CS390191A3 - Process and apparatus for carrying out regenerative fixation of sulfur - Google Patents

Description

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The present invention relates to a process for the regenerative desulfurization of process gas by recycling the mass in which sulfur-containing gases are brought into contact with a particle of absorbent material that forms a fluidized bed and conducted together with an absorbent material through a reaction zone where; the sulfur is absorbed by the absorbent material, then the absorbent with the sulfur bound from the process gas is separated. Operating gas Conducted for further processing and sulfur-laden absorbent material To be regenerated to separate sulfur from the absorbent. The sulfur separated from the absorbent for further processing and the sulfur-free absorbent is returned to the process gas.

The invention further relates to a device comprising a desulfurization reactor with a fluidized-bed chamber formed by particles of an abrasive into which a process gas, a reactor chamber of a fluidized-bed chamber, separators in the upper part of the reactor chamber, in the reactor chamber are fed. wherein the absorbent is saturated with sulfur from the process gas, a process gas discharge conduit, a regeneration reactor, at least one transport conduit through which the sulfur-saturated absorbent is fed into the recovery reactor, the regenerated gas conduit and conduit for the removal of the separated sulfur vapor recovery reactor and a return line for returning the absorbance from the bottom of the recovery reactor to the fluidized bed.

BACKGROUND OF THE INVENTION The central problem of the desulfurization process is based on the direct binding of sulfur, e.g. calcium, with a large amount of waste being produced. Furthermore, when water-soluble compounds of waste generated form the danger of diversion of waste by accumulating waste, it is evident that processes have long been developed where the amount of waste generated is minimized. A large number of sulfur oxides binding processes are now known in which the final bonding takes place in the form of a solid phase elemental sulfur. In principle, As an auxiliary step in all such procedures, the sulfur oxide content must first be concentrated to be very high so that sulfur production is economically feasible. In a concentrating process, the sulfur oxides are first bound to an absorbent having suitable properties, which is regenerable, in which case the sulfur is released and the absorbent is. thus capable of producing C6 bound sulfur. Binding of sulfur and sulfur deposits in absorbance v

They are carried out in separate reactors between which the absorber is conveyed in such a way that the absorbent saturated sulfur is fed to the recovery reactor and accordingly the regenerated absorbent is fed to the sulfur desulphurisation reactor. At the same time, the purified gas is discharged from the reactor and sulfur It is mainly removed from the regenerator. The transport of the absorbent must be carried out in a stable manner so that the mixing of the gaseous components between the reactors is small. Currently, the devices are based on a rigid bed, and fluid bed technology to perform a regenerative sulfur binding process. Because temperature control is. very important in the case of cooperative propagation, the prospect of a solid-state technique; not favorably due to the difficulty of regulating: temperature1 control of reactions. Thus, from the point of view of transporting the active mass, it would be important to use a finely divided absorbent that will be used; difficulties in the solid bed reactor. Accordingly, sufficient space is required to achieve the quantity of recycled mass and sufficient separation capacity, therefore, the diameters of the fluidized bed reactor are large. Since the amount of gas of the recovery reactor is typically only 1-3% of the gas of the cross-linking reactor, the problem of large diameter is mainly connected to the desulfurization reactor.

Podstatawyaálezu

BACKGROUND OF THE INVENTION It is an object of the present invention to provide a device for the above-mentioned disadvantages. The process according to the invention is characterized in that the sulfur-saturated absorbent, which has been separated from the process gas, is prior to conduction to regeneration to control the temperature of the recycle mass of the reactor.

The device according to the invention is characterized in that the chamber

The reactor T has a smaller cross-section in the gas flow direction than the fluidized-bed chamber, and the conveying pipe laying. bringing the sulfur-saturated absorbent into the recovery reactor, has a heat exchanger to control the temperature of the absorbent and thereby the entire reactor.

Thus, in the process according to the invention, in the reactor, the sulfur binding agent on the recycled mass occurs, which is a finely ground absorbent, such as e.g. metal oxides or better metal oxide mixtures, eg zinc oxides (Ů 0.05 - 0.3 mm), a considerable gas velocity (3-6 m / s) can be used. For this case; the desulfurization reactor diameter is not extremely large. If a bubbling fluidized bed technique was used, the gas velocity would be less than 0.5 m / s, regardless of the size of the absorbent particles. The gas stream in the recovery reactor is typically only 1-3% of the gas flow in the desulfurization reactor, so the diameter of the recovery reactor may not be large, although the gas velocity is reduced to a range of speeds v. fluidized bed fluid bed so that it is about 1 m / s.

