for freezing ^r% on objects may be used, for example, crabs). It is also known to generate steam using pipes carrying water that are immersed in a hot fluidized bed. Describes a recent publication that such S3 ^r stems, is the article by HB Locke in "Journal of the Institute of Fuel", Sept. 1974, pages 190-197.

Use of systems with a fluidized bed in these cases is not difficult to grasp because heating by a fluidized bed has a number of advantages compared to gas convection heating. Such advantages are:

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I. The bed temperature can be set relatively low and uniform, eliminating the risk of hot spots and burnout is reduced and thinner-walled tubes can be used;

II. The outer tube surfaces "become clean and relative kept free from corrosion, erosion and debris;

III. The result is high. Heat transfer numbers - about an order of magnitude higher than those for similar tubes in ovens with hot, convective gases fewer metal pipes can be used in the heat transfer system, which in turn increases the cost of capital of the system decreased.

In Australian patent application 83 215/75 it is mentioned that particulate, combustible or partially combustible Material (e.g. scrap material from coal washing) is fed to a fluidized bed so that the combustible material is burned within the fluidized bed and the temperature of the bed is maintained without additional fuel having to be added. The above Invention, in one of its aspects, provides an advantage over this system because coal or similar material is in dry particulate or in paste or slimy form carbonized or otherwise in a vessel can be made to react, which is immersed in a fluidized bed. At least part of the combustible Product of the reaction can also be burned within the bed to maintain its operating temperature. An essentially self-contained procedural system is therefore developed (one, with the exception of cases, For example, the treatment of waste or low-viscosity sludge, where the conveyed material is not sufficiently carbon-containing Material contains all of the heat needed

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to supply to maintain the temperature of the fluidized bed; in these cases some additional oil or fuel is also burned in the fluidized bed). As another Improvement, the fluidized bed can essentially also be used for separate steam generation. The one with it Produced steam is used to pressurize the coal to transport through the reactor, or to remove heat and / or power from the system.

According to the invention comprises a reactor system for particulate, fluid or suspended material, of which at least one Part of is carbonaceous, has the following characteristics:

I. A hot fluidized bed;

II. At least one tubular reactor which passes through the fluidized bed and the particle-shaped Material carrying fluids or suspended material;

III. Means to the gaseous, liquid and solid reaction products at the outlet from the tubular Reactor or to separate from at least one of the tubular reactors and

IV. Means to deliver at least a portion of the reaction products to the fluidized bed for combustion there to feed.

The tubular reactor can be of any suitable shape and have alignment in bed. It should enable a satisfactory throughput of the feed material of the reactor. The throughput can be done pneumatically or mechanically. If the throughput is effected or assisted by gas, that can Gas have been preheated, the waste heat of the fluidized bed can be used. Mechanical support

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of throughput is essentially achieved using an auger or vibrator, in accordance with known techniques. The conveyed material can be passed through a series of tubular reactors several times if necessary. This can involve recirculation of a part of the estea Frod-iktgaso :;> de f .; tar oöe-r of the coke or the inert hot bed -Particles with the supplied supply mean "Reactions can take place under high or low pressure. The temperature of the fluidized bed depends essentially on the type of reaction to be carried out in the reactor.

The invention is illustrated below with the aid of exemplary embodiments explained in more detail, from which other important features result. The figures show schematically fluidized bed reactor systems according to the invention.

In Fig. 1 is a tubular reactor. 10 horizontally within a fluidized bed 11 of particulate! Material arranged. A carbonaceous supply material (in this case Example particulate material 13 which is in a storage hopper 14-stored) is transported through the reactor 10 using gas or steam, which thereby has been preheated in that it has passed through pipes 18 which prevail in the area of waste gas (flue gas) above the bed. As a result, substantial thermal energy is recovered from the exhaust gas from the fluidized bed and the combustion gas.

The fluidized bed is typically operated in the temperature range between 700 and 1100 ° C., depending on the reaction required in the reactor 10. For simple carbonization of coal at low temperature, which occurs at temperatures of about 500 or 600 ° C, depending on whether the residence time of the coal is long or short, the fluidized bed is kept at a temperature of about 750 ° C. The reaction tubes can consist of austenitic steel (for example steel tubes with a diameter of 50 mm, which are traditionally used by Rohrervärn-arn! Yes).

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NitLseher steel can also be used for reactors in which a liquid and steam hydrogenation of coal takes place under pressure using a solvent and hydrogenation gas. At reacciorian with higher temperatures (for example the gasification ocl ^ r gas hydrogenation of coal (liydrogasixikation) or da :: i columns of hydrocarbons, ba Ki ^ pIeJ ev: eiaQ of brown cabbage ivA'o ¹ ':?.) However v- - ^ r the fle tallrohre required for the reactors, which can withstand the heat and corrosion.

