Catalytic oxidation furnace

Abstract

The utility model relates to a catalytic oxidation furnace which comprises a furnace body with an outlet at the upper end and an inlet at the lower end, and tail gas for preparing epoxypropane flows in the furnace body; the first bed layer is arranged in the furnace body and is honeycomb-shaped, and a noble metal main catalyst is arranged on the surface of the first bed layer; and the second bed layer is arranged in the furnace body, corresponds to the lower end of the precious metal bed layer in position, is honeycomb-shaped and is made of a desiliconizing agent. The service life of the noble metal main catalyst can reach more than four years, and the service life of the desiliconizing protective agent can reach more than one year, so that the service life of the noble metal catalyst is prolonged; and meanwhile, the integrated functions of catalytic oxidation, desilicication and the like are realized by utilizing one device, and the device has the advantages of high integration level and small occupied area.

Description

Technical Field

[0001] The utility model relates to the technical field of catalytic oxidation equipment, in particular to a catalytic oxidation furnace. Background Art

[0002] In the method for producing propylene oxide by ethylbenzene peroxidation, in the process of using a titanium-silicon heterogeneous catalyst as the epoxidation catalyst, the tail gas is usually treated by a catalytic oxidation furnace. The catalytic oxidation furnace includes a furnace body, and a noble metal catalytic bed layer is arranged inside the furnace body, and the surface is impregnated with a noble metal main catalyst. During production, the silicon element in the tail gas pollutes the noble metal main catalyst, resulting in a relatively short service life of the catalyst, which cannot be recycled and reused, and can only be treated as solid waste, cannot match the overhaul cycle of the main device, is not conducive to the long-term stable operation of the device, and affects the economic benefits.

[0003] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0004] In view of the deficiencies of the prior art, an embodiment of the utility model discloses a catalytic oxidation furnace to solve the problem of relatively short service life of the catalyst.

[0005] The technical solution adopted by the utility model is as follows:

[0006] A catalytic oxidation furnace for treating the tail gas of the method for producing propylene oxide by ethylbenzene peroxidation, the catalytic oxidation furnace includes a furnace body with an outlet at the upper end and an inlet at the lower end, and the tail gas for producing propylene oxide flows inside; a first bed layer, arranged inside the furnace body, is honeycomb-shaped, and the surface is provided with a noble metal main catalyst; a second bed layer, arranged inside the furnace body, corresponding to the lower end of the noble metal bed layer, is honeycomb-shaped and made of a desiliconizing agent.

[0007] A further technical solution thereof is that the second bed layer is honeycomb-shaped titanium oxide.

[0008] A further technical solution thereof is that the surface of the honeycomb-shaped titanium oxide is impregnated with an active metal.

[0009] A further technical solution thereof is that two sets of support components are further included inside the furnace body, the support components are arranged inside the furnace body, and the first bed layer and the second bed layer are arranged on the support components.

[0010] A further technical solution thereof is that the support component includes a support beam and a grille, the support beam is connected inside the furnace body, and the grille is arranged on the support beam.

[0011] A further technical solution thereof is that the support component further includes a screen, and the screen is laid between the grille and the support beam.

[0012] A further technical solution is that the connection modes between the grille and the screen, and between the grille and the support beam are spot welding connections.

[0013] A further technical solution is that a manhole is opened on the furnace body, and its position corresponds to above the first bed layer and the upper end of the second bed layer.

[0014] A further technical solution is that the inlet gas temperature of the second bed layer is 330 - 360 °C.

[0015] A further technical solution is that the gas flow rate passing through the first bed layer and the second bed layer is 80,000 Nm 3 / h.