The stabilization of the desulfurization reactor temperature is carried out in accordance with the main concept of the invention, in such a way that the cooling surfaces are largely arranged in the recycle or recycle material of the recycled mass, in which the solids stream passes through the die, while the efficiency of the cooler is. automatically adjusted in accordance with the gas stream being processed. Further, the temperature can be controlled, if necessary, by using a separate jet-cycling gas to adjust the cooler efficiency.

Thus, a method for controlling solids flows between reactors is an important part of the invention. This control method is performed by pulse dispensers and; Principle of Operation Following; a plug-like layer is located at the beginning of a pulse dispenser from the bottom of which the solids are dispensed by the pulse gas in a pneumatically most convenient manner. Controlled recirculation of solids between the desulfurization and regeneration reactor is achieved by combining the desulfurization reactor with a half-feed with a recovery reactor and vice versa. Λ Overview; pictures in the drawings

The invention will be elucidated with reference to the drawings, in which: FIG. 1 and 1 a schematic representation of a mass recycling reactor according to the invention and another embodiment of a recycling reactor, partially open section, according to the invention.

The recycled mass reactor shown in the figure includes a desulfurization reactor having an inlet port 1 through which the treated gas and possible recycled gas are fed into the fluidized bed chamber 2 located at the bottom of the recycle reactor. and

The bottom of the reactor, ie the fluidized bed chamber 2 is. longer in | transverse cross-section in the gas flow direction than the reactor working chamber 34 which is located above the fluidized bed chamber. Thereafter, a high particle density can be maintained at the bottom of the reactor without excessively increasing the particle density at the inlet of the reactor space. 5 in the circular chamber of the reactor 3 shown in FIG.

The gases and absorbent are fed to the reactor at the top As slurries are fed to the cyclone 4 flaps located at the top of the recycle reactor, the flaps serve as a separator and flow control. The slurry is fed tangentially to the chamber of the cyclone 5 'where the absorbent particles are separated from the gas. Pure gas is passed through a discharge line, i.e. & ampoule, in the center of the cyclone and the mass of particles separated on the walls of the cyclone falls into the separator chamber. 7, located below the separating plate. The purpose of the distribution chamber 7 is. dividing the recycled portion of the mass by a symmetrically transversal cross-sectional area of the cooling member, i.e., the heat exchanger 9, which is located symmetrically in the axial direction. This is a suitably shaped nozzle plate 8, FIG. 1a shows a schematic cross-section of the reactor at point A-A showing how the reactor is constructed. The heat exchanger in the center of the reactor is re-circulating. The heat exchanger 3 has several return tubes or heat exchange tubes 9a by means of which the recycled mass is returned through the cooler 9 to the bottom. There is a supply: coolant,

Such as gas, air, water, or other liquid or vapor that flows from the lower end of the cooler through line 11 to the upper end, ie. countercurrent to the direction of movement of the recycled mass. The cooling of the re-cycled mass takes place through the outer surface of the tubes 9a, which flows through them.

For supplying gas to the recycling reactor, Is. the bottom cone is located at the lower end of the cooler 9, the free end of the cone is no more than 10% of the cross section of the circular space. Internal and external pipes for coolant gas or other medium flow to cooler, indicated by numbers 11 and 12.