Although only a single tubular reactor 10 in FIG As shown, rows of tubes can also be used to increase throughput.

Up to about 50 ° of the heat supplied to the fluidized bed can be absorbed by the tubular reactors. In the case of a particulate coal material fed in at the entrance, it is necessary to remove some volatile constituents and tear, and to produce coke (char), even with short periods of time in the order of 1 sec. A cyclone 15 at the outlet end of the tubular reactor 10 enables the gas and the tar products to be separated from the solid coke and carried out via a line 16. The coke is collected in a vessel 17. Sufficient coke to maintain the temperature of the Fluidatbettes by combustion, is passed from the vessel 17 via a line 12 (or by other suitable means, as in the description are mentioned Australian Patent Application 215/75 S3 shown). Alternatively, product gas or tar can be added to the fluidized gas or the outflowing gas from your fluidized bed for the same purpose.

If it is necessary (for example to increase the yield To optimize gas and tar products), it can be twofold Pass-through system (for example that of Fig. 2) is used will. (In this figure as well as in the other figures

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Similar or identical components are provided with the same reference numerals as in Fig. 1.) This concept can be extended to general systems with several passes, where the desired reaction requires successive heat treatment of the stock in several stages. This treatment carried out in several stages \ ^ mn in aine-r Ksi'üe of tubes which are connected in series and / or parallel, with possibly only a part of?) Of the various products, it is used a preceding stage egg.

The temperature in the reactor tubes depends, among other things, on the rate of heat transfer distributed through the tube, the Bed temperature, the enthalpy of the flow rate and the reaction products, the heat of reaction and the arrangement of the tubes in the fluidate chamber (i.e. inside the bed or in the Smoke gases above the bed).

Figure 3 shows another modification that may be applied to the systems of Figures 1 and 2, some of which may be used Bed material is run down via a hood and is mixed with the particulate stock material when this is passed through the reactor tube 10. In this arrangement, the entrained gas stream is - if necessary, additionally preheated, and the heat transport across the reactor tube is supported. This arrangement also prevents clumping, when the flow has a tendency to clump or coke when heated.

Figure 4 shows an embodiment with preheating similar to Figure 3 with the exception that the product coke instead of the inert. Bed material is used. This prevents the product coke from being diluted with the bed material.

The embodiment according to FIG. 5 uses a coiled reactor tube 10, as a result of which longer residence times of the supply

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materials in the reaction zone (0.1-10 seconds).

In the embodiment of Figure 6, a vertical reactor tube is used. The particulate flow is fed in at the top and coke is withdrawn from the bottom. Residence times in the reactor of 1-100 seconds can be used in this embodiment can be achieved. The particles in the pipe can be moved or made into a fluid as they move are in the reaction zone, through one in the opposite direction flowing gas stream .19, which assists in the collection of tar and volatiles from the production or supply stream.

An alternative embodiment for achieving long residence times is shown in FIG. 7, where the feed stream is fed in at the bottom of a reactor of the type according to FIG but the reactor tube should be inclined). The conveying flow is transported through the reactor tube by being entrained in a conveying gas. As a result, the larger particles have longer residence times in the reaction zone than smaller particles. This is generally necessary for equivalent conversion of the larger particles. The inclination of the reactor tube facilitates the removal of volatile products from the flow.

The U-shaped reactor tube according to FIG. 1 makes it possible that the conveyed material and the coke obtained several times in one cycle is performed before the product coke is withdrawn. This can reduce the residence times of the solid particles in the reactor can be increased to 100-1000 seconds, depending on the volume of the stored solid particles and depending on the Circulation in relation to the supply or withdrawal of coke. The solid particles flow down in a moving one Bed 20 within a vertical leg of the U-shaped tube and are led back up again in the other Legs, being carried along by a conveying gas

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which is supplied at a gas inlet 21. A storage hopper 22 preferably contains hot bed material to be taken along in the circulating gas to facilitate circulation and heat transfer. Additional solid particles will be withdrawn continuously or intermittently from the top (as shown in the figure) or from the bottom of the reactor.

Although in 'the described exemplary embodiments' stocks with solid particulate material, other stock materials can also be used, for example Sludges or liquids containing carbonaceous materials and a solid, liquid or gaseous one Result in product that can be burned in the fluidized bed to maintain its temperature. at Sludge-like materials can be dewatered either as in the Australian patent application 83 2 * 17/75, or in an upstream drying tube reactor as the first pass or first passes of a multi-stage treatment system according to the invention.