[0016] The beneficial effects of the embodiments of the present utility model are as follows:

[0017] 1. The catalytic oxidation furnace body of the present utility model includes an outlet, an inlet, a first bed layer, and a second bed layer. A noble metal main catalyst is provided on the surface of the first bed layer, and the second bed layer is made of a desiliconizing agent. The tail gas for producing propylene oxide enters the furnace body from the inlet, undergoes desiliconization through the second bed layer, then undergoes catalytic oxidation through the first bed layer, and finally is discharged from the outlet of the furnace body. Under such a process, the total non-methane hydrocarbons at the outlet of the furnace body can be controlled to be < 60 mg / Nm 3 , and the content of organosiloxane is < 0.5 mg / Nm 3 . The service life of the noble metal main catalyst can reach more than 4 years, and the service life of the desiliconization protective agent can reach more than 1 year, extending the service life of the noble metal catalyst.

[0018] At the same time, the functions of catalytic oxidation, desiliconization, etc. are integrated by using one device, which has the advantages of high integration degree and small floor area.

[0019] 2. Further, the second bed layer is provided with a grille, a support part is provided between the grille and the furnace body, and the grille is connected to the furnace body through the support part. The second bed layer is also provided with a screen covering the grille. The connection modes between the grille and the screen, and between the grille and the support beam are spot welding reinforcement connections, reducing the gaps between them and preventing waste gas from flowing away through the gaps. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view structural schematic diagram of the catalytic oxidation furnace of the present utility model.

[0021] In the figure:

[0022] 1. Furnace body; 11. Inlet; 12. Support assembly; 121. Support beam; 122. Screen; 123. Grille; 13. Manhole; 14. Outlet; 2. First bed layer; 3. Second bed layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will describe the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the device proposed by the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and all use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the objectives of the embodiments of the present invention. In order to make the objectives, features and advantages of the present invention more obvious and understandable, please refer to the accompanying drawings. It should be noted that the structures, scales, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the objectives that can be achieved, should still fall within the scope covered by the technical content disclosed by the present invention.

[0025] Embodiment:

[0026] This embodiment discloses a catalytic oxidation furnace.

[0027] The catalytic oxidation furnace is used for the tail gas treatment of the production of propylene oxide by ethylbenzene peroxidation. The catalytic oxidation furnace includes a furnace body 1, which has an outlet 14 at the upper end and an inlet 11 at the lower end, and the tail gas for producing propylene oxide flows inside.

[0028] The first bed layer 2 is arranged inside the furnace body 1, is honeycomb-shaped, and is provided with a precious metal main catalyst on the surface. Exemplarily, the precious metal main catalyst uses honeycomb ceramics as the carrier, and the carrier is coated with a precious metal-containing coating. The coating method can use the impregnation method or the spraying method to load the precious metal active components and promoters, and finally is formed by reduction roasting, which belongs to the prior art.

[0029] The second bed layer 3 is arranged inside the furnace body 1, corresponding to the lower end of the first bed layer 2, is honeycomb-shaped, and is made of a desilication agent. Exemplarily, the second bed layer 3 is honeycomb-shaped titanium oxide. The surface of the honeycomb-shaped titanium oxide is impregnated with an active metal to further improve the desilication effect.

[0030] Further, the furnace body 1 further includes two sets of support assemblies 12. The support assemblies 12 are arranged inside the furnace body 1, and the first bed layer 2 and the second bed layer 3 are respectively arranged on the support assemblies 12. Exemplarily, the support assembly 12 includes a support beam 121 and a grille 123. The support beam 121 is connected inside the furnace body 1, and the grille 123 is arranged on the support beam 121. Exemplarily, the support assembly 12 further includes a screen 122, and the screen 122 is laid between the grille 123 and the support beam 121. Preferably, the connection methods between the grille 123 and the screen 122 and between the grille 123 and the support beam 121 are spot welding connections, reducing the gaps between them and preventing waste gas from flowing away through the gaps, so as to prevent the desilication protective agent from not contacting the waste gas and adsorbing organosiloxane.

[0031] Further, two manholes 13 are opened on the furnace body 1, and the positions of the manholes 13 correspond to above the first bed layer 2 and the upper end of the second bed layer 3 respectively, which is convenient for observation and maintenance.

