Spraying device for preparing durene through carbon dioxide hydrogenation
By designing a spray device for hydrogenation of carbon dioxide to make homotetratoluene, the liquid phase aromatic hydrocarbon return line is connected to the nozzle in the fluidized bed reactor, which solves the problem of low yield of target products in the prior art, and achieves the effect of improving homotetratoluene yield and system safety.
Patent Information
- Application Number
- CN202421793886.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-26
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-07-26
AI Technical Summary
In the prior art, the liquid-phase aromatic hydrocarbon by-products produced during the reaction of hydrogenation of carbon dioxide to tetratoluene leads to a low yield of the target product, which affects economic performance.
A spraying device is designed, including a liquid-phase aromatic hydrocarbon return pipeline and a nozzle in the fluidized bed reactor. The liquid-phase aromatic hydrocarbon return pipeline is connected to the nozzle. The nozzle is located at the bottom of the bed of the fluidized bed reactor, the injection angle is not less than 45°, and the front and rear pressure drop is not less than 4bar.
The liquid-phase aromatic hydrocarbons are directly returned to the fluidized bed reactor and then reacted, which improves the yield of the target product tetratoluene, ensures the safety of the system, prevents materials from being serialized and backflowed, and ensures good atomization effect of the liquid-phase aromatic hydrocarbons.
Smart Images
Figure CN222918651U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of chemical engineering, and specifically relates to a spraying device for hydrogenating carbon dioxide to prepare durene. Background Art
[0002] Durene is an important intermediate of organic chemical raw materials, which can be further reacted and converted into polyimide, and is widely used in cutting-edge technology fields such as aerospace, missiles, atomic energy industry, supersonic aircraft, and electromechanical industry, with a huge market space.
[0003] In the reaction of hydrogenating carbon dioxide to prepare durene with a fluidized bed reactor as the carrier, a large amount of liquid-phase aromatic by-products will be generated during the synthesis process, such as toluene, xylene, trimethylbenzene, durene isomers, etc., resulting in a low yield of the target product and affecting the economy. Content of the Utility Model
[0004] In order to overcome the deficiencies of the prior art, the utility model provides a spraying device for hydrogenating carbon dioxide to prepare durene, and solves the problems existing in the prior art such as the low yield of the target product.
[0005] The technical solution adopted by the utility model to solve the above problems is as follows:
[0006] A spraying device for hydrogenating carbon dioxide to prepare durene, including a liquid-phase aromatic return pipeline, a fluidized bed reactor, and a spray head arranged in the fluidized bed reactor, and the liquid-phase aromatic return pipeline is communicated with the spray head.
[0007] As a preferred technical solution, the spray head is arranged at the bottom of the fluidized bed reactor bed layer.
[0008] As a preferred technical solution, the spray head has a structure with a front-back pressure drop ≥ 4 bar.
[0009] As a preferred technical solution, the spray head has a structure with a spraying angle ≥ 45°.
[0010] As a preferred technical solution, it further includes a raw material gas pipeline communicated with the liquid-phase aromatic return pipeline.
[0011] As a preferred technical solution, check valves are arranged on both the liquid-phase aromatic return pipeline and the raw material gas pipeline.
[0012] As a preferred technical solution, cut-off valves are arranged on both the liquid-phase aromatic return pipeline and the raw material gas pipeline.
[0013] As a preferred technical solution, the cut-off valve on the liquid-phase aromatic return pipeline and the cut-off valve on the raw material gas pipeline are interlocked.
[0014] As a preferred technical solution, the cut-off valves on the liquid-phase aromatic hydrocarbon return pipeline and the raw material gas pipeline are both pneumatic cut-off valves.
[0015] As a preferred technical solution, a flow-limiting orifice plate is provided on the raw material gas pipeline.
[0016] Compared with the prior art, the present utility model has the following beneficial effects:
[0017] (1) By directly returning the liquid-phase aromatic hydrocarbon to the fluidized bed reactor for further reaction, the yield of the target product durene is increased;
[0018] (2) Check valves are provided on the liquid-phase aromatic hydrocarbon return pipeline and the high-pressure raw material gas pipeline, and the two pneumatic cut-off valves are interlocked to prevent the mutual mixing of materials in the two pipelines and the reverse flow of process materials, ensuring system safety;
[0019] (3) A flow-limiting orifice plate is provided on the high-pressure raw material gas pipeline to prevent the purge gas flow from being too large;
[0020] (4) Using the high-pressure raw material gas as the purge gas after the liquid-phase aromatic hydrocarbon return pipeline is deactivated to prevent the residual crystallization of heavy hydrocarbons or the blockage of the spray head by the catalyst powder in the reactor;
[0021] (5) One liquid-phase aromatic hydrocarbon spray head is provided in the fluidized bed reactor, and the spraying angle of the spray head is not less than 45° obliquely upward;
[0022] (6) The pressure drop before and after the spray head is not less than 4 bar to ensure good atomization effect of the liquid-phase aromatic hydrocarbon. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a schematic structural diagram of the present utility model.
[0024] Marks in the drawings and their corresponding names: 1, cut-off valve; 2, check valve; 3, flow-limiting orifice plate; 4, fluidized bed reactor; 5, spray head. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] The following will further elaborate on the present utility model in detail in conjunction with the embodiments and the drawings, but the embodiments of the present utility model are not limited thereto.
[0026] Embodiment 1
[0027] As Figure 1 shown, the present utility model proposes a spraying device for producing durene from carbon dioxide, which directly returns the separated aromatic hydrocarbon liquid by-product to the fluidized bed reactor for further reaction to increase the yield of the reaction of hydrogenating carbon dioxide to durene.