FIG. 1 shows a regeneration reactor 13 which is arranged circularly around a desulfurization reactor 2. A feed line for regeneration gas, such as steam or other suitable gas, is designated by number 14, number 13 indicates a circular regenerative chamber, FIG. 20 pipes for sulfur-containing gas emerging from the regeneration. a transport pipe, i.e., a pipe 16, to the bottom of the recovery reactor. The end of the chiller. 9 forms a vertical front portion of the conduit 15 where the ab-sorbent forms a sulfur-sealing layer. A secondary horizontal pipe 16 and a gas supply pipe 19, at the right end of said horizontal pipe 16, where it forms an extension, is fed in a pulsed manner, a gas and an absorbent sulfur-filled sulfur. transported via line 16 to the recovery reactor 13 ... Number 17 Indicates a return line for the regenerated absorbent that is connected to the bottom of the recovery reactor. The regenerated absorber forms a second sealing layer in the vertical portion of the said conduit, from where the gas essentially transports the absorbent into the desulfurization reactor by the pulse process again. The solids sealing layer serves as a seal and is formed by flowing rigid materials in a vertical conduit 15 or 17, in which the solids level is maintained high enough for the horizontal portion of the conveying pipe. If the gas is not sucked into the conveying pipe by the pipe. 19 or 18, the flow of solids is stopped, whereby these cannot themselves move into the horizontal conveying line. If the gas is fed into the conveyor line, the absorbent layer in the vertical duct begins to flow down in a closing manner while the bottom of the absorbent is conveyed along with; gas. The impermeability will remain unaffected by the gas in this state. The solids conveying pipe is connected to the lower end, a vertical portion of the pipe, to which the solids are conveyed pneumatically by a suitable carrier gas by means of its continuous flow or pulsation. In the desulfurization reactor, the characteristic gas velocity, calculated on the inlet of the cross-section 3, varies between 3-6 m / s. Water-Sulfurizing Reactor The density of the suspension, v. in the lower part, in the range 50-300 kg / m 2 and in the top part 5-30 kg / m 2, the temperature range varies between 450-150 ° C and is determined in accordance with the chemical kinetics of the desulfurization reactions. It is important that, when used in a mass recycling technology, it can be set to the desired value throughout the desulfurization reactor. In the recovery reactor, where. The gas stream is very small, compared to the gas flow in the desulfurization reactor, very small gas velocity can be used without substantially increasing its dimensions. A preferred solution in the technique of these devices is to dispose of the regeneration reactor in accordance with FIG. 1, which is located rotationally around the desulfurization reactor. A suitable speed in the recovery reactor is U, 2 - 1 m / s, apart from the finely divided absorbent. The average density of the slurry in the fluidized bed zone of the reactor is preferably in the bubbling state 10Q-SLJQ kg / m2.

The temperature is determined in accordance with the regeneration reaction kinetics and varies within 7UQ. - 13 ° C. The regenerative reactor temperature range is narrow for most absorbents, so it must be possible

Control its temperature precisely. Since the thermal energy release is small, the fine temperature control can be performed by a direct method based on the parow supply. In most cases, water is the most preferred cooling medium.

FIG. 2 shows another embodiment of the reactor according to the invention, in a partially open section. Fig. 2a shows a real desulfurization reactor, with sulfur-containing gases being fed through the conduit shown to the right. From there they are further fed to the fluidized bed chamber 2, where it flows through the fluidized bed material and further to a circular bed 3 into the upper part of the reactor, where they are directed in the flow direction by the flaps 41 and flow into the separator chamber 5 where it is of these, the recycle material, i.e. the sulfur-saturated absorbent, is separated. The gases are sucked off in the manner shown in Fig. 1, through line 6 from the separation chamber 5, and the absorptive material falls down from the separator chamber 5 and falls through the recycle material line 5a into chamber 2. Part of the absorbent material falls into the vertical the discharge conduit 15, from where it is directed to the horizontal portion of the discharge conduit 16, from where it flows. It is conveyed to the recovery reactor by means of a gas supplied through line 19. The regeneration reactor is in principle similar to a desulfurization reactor. The regeneration gas or steam is fed to the bottom of the recovery reactor via line 14, from where the fluidized bed chamber is fed to the chamber 16 as regenerative agents, and flows further through its orbital portion, i.e.. The regenerated chamber is separated from the regeneration gas and the vapor which entrains the sulfur is discharged via line 2D located in the center of the discharge chamber. The absorbent material separated in the separation chamber b falls further down through the second recycling line 7 and back into the chamber 13 and again comes into contact with the regenerating gas or steam. However, part of the recovered material falls again in the return pipe, tt. a conduit 15 * and further into the horizontal portion 17 at: the lower portion of the same conduit through which it is. the regenerated absorbent is conveyed to the desulfurization reactor chamber by means of the transport gas supplied via line 18. In the case of the desiccant reactor, 2, the heat exchangers are positioned around a horizontal conveying line, ie, a line 16, leading from the desulfurization reactor to the recovery reactor, and around the return line 17, for the absorbent. Cooling medium Is. it is fed to a heat exchanger 21 located around the conveying line 11, via line 22 and discharged via line 23, the heat exchanger being operated on a counter-current principle. Accordingly, the coolant is supplied to the heat exchanger located around the return line 17 via line 22 ' and is discharged by the tube 23 ' 24 and 24 * around the desulfurization and regeneration reactor. To these heat exchangers or coolers, the heat transfer medium is fed and discharged therefrom by means of a pipe 11, 11 11, In the foregoing description and in the figures, the invention has been construed as an example only, and the example is not limited to the description and drawings. 5. Except for the reactor equipment constructed as a single unit with a stable body, the separating devices may be used in the manner shown in Fig. 2. In this case, the desulphurisation reactor may be constructed with respect to the efficiency of the sulfurization and the regeneration reactor may be constructed. In another way, specifically with regard to the regeneration efficiency.