[0032] Further, the inlet gas temperature of the second bed layer 3 is 330 - 360 °C, which is beneficial to the catalytic oxidation of organosilicon by the desilication agent, and the desilication efficiency is greater than 90%. Preferably, the inlet gas temperature of the second bed layer 3 is 350 - 360 °C, and the desilication efficiency can reach 95 - 100%. If the inlet gas temperature of the second bed layer 3 is less than 330 °C, the desilication efficiency will be further reduced.

[0033] Further, the gas flow rate passing through the first bed layer 2 and the second bed layer 3 is 80000 Nm 3 / h, and the sizes of the catalyst carrier and the catalyst coating material are strictly calculated and precisely designed to control the bed pressure drop within the design range.

[0034] When this embodiment works:

[0035] Hot air at 120 - 150 °C is introduced to purge the inside of the furnace body 1 for at least 4 hours. First, it is heated to 150 °C at a rate not exceeding 10 °C / min, and then at least heated to 330 °C, preferably 350 °C, at a rate not exceeding 20 °C / min. At this temperature, it is continuously purged for at least 6 hours. The tail gas for producing propylene oxide at 350 - 360 °C is introduced. The tail gas enters from the inlet 11 of the furnace body 1, undergoes desilication treatment through the second bed layer 3, the desilicated tail gas flows upward, undergoes catalytic oxidation treatment through the first bed layer 2, and the catalytically oxidized tail gas is discharged from the furnace body outlet 14. Under such processes, the total non-methane hydrocarbons at the furnace body outlet 14 can be controlled to be < 60 mg / Nm 3 and the organosiloxane content is < 0.5 mg / Nm 3 , the service life of the noble metal main catalyst can reach more than 4 years, and the service life of the desilication protective agent can reach more than 1 year.

[0036] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0037] The above-described embodiments merely represent several implementation manners of the present utility model. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several deformations and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the present utility model patent shall be subject to the appended claims.

Claims

1. Catalytic oxidation furnace, characterized in that, Comprising: A furnace body, having an outlet at the upper end and an inlet at the lower end, with the tail gas of propylene oxide flowing inside; A first bed layer, arranged inside the furnace body, in a honeycomb shape, with a noble metal main catalyst provided on the surface; A second bed layer, arranged inside the furnace body, corresponding to the lower end of the first bed layer in position, in a honeycomb shape, made of a desilicating agent.

2. The catalytic oxidation furnace according to claim 1, wherein The second bed layer is honeycomb-shaped titanium oxide.

3. The catalytic oxidation furnace according to claim 2, characterized in that, The surface of the honeycomb-shaped titanium oxide is impregnated with an active metal.

4. The catalytic oxidation furnace according to claim 1, characterized in that, The furnace body also includes two groups of support components, the support components are arranged inside the furnace body, and the first bed layer and the second bed layer are respectively arranged on the support components.

5. The catalytic oxidation furnace according to claim 4, characterized in that, The support component includes a support beam and a grille, the support beam is connected inside the furnace body, and the grille is arranged on the support beam.

6. The catalytic oxidation furnace according to claim 5, wherein The support component further includes a screen, and the screen is laid between the grille and the support beam.

7. The catalytic oxidation furnace according to claim 6, wherein, The connection methods between the grille and the screen, and between the grille and the support beam are spot welding connections.

8. The catalytic oxidation furnace according to claim 1, characterized in that, Two manholes are opened on the furnace body, corresponding to above the first bed layer and the upper end of the second bed layer respectively in position.

9. The catalytic oxidation furnace according to claim 1, wherein The inlet gas temperature of the second bed layer is 330 - 360 °C.

10. The catalytic oxidation furnace according to claim 1, wherein The gas flow rate passing through the first bed layer and the second bed layer is 80,000 Nm 3 / h.

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