[0028] Specifically as follows:
[0029] After being pressurized, the liquid-phase by-products of aromatic hydrocarbons enter directly from the bottom of the fluidized bed reactor 4. A spray head 5 is provided at the bottom feed port of the fluidized bed reactor 4 (preferably, the spray head 5 is arranged inside the catalyst bed of the fluidized bed reactor 4). The pressure drop before and after the spray head 5 is not less than 4 bar to ensure that the liquid-phase aromatic hydrocarbons can be fully atomized and quickly gasified at the operating temperature of 250-450 °C in the fluidized bed reactor, avoiding catalyst caking caused by liquid-phase aggregation; the spraying angle is not less than 45°, ensuring that the liquid-phase aromatic hydrocarbons can directly contact the catalyst bed.
[0030] A gas-phase purge line is provided to ensure the continuous and stable operation of this spraying device. A small stream of gas is separated from the raw material gas of the high-pressure ratio fluidized bed reactor, which is higher than the raw material gas before pressure reduction, as the purge gas for the liquid-phase aromatic hydrocarbon return pipeline; the composition of the purge gas is exactly the same as that of the raw material gas, which has no adverse effect on the reaction in the fluidized bed reactor 4 and does not increase the flow rate of the purge gas. The high-pressure raw material gas branch pipe is connected to the top of the liquid-phase aromatic hydrocarbon return pipeline. A flow-limiting orifice plate 3 is provided on the branch pipe to prevent the purge gas flow rate from being too large. Check valves 2 are provided on both the high-pressure raw material gas purge pipeline and the liquid-phase aromatic hydrocarbon return pipeline to prevent the intermixing of materials in the two pipelines and the backflow of process materials.
[0031] Pneumatic cut-off valves (cut-off valve 1) are provided on both the high-pressure raw material gas pipeline and the liquid-phase aromatic hydrocarbon return pipeline. The two pneumatic cut-off valves are provided with an interlock function: when the liquid-phase aromatic hydrocarbon returns, the pneumatic cut-off valve on the aromatic hydrocarbon pipeline opens, and the pneumatic cut-off valve on the high-pressure raw material gas pipeline automatically closes; when the liquid-phase aromatic hydrocarbon feed is stopped, the pneumatic cut-off valve on the aromatic hydrocarbon pipeline closes, and the cut-off valve 1 on the high-pressure raw material gas pipeline automatically opens to maintain continuous purging of the pipeline and the spray head 5, avoiding problems such as crystallization caused by the accumulation of heavy hydrocarbons in the pipeline and the spray head and blockage of the spray head by catalyst particles.
[0032] The utility model has the following features:
[0033] (1) By directly returning the liquid-phase aromatic hydrocarbons to the fluidized bed reactor for further reaction, the yield of the target product durene is increased;
[0034] (2) Check valves are provided on the liquid-phase aromatic hydrocarbon return pipeline and the high-pressure raw material gas pipeline, and the two pneumatic cut-off valves are provided with an interlock to prevent the intermixing of materials in the two pipelines and the backflow of process materials, ensuring system safety;
[0035] (3) A flow-limiting orifice plate is provided on the high-pressure raw material gas pipeline to prevent the purge gas flow from being too large;
[0036] (4) Using the high-pressure raw material gas as the purge gas after the liquid-phase aromatic hydrocarbon return pipeline is deactivated to prevent the residual crystallization of heavy hydrocarbons or the blockage of the spray head by catalyst powder in the reactor;
[0037] (5) A liquid-phase aromatic hydrocarbon spray head is arranged inside the fluidized bed reactor, and the spraying angle of the spray head is not less than 45° obliquely upward;
[0038] (6) The pressure drop before and after the nozzle shall not be less than 4 bar to ensure good atomization effect of liquid-phase aromatic hydrocarbons.
[0039] As described above, the present utility model can be preferably realized.
[0040] The above are only the preferred embodiments of the present utility model, and do not impose any formal limitations on the present utility model. Based on the technical essence of the present utility model, any simple modifications, equivalent replacements and improvements made to the above embodiments within the spirit and principle of the present utility model still fall within the protection scope of the technical solution of the present utility model.
Claims
1. A spraying device for preparing durene by hydrogenation of carbon dioxide, characterized in that: The invention comprises a liquid-phase aromatic hydrocarbon return pipeline, a fluidized bed reactor (4), and a nozzle (5) arranged in the fluidized bed reactor (4); the liquid-phase aromatic hydrocarbon return pipeline is connected to the nozzle (5).
2. A spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 1, characterized in that: The nozzle (5) is arranged at the bottom of the bed layer of the fluidized bed reactor (4).
3. A spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 1, characterized in that: The nozzle (5) has a structure with a front-to-rear resistance drop of ≥4 bar.
4. The spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 1, characterized in that: The nozzle (5) has a structure with a spray angle of ≥45°.
5. A spraying device for preparing durene by hydrogenation of carbon dioxide according to any one of claims 1 to 4, characterized in that: Also included is a raw gas pipeline connected to the liquid phase aromatic hydrocarbon return pipeline.
6. A spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 5, characterized in that: Check valves (2) are provided on the liquid phase aromatics return pipeline and the raw gas pipeline.
7. The spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 1, characterized in that: Shut-off valves (1) are provided on the liquid aromatics return pipeline and the raw gas pipeline.
8. The spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 7, characterized in that: The shut-off valve (1) on the liquid phase aromatics return pipeline and the shut-off valve (1) on the raw gas pipeline are interlocked.
9. The spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 7, characterized in that: The shut-off valve (1) on the liquid phase aromatic hydrocarbon return pipeline and the shut-off valve (1) on the raw gas pipeline are both pneumatic shut-off valves.
10. The spraying device for preparing durene by hydrogenation of carbon dioxide according to claim 5, characterized in that: A flow limiting orifice plate (3) is provided on the raw gas pipeline.