Claims (10)

PATENT RATES ilsob Ρ regenerative desulphurisation of the recycling of the mass in which the sulfur-containing gases are contacted with the absorbent particles. which forms a fluidized bed, and passes together with the absorbent reaction zone where sulfur is bound to the absorbent material, and the sulfur-absorbent absorbent is removed from the process gas which is further processed for further processing and absorbent saturated with sulfur. Conducted into regeneration where the sulfur from the absorbent is separated off and processed for further processing, and the sulfur-free absorbent is returned to contact with the process gas, characterized; wherein the sulfur-saturated absorbent which has been separated from the process gas is cooled down before regeneration. to control the temperature of not only the recycled mass, but also the reactor. 2 ,. Fastening according to claim 1, characterized in that it is cooled. realized in heat exchangers (9, 21), which is formed in the conveying line (15, 16) in order to regulate the flow of gas and the absorbent is conveyed from this layer to the regenerator a reactor (13) by means of a pulsed gas supplied to the conveying line (16) and a second closing layer of regeneratedabsorbent is formed at the lower end of the recovery reactor (13), the absorbent being conveyed from the secondary closing layer to the flushed bed by pulse gas supplied to the gate piping (17). 9 Back Qb 3. The process according to claim 1 or 2, characterized by: It is regulated by supplying a suitable recycled gas or equivalent medium to the flushed bed. - 9 - 4, Faotup of clause 2 or 3, characterized in that the fluidized bed employs particles of material of at least two grades of granularity so as to achieve a suitable density for the suspension. The material consists of a material of substantially smaller diameter, preferably 0.05 - 0.3 mm. 5. Pootrup according to any one of the preceding claims. characterized in that the absorbent comprises at least metal oxides or mixed metal oxides. > Apparatus for carrying out the process according to item 1, comprising a fluidized bed reactor (2) having a fluidized bed of particles of finely divided absorbent to which the process gas is fed, the reactor chamber (3), above the fluidized-bed chamber (2), separators in the upper part of the reactor chamber (3) for separating the absorbent saturated with the process gas, the exhaust gas line (& / for operating gas discharge, the regeneration reactor (13), at least One conveyor line (15, 16) for conveying the sulfur-saturated absorbent to the regeneration reactor (13), the conveyor-generating gas line (20) and the separated sulfur out of the regeneration reactor (13) and return line (17) / for returning the absorbent from the lower part of the regeneration reactor (13) to the fluidized bed, characterized in that the reactor chamber (-3) has a smaller cross section in the gas flow direction than the fluid chamber m, and that the absorbent conveyor line saturated with sulfur into the recovery reactor (13) has a heat exchanger (9, 21) for controlling the temperature of the absorbent and the actual ring reactor. 7. Apparatus according to claim 5, characterized in that the fluidized bed of the chamber (2), the reactor chamber (3), and a portion of the conveying pipe (15, 1 & /) transport the absorbent to the regenerative reactor are designed to be substantially coaxial-cylindrical, so that a portion of the conveying pipe (15) conveying the absorbent to the regeneration reactor is above the fluidized bed chamber (2) substantially coaxially thereto, and that the reactor chamber (3) is constructed around the conveying pipe as a circular pipe, and in the top of the reactor chamber (3) It is a cyclone chamber (5) where ILj - Is. flow control, so that the slurry formed by the process gas and the absorbent is directed tangentially to the center of the column chamber (5), the discharge line (5) is in the center of the cyclone chamber (5) coaxially with it, operating the gas is drawn off through the discharge pipe (6) and the absorbent falls into the distribution chamber (7) located below the cyclone chamber (5) and thence at least partially further into the other portion of the conveying pipe (15) which is below the manifold ko- vora / 7 /. A device according to claim 7, characterized in that the heat exchanger (s) is constructed in a conveying duct which is located above the fluidized bed chamber (2) substantially coaxial and that the transport duct comprises several thermally interchangeable tubes passing through a heat exchanger through which absorbent saturation flows. with sulfur, and whose outer surface is cooled by a cooling fluid flowing through the heat exchanger (9). 