Different types of reactions can be carried out in one system. For example, in the case of coal, sludge can be dewatered (in the case of treating waste from a coal laundry) in a drying tube reactor, the dried sludge can be carbonized at low temperatures in a multi-tube carbonation reactor to produce various tar products, gas and coke, some of the tar can be thermally cracked or dealkylated to produce lighter aromatic hydrocarbons, ethylene and pyrolytic carbon, some of the coke3 can be steam gasified to produce synthesis gas and activated carbon, and some of the coke can be used as fuel in the Burn the furnace to add heat to the various reactions and to generate steam and energy. Such an integrated scheme converts ¹ coal into oil, gas, activated carbon, coke., Steam and energy.

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The system of the present invention also finds useful application in the recovery of products from industrial and municipal waste. In addition, it has applications in the heat treatment of minerals through processes such as drying, roasting, calcining, reducing (for example of iron ore) and other pyronietallurgical processes Procedure when using parallel reactor systems. A The system treats the carbonaceous materials to provide the heat for the fluidized bed. Similarly, the present invention can be used for distillation and pyrolysis of solid and liquid organic materials can be used.

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Claims (13)

1. Fteactor system for particulate, fluid or suspended Material at least part of which is carbonaceous, marked by I. a hot fluidatbött, II, at least one tubular reactor running through the fluidized bed goes and the particulate material, the fluid or the suspended material carries with him III. Means to. the gaseous, liquid and solid Reaction products at the outlet from the tubular reactor or from at least one tubular reactor Separate reactors and IV, means to at least part of the reaction products to the pluidate bed for incineration there to feed. 2. reactor system according to claim 1,
characterized in that means are provided for the supply of gas for conveying the material through the tubular reactor or reactors. 3. Reactor system according to claim 1 or claim 2, characterized in that that the separating means are designed as a cyclone (15), 7 0 3 8 2 7/0930 INSPECTED 26 ^f V / 856 4. Reactor system according to one of claims 1 - J, rl ο. you raw marked, then the tubular reactor (10) or at least one of the tubular reactor is twisted to enlarge the dwelling tent in the reactor or reactors see below (FIc-3K 5. ^{Reaktors3 '-} 3 "texT: according to one of claims 1 - 3, d α durchgeke η η;: 9 I η ο t that the tubular« reactor (K)) or at least one of the tubular reactors makes an angle with the horizontal ο η includes and that the material is conveyed up there through (Fig. 7). 6. reactor system according to claim 1,
in that the tubular reactor (10) or at least one of the tubular reactors is located vertically within the fluidized bed (11), that the treated material is in particle form and is passed through the vertical reactor or reactors through P ^ hv / Erkraf t is promoted, and that means are provided for the supply of gas, namely in a countercurrent to the particle bromine through the vertical reactor or reactors, whereby the particles contained therein are moved or fluidized (Fig. 6) . 7. Reaktorsysten according to claim 2, dadurc Ii geke η η: t verifiable η et that the rohrföraige reactor (10) or at least one of the tubular reactors is substantially U-shaped, that the particulate is present material to be treated, \ vad that the means for the supply of gas the gas can be taken at a rate _sufficient} teilchenxörmige around the material in the gas stream through the or each reactor take-fÖrmigan U (Fig. 8). -3 7 Π 9 ft 2 7/0 9 3 0 8. Reactor system according to claim 7, characterized marked that the or each U-shaped reactor (10) is arranged in such a way is that the plane containing the arms of the U forms an acute angle with the vertical. 9. Reactor system according to one of claims 1-8, characterized in that a second tubular reactor (10) or a series of tubular reactors is provided which are passed through the fluidized bed (11), at least some of the reaction products from the first tubular is promoted reactor or series of tubular reactors through the second reactor or reactors for a subsequent treatment B _e (Flg. 2). 10. Reactor system according to claim 9, characterized in that at least one further tubular reactor (10) or a series of tubular reactors is provided which for a further treatment of at least part of the reaction product or products of a previous treatment stage through the fluidized bed ( 11) go. 11. Reactor system according to one of claims 1-10, characterized in that that means (118) are provided to pull particles out of the hot fluidized bed (11) and these with the to mix the material to be treated, whereby the material is pretreated. 12. Reactor system according to one of claims 1 - 10, characterized in that that means (15) are provided to solid particles from the. to withdraw solid reaction products and these withdrawn -4 709827/0930 Particles are mixed with the material to be treated, thereby pretreating the material (Fig. 4). 13. Reactor system according to one of claims 1 -12, characterized in that a heat exchanger (18) extends inside or over the fluidized bed (11) is located (Fig. 1). 709827/0930