9. Apparatus according to claim 8, wherein the regenerative reactor is; placed, circularly around the reactor chamber (3). 1ϋ. 7. The apparatus of claim 7, wherein the regeneration reactor. (13) A separate reactor is introduced into which an absorbent which has been reacted with sulfur is fed and, after regeneration, is returned to the fluidized bed chamber (2) of the desulfurization reactor and that there is a recycling line (5a) in the desulfurization reactor. / around the transport pipe (15), which are substantially coaxial, for transporting portions of the absorbent to be transported. returns directly to the flush bed of the chamber (2). . The apparatus according to claim 10, wherein the regenerative reactor (13) has a second fluidized bed chamber (13) having a fluidized bed of crushed absorbent and into which regenerative gas is supplied, a regeneration chamber (13a) above the regenerative a secondary fluidized bed chamber (13), the chamber has a smaller cross-section in the flow direction of the regeneration gas than the secondary fluidized bed chamber (13), in the upper part of the regeneration chamber (13a). and a discharge gas discharge conduit (20) and a return conduit (1b, 17) for returning the regenerated absorbent from the bottom of the recovery reactor (13) to the fluidized bed reactor (13). 12. An apparatus according to claim 11, wherein the second secondary fluidized bed chamber (13), the regeneration chamber (13a), and a portion of the return line (15) that feed regenerated absorbent into the fluidized bed of the chamber (2). . The reactor is constructed essentially coaxially to the cylinder. in such a way that a portion of the return line (15) that transports the absorbent to the desulfurization reactor is above the secondary fluidized bed (13), and is there. a second cyclone chamber (5) in the upper portion of the regeneration chamber (13a) having a plurality of upper flow control portions (4) such that the slurry formed by the regeneration gas and the absorbent is tangentially directed towards the second cyclone chamber (5); in the middle of the second cyclone chamber (5) coaxially with it, and the other case are regenerative gas and separated sulfur are discharged through the drain line (20) and at least a portion of the regenerated absorber falls into the return line (15) located below: secondary cyclone chamber. / 5 /. 13. An apparatus as claimed in claim 12, wherein the secondary recycling line (5a) is substantially coaxial about the return liner (15) to return the absorbent portion to the secondary fluidized bed (1.3). 14. One of points 10 to 13, you from n. se. thus, at least one heat exchanger (21) is. installed in a conduit (16) which flows from the desulphurisation reactor to a re-generation reactor and serves as a conveying pipe. 15. Apparatus according to one of clauses 10 to 14, wherein at least one heat exchanger (21) is installed in a conduit (17) which conducts the 2 recovery reactor to a desulfurization reactor and leaches as a conveyor line. - 12 - 16. Apparatus according to one of Claims 6 to 15, characterized in that the main part (16) of the transport tube leading to the regeneration reactor (13) is connected by a lower end of the vertical portion (15) absorbing sulfur-saturated material. from a sealing layer to a pipe section (16) which is connected to a pulsating gas conduit (19) to provide an absorbent from the sealing layer, by pulsating the gas, a horizontal conduit (16) to the recovery reactor, and a substantially horizontal portion of the conduit (17) leading into the fluidized bed chamber (2) is connected to the lower end of the tube section (15) of the vertical return tube of the absorbent which is located in the center of the recovery reactor (13) and saturated with sulfur creates another sealing layer and this end is connected to the pipe / 10 / supplying pulsating gas as, piping parts / 17 /, for transporting abs orbent by pulsating gas from the secondary closing layer into the fluidized bed chamber (2). 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